\n", argv[0]);
- return 1;
- }
-
- av_register_all();
- avfilter_register_all();
-
- if ((ret = open_input_file(argv[1])) < 0)
- goto end;
- if ((ret = open_output_file(argv[2])) < 0)
- goto end;
- if ((ret = init_filters()) < 0)
- goto end;
-
- /* read all packets */
- while (1) {
- if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
- break;
- stream_index = packet.stream_index;
- type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
- av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
- stream_index);
-
- if (filter_ctx[stream_index].filter_graph) {
- av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
- frame = av_frame_alloc();
- if (!frame) {
- ret = AVERROR(ENOMEM);
- break;
- }
- av_packet_rescale_ts(&packet,
- ifmt_ctx->streams[stream_index]->time_base,
- ifmt_ctx->streams[stream_index]->codec->time_base);
- dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
- avcodec_decode_audio4;
- ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
- &got_frame, &packet);
- if (ret < 0) {
- av_frame_free(&frame);
- av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
- break;
- }
-
- if (got_frame) {
- frame->pts = av_frame_get_best_effort_timestamp(frame);
- ret = filter_encode_write_frame(frame, stream_index);
- av_frame_free(&frame);
- if (ret < 0)
- goto end;
- } else {
- av_frame_free(&frame);
- }
- } else {
- /* remux this frame without reencoding */
- av_packet_rescale_ts(&packet,
- ifmt_ctx->streams[stream_index]->time_base,
- ofmt_ctx->streams[stream_index]->time_base);
-
- ret = av_interleaved_write_frame(ofmt_ctx, &packet);
- if (ret < 0)
- goto end;
- }
- av_free_packet(&packet);
- }
-
- /* flush filters and encoders */
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- /* flush filter */
- if (!filter_ctx[i].filter_graph)
- continue;
- ret = filter_encode_write_frame(NULL, i);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
- goto end;
- }
-
- /* flush encoder */
- ret = flush_encoder(i);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
- goto end;
- }
- }
-
- av_write_trailer(ofmt_ctx);
-end:
- av_free_packet(&packet);
- av_frame_free(&frame);
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- avcodec_close(ifmt_ctx->streams[i]->codec);
- if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
- avcodec_close(ofmt_ctx->streams[i]->codec);
- if (filter_ctx && filter_ctx[i].filter_graph)
- avfilter_graph_free(&filter_ctx[i].filter_graph);
- }
- av_free(filter_ctx);
- avformat_close_input(&ifmt_ctx);
- if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
- avio_closep(&ofmt_ctx->pb);
- avformat_free_context(ofmt_ctx);
-
- if (ret < 0)
- av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
-
- return ret ? 1 : 0;
-}
diff --git a/Externals/ffmpeg/dev/doc/faq.html b/Externals/ffmpeg/dev/doc/faq.html
deleted file mode 100644
index be6ea62995..0000000000
--- a/Externals/ffmpeg/dev/doc/faq.html
+++ /dev/null
@@ -1,719 +0,0 @@
-
-
-
-
-
- FFmpeg FAQ
-
-
-
- FFmpeg FAQ
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 General Questions# TOC
-
-
-
1.1 Why doesn’t FFmpeg support feature [xyz]?# TOC
-
-
Because no one has taken on that task yet. FFmpeg development is
-driven by the tasks that are important to the individual developers.
-If there is a feature that is important to you, the best way to get
-it implemented is to undertake the task yourself or sponsor a developer.
-
-
-
1.2 FFmpeg does not support codec XXX. Can you include a Windows DLL loader to support it?# TOC
-
-
No. Windows DLLs are not portable, bloated and often slow.
-Moreover FFmpeg strives to support all codecs natively.
-A DLL loader is not conducive to that goal.
-
-
-
1.3 I cannot read this file although this format seems to be supported by ffmpeg.# TOC
-
-
Even if ffmpeg can read the container format, it may not support all its
-codecs. Please consult the supported codec list in the ffmpeg
-documentation.
-
-
-
1.4 Which codecs are supported by Windows?# TOC
-
-
Windows does not support standard formats like MPEG very well, unless you
-install some additional codecs.
-
-
The following list of video codecs should work on most Windows systems:
-
-msmpeg4v2 .avi/.asf
-
msmpeg4 .asf only
-
wmv1 .asf only
-
wmv2 .asf only
-
mpeg4 Only if you have some MPEG-4 codec like ffdshow or Xvid installed.
-
mpeg1video .mpg only
-
-
Note, ASF files often have .wmv or .wma extensions in Windows. It should also
-be mentioned that Microsoft claims a patent on the ASF format, and may sue
-or threaten users who create ASF files with non-Microsoft software. It is
-strongly advised to avoid ASF where possible.
-
-
The following list of audio codecs should work on most Windows systems:
-
-adpcm_ima_wav adpcm_ms pcm_s16le always
-
libmp3lame If some MP3 codec like LAME is installed.
-
-
-
-
-
2 Compilation# TOC
-
-
-
2.1 error: can't find a register in class 'GENERAL_REGS' while reloading 'asm'# TOC
-
-
This is a bug in gcc. Do not report it to us. Instead, please report it to
-the gcc developers. Note that we will not add workarounds for gcc bugs.
-
-
Also note that (some of) the gcc developers believe this is not a bug or
-not a bug they should fix:
-http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11203 .
-Then again, some of them do not know the difference between an undecidable
-problem and an NP-hard problem...
-
-
-
2.2 I have installed this library with my distro’s package manager. Why does configure not see it?# TOC
-
-
Distributions usually split libraries in several packages. The main package
-contains the files necessary to run programs using the library. The
-development package contains the files necessary to build programs using the
-library. Sometimes, docs and/or data are in a separate package too.
-
-
To build FFmpeg, you need to install the development package. It is usually
-called libfoo-dev or libfoo-devel . You can remove it after the
-build is finished, but be sure to keep the main package.
-
-
-
2.3 How do I make pkg-config find my libraries?# TOC
-
-
Somewhere along with your libraries, there is a .pc file (or several)
-in a pkgconfig directory. You need to set environment variables to
-point pkg-config to these files.
-
-
If you need to add directories to pkg-config’s search list
-(typical use case: library installed separately), add it to
-$PKG_CONFIG_PATH:
-
-
-
export PKG_CONFIG_PATH=/opt/x264/lib/pkgconfig:/opt/opus/lib/pkgconfig
-
-
-
If you need to replace pkg-config’s search list
-(typical use case: cross-compiling), set it in
-$PKG_CONFIG_LIBDIR:
-
-
-
export PKG_CONFIG_LIBDIR=/home/me/cross/usr/lib/pkgconfig:/home/me/cross/usr/local/lib/pkgconfig
-
-
-
If you need to know the library’s internal dependencies (typical use: static
-linking), add the --static option to pkg-config:
-
-
-
./configure --pkg-config-flags=--static
-
-
-
-
2.4 How do I use pkg-config when cross-compiling?# TOC
-
-
The best way is to install pkg-config in your cross-compilation
-environment. It will automatically use the cross-compilation libraries.
-
-
You can also use pkg-config from the host environment by
-specifying explicitly --pkg-config=pkg-config to configure.
-In that case, you must point pkg-config to the correct directories
-using the PKG_CONFIG_LIBDIR, as explained in the previous entry.
-
-
As an intermediate solution, you can place in your cross-compilation
-environment a script that calls the host pkg-config with
-PKG_CONFIG_LIBDIR set. That script can look like that:
-
-
-
#!/bin/sh
-PKG_CONFIG_LIBDIR=/path/to/cross/lib/pkgconfig
-export PKG_CONFIG_LIBDIR
-exec /usr/bin/pkg-config "$@"
-
-
-
-
-
-
-
3.1 ffmpeg does not work; what is wrong?# TOC
-
-
Try a make distclean in the ffmpeg source directory before the build.
-If this does not help see
-(http://ffmpeg.org/bugreports.html ).
-
-
-
3.2 How do I encode single pictures into movies?# TOC
-
-
First, rename your pictures to follow a numerical sequence.
-For example, img1.jpg, img2.jpg, img3.jpg,...
-Then you may run:
-
-
-
ffmpeg -f image2 -i img%d.jpg /tmp/a.mpg
-
-
-
Notice that ‘%d ’ is replaced by the image number.
-
-
img%03d.jpg means the sequence img001.jpg , img002.jpg , etc.
-
-
Use the -start_number option to declare a starting number for
-the sequence. This is useful if your sequence does not start with
-img001.jpg but is still in a numerical order. The following
-example will start with img100.jpg :
-
-
-
ffmpeg -f image2 -start_number 100 -i img%d.jpg /tmp/a.mpg
-
-
-
If you have large number of pictures to rename, you can use the
-following command to ease the burden. The command, using the bourne
-shell syntax, symbolically links all files in the current directory
-that match *jpg to the /tmp directory in the sequence of
-img001.jpg , img002.jpg and so on.
-
-
-
x=1; for i in *jpg; do counter=$(printf %03d $x); ln -s "$i" /tmp/img"$counter".jpg; x=$(($x+1)); done
-
-
-
If you want to sequence them by oldest modified first, substitute
-$(ls -r -t *jpg) in place of *jpg.
-
-
Then run:
-
-
-
ffmpeg -f image2 -i /tmp/img%03d.jpg /tmp/a.mpg
-
-
-
The same logic is used for any image format that ffmpeg reads.
-
-
You can also use cat to pipe images to ffmpeg:
-
-
-
cat *.jpg | ffmpeg -f image2pipe -c:v mjpeg -i - output.mpg
-
-
-
-
3.3 How do I encode movie to single pictures?# TOC
-
-
Use:
-
-
-
ffmpeg -i movie.mpg movie%d.jpg
-
-
-
The movie.mpg used as input will be converted to
-movie1.jpg , movie2.jpg , etc...
-
-
Instead of relying on file format self-recognition, you may also use
-
--c:v ppm -c:v png -c:v mjpeg
-
to force the encoding.
-
-
Applying that to the previous example:
-
-
ffmpeg -i movie.mpg -f image2 -c:v mjpeg menu%d.jpg
-
-
-
Beware that there is no "jpeg" codec. Use "mjpeg" instead.
-
-
-
3.4 Why do I see a slight quality degradation with multithreaded MPEG* encoding?# TOC
-
-
For multithreaded MPEG* encoding, the encoded slices must be independent,
-otherwise thread n would practically have to wait for n-1 to finish, so it’s
-quite logical that there is a small reduction of quality. This is not a bug.
-
-
-
3.5 How can I read from the standard input or write to the standard output?# TOC
-
-
Use - as file name.
-
-
-
3.6 -f jpeg doesn’t work.# TOC
-
-
Try ’-f image2 test%d.jpg’.
-
-
-
3.7 Why can I not change the frame rate?# TOC
-
-
Some codecs, like MPEG-1/2, only allow a small number of fixed frame rates.
-Choose a different codec with the -c:v command line option.
-
-
-
3.8 How do I encode Xvid or DivX video with ffmpeg?# TOC
-
-
Both Xvid and DivX (version 4+) are implementations of the ISO MPEG-4
-standard (note that there are many other coding formats that use this
-same standard). Thus, use ’-c:v mpeg4’ to encode in these formats. The
-default fourcc stored in an MPEG-4-coded file will be ’FMP4’. If you want
-a different fourcc, use the ’-vtag’ option. E.g., ’-vtag xvid’ will
-force the fourcc ’xvid’ to be stored as the video fourcc rather than the
-default.
-
-
-
3.9 Which are good parameters for encoding high quality MPEG-4?# TOC
-
-
’-mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -pass 1/2’,
-things to try: ’-bf 2’, ’-flags qprd’, ’-flags mv0’, ’-flags skiprd’.
-
-
-
3.10 Which are good parameters for encoding high quality MPEG-1/MPEG-2?# TOC
-
-
’-mbd rd -trellis 2 -cmp 2 -subcmp 2 -g 100 -pass 1/2’
-but beware the ’-g 100’ might cause problems with some decoders.
-Things to try: ’-bf 2’, ’-flags qprd’, ’-flags mv0’, ’-flags skiprd.
-
-
-
3.11 Interlaced video looks very bad when encoded with ffmpeg, what is wrong?# TOC
-
-
You should use ’-flags +ilme+ildct’ and maybe ’-flags +alt’ for interlaced
-material, and try ’-top 0/1’ if the result looks really messed-up.
-
-
-
3.12 How can I read DirectShow files?# TOC
-
-
If you have built FFmpeg with ./configure --enable-avisynth
-(only possible on MinGW/Cygwin platforms),
-then you may use any file that DirectShow can read as input.
-
-
Just create an "input.avs" text file with this single line ...
-
-
DirectShowSource("C:\path to your file\yourfile.asf")
-
-
... and then feed that text file to ffmpeg:
-
-
-
For ANY other help on AviSynth, please visit the
-AviSynth homepage .
-
-
-
3.13 How can I join video files?# TOC
-
-
To "join" video files is quite ambiguous. The following list explains the
-different kinds of "joining" and points out how those are addressed in
-FFmpeg. To join video files may mean:
-
-
- To put them one after the other: this is called to concatenate them
-(in short: concat) and is addressed
-in this very faq .
-
- To put them together in the same file, to let the user choose between the
-different versions (example: different audio languages): this is called to
-multiplex them together (in short: mux), and is done by simply
-invoking ffmpeg with several -i options.
-
- For audio, to put all channels together in a single stream (example: two
-mono streams into one stereo stream): this is sometimes called to
-merge them, and can be done using the
-amerge For audio, to play one on top of the other: this is called to mix
-them, and can be done by first merging them into a single stream and then
-using the pan For video, to display both together, side by side or one on top of a part of
-the other; it can be done using the
-overlay
-
-
-
3.14 How can I concatenate video files?# TOC
-
-
There are several solutions, depending on the exact circumstances.
-
-
-
3.14.1 Concatenating using the concat filter # TOC
-
-
FFmpeg has a concat
-
-
3.14.2 Concatenating using the concat demuxer # TOC
-
-
FFmpeg has a concat
-
-
3.14.3 Concatenating using the concat protocol (file level)# TOC
-
-
FFmpeg has a concat
-
A few multimedia containers (MPEG-1, MPEG-2 PS, DV) allow to concatenate
-video by merely concatenating the files containing them.
-
-
Hence you may concatenate your multimedia files by first transcoding them to
-these privileged formats, then using the humble cat command (or the
-equally humble copy under Windows), and finally transcoding back to your
-format of choice.
-
-
-
ffmpeg -i input1.avi -qscale:v 1 intermediate1.mpg
-ffmpeg -i input2.avi -qscale:v 1 intermediate2.mpg
-cat intermediate1.mpg intermediate2.mpg > intermediate_all.mpg
-ffmpeg -i intermediate_all.mpg -qscale:v 2 output.avi
-
-
-
Additionally, you can use the concat protocol instead of cat or
-copy which will avoid creation of a potentially huge intermediate file.
-
-
-
ffmpeg -i input1.avi -qscale:v 1 intermediate1.mpg
-ffmpeg -i input2.avi -qscale:v 1 intermediate2.mpg
-ffmpeg -i concat:"intermediate1.mpg|intermediate2.mpg" -c copy intermediate_all.mpg
-ffmpeg -i intermediate_all.mpg -qscale:v 2 output.avi
-
-
-
Note that you may need to escape the character "|" which is special for many
-shells.
-
-
Another option is usage of named pipes, should your platform support it:
-
-
-
mkfifo intermediate1.mpg
-mkfifo intermediate2.mpg
-ffmpeg -i input1.avi -qscale:v 1 -y intermediate1.mpg < /dev/null &
-ffmpeg -i input2.avi -qscale:v 1 -y intermediate2.mpg < /dev/null &
-cat intermediate1.mpg intermediate2.mpg |\
-ffmpeg -f mpeg -i - -c:v mpeg4 -acodec libmp3lame output.avi
-
-
-
-
3.14.4 Concatenating using raw audio and video# TOC
-
-
Similarly, the yuv4mpegpipe format, and the raw video, raw audio codecs also
-allow concatenation, and the transcoding step is almost lossless.
-When using multiple yuv4mpegpipe(s), the first line needs to be discarded
-from all but the first stream. This can be accomplished by piping through
-tail as seen below. Note that when piping through tail you
-must use command grouping, { ;}, to background properly.
-
-
For example, let’s say we want to concatenate two FLV files into an
-output.flv file:
-
-
-
mkfifo temp1.a
-mkfifo temp1.v
-mkfifo temp2.a
-mkfifo temp2.v
-mkfifo all.a
-mkfifo all.v
-ffmpeg -i input1.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp1.a < /dev/null &
-ffmpeg -i input2.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp2.a < /dev/null &
-ffmpeg -i input1.flv -an -f yuv4mpegpipe - > temp1.v < /dev/null &
-{ ffmpeg -i input2.flv -an -f yuv4mpegpipe - < /dev/null | tail -n +2 > temp2.v ; } &
-cat temp1.a temp2.a > all.a &
-cat temp1.v temp2.v > all.v &
-ffmpeg -f u16le -acodec pcm_s16le -ac 2 -ar 44100 -i all.a \
- -f yuv4mpegpipe -i all.v \
- -y output.flv
-rm temp[12].[av] all.[av]
-
-
-
-
3.15 Using -f lavfi , audio becomes mono for no apparent reason.# TOC
-
-
Use -dumpgraph - to find out exactly where the channel layout is
-lost.
-
-
Most likely, it is through auto-inserted aresample. Try to understand
-why the converting filter was needed at that place.
-
-
Just before the output is a likely place, as -f lavfi currently
-only support packed S16.
-
-
Then insert the correct aformat explicitly in the filtergraph,
-specifying the exact format.
-
-
-
aformat=sample_fmts=s16:channel_layouts=stereo
-
-
-
-
3.16 Why does FFmpeg not see the subtitles in my VOB file?# TOC
-
-
VOB and a few other formats do not have a global header that describes
-everything present in the file. Instead, applications are supposed to scan
-the file to see what it contains. Since VOB files are frequently large, only
-the beginning is scanned. If the subtitles happen only later in the file,
-they will not be initially detected.
-
-
Some applications, including the ffmpeg command-line tool, can only
-work with streams that were detected during the initial scan; streams that
-are detected later are ignored.
-
-
The size of the initial scan is controlled by two options: probesize
-(default ~5 Mo) and analyzeduration (default 5,000,000 µs = 5 s). For
-the subtitle stream to be detected, both values must be large enough.
-
-
-
3.17 Why was the ffmpeg -sameq option removed? What to use instead?# TOC
-
-
The -sameq option meant "same quantizer", and made sense only in a
-very limited set of cases. Unfortunately, a lot of people mistook it for
-"same quality" and used it in places where it did not make sense: it had
-roughly the expected visible effect, but achieved it in a very inefficient
-way.
-
-
Each encoder has its own set of options to set the quality-vs-size balance,
-use the options for the encoder you are using to set the quality level to a
-point acceptable for your tastes. The most common options to do that are
--qscale and -qmax , but you should peruse the documentation
-of the encoder you chose.
-
-
-
4 Development# TOC
-
-
-
4.1 Are there examples illustrating how to use the FFmpeg libraries, particularly libavcodec and libavformat?# TOC
-
-
Yes. Check the doc/examples directory in the source
-repository, also available online at:
-https://github.com/FFmpeg/FFmpeg/tree/master/doc/examples .
-
-
Examples are also installed by default, usually in
-$PREFIX/share/ffmpeg/examples.
-
-
Also you may read the Developers Guide of the FFmpeg documentation. Alternatively,
-examine the source code for one of the many open source projects that
-already incorporate FFmpeg at (projects.html ).
-
-
-
4.2 Can you support my C compiler XXX?# TOC
-
-
It depends. If your compiler is C99-compliant, then patches to support
-it are likely to be welcome if they do not pollute the source code
-with #ifdefs related to the compiler.
-
-
-
4.3 Is Microsoft Visual C++ supported?# TOC
-
-
Yes. Please see the Microsoft Visual C++
-section in the FFmpeg documentation.
-
-
-
4.4 Can you add automake, libtool or autoconf support?# TOC
-
-
No. These tools are too bloated and they complicate the build.
-
-
-
4.5 Why not rewrite FFmpeg in object-oriented C++?# TOC
-
-
FFmpeg is already organized in a highly modular manner and does not need to
-be rewritten in a formal object language. Further, many of the developers
-favor straight C; it works for them. For more arguments on this matter,
-read "Programming Religion" .
-
-
-
4.6 Why are the ffmpeg programs devoid of debugging symbols?# TOC
-
-
The build process creates ffmpeg_g, ffplay_g, etc. which
-contain full debug information. Those binaries are stripped to create
-ffmpeg, ffplay, etc. If you need the debug information, use
-the *_g versions.
-
-
-
4.7 I do not like the LGPL, can I contribute code under the GPL instead?# TOC
-
-
Yes, as long as the code is optional and can easily and cleanly be placed
-under #if CONFIG_GPL without breaking anything. So, for example, a new codec
-or filter would be OK under GPL while a bug fix to LGPL code would not.
-
-
-
4.8 I’m using FFmpeg from within my C application but the linker complains about missing symbols from the libraries themselves.# TOC
-
-
FFmpeg builds static libraries by default. In static libraries, dependencies
-are not handled. That has two consequences. First, you must specify the
-libraries in dependency order: -lavdevice must come before
--lavformat, -lavutil must come after everything else, etc.
-Second, external libraries that are used in FFmpeg have to be specified too.
-
-
An easy way to get the full list of required libraries in dependency order
-is to use pkg-config.
-
-
-
c99 -o program program.c $(pkg-config --cflags --libs libavformat libavcodec)
-
-
-
See doc/example/Makefile and doc/example/pc-uninstalled for
-more details.
-
-
-
4.9 I’m using FFmpeg from within my C++ application but the linker complains about missing symbols which seem to be available.# TOC
-
-
FFmpeg is a pure C project, so to use the libraries within your C++ application
-you need to explicitly state that you are using a C library. You can do this by
-encompassing your FFmpeg includes using extern "C".
-
-
See http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html#faq-32.3
-
-
-
4.10 I’m using libavutil from within my C++ application but the compiler complains about ’UINT64_C’ was not declared in this scope# TOC
-
-
FFmpeg is a pure C project using C99 math features, in order to enable C++
-to use them you have to append -D__STDC_CONSTANT_MACROS to your CXXFLAGS
-
-
-
4.11 I have a file in memory / a API different from *open/*read/ libc how do I use it with libavformat?# TOC
-
-
You have to create a custom AVIOContext using avio_alloc_context,
-see libavformat/aviobuf.c in FFmpeg and libmpdemux/demux_lavf.c in MPlayer or MPlayer2 sources.
-
-
-
4.12 Where is the documentation about ffv1, msmpeg4, asv1, 4xm?# TOC
-
-
see http://www.ffmpeg.org/~michael/
-
-
-
4.13 How do I feed H.263-RTP (and other codecs in RTP) to libavcodec?# TOC
-
-
Even if peculiar since it is network oriented, RTP is a container like any
-other. You have to demux RTP before feeding the payload to libavcodec.
-In this specific case please look at RFC 4629 to see how it should be done.
-
-
-
4.14 AVStream.r_frame_rate is wrong, it is much larger than the frame rate.# TOC
-
-
r_frame_rate is NOT the average frame rate, it is the smallest frame rate
-that can accurately represent all timestamps. So no, it is not
-wrong if it is larger than the average!
-For example, if you have mixed 25 and 30 fps content, then r_frame_rate
-will be 150 (it is the least common multiple).
-If you are looking for the average frame rate, see AVStream.avg_frame_rate.
-
-
-
4.15 Why is make fate not running all tests?# TOC
-
-
Make sure you have the fate-suite samples and the SAMPLES Make variable
-or FATE_SAMPLES environment variable or the --samples
-configure option is set to the right path.
-
-
-
4.16 Why is make fate not finding the samples?# TOC
-
-
Do you happen to have a ~ character in the samples path to indicate a
-home directory? The value is used in ways where the shell cannot expand it,
-causing FATE to not find files. Just replace ~ by the full path.
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Automated Testing Environment
-
-
-
- FFmpeg Automated Testing Environment
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Introduction# TOC
-
-
FATE is an extended regression suite on the client-side and a means
-for results aggregation and presentation on the server-side.
-
-
The first part of this document explains how you can use FATE from
-your FFmpeg source directory to test your ffmpeg binary. The second
-part describes how you can run FATE to submit the results to FFmpeg’s
-FATE server.
-
-
In any way you can have a look at the publicly viewable FATE results
-by visiting this website:
-
-
http://fate.ffmpeg.org/
-
-
This is especially recommended for all people contributing source
-code to FFmpeg, as it can be seen if some test on some platform broke
-with their recent contribution. This usually happens on the platforms
-the developers could not test on.
-
-
The second part of this document describes how you can run FATE to
-submit your results to FFmpeg’s FATE server. If you want to submit your
-results be sure to check that your combination of CPU, OS and compiler
-is not already listed on the above mentioned website.
-
-
In the third part you can find a comprehensive listing of FATE makefile
-targets and variables.
-
-
-
-
2 Using FATE from your FFmpeg source directory# TOC
-
-
If you want to run FATE on your machine you need to have the samples
-in place. You can get the samples via the build target fate-rsync.
-Use this command from the top-level source directory:
-
-
-
make fate-rsync SAMPLES=fate-suite/
-make fate SAMPLES=fate-suite/
-
-
-
The above commands set the samples location by passing a makefile
-variable via command line. It is also possible to set the samples
-location at source configuration time by invoking configure with
-‘–samples=<path to the samples directory>’. Afterwards you can
-invoke the makefile targets without setting the SAMPLES makefile
-variable. This is illustrated by the following commands:
-
-
-
./configure --samples=fate-suite/
-make fate-rsync
-make fate
-
-
-
Yet another way to tell FATE about the location of the sample
-directory is by making sure the environment variable FATE_SAMPLES
-contains the path to your samples directory. This can be achieved
-by e.g. putting that variable in your shell profile or by setting
-it in your interactive session.
-
-
-
FATE_SAMPLES=fate-suite/ make fate
-
-
-
-
Do not put a ’~’ character in the samples path to indicate a home
-directory. Because of shell nuances, this will cause FATE to fail.
-
-
To use a custom wrapper to run the test, pass --target-exec to
-configure or set the TARGET_EXEC Make variable.
-
-
-
-
3 Submitting the results to the FFmpeg result aggregation server# TOC
-
-
To submit your results to the server you should run fate through the
-shell script tests/fate.sh from the FFmpeg sources. This script needs
-to be invoked with a configuration file as its first argument.
-
-
-
tests/fate.sh /path/to/fate_config
-
-
-
A configuration file template with comments describing the individual
-configuration variables can be found at doc/fate_config.sh.template .
-
-
The mentioned configuration template is also available here:
-
slot= # some unique identifier
-repo=git://source.ffmpeg.org/ffmpeg.git # the source repository
-samples= # path to samples directory
-workdir= # directory in which to do all the work
-#fate_recv="ssh -T fate@fate.ffmpeg.org" # command to submit report
-comment= # optional description
-build_only= # set to "yes" for a compile-only instance that skips tests
-
-# the following are optional and map to configure options
-arch=
-cpu=
-cross_prefix=
-as=
-cc=
-ld=
-target_os=
-sysroot=
-target_exec=
-target_path=
-target_samples=
-extra_cflags=
-extra_ldflags=
-extra_libs=
-extra_conf= # extra configure options not covered above
-
-#make= # name of GNU make if not 'make'
-makeopts= # extra options passed to 'make'
-#tar= # command to create a tar archive from its arguments on stdout,
- # defaults to 'tar c'
-
-
Create a configuration that suits your needs, based on the configuration
-template. The ‘slot’ configuration variable can be any string that is not
-yet used, but it is suggested that you name it adhering to the following
-pattern <arch>-<os>-<compiler>-<compiler version>. The configuration file
-itself will be sourced in a shell script, therefore all shell features may
-be used. This enables you to setup the environment as you need it for your
-build.
-
-
For your first test runs the ‘fate_recv’ variable should be empty or
-commented out. This will run everything as normal except that it will omit
-the submission of the results to the server. The following files should be
-present in $workdir as specified in the configuration file:
-
-
- configure.log
- compile.log
- test.log
- report
- version
-
-
-
When you have everything working properly you can create an SSH key pair
-and send the public key to the FATE server administrator who can be contacted
-at the email address fate-admin@ffmpeg.org .
-
-
Configure your SSH client to use public key authentication with that key
-when connecting to the FATE server. Also do not forget to check the identity
-of the server and to accept its host key. This can usually be achieved by
-running your SSH client manually and killing it after you accepted the key.
-The FATE server’s fingerprint is:
-
-
-RSA d3:f1:83:97:a4:75:2b:a6:fb:d6:e8:aa:81:93:97:51
-
ECDSA 76:9f:68:32:04:1e:d5:d4:ec:47:3f:dc:fc:18:17:86
-
-
-
If you have problems connecting to the FATE server, it may help to try out
-the ssh command with one or more -v options. You should
-get detailed output concerning your SSH configuration and the authentication
-process.
-
-
The only thing left is to automate the execution of the fate.sh script and
-the synchronisation of the samples directory.
-
-
-
-
4 FATE makefile targets and variables# TOC
-
-
-
4.1 Makefile targets# TOC
-
-
-fate-rsync Download/synchronize sample files to the configured samples directory.
-
-fate-list Will list all fate/regression test targets.
-
-fate Run the FATE test suite (requires the fate-suite dataset).
-
-
-
-
4.2 Makefile variables# TOC
-
-
-V Verbosity level, can be set to 0, 1 or 2.
-
- 0: show just the test arguments
- 1: show just the command used in the test
- 2: show everything
-
-
-SAMPLES Specify or override the path to the FATE samples at make time, it has a
-meaning only while running the regression tests.
-
-THREADS Specify how many threads to use while running regression tests, it is
-quite useful to detect thread-related regressions.
-
-THREAD_TYPE Specify which threading strategy test, either slice or frame ,
-by default slice+frame
-
-CPUFLAGS Specify CPU flags.
-
-TARGET_EXEC Specify or override the wrapper used to run the tests.
-The TARGET_EXEC option provides a way to run FATE wrapped in
-valgrind, qemu-user or wine or on remote targets
-through ssh.
-
-GEN Set to 1 to generate the missing or mismatched references.
-
-
-
-
4.3 Examples# TOC
-
-
-
make V=1 SAMPLES=/var/fate/samples THREADS=2 CPUFLAGS=mmx fate
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffmpeg Documentation
-
-
-
- ffmpeg Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffmpeg [global_options ] {[input_file_options ] -i input_file } ... {[output_file_options ] output_file } ...
-
-
-
2 Description# TOC
-
-
ffmpeg is a very fast video and audio converter that can also grab from
-a live audio/video source. It can also convert between arbitrary sample
-rates and resize video on the fly with a high quality polyphase filter.
-
-
ffmpeg reads from an arbitrary number of input "files" (which can be regular
-files, pipes, network streams, grabbing devices, etc.), specified by the
--i option, and writes to an arbitrary number of output "files", which are
-specified by a plain output filename. Anything found on the command line which
-cannot be interpreted as an option is considered to be an output filename.
-
-
Each input or output file can, in principle, contain any number of streams of
-different types (video/audio/subtitle/attachment/data). The allowed number and/or
-types of streams may be limited by the container format. Selecting which
-streams from which inputs will go into which output is either done automatically
-or with the -map option (see the Stream selection chapter).
-
-
To refer to input files in options, you must use their indices (0-based). E.g.
-the first input file is 0, the second is 1, etc. Similarly, streams
-within a file are referred to by their indices. E.g. 2:3 refers to the
-fourth stream in the third input file. Also see the Stream specifiers chapter.
-
-
As a general rule, options are applied to the next specified
-file. Therefore, order is important, and you can have the same
-option on the command line multiple times. Each occurrence is
-then applied to the next input or output file.
-Exceptions from this rule are the global options (e.g. verbosity level),
-which should be specified first.
-
-
Do not mix input and output files – first specify all input files, then all
-output files. Also do not mix options which belong to different files. All
-options apply ONLY to the next input or output file and are reset between files.
-
-
- To set the video bitrate of the output file to 64 kbit/s:
-
-
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
- To force the frame rate of the output file to 24 fps:
-
-
ffmpeg -i input.avi -r 24 output.avi
- To force the frame rate of the input file (valid for raw formats only)
-to 1 fps and the frame rate of the output file to 24 fps:
-
-
ffmpeg -r 1 -i input.m2v -r 24 output.avi
-
-
-
The format option may be needed for raw input files.
-
-
-
-
3 Detailed description# TOC
-
-
The transcoding process in ffmpeg for each output can be described by
-the following diagram:
-
-
-
_______ ______________
-| | | |
-| input | demuxer | encoded data | decoder
-| file | ---------> | packets | -----+
-|_______| |______________| |
- v
- _________
- | |
- | decoded |
- | frames |
- |_________|
- ________ ______________ |
-| | | | |
-| output | <-------- | encoded data | <----+
-| file | muxer | packets | encoder
-|________| |______________|
-
-
-
-
-
ffmpeg calls the libavformat library (containing demuxers) to read
-input files and get packets containing encoded data from them. When there are
-multiple input files, ffmpeg tries to keep them synchronized by
-tracking lowest timestamp on any active input stream.
-
-
Encoded packets are then passed to the decoder (unless streamcopy is selected
-for the stream, see further for a description). The decoder produces
-uncompressed frames (raw video/PCM audio/...) which can be processed further by
-filtering (see next section). After filtering, the frames are passed to the
-encoder, which encodes them and outputs encoded packets. Finally those are
-passed to the muxer, which writes the encoded packets to the output file.
-
-
-
3.1 Filtering# TOC
-
Before encoding, ffmpeg can process raw audio and video frames using
-filters from the libavfilter library. Several chained filters form a filter
-graph. ffmpeg distinguishes between two types of filtergraphs:
-simple and complex.
-
-
-
3.1.1 Simple filtergraphs# TOC
-
Simple filtergraphs are those that have exactly one input and output, both of
-the same type. In the above diagram they can be represented by simply inserting
-an additional step between decoding and encoding:
-
-
-
_________ ______________
-| | | |
-| decoded | | encoded data |
-| frames |\ _ | packets |
-|_________| \ /||______________|
- \ __________ /
- simple _\|| | / encoder
- filtergraph | filtered |/
- | frames |
- |__________|
-
-
-
-
Simple filtergraphs are configured with the per-stream -filter option
-(with -vf and -af aliases for video and audio respectively).
-A simple filtergraph for video can look for example like this:
-
-
-
_______ _____________ _______ ________
-| | | | | | | |
-| input | ---> | deinterlace | ---> | scale | ---> | output |
-|_______| |_____________| |_______| |________|
-
-
-
-
Note that some filters change frame properties but not frame contents. E.g. the
-fps filter in the example above changes number of frames, but does not
-touch the frame contents. Another example is the setpts filter, which
-only sets timestamps and otherwise passes the frames unchanged.
-
-
-
3.1.2 Complex filtergraphs# TOC
-
Complex filtergraphs are those which cannot be described as simply a linear
-processing chain applied to one stream. This is the case, for example, when the graph has
-more than one input and/or output, or when output stream type is different from
-input. They can be represented with the following diagram:
-
-
-
_________
-| |
-| input 0 |\ __________
-|_________| \ | |
- \ _________ /| output 0 |
- \ | | / |__________|
- _________ \| complex | /
-| | | |/
-| input 1 |---->| filter |\
-|_________| | | \ __________
- /| graph | \ | |
- / | | \| output 1 |
- _________ / |_________| |__________|
-| | /
-| input 2 |/
-|_________|
-
-
-
-
Complex filtergraphs are configured with the -filter_complex option.
-Note that this option is global, since a complex filtergraph, by its nature,
-cannot be unambiguously associated with a single stream or file.
-
-
The -lavfi option is equivalent to -filter_complex .
-
-
A trivial example of a complex filtergraph is the overlay filter, which
-has two video inputs and one video output, containing one video overlaid on top
-of the other. Its audio counterpart is the amix filter.
-
-
-
3.2 Stream copy# TOC
-
Stream copy is a mode selected by supplying the copy parameter to the
--codec option. It makes ffmpeg omit the decoding and encoding
-step for the specified stream, so it does only demuxing and muxing. It is useful
-for changing the container format or modifying container-level metadata. The
-diagram above will, in this case, simplify to this:
-
-
-
_______ ______________ ________
-| | | | | |
-| input | demuxer | encoded data | muxer | output |
-| file | ---------> | packets | -------> | file |
-|_______| |______________| |________|
-
-
-
-
Since there is no decoding or encoding, it is very fast and there is no quality
-loss. However, it might not work in some cases because of many factors. Applying
-filters is obviously also impossible, since filters work on uncompressed data.
-
-
-
-
4 Stream selection# TOC
-
-
By default, ffmpeg includes only one stream of each type (video, audio, subtitle)
-present in the input files and adds them to each output file. It picks the
-"best" of each based upon the following criteria: for video, it is the stream
-with the highest resolution, for audio, it is the stream with the most channels, for
-subtitles, it is the first subtitle stream. In the case where several streams of
-the same type rate equally, the stream with the lowest index is chosen.
-
-
You can disable some of those defaults by using the -vn/-an/-sn options. For
-full manual control, use the -map option, which disables the defaults just
-described.
-
-
-
-
5 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
5.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
5.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
5.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
5.4 Main options# TOC
-
-
--f fmt (input/output ) Force input or output file format. The format is normally auto detected for input
-files and guessed from the file extension for output files, so this option is not
-needed in most cases.
-
--i filename (input ) input file name
-
--y (global ) Overwrite output files without asking.
-
--n (global ) Do not overwrite output files, and exit immediately if a specified
-output file already exists.
-
--c[:stream_specifier ] codec (input/output,per-stream ) -codec[:stream_specifier ] codec (input/output,per-stream ) Select an encoder (when used before an output file) or a decoder (when used
-before an input file) for one or more streams. codec is the name of a
-decoder/encoder or a special value copy (output only) to indicate that
-the stream is not to be re-encoded.
-
-For example
-
-
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
- encodes all video streams with libx264 and copies all audio streams.
-
-For each stream, the last matching c option is applied, so
-
-
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
- will copy all the streams except the second video, which will be encoded with
-libx264, and the 138th audio, which will be encoded with libvorbis.
-
--t duration (input/output ) When used as an input option (before -i), limit the duration of
-data read from the input file.
-
-When used as an output option (before an output filename), stop writing the
-output after its duration reaches duration .
-
-duration may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--to position (output ) Stop writing the output at position .
-position may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--fs limit_size (output ) Set the file size limit, expressed in bytes.
-
--ss position (input/output ) When used as an input option (before -i), seeks in this input file to
-position . Note the in most formats it is not possible to seek exactly, so
-ffmpeg will seek to the closest seek point before position .
-When transcoding and -accurate_seek is enabled (the default), this
-extra segment between the seek point and position will be decoded and
-discarded. When doing stream copy or when -noaccurate_seek is used, it
-will be preserved.
-
-When used as an output option (before an output filename), decodes but discards
-input until the timestamps reach position .
-
-position may be either in seconds or in hh:mm:ss[.xxx] form.
-
--itsoffset offset (input ) Set the input time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added to the timestamps of the input files. Specifying
-a positive offset means that the corresponding streams are delayed by
-the time duration specified in offset .
-
--timestamp date (output ) Set the recording timestamp in the container.
-
-date must be a time duration specification,
-see (ffmpeg-utils)the Date section in the ffmpeg-utils(1) manual .
-
--metadata[:metadata_specifier] key =value (output,per-metadata ) Set a metadata key/value pair.
-
-An optional metadata_specifier may be given to set metadata
-on streams or chapters. See -map_metadata documentation for
-details.
-
-This option overrides metadata set with -map_metadata. It is
-also possible to delete metadata by using an empty value.
-
-For example, for setting the title in the output file:
-
-
ffmpeg -i in.avi -metadata title="my title" out.flv
- To set the language of the first audio stream:
-
-
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
- -target type (output ) Specify target file type (vcd, svcd, dvd, dv,
-dv50). type may be prefixed with pal-, ntsc- or
-film- to use the corresponding standard. All the format options
-(bitrate, codecs, buffer sizes) are then set automatically. You can just type:
-
-
-
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
- Nevertheless you can specify additional options as long as you know
-they do not conflict with the standard, as in:
-
-
-
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
- -dframes number (output ) Set the number of data frames to output. This is an alias for -frames:d.
-
--frames[:stream_specifier ] framecount (output,per-stream ) Stop writing to the stream after framecount frames.
-
--q[:stream_specifier ] q (output,per-stream ) -qscale[:stream_specifier ] q (output,per-stream ) Use fixed quality scale (VBR). The meaning of q /qscale is
-codec-dependent.
-If qscale is used without a stream_specifier then it applies only
-to the video stream, this is to maintain compatibility with previous behavior
-and as specifying the same codec specific value to 2 different codecs that is
-audio and video generally is not what is intended when no stream_specifier is
-used.
-
--filter[:stream_specifier ] filtergraph (output,per-stream ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single input and a single output of the
-same type of the stream. In the filtergraph, the input is associated
-to the label in, and the output to the label out. See
-the ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-See the -filter_complex option if you
-want to create filtergraphs with multiple inputs and/or outputs.
-
--filter_script[:stream_specifier ] filename (output,per-stream ) This option is similar to -filter , the only difference is that its
-argument is the name of the file from which a filtergraph description is to be
-read.
-
--pre[:stream_specifier ] preset_name (output,per-stream ) Specify the preset for matching stream(s).
-
--stats (global ) Print encoding progress/statistics. It is on by default, to explicitly
-disable it you need to specify -nostats.
-
--progress url (global ) Send program-friendly progress information to url .
-
-Progress information is written approximately every second and at the end of
-the encoding process. It is made of "key =value " lines. key
-consists of only alphanumeric characters. The last key of a sequence of
-progress information is always "progress".
-
--stdin Enable interaction on standard input. On by default unless standard input is
-used as an input. To explicitly disable interaction you need to specify
--nostdin.
-
-Disabling interaction on standard input is useful, for example, if
-ffmpeg is in the background process group. Roughly the same result can
-be achieved with ffmpeg ... < /dev/null but it requires a
-shell.
-
--debug_ts (global ) Print timestamp information. It is off by default. This option is
-mostly useful for testing and debugging purposes, and the output
-format may change from one version to another, so it should not be
-employed by portable scripts.
-
-See also the option -fdebug ts.
-
--attach filename (output ) Add an attachment to the output file. This is supported by a few formats
-like Matroska for e.g. fonts used in rendering subtitles. Attachments
-are implemented as a specific type of stream, so this option will add
-a new stream to the file. It is then possible to use per-stream options
-on this stream in the usual way. Attachment streams created with this
-option will be created after all the other streams (i.e. those created
-with -map or automatic mappings).
-
-Note that for Matroska you also have to set the mimetype metadata tag:
-
-
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
- (assuming that the attachment stream will be third in the output file).
-
--dump_attachment[:stream_specifier ] filename (input,per-stream ) Extract the matching attachment stream into a file named filename . If
-filename is empty, then the value of the filename metadata tag
-will be used.
-
-E.g. to extract the first attachment to a file named ’out.ttf’:
-
-
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
- To extract all attachments to files determined by the filename tag:
-
-
ffmpeg -dump_attachment:t "" -i INPUT
- Technical note – attachments are implemented as codec extradata, so this
-option can actually be used to extract extradata from any stream, not just
-attachments.
-
-
-
-
-
5.5 Video Options# TOC
-
-
--vframes number (output ) Set the number of video frames to output. This is an alias for -frames:v.
-
-r[:stream_specifier ] fps (input/output,per-stream ) Set frame rate (Hz value, fraction or abbreviation).
-
-As an input option, ignore any timestamps stored in the file and instead
-generate timestamps assuming constant frame rate fps .
-This is not the same as the -framerate option used for some input formats
-like image2 or v4l2 (it used to be the same in older versions of FFmpeg).
-If in doubt use -framerate instead of the input option -r .
-
-As an output option, duplicate or drop input frames to achieve constant output
-frame rate fps .
-
--s[:stream_specifier ] size (input/output,per-stream ) Set frame size.
-
-As an input option, this is a shortcut for the video_size private
-option, recognized by some demuxers for which the frame size is either not
-stored in the file or is configurable – e.g. raw video or video grabbers.
-
-As an output option, this inserts the scale video filter to the
-end of the corresponding filtergraph. Please use the scale filter
-directly to insert it at the beginning or some other place.
-
-The format is ‘wxh ’ (default - same as source).
-
--aspect[:stream_specifier ] aspect (output,per-stream ) Set the video display aspect ratio specified by aspect .
-
-aspect can be a floating point number string, or a string of the
-form num :den , where num and den are the
-numerator and denominator of the aspect ratio. For example "4:3",
-"16:9", "1.3333", and "1.7777" are valid argument values.
-
-If used together with -vcodec copy , it will affect the aspect ratio
-stored at container level, but not the aspect ratio stored in encoded
-frames, if it exists.
-
--vn (output ) Disable video recording.
-
--vcodec codec (output ) Set the video codec. This is an alias for -codec:v.
-
--pass[:stream_specifier ] n (output,per-stream ) Select the pass number (1 or 2). It is used to do two-pass
-video encoding. The statistics of the video are recorded in the first
-pass into a log file (see also the option -passlogfile),
-and in the second pass that log file is used to generate the video
-at the exact requested bitrate.
-On pass 1, you may just deactivate audio and set output to null,
-examples for Windows and Unix:
-
-
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
-ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
- -passlogfile[:stream_specifier ] prefix (output,per-stream ) Set two-pass log file name prefix to prefix , the default file name
-prefix is “ffmpeg2pass”. The complete file name will be
-PREFIX-N.log , where N is a number specific to the output
-stream
-
--vf filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:v, see the -filter option .
-
-
-
-
5.6 Advanced Video options# TOC
-
-
--pix_fmt[:stream_specifier ] format (input/output,per-stream ) Set pixel format. Use -pix_fmts to show all the supported
-pixel formats.
-If the selected pixel format can not be selected, ffmpeg will print a
-warning and select the best pixel format supported by the encoder.
-If pix_fmt is prefixed by a +, ffmpeg will exit with an error
-if the requested pixel format can not be selected, and automatic conversions
-inside filtergraphs are disabled.
-If pix_fmt is a single +, ffmpeg selects the same pixel format
-as the input (or graph output) and automatic conversions are disabled.
-
--sws_flags flags (input/output ) Set SwScaler flags.
-
-vdt n Discard threshold.
-
--rc_override[:stream_specifier ] override (output,per-stream ) Rate control override for specific intervals, formatted as "int,int,int"
-list separated with slashes. Two first values are the beginning and
-end frame numbers, last one is quantizer to use if positive, or quality
-factor if negative.
-
--ilme Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
-Use this option if your input file is interlaced and you want
-to keep the interlaced format for minimum losses.
-The alternative is to deinterlace the input stream with
--deinterlace , but deinterlacing introduces losses.
-
-psnr Calculate PSNR of compressed frames.
-
-vstats Dump video coding statistics to vstats_HHMMSS.log .
-
-vstats_file file Dump video coding statistics to file .
-
-top[:stream_specifier ] n (output,per-stream ) top=1/bottom=0/auto=-1 field first
-
-dc precision Intra_dc_precision.
-
-vtag fourcc/tag (output ) Force video tag/fourcc. This is an alias for -tag:v.
-
-qphist (global ) Show QP histogram
-
-vbsf bitstream_filter Deprecated see -bsf
-
--force_key_frames[:stream_specifier ] time [,time ...] (output,per-stream ) -force_key_frames[:stream_specifier ] expr:expr (output,per-stream ) Force key frames at the specified timestamps, more precisely at the first
-frames after each specified time.
-
-If the argument is prefixed with expr:, the string expr
-is interpreted like an expression and is evaluated for each frame. A
-key frame is forced in case the evaluation is non-zero.
-
-If one of the times is "chapters[delta ]", it is expanded into
-the time of the beginning of all chapters in the file, shifted by
-delta , expressed as a time in seconds.
-This option can be useful to ensure that a seek point is present at a
-chapter mark or any other designated place in the output file.
-
-For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
-before the beginning of every chapter:
-
-
-force_key_frames 0:05:00,chapters-0.1
- The expression in expr can contain the following constants:
-
-n the number of current processed frame, starting from 0
-
n_forced the number of forced frames
-
prev_forced_n the number of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
prev_forced_t the time of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
t the time of the current processed frame
-
-
-For example to force a key frame every 5 seconds, you can specify:
-
-
-force_key_frames expr:gte(t,n_forced*5)
- To force a key frame 5 seconds after the time of the last forced one,
-starting from second 13:
-
-
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
- Note that forcing too many keyframes is very harmful for the lookahead
-algorithms of certain encoders: using fixed-GOP options or similar
-would be more efficient.
-
--copyinkf[:stream_specifier ] (output,per-stream ) When doing stream copy, copy also non-key frames found at the
-beginning.
-
--hwaccel[:stream_specifier ] hwaccel (input,per-stream ) Use hardware acceleration to decode the matching stream(s). The allowed values
-of hwaccel are:
-
-none Do not use any hardware acceleration (the default).
-
-auto Automatically select the hardware acceleration method.
-
-vda Use Apple VDA hardware acceleration.
-
-vdpau Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
-
-dxva2 Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
-
-
-This option has no effect if the selected hwaccel is not available or not
-supported by the chosen decoder.
-
-Note that most acceleration methods are intended for playback and will not be
-faster than software decoding on modern CPUs. Additionally, ffmpeg
-will usually need to copy the decoded frames from the GPU memory into the system
-memory, resulting in further performance loss. This option is thus mainly
-useful for testing.
-
--hwaccel_device[:stream_specifier ] hwaccel_device (input,per-stream ) Select a device to use for hardware acceleration.
-
-This option only makes sense when the -hwaccel option is also
-specified. Its exact meaning depends on the specific hardware acceleration
-method chosen.
-
-
-vdpau For VDPAU, this option specifies the X11 display/screen to use. If this option
-is not specified, the value of the DISPLAY environment variable is used
-
-dxva2 For DXVA2, this option should contain the number of the display adapter to use.
-If this option is not specified, the default adapter is used.
-
-
-
-
-
5.7 Audio Options# TOC
-
-
--aframes number (output ) Set the number of audio frames to output. This is an alias for -frames:a.
-
-ar[:stream_specifier ] freq (input/output,per-stream ) Set the audio sampling frequency. For output streams it is set by
-default to the frequency of the corresponding input stream. For input
-streams this option only makes sense for audio grabbing devices and raw
-demuxers and is mapped to the corresponding demuxer options.
-
-aq q (output ) Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
-
-ac[:stream_specifier ] channels (input/output,per-stream ) Set the number of audio channels. For output streams it is set by
-default to the number of input audio channels. For input streams
-this option only makes sense for audio grabbing devices and raw demuxers
-and is mapped to the corresponding demuxer options.
-
-an (output ) Disable audio recording.
-
-acodec codec (input/output ) Set the audio codec. This is an alias for -codec:a.
-
-sample_fmt[:stream_specifier ] sample_fmt (output,per-stream ) Set the audio sample format. Use -sample_fmts to get a list
-of supported sample formats.
-
--af filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:a, see the -filter option .
-
-
-
-
5.8 Advanced Audio options# TOC
-
-
--atag fourcc/tag (output ) Force audio tag/fourcc. This is an alias for -tag:a.
-
-absf bitstream_filter Deprecated, see -bsf
-
-guess_layout_max channels (input,per-stream ) If some input channel layout is not known, try to guess only if it
-corresponds to at most the specified number of channels. For example, 2
-tells to ffmpeg to recognize 1 channel as mono and 2 channels as
-stereo but not 6 channels as 5.1. The default is to always try to guess. Use
-0 to disable all guessing.
-
-
-
-
5.9 Subtitle options# TOC
-
-
--scodec codec (input/output ) Set the subtitle codec. This is an alias for -codec:s.
-
-sn (output ) Disable subtitle recording.
-
-sbsf bitstream_filter Deprecated, see -bsf
-
-
-
-
5.10 Advanced Subtitle options# TOC
-
-
--fix_sub_duration Fix subtitles durations. For each subtitle, wait for the next packet in the
-same stream and adjust the duration of the first to avoid overlap. This is
-necessary with some subtitles codecs, especially DVB subtitles, because the
-duration in the original packet is only a rough estimate and the end is
-actually marked by an empty subtitle frame. Failing to use this option when
-necessary can result in exaggerated durations or muxing failures due to
-non-monotonic timestamps.
-
-Note that this option will delay the output of all data until the next
-subtitle packet is decoded: it may increase memory consumption and latency a
-lot.
-
--canvas_size size Set the size of the canvas used to render subtitles.
-
-
-
-
-
5.11 Advanced options# TOC
-
-
--map [-]input_file_id [:stream_specifier ][,sync_file_id [:stream_specifier ]] | [linklabel] (output )
-Designate one or more input streams as a source for the output file. Each input
-stream is identified by the input file index input_file_id and
-the input stream index input_stream_id within the input
-file. Both indices start at 0. If specified,
-sync_file_id :stream_specifier sets which input stream
-is used as a presentation sync reference.
-
-The first -map option on the command line specifies the
-source for output stream 0, the second -map option specifies
-the source for output stream 1, etc.
-
-A - character before the stream identifier creates a "negative" mapping.
-It disables matching streams from already created mappings.
-
-An alternative [linklabel] form will map outputs from complex filter
-graphs (see the -filter_complex option) to the output file.
-linklabel must correspond to a defined output link label in the graph.
-
-For example, to map ALL streams from the first input file to output
-
-
ffmpeg -i INPUT -map 0 output
- For example, if you have two audio streams in the first input file,
-these streams are identified by "0:0" and "0:1". You can use
--map to select which streams to place in an output file. For
-example:
-
-
ffmpeg -i INPUT -map 0:1 out.wav
- will map the input stream in INPUT identified by "0:1" to
-the (single) output stream in out.wav .
-
-For example, to select the stream with index 2 from input file
-a.mov (specified by the identifier "0:2"), and stream with
-index 6 from input b.mov (specified by the identifier "1:6"),
-and copy them to the output file out.mov :
-
-
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
- To select all video and the third audio stream from an input file:
-
-
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
- To map all the streams except the second audio, use negative mappings
-
-
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
- To pick the English audio stream:
-
-
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
- Note that using this option disables the default mappings for this output file.
-
-
--map_channel [input_file_id .stream_specifier .channel_id |-1][:output_file_id .stream_specifier ] Map an audio channel from a given input to an output. If
-output_file_id .stream_specifier is not set, the audio channel will
-be mapped on all the audio streams.
-
-Using "-1" instead of
-input_file_id .stream_specifier .channel_id will map a muted
-channel.
-
-For example, assuming INPUT is a stereo audio file, you can switch the
-two audio channels with the following command:
-
-
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
- If you want to mute the first channel and keep the second:
-
-
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
- The order of the "-map_channel" option specifies the order of the channels in
-the output stream. The output channel layout is guessed from the number of
-channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
-in combination of "-map_channel" makes the channel gain levels to be updated if
-input and output channel layouts don’t match (for instance two "-map_channel"
-options and "-ac 6").
-
-You can also extract each channel of an input to specific outputs; the following
-command extracts two channels of the INPUT audio stream (file 0, stream 0)
-to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:
-
-
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
- The following example splits the channels of a stereo input into two separate
-streams, which are put into the same output file:
-
-
ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
- Note that currently each output stream can only contain channels from a single
-input stream; you can’t for example use "-map_channel" to pick multiple input
-audio channels contained in different streams (from the same or different files)
-and merge them into a single output stream. It is therefore not currently
-possible, for example, to turn two separate mono streams into a single stereo
-stream. However splitting a stereo stream into two single channel mono streams
-is possible.
-
-If you need this feature, a possible workaround is to use the amerge
-filter. For example, if you need to merge a media (here input.mkv ) with 2
-mono audio streams into one single stereo channel audio stream (and keep the
-video stream), you can use the following command:
-
-
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
- -map_metadata[:metadata_spec_out ] infile [:metadata_spec_in ] (output,per-metadata ) Set metadata information of the next output file from infile . Note that
-those are file indices (zero-based), not filenames.
-Optional metadata_spec_in/out parameters specify, which metadata to copy.
-A metadata specifier can have the following forms:
-
-g global metadata, i.e. metadata that applies to the whole file
-
-s [:stream_spec ]per-stream metadata. stream_spec is a stream specifier as described
-in the Stream specifiers chapter. In an input metadata specifier, the first
-matching stream is copied from. In an output metadata specifier, all matching
-streams are copied to.
-
-c :chapter_index per-chapter metadata. chapter_index is the zero-based chapter index.
-
-p :program_index per-program metadata. program_index is the zero-based program index.
-
-If metadata specifier is omitted, it defaults to global.
-
-By default, global metadata is copied from the first input file,
-per-stream and per-chapter metadata is copied along with streams/chapters. These
-default mappings are disabled by creating any mapping of the relevant type. A negative
-file index can be used to create a dummy mapping that just disables automatic copying.
-
-For example to copy metadata from the first stream of the input file to global metadata
-of the output file:
-
-
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
- To do the reverse, i.e. copy global metadata to all audio streams:
-
-
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
- Note that simple 0 would work as well in this example, since global
-metadata is assumed by default.
-
--map_chapters input_file_index (output ) Copy chapters from input file with index input_file_index to the next
-output file. If no chapter mapping is specified, then chapters are copied from
-the first input file with at least one chapter. Use a negative file index to
-disable any chapter copying.
-
--benchmark (global ) Show benchmarking information at the end of an encode.
-Shows CPU time used and maximum memory consumption.
-Maximum memory consumption is not supported on all systems,
-it will usually display as 0 if not supported.
-
-benchmark_all (global ) Show benchmarking information during the encode.
-Shows CPU time used in various steps (audio/video encode/decode).
-
-timelimit duration (global ) Exit after ffmpeg has been running for duration seconds.
-
-dump (global ) Dump each input packet to stderr.
-
-hex (global ) When dumping packets, also dump the payload.
-
-re (input ) Read input at native frame rate. Mainly used to simulate a grab device.
-or live input stream (e.g. when reading from a file). Should not be used
-with actual grab devices or live input streams (where it can cause packet
-loss).
-By default ffmpeg attempts to read the input(s) as fast as possible.
-This option will slow down the reading of the input(s) to the native frame rate
-of the input(s). It is useful for real-time output (e.g. live streaming).
-
-loop_input Loop over the input stream. Currently it works only for image
-streams. This option is used for automatic FFserver testing.
-This option is deprecated, use -loop 1.
-
-loop_output number_of_times Repeatedly loop output for formats that support looping such as animated GIF
-(0 will loop the output infinitely).
-This option is deprecated, use -loop.
-
-vsync parameter Video sync method.
-For compatibility reasons old values can be specified as numbers.
-Newly added values will have to be specified as strings always.
-
-
-0, passthrough Each frame is passed with its timestamp from the demuxer to the muxer.
-
1, cfr Frames will be duplicated and dropped to achieve exactly the requested
-constant frame rate.
-
2, vfr Frames are passed through with their timestamp or dropped so as to
-prevent 2 frames from having the same timestamp.
-
drop As passthrough but destroys all timestamps, making the muxer generate
-fresh timestamps based on frame-rate.
-
-1, auto Chooses between 1 and 2 depending on muxer capabilities. This is the
-default method.
-
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-With -map you can select from which stream the timestamps should be
-taken. You can leave either video or audio unchanged and sync the
-remaining stream(s) to the unchanged one.
-
--async samples_per_second Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
-the parameter is the maximum samples per second by which the audio is changed.
--async 1 is a special case where only the start of the audio stream is corrected
-without any later correction.
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-This option has been deprecated. Use the aresample audio filter instead.
-
--copyts Do not process input timestamps, but keep their values without trying
-to sanitize them. In particular, do not remove the initial start time
-offset value.
-
-Note that, depending on the vsync option or on specific muxer
-processing (e.g. in case the format option avoid_negative_ts
-is enabled) the output timestamps may mismatch with the input
-timestamps even when this option is selected.
-
--start_at_zero When used with copyts , shift input timestamps so they start at zero.
-
-This means that using e.g. -ss 50 will make output timestamps start at
-50 seconds, regardless of what timestamp the input file started at.
-
--copytb mode Specify how to set the encoder timebase when stream copying. mode is an
-integer numeric value, and can assume one of the following values:
-
-
-1 Use the demuxer timebase.
-
-The time base is copied to the output encoder from the corresponding input
-demuxer. This is sometimes required to avoid non monotonically increasing
-timestamps when copying video streams with variable frame rate.
-
-0 Use the decoder timebase.
-
-The time base is copied to the output encoder from the corresponding input
-decoder.
-
--1 Try to make the choice automatically, in order to generate a sane output.
-
-
-Default value is -1.
-
--shortest (output ) Finish encoding when the shortest input stream ends.
-
-dts_delta_threshold Timestamp discontinuity delta threshold.
-
-muxdelay seconds (input ) Set the maximum demux-decode delay.
-
-muxpreload seconds (input ) Set the initial demux-decode delay.
-
-streamid output-stream-index :new-value (output ) Assign a new stream-id value to an output stream. This option should be
-specified prior to the output filename to which it applies.
-For the situation where multiple output files exist, a streamid
-may be reassigned to a different value.
-
-For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
-an output mpegts file:
-
-
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
- -bsf[:stream_specifier ] bitstream_filters (output,per-stream ) Set bitstream filters for matching streams. bitstream_filters is
-a comma-separated list of bitstream filters. Use the -bsfs option
-to get the list of bitstream filters.
-
-
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
-
-
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
- -tag[:stream_specifier ] codec_tag (input/output,per-stream ) Force a tag/fourcc for matching streams.
-
--timecode hh :mm :ss SEPff Specify Timecode for writing. SEP is ’:’ for non drop timecode and ’;’
-(or ’.’) for drop.
-
-
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
- -filter_complex filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. For simple graphs – those with one input and one output of the same
-type – see the -filter options. filtergraph is a description of
-the filtergraph, as described in the “Filtergraph syntax” section of the
-ffmpeg-filters manual.
-
-Input link labels must refer to input streams using the
-[file_index:stream_specifier] syntax (i.e. the same as -map
-uses). If stream_specifier matches multiple streams, the first one will be
-used. An unlabeled input will be connected to the first unused input stream of
-the matching type.
-
-Output link labels are referred to with -map . Unlabeled outputs are
-added to the first output file.
-
-Note that with this option it is possible to use only lavfi sources without
-normal input files.
-
-For example, to overlay an image over video
-
-
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
-'[out]' out.mkv
- Here [0:v] refers to the first video stream in the first input file,
-which is linked to the first (main) input of the overlay filter. Similarly the
-first video stream in the second input is linked to the second (overlay) input
-of overlay.
-
-Assuming there is only one video stream in each input file, we can omit input
-labels, so the above is equivalent to
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
-'[out]' out.mkv
- Furthermore we can omit the output label and the single output from the filter
-graph will be added to the output file automatically, so we can simply write
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
- To generate 5 seconds of pure red video using lavfi color source:
-
-
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
- -lavfi filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. Equivalent to -filter_complex .
-
--filter_complex_script filename (global ) This option is similar to -filter_complex , the only difference is that
-its argument is the name of the file from which a complex filtergraph
-description is to be read.
-
--accurate_seek (input ) This option enables or disables accurate seeking in input files with the
--ss option. It is enabled by default, so seeking is accurate when
-transcoding. Use -noaccurate_seek to disable it, which may be useful
-e.g. when copying some streams and transcoding the others.
-
--override_ffserver (global ) Overrides the input specifications from ffserver. Using this
-option you can map any input stream to ffserver and control
-many aspects of the encoding from ffmpeg. Without this
-option ffmpeg will transmit to ffserver what is
-requested by ffserver.
-
-The option is intended for cases where features are needed that cannot be
-specified to ffserver but can be to ffmpeg.
-
--sdp_file file (global ) Print sdp information to file .
-This allows dumping sdp information when at least one output isn’t an
-rtp stream.
-
--discard (input ) Allows discarding specific streams or frames of streams at the demuxer.
-Not all demuxers support this.
-
-
-none Discard no frame.
-
-default Default, which discards no frames.
-
-noref Discard all non-reference frames.
-
-bidir Discard all bidirectional frames.
-
-nokey Discard all frames excepts keyframes.
-
-all Discard all frames.
-
-
-
-
-
As a special exception, you can use a bitmap subtitle stream as input: it
-will be converted into a video with the same size as the largest video in
-the file, or 720x576 if no video is present. Note that this is an
-experimental and temporary solution. It will be removed once libavfilter has
-proper support for subtitles.
-
-
For example, to hardcode subtitles on top of a DVB-T recording stored in
-MPEG-TS format, delaying the subtitles by 1 second:
-
-
ffmpeg -i input.ts -filter_complex \
- '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
- -sn -map '#0x2dc' output.mkv
-
-
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
-audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
-
-
-
5.12 Preset files# TOC
-
A preset file contains a sequence of option =value pairs,
-one for each line, specifying a sequence of options which would be
-awkward to specify on the command line. Lines starting with the hash
-(’#’) character are ignored and are used to provide comments. Check
-the presets directory in the FFmpeg source tree for examples.
-
-
There are two types of preset files: ffpreset and avpreset files.
-
-
-
5.12.1 ffpreset files# TOC
-
ffpreset files are specified with the vpre, apre,
-spre, and fpre options. The fpre option takes the
-filename of the preset instead of a preset name as input and can be
-used for any kind of codec. For the vpre, apre, and
-spre options, the options specified in a preset file are
-applied to the currently selected codec of the same type as the preset
-option.
-
-
The argument passed to the vpre, apre, and spre
-preset options identifies the preset file to use according to the
-following rules:
-
-
First ffmpeg searches for a file named arg .ffpreset in the
-directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg , and in
-the datadir defined at configuration time (usually PREFIX/share/ffmpeg )
-or in a ffpresets folder along the executable on win32,
-in that order. For example, if the argument is libvpx-1080p, it will
-search for the file libvpx-1080p.ffpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-codec_name -arg .ffpreset in the above-mentioned
-directories, where codec_name is the name of the codec to which
-the preset file options will be applied. For example, if you select
-the video codec with -vcodec libvpx and use -vpre 1080p,
-then it will search for the file libvpx-1080p.ffpreset .
-
-
-
5.12.2 avpreset files# TOC
-
avpreset files are specified with the pre option. They work similar to
-ffpreset files, but they only allow encoder- specific options. Therefore, an
-option =value pair specifying an encoder cannot be used.
-
-
When the pre option is specified, ffmpeg will look for files with the
-suffix .avpreset in the directories $AVCONV_DATADIR (if set), and
-$HOME/.avconv , and in the datadir defined at configuration time (usually
-PREFIX/share/ffmpeg ), in that order.
-
-
First ffmpeg searches for a file named codec_name -arg .avpreset in
-the above-mentioned directories, where codec_name is the name of the codec
-to which the preset file options will be applied. For example, if you select the
-video codec with -vcodec libvpx and use -pre 1080p, then it will
-search for the file libvpx-1080p.avpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-arg .avpreset in the same directories.
-
-
-
-
-
-
- For streaming at very low bitrates, use a low frame rate
-and a small GOP size. This is especially true for RealVideo where
-the Linux player does not seem to be very fast, so it can miss
-frames. An example is:
-
-
-
ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
- The parameter ’q’ which is displayed while encoding is the current
-quantizer. The value 1 indicates that a very good quality could
-be achieved. The value 31 indicates the worst quality. If q=31 appears
-too often, it means that the encoder cannot compress enough to meet
-your bitrate. You must either increase the bitrate, decrease the
-frame rate or decrease the frame size.
-
- If your computer is not fast enough, you can speed up the
-compression at the expense of the compression ratio. You can use
-’-me zero’ to speed up motion estimation, and ’-g 0’ to disable
-motion estimation completely (you have only I-frames, which means it
-is about as good as JPEG compression).
-
- To have very low audio bitrates, reduce the sampling frequency
-(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
-
- To have a constant quality (but a variable bitrate), use the option
-’-qscale n’ when ’n’ is between 1 (excellent quality) and 31 (worst
-quality).
-
-
-
-
-
7 Examples# TOC
-
-
-
7.1 Video and Audio grabbing# TOC
-
-
If you specify the input format and device then ffmpeg can grab video
-and audio directly.
-
-
-
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
-
-
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Note that you must activate the right video source and channel before
-launching ffmpeg with any TV viewer such as
-xawtv by Gerd Knorr. You also
-have to set the audio recording levels correctly with a
-standard mixer.
-
-
-
7.2 X11 grabbing# TOC
-
-
Grab the X11 display with ffmpeg via
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as
-the DISPLAY environment variable.
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
-variable. 10 is the x-offset and 20 the y-offset for the grabbing.
-
-
-
7.3 Video and Audio file format conversion# TOC
-
-
Any supported file format and protocol can serve as input to ffmpeg:
-
-
Examples:
-
- You can use YUV files as input:
-
-
-
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
- It will use the files:
-
-
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
-/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
- The Y files use twice the resolution of the U and V files. They are
-raw files, without header. They can be generated by all decent video
-decoders. You must specify the size of the image with the -s option
-if ffmpeg cannot guess it.
-
- You can input from a raw YUV420P file:
-
-
-
ffmpeg -i /tmp/test.yuv /tmp/out.avi
- test.yuv is a file containing raw YUV planar data. Each frame is composed
-of the Y plane followed by the U and V planes at half vertical and
-horizontal resolution.
-
- You can output to a raw YUV420P file:
-
-
-
ffmpeg -i mydivx.avi hugefile.yuv
- You can set several input files and output files:
-
-
-
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
- Converts the audio file a.wav and the raw YUV video file a.yuv
-to MPEG file a.mpg.
-
- You can also do audio and video conversions at the same time:
-
-
-
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
- Converts a.wav to MPEG audio at 22050 Hz sample rate.
-
- You can encode to several formats at the same time and define a
-mapping from input stream to output streams:
-
-
-
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
- Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map
-file:index’ specifies which input stream is used for each output
-stream, in the order of the definition of output streams.
-
- You can transcode decrypted VOBs:
-
-
-
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
- This is a typical DVD ripping example; the input is a VOB file, the
-output an AVI file with MPEG-4 video and MP3 audio. Note that in this
-command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
-GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
-input video. Furthermore, the audio stream is MP3-encoded so you need
-to enable LAME support by passing --enable-libmp3lame to configure.
-The mapping is particularly useful for DVD transcoding
-to get the desired audio language.
-
-NOTE: To see the supported input formats, use ffmpeg -formats.
-
- You can extract images from a video, or create a video from many images:
-
-For extracting images from a video:
-
-
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
- This will extract one video frame per second from the video and will
-output them in files named foo-001.jpeg , foo-002.jpeg ,
-etc. Images will be rescaled to fit the new WxH values.
-
-If you want to extract just a limited number of frames, you can use the
-above command in combination with the -vframes or -t option, or in
-combination with -ss to start extracting from a certain point in time.
-
-For creating a video from many images:
-
-
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
- The syntax foo-%03d.jpeg specifies to use a decimal number
-composed of three digits padded with zeroes to express the sequence
-number. It is the same syntax supported by the C printf function, but
-only formats accepting a normal integer are suitable.
-
-When importing an image sequence, -i also supports expanding
-shell-like wildcard patterns (globbing) internally, by selecting the
-image2-specific -pattern_type glob option.
-
-For example, for creating a video from filenames matching the glob pattern
-foo-*.jpeg:
-
-
ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
- You can put many streams of the same type in the output:
-
-
-
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
- The resulting output file test12.nut will contain the first four streams
-from the input files in reverse order.
-
- To force CBR video output:
-
-
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
- The four options lmin, lmax, mblmin and mblmax use ’lambda’ units,
-but you may use the QP2LAMBDA constant to easily convert from ’q’ units:
-
-
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
-
-
-
-
8 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
8.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
8.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
8.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
8.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
8.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
8.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
8.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
8.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
8.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
8.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
9 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
10 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
11 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
12 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
13 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
13.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
13.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
14 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
14.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
14.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
14.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
14.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
14.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
14.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
14.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
14.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
14.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
14.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
15 Subtitles Decoders# TOC
-
-
-
15.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
15.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
15.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
15.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
16 Encoders# TOC
-
-
Encoders are configured elements in FFmpeg which allow the encoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native encoders
-are enabled by default. Encoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available encoders using the configure option --list-encoders.
-
-
You can disable all the encoders with the configure option
---disable-encoders and selectively enable / disable single encoders
-with the options --enable-encoder=ENCODER /
---disable-encoder=ENCODER .
-
-
The option -encoders of the ff* tools will display the list of
-enabled encoders.
-
-
-
-
17 Audio Encoders# TOC
-
-
A description of some of the currently available audio encoders
-follows.
-
-
-
17.1 aac# TOC
-
-
Advanced Audio Coding (AAC) encoder.
-
-
This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
-low complexity (AAC-LC) profile is supported. To use this encoder, you must set
-strict option to ‘experimental ’ or lower.
-
-
As this encoder is experimental, unexpected behavior may exist from time to
-time. For a more stable AAC encoder, see libvo-aacenc . However, be warned
-that it has a worse quality reported by some users.
-
-
See also libfdk_aac and libfaac .
-
-
-
17.1.1 Options# TOC
-
-
-b Set bit rate in bits/s. Setting this automatically activates constant bit rate
-(CBR) mode.
-
-q Set quality for variable bit rate (VBR) mode. This option is valid only using
-the ffmpeg command-line tool. For library interface users, use
-global_quality .
-
-stereo_mode Set stereo encoding mode. Possible values:
-
-
-‘auto ’
-Automatically selected by the encoder.
-
-‘ms_off ’
-Disable middle/side encoding. This is the default.
-
-‘ms_force ’
-Force middle/side encoding.
-
-
-aac_coder Set AAC encoder coding method. Possible values:
-
-
-‘faac ’
-FAAC-inspired method.
-
-This method is a simplified reimplementation of the method used in FAAC, which
-sets thresholds proportional to the band energies, and then decreases all the
-thresholds with quantizer steps to find the appropriate quantization with
-distortion below threshold band by band.
-
-The quality of this method is comparable to the two loop searching method
-described below, but somewhat a little better and slower.
-
-‘anmr ’
-Average noise to mask ratio (ANMR) trellis-based solution.
-
-This has a theoretic best quality out of all the coding methods, but at the
-cost of the slowest speed.
-
-‘twoloop ’
-Two loop searching (TLS) method.
-
-This method first sets quantizers depending on band thresholds and then tries
-to find an optimal combination by adding or subtracting a specific value from
-all quantizers and adjusting some individual quantizer a little.
-
-This method produces similar quality with the FAAC method and is the default.
-
-‘fast ’
-Constant quantizer method.
-
-This method sets a constant quantizer for all bands. This is the fastest of all
-the methods, yet produces the worst quality.
-
-
-
-
-
-
-
17.2 ac3 and ac3_fixed# TOC
-
-
AC-3 audio encoders.
-
-
These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
The ac3 encoder uses floating-point math, while the ac3_fixed
-encoder only uses fixed-point integer math. This does not mean that one is
-always faster, just that one or the other may be better suited to a
-particular system. The floating-point encoder will generally produce better
-quality audio for a given bitrate. The ac3_fixed encoder is not the
-default codec for any of the output formats, so it must be specified explicitly
-using the option -acodec ac3_fixed in order to use it.
-
-
-
17.2.1 AC-3 Metadata# TOC
-
-
The AC-3 metadata options are used to set parameters that describe the audio,
-but in most cases do not affect the audio encoding itself. Some of the options
-do directly affect or influence the decoding and playback of the resulting
-bitstream, while others are just for informational purposes. A few of the
-options will add bits to the output stream that could otherwise be used for
-audio data, and will thus affect the quality of the output. Those will be
-indicated accordingly with a note in the option list below.
-
-
These parameters are described in detail in several publicly-available
-documents.
-
-
-
-
17.2.1.1 Metadata Control Options# TOC
-
-
--per_frame_metadata boolean Allow Per-Frame Metadata. Specifies if the encoder should check for changing
-metadata for each frame.
-
-0 The metadata values set at initialization will be used for every frame in the
-stream. (default)
-
1 Metadata values can be changed before encoding each frame.
-
-
-
-
-
-
17.2.1.2 Downmix Levels# TOC
-
-
--center_mixlev level Center Mix Level. The amount of gain the decoder should apply to the center
-channel when downmixing to stereo. This field will only be written to the
-bitstream if a center channel is present. The value is specified as a scale
-factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6dB gain
-
-
--surround_mixlev level Surround Mix Level. The amount of gain the decoder should apply to the surround
-channel(s) when downmixing to stereo. This field will only be written to the
-bitstream if one or more surround channels are present. The value is specified
-as a scale factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.500 Apply -6dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
17.2.1.3 Audio Production Information# TOC
-
Audio Production Information is optional information describing the mixing
-environment. Either none or both of the fields are written to the bitstream.
-
-
--mixing_level number Mixing Level. Specifies peak sound pressure level (SPL) in the production
-environment when the mix was mastered. Valid values are 80 to 111, or -1 for
-unknown or not indicated. The default value is -1, but that value cannot be
-used if the Audio Production Information is written to the bitstream. Therefore,
-if the room_type option is not the default value, the mixing_level
-option must not be -1.
-
--room_type type Room Type. Describes the equalization used during the final mixing session at
-the studio or on the dubbing stage. A large room is a dubbing stage with the
-industry standard X-curve equalization; a small room has flat equalization.
-This field will not be written to the bitstream if both the mixing_level
-option and the room_type option have the default values.
-
-0 notindicated Not Indicated (default)
-
1 large Large Room
-
2 small Small Room
-
-
-
-
-
-
17.2.1.4 Other Metadata Options# TOC
-
-
--copyright boolean Copyright Indicator. Specifies whether a copyright exists for this audio.
-
-0 off No Copyright Exists (default)
-
1 on Copyright Exists
-
-
--dialnorm value Dialogue Normalization. Indicates how far the average dialogue level of the
-program is below digital 100% full scale (0 dBFS). This parameter determines a
-level shift during audio reproduction that sets the average volume of the
-dialogue to a preset level. The goal is to match volume level between program
-sources. A value of -31dB will result in no volume level change, relative to
-the source volume, during audio reproduction. Valid values are whole numbers in
-the range -31 to -1, with -31 being the default.
-
--dsur_mode mode Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
-(Pro Logic). This field will only be written to the bitstream if the audio
-stream is stereo. Using this option does NOT mean the encoder will actually
-apply Dolby Surround processing.
-
-0 notindicated Not Indicated (default)
-
1 off Not Dolby Surround Encoded
-
2 on Dolby Surround Encoded
-
-
--original boolean Original Bit Stream Indicator. Specifies whether this audio is from the
-original source and not a copy.
-
-0 off Not Original Source
-
1 on Original Source (default)
-
-
-
-
-
-
17.2.2 Extended Bitstream Information# TOC
-
The extended bitstream options are part of the Alternate Bit Stream Syntax as
-specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
-If any one parameter in a group is specified, all values in that group will be
-written to the bitstream. Default values are used for those that are written
-but have not been specified. If the mixing levels are written, the decoder
-will use these values instead of the ones specified in the center_mixlev
-and surround_mixlev options if it supports the Alternate Bit Stream
-Syntax.
-
-
-
17.2.2.1 Extended Bitstream Information - Part 1# TOC
-
-
--dmix_mode mode Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
-(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
-
-0 notindicated Not Indicated (default)
-
1 ltrt Lt/Rt Downmix Preferred
-
2 loro Lo/Ro Downmix Preferred
-
-
--ltrt_cmixlev level Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lt/Rt mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--ltrt_surmixlev level Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lt/Rt mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
--loro_cmixlev level Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lo/Ro mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--loro_surmixlev level Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lo/Ro mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
17.2.2.2 Extended Bitstream Information - Part 2# TOC
-
-
--dsurex_mode mode Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
-(7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually
-apply Dolby Surround EX processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Surround EX Off
-
2 off Dolby Surround EX On
-
-
--dheadphone_mode mode Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
-encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
-option does NOT mean the encoder will actually apply Dolby Headphone
-processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Headphone Off
-
2 off Dolby Headphone On
-
-
--ad_conv_type type A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
-conversion.
-
-0 standard Standard A/D Converter (default)
-
1 hdcd HDCD A/D Converter
-
-
-
-
-
-
17.2.3 Other AC-3 Encoding Options# TOC
-
-
--stereo_rematrixing boolean Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
-is an optional AC-3 feature that increases quality by selectively encoding
-the left/right channels as mid/side. This option is enabled by default, and it
-is highly recommended that it be left as enabled except for testing purposes.
-
-
-
-
-
17.2.4 Floating-Point-Only AC-3 Encoding Options# TOC
-
-
These options are only valid for the floating-point encoder and do not exist
-for the fixed-point encoder due to the corresponding features not being
-implemented in fixed-point.
-
-
--channel_coupling boolean Enables/Disables use of channel coupling, which is an optional AC-3 feature
-that increases quality by combining high frequency information from multiple
-channels into a single channel. The per-channel high frequency information is
-sent with less accuracy in both the frequency and time domains. This allows
-more bits to be used for lower frequencies while preserving enough information
-to reconstruct the high frequencies. This option is enabled by default for the
-floating-point encoder and should generally be left as enabled except for
-testing purposes or to increase encoding speed.
-
--1 auto Selected by Encoder (default)
-
0 off Disable Channel Coupling
-
1 on Enable Channel Coupling
-
-
--cpl_start_band number Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
-value higher than the bandwidth is used, it will be reduced to 1 less than the
-coupling end band. If auto is used, the start band will be determined by
-the encoder based on the bit rate, sample rate, and channel layout. This option
-has no effect if channel coupling is disabled.
-
--1 auto Selected by Encoder (default)
-
-
-
-
-
-
17.3 libfaac# TOC
-
-
libfaac AAC (Advanced Audio Coding) encoder wrapper.
-
-
Requires the presence of the libfaac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfaac --enable-nonfree.
-
-
This encoder is considered to be of higher quality with respect to the
-the native experimental FFmpeg AAC encoder .
-
-
For more information see the libfaac project at
-http://www.audiocoding.com/faac.html/ .
-
-
-
17.3.1 Options# TOC
-
-
The following shared FFmpeg codec options are recognized.
-
-
The following options are supported by the libfaac wrapper. The
-faac-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bit rate in bits/s for ABR (Average Bit Rate) mode. If the bit rate
-is not explicitly specified, it is automatically set to a suitable
-value depending on the selected profile. faac bitrate is
-expressed in kilobits/s.
-
-Note that libfaac does not support CBR (Constant Bit Rate) but only
-ABR (Average Bit Rate).
-
-If VBR mode is enabled this option is ignored.
-
-ar (-R ) Set audio sampling rate (in Hz).
-
-ac (-c ) Set the number of audio channels.
-
-cutoff (-C ) Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_main ’
-Main AAC (Main)
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_ssr ’
-Scalable Sample Rate (SSR)
-
-‘aac_ltp ’
-Long Term Prediction (LTP)
-
-
-If not specified it is set to ‘aac_low ’.
-
-flags +qscale Set constant quality VBR (Variable Bit Rate) mode.
-
-global_quality Set quality in VBR mode as an integer number of lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-and used to set the quality value used by libfaac. A reasonable range
-for the option value in QP units is [10-500], the higher the value the
-higher the quality.
-
-q (-q ) Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value sets the quality value used by libfaac. A reasonable range
-for the option value is [10-500], the higher the value the higher the
-quality.
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
17.3.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to ABR 128 kbps AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfaac -b:a 128k -output.m4a
- Use ffmpeg to convert an audio file to VBR AAC, using the
-LTP AAC profile:
-
-
ffmpeg -i input.wav -c:a libfaac -profile:a aac_ltp -q:a 100 output.m4a
-
-
-
-
17.4 libfdk_aac# TOC
-
-
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
-
-
The libfdk-aac library is based on the Fraunhofer FDK AAC code from
-the Android project.
-
-
Requires the presence of the libfdk-aac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfdk-aac. The library is also incompatible with GPL,
-so if you allow the use of GPL, you should configure with
---enable-gpl --enable-nonfree --enable-libfdk-aac.
-
-
This encoder is considered to be of higher quality with respect to
-both the native experimental FFmpeg AAC encoder and
-libfaac .
-
-
VBR encoding, enabled through the vbr or flags
-+qscale options, is experimental and only works with some
-combinations of parameters.
-
-
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
-higher.
-
-
For more information see the fdk-aac project at
-http://sourceforge.net/p/opencore-amr/fdk-aac/ .
-
-
-
17.4.1 Options# TOC
-
-
The following options are mapped on the shared FFmpeg codec options.
-
-
-b Set bit rate in bits/s. If the bitrate is not explicitly specified, it
-is automatically set to a suitable value depending on the selected
-profile.
-
-In case VBR mode is enabled the option is ignored.
-
-ar Set audio sampling rate (in Hz).
-
-channels Set the number of audio channels.
-
-flags +qscale Enable fixed quality, VBR (Variable Bit Rate) mode.
-Note that VBR is implicitly enabled when the vbr value is
-positive.
-
-cutoff Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_he ’
-High Efficiency AAC (HE-AAC)
-
-‘aac_he_v2 ’
-High Efficiency AAC version 2 (HE-AACv2)
-
-‘aac_ld ’
-Low Delay AAC (LD)
-
-‘aac_eld ’
-Enhanced Low Delay AAC (ELD)
-
-
-If not specified it is set to ‘aac_low ’.
-
-
-
The following are private options of the libfdk_aac encoder.
-
-
-afterburner Enable afterburner feature if set to 1, disabled if set to 0. This
-improves the quality but also the required processing power.
-
-Default value is 1.
-
-eld_sbr Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
-if set to 0.
-
-Default value is 0.
-
-signaling Set SBR/PS signaling style.
-
-It can assume one of the following values:
-
-‘default ’
-choose signaling implicitly (explicit hierarchical by default,
-implicit if global header is disabled)
-
-‘implicit ’
-implicit backwards compatible signaling
-
-‘explicit_sbr ’
-explicit SBR, implicit PS signaling
-
-‘explicit_hierarchical ’
-explicit hierarchical signaling
-
-
-Default value is ‘default ’.
-
-latm Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
-
-Default value is 0.
-
-header_period Set StreamMuxConfig and PCE repetition period (in frames) for sending
-in-band configuration buffers within LATM/LOAS transport layer.
-
-Must be a 16-bits non-negative integer.
-
-Default value is 0.
-
-vbr Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
-good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
-(Constant Bit Rate) is enabled.
-
-Currently only the ‘aac_low ’ profile supports VBR encoding.
-
-VBR modes 1-5 correspond to roughly the following average bit rates:
-
-
-‘1 ’
-32 kbps/channel
-
‘2 ’
-40 kbps/channel
-
‘3 ’
-48-56 kbps/channel
-
‘4 ’
-64 kbps/channel
-
‘5 ’
-about 80-96 kbps/channel
-
-
-Default value is 0.
-
-
-
-
17.4.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to VBR AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
- Use ffmpeg to convert an audio file to CBR 64k kbps AAC, using the
-High-Efficiency AAC profile:
-
-
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
-
-
-
-
17.5 libmp3lame# TOC
-
-
LAME (Lame Ain’t an MP3 Encoder) MP3 encoder wrapper.
-
-
Requires the presence of the libmp3lame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libmp3lame.
-
-
See libshine for a fixed-point MP3 encoder, although with a
-lower quality.
-
-
-
17.5.1 Options# TOC
-
-
The following options are supported by the libmp3lame wrapper. The
-lame-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR or ABR. LAME bitrate is
-expressed in kilobits/s.
-
-q (-V ) Set constant quality setting for VBR. This option is valid only
-using the ffmpeg command-line tool. For library interface
-users, use global_quality .
-
-compression_level (-q ) Set algorithm quality. Valid arguments are integers in the 0-9 range,
-with 0 meaning highest quality but slowest, and 9 meaning fastest
-while producing the worst quality.
-
-reservoir Enable use of bit reservoir when set to 1. Default value is 1. LAME
-has this enabled by default, but can be overridden by use
---nores option.
-
-joint_stereo (-m j ) Enable the encoder to use (on a frame by frame basis) either L/R
-stereo or mid/side stereo. Default value is 1.
-
-abr (--abr ) Enable the encoder to use ABR when set to 1. The lame
---abr sets the target bitrate, while this options only
-tells FFmpeg to use ABR still relies on b to set bitrate.
-
-
-
-
-
17.6 libopencore-amrnb# TOC
-
-
OpenCORE Adaptive Multi-Rate Narrowband encoder.
-
-
Requires the presence of the libopencore-amrnb headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopencore-amrnb --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
-but you can override it by setting strict to ‘unofficial ’ or
-lower.
-
-
-
17.6.1 Options# TOC
-
-
-b Set bitrate in bits per second. Only the following bitrates are supported,
-otherwise libavcodec will round to the nearest valid bitrate.
-
-
-4750 5150 5900 6700 7400 7950 10200 12200
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
17.7 libshine# TOC
-
-
Shine Fixed-Point MP3 encoder wrapper.
-
-
Shine is a fixed-point MP3 encoder. It has a far better performance on
-platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
-However, as it is more targeted on performance than quality, it is not on par
-with LAME and other production-grade encoders quality-wise. Also, according to
-the project’s homepage, this encoder may not be free of bugs as the code was
-written a long time ago and the project was dead for at least 5 years.
-
-
This encoder only supports stereo and mono input. This is also CBR-only.
-
-
The original project (last updated in early 2007) is at
-http://sourceforge.net/projects/libshine-fxp/ . We only support the
-updated fork by the Savonet/Liquidsoap project at https://github.com/savonet/shine .
-
-
Requires the presence of the libshine headers and library during
-configuration. You need to explicitly configure the build with
---enable-libshine.
-
-
See also libmp3lame .
-
-
-
17.7.1 Options# TOC
-
-
The following options are supported by the libshine wrapper. The
-shineenc-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. shineenc -b option
-is expressed in kilobits/s.
-
-
-
-
-
17.8 libtwolame# TOC
-
-
TwoLAME MP2 encoder wrapper.
-
-
Requires the presence of the libtwolame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtwolame.
-
-
-
17.8.1 Options# TOC
-
-
The following options are supported by the libtwolame wrapper. The
-twolame-equivalent options follow the FFmpeg ones and are in
-parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. twolame b
-option is expressed in kilobits/s. Default value is 128k.
-
-q (-V ) Set quality for experimental VBR support. Maximum value range is
-from -50 to 50, useful range is from -10 to 10. The higher the
-value, the better the quality. This option is valid only using the
-ffmpeg command-line tool. For library interface users,
-use global_quality .
-
-mode (--mode ) Set the mode of the resulting audio. Possible values:
-
-
-‘auto ’
-Choose mode automatically based on the input. This is the default.
-
‘stereo ’
-Stereo
-
‘joint_stereo ’
-Joint stereo
-
‘dual_channel ’
-Dual channel
-
‘mono ’
-Mono
-
-
-psymodel (--psyc-mode ) Set psychoacoustic model to use in encoding. The argument must be
-an integer between -1 and 4, inclusive. The higher the value, the
-better the quality. The default value is 3.
-
-energy_levels (--energy ) Enable energy levels extensions when set to 1. The default value is
-0 (disabled).
-
-error_protection (--protect ) Enable CRC error protection when set to 1. The default value is 0
-(disabled).
-
-copyright (--copyright ) Set MPEG audio copyright flag when set to 1. The default value is 0
-(disabled).
-
-original (--original ) Set MPEG audio original flag when set to 1. The default value is 0
-(disabled).
-
-
-
-
-
17.9 libvo-aacenc# TOC
-
-
VisualOn AAC encoder.
-
-
Requires the presence of the libvo-aacenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-aacenc --enable-version3.
-
-
This encoder is considered to be worse than the
-native experimental FFmpeg AAC encoder , according to
-multiple sources.
-
-
-
17.9.1 Options# TOC
-
-
The VisualOn AAC encoder only support encoding AAC-LC and up to 2
-channels. It is also CBR-only.
-
-
-b Set bit rate in bits/s.
-
-
-
-
-
17.10 libvo-amrwbenc# TOC
-
-
VisualOn Adaptive Multi-Rate Wideband encoder.
-
-
Requires the presence of the libvo-amrwbenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-amrwbenc --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 16000Hz sample
-rate, but you can override it by setting strict to
-‘unofficial ’ or lower.
-
-
-
17.10.1 Options# TOC
-
-
-b Set bitrate in bits/s. Only the following bitrates are supported, otherwise
-libavcodec will round to the nearest valid bitrate.
-
-
-‘6600 ’
-‘8850 ’
-‘12650 ’
-‘14250 ’
-‘15850 ’
-‘18250 ’
-‘19850 ’
-‘23050 ’
-‘23850 ’
-
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
17.11 libopus# TOC
-
-
libopus Opus Interactive Audio Codec encoder wrapper.
-
-
Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
-
17.11.1 Option Mapping# TOC
-
-
Most libopus options are modelled after the opusenc utility from
-opus-tools. The following is an option mapping chart describing options
-supported by the libopus wrapper, and their opusenc-equivalent
-in parentheses.
-
-
-b (bitrate ) Set the bit rate in bits/s. FFmpeg’s b option is
-expressed in bits/s, while opusenc’s bitrate in
-kilobits/s.
-
-vbr (vbr , hard-cbr , and cvbr ) Set VBR mode. The FFmpeg vbr option has the following
-valid arguments, with the their opusenc equivalent options
-in parentheses:
-
-
-‘off (hard-cbr ) ’
-Use constant bit rate encoding.
-
-‘on (vbr ) ’
-Use variable bit rate encoding (the default).
-
-‘constrained (cvbr ) ’
-Use constrained variable bit rate encoding.
-
-
-compression_level (comp ) Set encoding algorithm complexity. Valid options are integers in
-the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
-gives the highest quality but slowest encoding. The default is 10.
-
-frame_duration (framesize ) Set maximum frame size, or duration of a frame in milliseconds. The
-argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
-frame sizes achieve lower latency but less quality at a given bitrate.
-Sizes greater than 20ms are only interesting at fairly low bitrates.
-The default is 20ms.
-
-packet_loss (expect-loss ) Set expected packet loss percentage. The default is 0.
-
-application (N.A.) Set intended application type. Valid options are listed below:
-
-
-‘voip ’
-Favor improved speech intelligibility.
-
‘audio ’
-Favor faithfulness to the input (the default).
-
‘lowdelay ’
-Restrict to only the lowest delay modes.
-
-
-cutoff (N.A.) Set cutoff bandwidth in Hz. The argument must be exactly one of the
-following: 4000, 6000, 8000, 12000, or 20000, corresponding to
-narrowband, mediumband, wideband, super wideband, and fullband
-respectively. The default is 0 (cutoff disabled).
-
-
-
-
-
17.12 libvorbis# TOC
-
-
libvorbis encoder wrapper.
-
-
Requires the presence of the libvorbisenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvorbis.
-
-
-
17.12.1 Options# TOC
-
-
The following options are supported by the libvorbis wrapper. The
-oggenc-equivalent of the options are listed in parentheses.
-
-
To get a more accurate and extensive documentation of the libvorbis
-options, consult the libvorbisenc’s and oggenc’s documentations.
-See http://xiph.org/vorbis/ ,
-http://wiki.xiph.org/Vorbis-tools , and oggenc(1).
-
-
-b (-b ) Set bitrate expressed in bits/s for ABR. oggenc -b is
-expressed in kilobits/s.
-
-q (-q ) Set constant quality setting for VBR. The value should be a float
-number in the range of -1.0 to 10.0. The higher the value, the better
-the quality. The default value is ‘3.0 ’.
-
-This option is valid only using the ffmpeg command-line tool.
-For library interface users, use global_quality .
-
-cutoff (--advanced-encode-option lowpass_frequency=N ) Set cutoff bandwidth in Hz, a value of 0 disables cutoff. oggenc’s
-related option is expressed in kHz. The default value is ‘0 ’ (cutoff
-disabled).
-
-minrate (-m ) Set minimum bitrate expressed in bits/s. oggenc -m is
-expressed in kilobits/s.
-
-maxrate (-M ) Set maximum bitrate expressed in bits/s. oggenc -M is
-expressed in kilobits/s. This only has effect on ABR mode.
-
-iblock (--advanced-encode-option impulse_noisetune=N ) Set noise floor bias for impulse blocks. The value is a float number from
--15.0 to 0.0. A negative bias instructs the encoder to pay special attention
-to the crispness of transients in the encoded audio. The tradeoff for better
-transient response is a higher bitrate.
-
-
-
-
-
17.13 libwavpack# TOC
-
-
A wrapper providing WavPack encoding through libwavpack.
-
-
Only lossless mode using 32-bit integer samples is supported currently.
-
-
Requires the presence of the libwavpack headers and library during
-configuration. You need to explicitly configure the build with
---enable-libwavpack.
-
-
Note that a libavcodec-native encoder for the WavPack codec exists so users can
-encode audios with this codec without using this encoder. See wavpackenc .
-
-
-
17.13.1 Options# TOC
-
-
wavpack command line utility’s corresponding options are listed in
-parentheses, if any.
-
-
-frame_size (--blocksize ) Default is 32768.
-
-compression_level Set speed vs. compression tradeoff. Acceptable arguments are listed below:
-
-
-‘0 (-f ) ’
-Fast mode.
-
-‘1 ’
-Normal (default) settings.
-
-‘2 (-h ) ’
-High quality.
-
-‘3 (-hh ) ’
-Very high quality.
-
-‘4-8 (-hh -x EXTRAPROC ) ’
-Same as ‘3 ’, but with extra processing enabled.
-
-‘4 ’ is the same as -x2 and ‘8 ’ is the same as -x6 .
-
-
-
-
-
-
17.14 wavpack# TOC
-
-
WavPack lossless audio encoder.
-
-
This is a libavcodec-native WavPack encoder. There is also an encoder based on
-libwavpack, but there is virtually no reason to use that encoder.
-
-
See also libwavpack .
-
-
-
17.14.1 Options# TOC
-
-
The equivalent options for wavpack command line utility are listed in
-parentheses.
-
-
-
17.14.1.1 Shared options# TOC
-
-
The following shared options are effective for this encoder. Only special notes
-about this particular encoder will be documented here. For the general meaning
-of the options, see the Codec Options chapter .
-
-
-frame_size (--blocksize ) For this encoder, the range for this option is between 128 and 131072. Default
-is automatically decided based on sample rate and number of channel.
-
-For the complete formula of calculating default, see
-libavcodec/wavpackenc.c .
-
-compression_level (-f , -h , -hh , and -x ) This option’s syntax is consistent with libwavpack ’s.
-
-
-
-
17.14.1.2 Private options# TOC
-
-
-joint_stereo (-j ) Set whether to enable joint stereo. Valid values are:
-
-
-‘on (1 ) ’
-Force mid/side audio encoding.
-
‘off (0 ) ’
-Force left/right audio encoding.
-
‘auto ’
-Let the encoder decide automatically.
-
-
-optimize_mono Set whether to enable optimization for mono. This option is only effective for
-non-mono streams. Available values:
-
-
-‘on ’
-enabled
-
‘off ’
-disabled
-
-
-
-
-
-
-
18 Video Encoders# TOC
-
-
A description of some of the currently available video encoders
-follows.
-
-
-
18.1 libtheora# TOC
-
-
libtheora Theora encoder wrapper.
-
-
Requires the presence of the libtheora headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtheora.
-
-
For more information about the libtheora project see
-http://www.theora.org/ .
-
-
-
18.1.1 Options# TOC
-
-
The following global options are mapped to internal libtheora options
-which affect the quality and the bitrate of the encoded stream.
-
-
-b Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
-case VBR (Variable Bit Rate) mode is enabled this option is ignored.
-
-flags Used to enable constant quality mode (VBR) encoding through the
-qscale flag, and to enable the pass1 and pass2
-modes.
-
-g Set the GOP size.
-
-global_quality Set the global quality as an integer in lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
-value in the native libtheora range [0-63]. A higher value corresponds
-to a higher quality.
-
-q Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value is clipped in the [0-10] range, and then multiplied by 6.3
-to get a value in the native libtheora range [0-63].
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
18.1.2 Examples# TOC
-
-
- Set maximum constant quality (VBR) encoding with ffmpeg:
-
-
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
- Use ffmpeg to convert a CBR 1000 kbps Theora video stream:
-
-
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
-
-
-
-
18.2 libvpx# TOC
-
-
VP8/VP9 format supported through libvpx.
-
-
Requires the presence of the libvpx headers and library during configuration.
-You need to explicitly configure the build with --enable-libvpx.
-
-
-
18.2.1 Options# TOC
-
-
Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
-
-
-threads g_threads
-
-profile g_profile
-
-vb rc_target_bitrate
-
-g kf_max_dist
-
-keyint_min kf_min_dist
-
-qmin rc_min_quantizer
-
-qmax rc_max_quantizer
-
-bufsize, vb rc_buf_sz
-(bufsize * 1000 / vb)
-
-rc_buf_optimal_sz
-(bufsize * 1000 / vb * 5 / 6)
-
-rc_init_occupancy, vb rc_buf_initial_sz
-(rc_init_occupancy * 1000 / vb)
-
-rc_buffer_aggressivity rc_undershoot_pct
-
-skip_threshold rc_dropframe_thresh
-
-qcomp rc_2pass_vbr_bias_pct
-
-maxrate, vb rc_2pass_vbr_maxsection_pct
-(maxrate * 100 / vb)
-
-minrate, vb rc_2pass_vbr_minsection_pct
-(minrate * 100 / vb)
-
-minrate, maxrate, vb VPX_CBR
-(minrate == maxrate == vb)
-
-crf VPX_CQ, VP8E_SET_CQ_LEVEL
-
-quality
-best VPX_DL_BEST_QUALITY
-
good VPX_DL_GOOD_QUALITY
-
realtime VPX_DL_REALTIME
-
-
-speed VP8E_SET_CPUUSED
-
-nr VP8E_SET_NOISE_SENSITIVITY
-
-mb_threshold VP8E_SET_STATIC_THRESHOLD
-
-slices VP8E_SET_TOKEN_PARTITIONS
-
-max-intra-rate VP8E_SET_MAX_INTRA_BITRATE_PCT
-
-force_key_frames VPX_EFLAG_FORCE_KF
-
-Alternate reference frame related
-vp8flags altref VP8E_SET_ENABLEAUTOALTREF
-
arnr_max_frames VP8E_SET_ARNR_MAXFRAMES
-
arnr_type VP8E_SET_ARNR_TYPE
-
arnr_strength VP8E_SET_ARNR_STRENGTH
-
rc_lookahead g_lag_in_frames
-
-
-vp8flags error_resilient g_error_resilient
-
-aq_mode VP9E_SET_AQ_MODE
-
-
-
-
For more information about libvpx see:
-http://www.webmproject.org/
-
-
-
-
18.3 libwebp# TOC
-
-
libwebp WebP Image encoder wrapper
-
-
libwebp is Google’s official encoder for WebP images. It can encode in either
-lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
-frame. Lossless images are a separate codec developed by Google.
-
-
-
18.3.1 Pixel Format# TOC
-
-
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
-to limitations of the format and libwebp. Alpha is supported for either mode.
-Because of API limitations, if RGB is passed in when encoding lossy or YUV is
-passed in for encoding lossless, the pixel format will automatically be
-converted using functions from libwebp. This is not ideal and is done only for
-convenience.
-
-
-
18.3.2 Options# TOC
-
-
--lossless boolean Enables/Disables use of lossless mode. Default is 0.
-
--compression_level integer For lossy, this is a quality/speed tradeoff. Higher values give better quality
-for a given size at the cost of increased encoding time. For lossless, this is
-a size/speed tradeoff. Higher values give smaller size at the cost of increased
-encoding time. More specifically, it controls the number of extra algorithms
-and compression tools used, and varies the combination of these tools. This
-maps to the method option in libwebp. The valid range is 0 to 6.
-Default is 4.
-
--qscale float For lossy encoding, this controls image quality, 0 to 100. For lossless
-encoding, this controls the effort and time spent at compressing more. The
-default value is 75. Note that for usage via libavcodec, this option is called
-global_quality and must be multiplied by FF_QP2LAMBDA .
-
--preset type Configuration preset. This does some automatic settings based on the general
-type of the image.
-
-none Do not use a preset.
-
default Use the encoder default.
-
picture Digital picture, like portrait, inner shot
-
photo Outdoor photograph, with natural lighting
-
drawing Hand or line drawing, with high-contrast details
-
icon Small-sized colorful images
-
text Text-like
-
-
-
-
-
-
18.4 libx264, libx264rgb# TOC
-
-
x264 H.264/MPEG-4 AVC encoder wrapper.
-
-
This encoder requires the presence of the libx264 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx264.
-
-
libx264 supports an impressive number of features, including 8x8 and
-4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
-entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
-for detail retention (adaptive quantization, psy-RD, psy-trellis).
-
-
Many libx264 encoder options are mapped to FFmpeg global codec
-options, while unique encoder options are provided through private
-options. Additionally the x264opts and x264-params
-private options allows one to pass a list of key=value tuples as accepted
-by the libx264 x264_param_parse function.
-
-
The x264 project website is at
-http://www.videolan.org/developers/x264.html .
-
-
The libx264rgb encoder is the same as libx264, except it accepts packed RGB
-pixel formats as input instead of YUV.
-
-
-
18.4.1 Supported Pixel Formats# TOC
-
-
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
-x264’s configure time. FFmpeg only supports one bit depth in one particular
-build. In other words, it is not possible to build one FFmpeg with multiple
-versions of x264 with different bit depths.
-
-
-
18.4.2 Options# TOC
-
-
The following options are supported by the libx264 wrapper. The
-x264-equivalent options or values are listed in parentheses
-for easy migration.
-
-
To reduce the duplication of documentation, only the private options
-and some others requiring special attention are documented here. For
-the documentation of the undocumented generic options, see
-the Codec Options chapter .
-
-
To get a more accurate and extensive documentation of the libx264
-options, invoke the command x264 --full-help or consult
-the libx264 documentation.
-
-
-b (bitrate ) Set bitrate in bits/s. Note that FFmpeg’s b option is
-expressed in bits/s, while x264’s bitrate is in
-kilobits/s.
-
-bf (bframes ) g (keyint ) qmin (qpmin ) Minimum quantizer scale.
-
-qmax (qpmax ) Maximum quantizer scale.
-
-qdiff (qpstep ) Maximum difference between quantizer scales.
-
-qblur (qblur ) Quantizer curve blur
-
-qcomp (qcomp ) Quantizer curve compression factor
-
-refs (ref ) Number of reference frames each P-frame can use. The range is from 0-16 .
-
-sc_threshold (scenecut ) Sets the threshold for the scene change detection.
-
-trellis (trellis ) Performs Trellis quantization to increase efficiency. Enabled by default.
-
-nr (nr ) me_range (merange ) Maximum range of the motion search in pixels.
-
-me_method (me ) Set motion estimation method. Possible values in the decreasing order
-of speed:
-
-
-‘dia (dia ) ’
-‘epzs (dia ) ’
-Diamond search with radius 1 (fastest). ‘epzs ’ is an alias for
-‘dia ’.
-
‘hex (hex ) ’
-Hexagonal search with radius 2.
-
‘umh (umh ) ’
-Uneven multi-hexagon search.
-
‘esa (esa ) ’
-Exhaustive search.
-
‘tesa (tesa ) ’
-Hadamard exhaustive search (slowest).
-
-
-subq (subme ) Sub-pixel motion estimation method.
-
-b_strategy (b-adapt ) Adaptive B-frame placement decision algorithm. Use only on first-pass.
-
-keyint_min (min-keyint ) Minimum GOP size.
-
-coder Set entropy encoder. Possible values:
-
-
-‘ac ’
-Enable CABAC.
-
-‘vlc ’
-Enable CAVLC and disable CABAC. It generates the same effect as
-x264’s --no-cabac option.
-
-
-cmp Set full pixel motion estimation comparation algorithm. Possible values:
-
-
-‘chroma ’
-Enable chroma in motion estimation.
-
-‘sad ’
-Ignore chroma in motion estimation. It generates the same effect as
-x264’s --no-chroma-me option.
-
-
-threads (threads ) Number of encoding threads.
-
-thread_type Set multithreading technique. Possible values:
-
-
-‘slice ’
-Slice-based multithreading. It generates the same effect as
-x264’s --sliced-threads option.
-
‘frame ’
-Frame-based multithreading.
-
-
-flags Set encoding flags. It can be used to disable closed GOP and enable
-open GOP by setting it to -cgop. The result is similar to
-the behavior of x264’s --open-gop option.
-
-rc_init_occupancy (vbv-init ) preset (preset ) Set the encoding preset.
-
-tune (tune ) Set tuning of the encoding params.
-
-profile (profile ) Set profile restrictions.
-
-fastfirstpass Enable fast settings when encoding first pass, when set to 1. When set
-to 0, it has the same effect of x264’s
---slow-firstpass option.
-
-crf (crf ) Set the quality for constant quality mode.
-
-crf_max (crf-max ) In CRF mode, prevents VBV from lowering quality beyond this point.
-
-qp (qp ) Set constant quantization rate control method parameter.
-
-aq-mode (aq-mode ) Set AQ method. Possible values:
-
-
-‘none (0 ) ’
-Disabled.
-
-‘variance (1 ) ’
-Variance AQ (complexity mask).
-
-‘autovariance (2 ) ’
-Auto-variance AQ (experimental).
-
-
-aq-strength (aq-strength ) Set AQ strength, reduce blocking and blurring in flat and textured areas.
-
-psy Use psychovisual optimizations when set to 1. When set to 0, it has the
-same effect as x264’s --no-psy option.
-
-psy-rd (psy-rd ) Set strength of psychovisual optimization, in
-psy-rd :psy-trellis format.
-
-rc-lookahead (rc-lookahead ) Set number of frames to look ahead for frametype and ratecontrol.
-
-weightb Enable weighted prediction for B-frames when set to 1. When set to 0,
-it has the same effect as x264’s --no-weightb option.
-
-weightp (weightp ) Set weighted prediction method for P-frames. Possible values:
-
-
-‘none (0 ) ’
-Disabled
-
‘simple (1 ) ’
-Enable only weighted refs
-
‘smart (2 ) ’
-Enable both weighted refs and duplicates
-
-
-ssim (ssim ) Enable calculation and printing SSIM stats after the encoding.
-
-intra-refresh (intra-refresh ) Enable the use of Periodic Intra Refresh instead of IDR frames when set
-to 1.
-
-avcintra-class (class ) Configure the encoder to generate AVC-Intra.
-Valid values are 50,100 and 200
-
-bluray-compat (bluray-compat ) Configure the encoder to be compatible with the bluray standard.
-It is a shorthand for setting "bluray-compat=1 force-cfr=1".
-
-b-bias (b-bias ) Set the influence on how often B-frames are used.
-
-b-pyramid (b-pyramid ) Set method for keeping of some B-frames as references. Possible values:
-
-
-‘none (none ) ’
-Disabled.
-
‘strict (strict ) ’
-Strictly hierarchical pyramid.
-
‘normal (normal ) ’
-Non-strict (not Blu-ray compatible).
-
-
-mixed-refs Enable the use of one reference per partition, as opposed to one
-reference per macroblock when set to 1. When set to 0, it has the
-same effect as x264’s --no-mixed-refs option.
-
-8x8dct Enable adaptive spatial transform (high profile 8x8 transform)
-when set to 1. When set to 0, it has the same effect as
-x264’s --no-8x8dct option.
-
-fast-pskip Enable early SKIP detection on P-frames when set to 1. When set
-to 0, it has the same effect as x264’s
---no-fast-pskip option.
-
-aud (aud ) Enable use of access unit delimiters when set to 1.
-
-mbtree Enable use macroblock tree ratecontrol when set to 1. When set
-to 0, it has the same effect as x264’s
---no-mbtree option.
-
-deblock (deblock ) Set loop filter parameters, in alpha :beta form.
-
-cplxblur (cplxblur ) Set fluctuations reduction in QP (before curve compression).
-
-partitions (partitions ) Set partitions to consider as a comma-separated list of. Possible
-values in the list:
-
-
-‘p8x8 ’
-8x8 P-frame partition.
-
‘p4x4 ’
-4x4 P-frame partition.
-
‘b8x8 ’
-4x4 B-frame partition.
-
‘i8x8 ’
-8x8 I-frame partition.
-
‘i4x4 ’
-4x4 I-frame partition.
-(Enabling ‘p4x4 ’ requires ‘p8x8 ’ to be enabled. Enabling
-‘i8x8 ’ requires adaptive spatial transform (8x8dct
-option) to be enabled.)
-
‘none (none ) ’
-Do not consider any partitions.
-
‘all (all ) ’
-Consider every partition.
-
-
-direct-pred (direct ) Set direct MV prediction mode. Possible values:
-
-
-‘none (none ) ’
-Disable MV prediction.
-
‘spatial (spatial ) ’
-Enable spatial predicting.
-
‘temporal (temporal ) ’
-Enable temporal predicting.
-
‘auto (auto ) ’
-Automatically decided.
-
-
-slice-max-size (slice-max-size ) Set the limit of the size of each slice in bytes. If not specified
-but RTP payload size (ps ) is specified, that is used.
-
-stats (stats ) Set the file name for multi-pass stats.
-
-nal-hrd (nal-hrd ) Set signal HRD information (requires vbv-bufsize to be set).
-Possible values:
-
-
-‘none (none ) ’
-Disable HRD information signaling.
-
‘vbr (vbr ) ’
-Variable bit rate.
-
‘cbr (cbr ) ’
-Constant bit rate (not allowed in MP4 container).
-
-
-x264opts (N.A.) Set any x264 option, see x264 --fullhelp for a list.
-
-Argument is a list of key =value couples separated by
-":". In filter and psy-rd options that use ":" as a separator
-themselves, use "," instead. They accept it as well since long ago but this
-is kept undocumented for some reason.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
- x264-params (N.A.) Override the x264 configuration using a :-separated list of key=value
-parameters.
-
-This option is functionally the same as the x264opts , but is
-duplicated for compatibility with the Libav fork.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
-cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
-no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
-
-
-
Encoding ffpresets for common usages are provided so they can be used with the
-general presets system (e.g. passing the pre option).
-
-
-
18.5 libx265# TOC
-
-
x265 H.265/HEVC encoder wrapper.
-
-
This encoder requires the presence of the libx265 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx265 .
-
-
-
18.5.1 Options# TOC
-
-
-preset Set the x265 preset.
-
-tune Set the x265 tune parameter.
-
-x265-params Set x265 options using a list of key =value couples separated
-by ":". See x265 --help for a list of options.
-
-For example to specify libx265 encoding options with -x265-params :
-
-
-
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
-
-
-
-
18.6 libxvid# TOC
-
-
Xvid MPEG-4 Part 2 encoder wrapper.
-
-
This encoder requires the presence of the libxvidcore headers and library
-during configuration. You need to explicitly configure the build with
---enable-libxvid --enable-gpl.
-
-
The native mpeg4 encoder supports the MPEG-4 Part 2 format, so
-users can encode to this format without this library.
-
-
-
18.6.1 Options# TOC
-
-
The following options are supported by the libxvid wrapper. Some of
-the following options are listed but are not documented, and
-correspond to shared codec options. See the Codec
-Options chapter for their documentation. The other shared options
-which are not listed have no effect for the libxvid encoder.
-
-
-b g qmin qmax mpeg_quant threads bf b_qfactor b_qoffset flags Set specific encoding flags. Possible values:
-
-
-‘mv4 ’
-Use four motion vector by macroblock.
-
-‘aic ’
-Enable high quality AC prediction.
-
-‘gray ’
-Only encode grayscale.
-
-‘gmc ’
-Enable the use of global motion compensation (GMC).
-
-‘qpel ’
-Enable quarter-pixel motion compensation.
-
-‘cgop ’
-Enable closed GOP.
-
-‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
-
-
-trellis me_method Set motion estimation method. Possible values in decreasing order of
-speed and increasing order of quality:
-
-
-‘zero ’
-Use no motion estimation (default).
-
-‘phods ’
-‘x1 ’
-‘log ’
-Enable advanced diamond zonal search for 16x16 blocks and half-pixel
-refinement for 16x16 blocks. ‘x1 ’ and ‘log ’ are aliases for
-‘phods ’.
-
-‘epzs ’
-Enable all of the things described above, plus advanced diamond zonal
-search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
-estimation on chroma planes.
-
-‘full ’
-Enable all of the things described above, plus extended 16x16 and 8x8
-blocks search.
-
-
-mbd Set macroblock decision algorithm. Possible values in the increasing
-order of quality:
-
-
-‘simple ’
-Use macroblock comparing function algorithm (default).
-
-‘bits ’
-Enable rate distortion-based half pixel and quarter pixel refinement for
-16x16 blocks.
-
-‘rd ’
-Enable all of the things described above, plus rate distortion-based
-half pixel and quarter pixel refinement for 8x8 blocks, and rate
-distortion-based search using square pattern.
-
-
-lumi_aq Enable lumi masking adaptive quantization when set to 1. Default is 0
-(disabled).
-
-variance_aq Enable variance adaptive quantization when set to 1. Default is 0
-(disabled).
-
-When combined with lumi_aq , the resulting quality will not
-be better than any of the two specified individually. In other
-words, the resulting quality will be the worse one of the two
-effects.
-
-ssim Set structural similarity (SSIM) displaying method. Possible values:
-
-
-‘off ’
-Disable displaying of SSIM information.
-
-‘avg ’
-Output average SSIM at the end of encoding to stdout. The format of
-showing the average SSIM is:
-
-
-
-For users who are not familiar with C, %f means a float number, or
-a decimal (e.g. 0.939232).
-
-‘frame ’
-Output both per-frame SSIM data during encoding and average SSIM at
-the end of encoding to stdout. The format of per-frame information
-is:
-
-
-
SSIM: avg: %1.3f min: %1.3f max: %1.3f
- For users who are not familiar with C, %1.3f means a float number
-rounded to 3 digits after the dot (e.g. 0.932).
-
-
-
-ssim_acc Set SSIM accuracy. Valid options are integers within the range of
-0-4, while 0 gives the most accurate result and 4 computes the
-fastest.
-
-
-
-
-
18.7 mpeg2# TOC
-
-
MPEG-2 video encoder.
-
-
-
18.7.1 Options# TOC
-
-
-seq_disp_ext integer Specifies if the encoder should write a sequence_display_extension to the
-output.
-
--1 auto Decide automatically to write it or not (this is the default) by checking if
-the data to be written is different from the default or unspecified values.
-
0 never Never write it.
-
1 always Always write it.
-
-
-
-
-
18.8 png# TOC
-
-
PNG image encoder.
-
-
-
18.8.1 Private options# TOC
-
-
-dpi integer Set physical density of pixels, in dots per inch, unset by default
-
dpm integer Set physical density of pixels, in dots per meter, unset by default
-
-
-
-
18.9 ProRes# TOC
-
-
Apple ProRes encoder.
-
-
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
-The used encoder can be chosen with the -vcodec option.
-
-
-
18.9.1 Private Options for prores-ks# TOC
-
-
-profile integer Select the ProRes profile to encode
-
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-‘4444 ’
-
-
-quant_mat integer Select quantization matrix.
-
-‘auto ’
-‘default ’
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-
-If set to auto , the matrix matching the profile will be picked.
-If not set, the matrix providing the highest quality, default , will be
-picked.
-
-bits_per_mb integer How many bits to allot for coding one macroblock. Different profiles use
-between 200 and 2400 bits per macroblock, the maximum is 8000.
-
-mbs_per_slice integer Number of macroblocks in each slice (1-8); the default value (8)
-should be good in almost all situations.
-
-vendor string Override the 4-byte vendor ID.
-A custom vendor ID like apl0 would claim the stream was produced by
-the Apple encoder.
-
-alpha_bits integer Specify number of bits for alpha component.
-Possible values are 0 , 8 and 16 .
-Use 0 to disable alpha plane coding.
-
-
-
-
-
18.9.2 Speed considerations# TOC
-
-
In the default mode of operation the encoder has to honor frame constraints
-(i.e. not produce frames with size bigger than requested) while still making
-output picture as good as possible.
-A frame containing a lot of small details is harder to compress and the encoder
-would spend more time searching for appropriate quantizers for each slice.
-
-
Setting a higher bits_per_mb limit will improve the speed.
-
-
For the fastest encoding speed set the qscale parameter (4 is the
-recommended value) and do not set a size constraint.
-
-
-
-
19 Subtitles Encoders# TOC
-
-
-
19.1 dvdsub# TOC
-
-
This codec encodes the bitmap subtitle format that is used in DVDs.
-Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
-and they can also be used in Matroska files.
-
-
-
19.1.1 Options# TOC
-
-
-even_rows_fix When set to 1, enable a work-around that makes the number of pixel rows
-even in all subtitles. This fixes a problem with some players that
-cut off the bottom row if the number is odd. The work-around just adds
-a fully transparent row if needed. The overhead is low, typically
-one byte per subtitle on average.
-
-By default, this work-around is disabled.
-
-
-
-
20 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
20.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
20.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
20.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
20.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
20.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
20.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
20.7 mjpega_dump_header# TOC
-
-
-
20.8 movsub# TOC
-
-
-
20.9 mp3_header_decompress# TOC
-
-
-
20.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
20.11 remove_extra# TOC
-
-
-
21 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
21.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
22 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
22.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
22.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
22.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
22.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
22.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
22.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
22.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
22.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
22.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
22.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
22.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
22.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
22.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
22.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
22.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
22.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
23 Muxers# TOC
-
-
Muxers are configured elements in FFmpeg which allow writing
-multimedia streams to a particular type of file.
-
-
When you configure your FFmpeg build, all the supported muxers
-are enabled by default. You can list all available muxers using the
-configure option --list-muxers.
-
-
You can disable all the muxers with the configure option
---disable-muxers and selectively enable / disable single muxers
-with the options --enable-muxer=MUXER /
---disable-muxer=MUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled muxers.
-
-
A description of some of the currently available muxers follows.
-
-
-
23.1 aiff# TOC
-
-
Audio Interchange File Format muxer.
-
-
-
23.1.1 Options# TOC
-
-
It accepts the following options:
-
-
-write_id3v2 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
-
-id3v2_version Select ID3v2 version to write. Currently only version 3 and 4 (aka.
-ID3v2.3 and ID3v2.4) are supported. The default is version 4.
-
-
-
-
-
23.2 crc# TOC
-
-
CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a single line of the form:
-CRC=0xCRC , where CRC is a hexadecimal number 0-padded to
-8 digits containing the CRC for all the decoded input frames.
-
-
See also the framecrc muxer.
-
-
-
23.2.1 Examples# TOC
-
-
For example to compute the CRC of the input, and store it in the file
-out.crc :
-
-
ffmpeg -i INPUT -f crc out.crc
-
-
-
You can print the CRC to stdout with the command:
-
-
ffmpeg -i INPUT -f crc -
-
-
-
You can select the output format of each frame with ffmpeg by
-specifying the audio and video codec and format. For example to
-compute the CRC of the input audio converted to PCM unsigned 8-bit
-and the input video converted to MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
-
-
-
-
23.3 framecrc# TOC
-
-
Per-packet CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , 0xCRC
-
-
-
CRC is a hexadecimal number 0-padded to 8 digits containing the
-CRC of the packet.
-
-
-
23.3.1 Examples# TOC
-
-
For example to compute the CRC of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.crc :
-
-
ffmpeg -i INPUT -f framecrc out.crc
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framecrc -
-
-
-
With ffmpeg, you can select the output format to which the
-audio and video frames are encoded before computing the CRC for each
-packet by specifying the audio and video codec. For example, to
-compute the CRC of each decoded input audio frame converted to PCM
-unsigned 8-bit and of each decoded input video frame converted to
-MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
-
-
-
See also the crc muxer.
-
-
-
23.4 framemd5# TOC
-
-
Per-packet MD5 testing format.
-
-
This muxer computes and prints the MD5 hash for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , MD5
-
-
-
MD5 is a hexadecimal number representing the computed MD5 hash
-for the packet.
-
-
-
23.4.1 Examples# TOC
-
-
For example to compute the MD5 of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.md5 :
-
-
ffmpeg -i INPUT -f framemd5 out.md5
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framemd5 -
-
-
-
See also the md5 muxer.
-
-
-
23.5 gif# TOC
-
-
Animated GIF muxer.
-
-
It accepts the following options:
-
-
-loop Set the number of times to loop the output. Use -1 for no loop, 0
-for looping indefinitely (default).
-
-final_delay Force the delay (expressed in centiseconds) after the last frame. Each frame
-ends with a delay until the next frame. The default is -1, which is a
-special value to tell the muxer to re-use the previous delay. In case of a
-loop, you might want to customize this value to mark a pause for instance.
-
-
-
For example, to encode a gif looping 10 times, with a 5 seconds delay between
-the loops:
-
-
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
-
-
-
Note 1: if you wish to extract the frames in separate GIF files, you need to
-force the image2 muxer:
-
-
ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
-
-
-
Note 2: the GIF format has a very small time base: the delay between two frames
-can not be smaller than one centi second.
-
-
-
23.6 hls# TOC
-
-
Apple HTTP Live Streaming muxer that segments MPEG-TS according to
-the HTTP Live Streaming (HLS) specification.
-
-
It creates a playlist file, and one or more segment files. The output filename
-specifies the playlist filename.
-
-
By default, the muxer creates a file for each segment produced. These files
-have the same name as the playlist, followed by a sequential number and a
-.ts extension.
-
-
For example, to convert an input file with ffmpeg:
-
-
ffmpeg -i in.nut out.m3u8
-
-
This example will produce the playlist, out.m3u8 , and segment files:
-out0.ts , out1.ts , out2.ts , etc.
-
-
See also the segment muxer, which provides a more generic and
-flexible implementation of a segmenter, and can be used to perform HLS
-segmentation.
-
-
-
23.6.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-hls_time seconds Set the segment length in seconds. Default value is 2.
-
-hls_list_size size Set the maximum number of playlist entries. If set to 0 the list file
-will contain all the segments. Default value is 5.
-
-hls_ts_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing : special characters must be
-escaped.
-
-hls_wrap wrap Set the number after which the segment filename number (the number
-specified in each segment file) wraps. If set to 0 the number will be
-never wrapped. Default value is 0.
-
-This option is useful to avoid to fill the disk with many segment
-files, and limits the maximum number of segment files written to disk
-to wrap .
-
-start_number number Start the playlist sequence number from number . Default value is
-0.
-
-hls_allow_cache allowcache Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
-
-hls_base_url baseurl Append baseurl to every entry in the playlist.
-Useful to generate playlists with absolute paths.
-
-Note that the playlist sequence number must be unique for each segment
-and it is not to be confused with the segment filename sequence number
-which can be cyclic, for example if the wrap option is
-specified.
-
-hls_segment_filename filename Set the segment filename. Unless hls_flags single_file is set filename
-is used as a string format with the segment number:
-
-
ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
- This example will produce the playlist, out.m3u8 , and segment files:
-file000.ts , file001.ts , file002.ts , etc.
-
-hls_flags single_file If this flag is set, the muxer will store all segments in a single MPEG-TS
-file, and will use byte ranges in the playlist. HLS playlists generated with
-this way will have the version number 4.
-For example:
-
-
ffmpeg -i in.nut -hls_flags single_file out.m3u8
- Will produce the playlist, out.m3u8 , and a single segment file,
-out.ts .
-
-hls_flags delete_segments Segment files removed from the playlist are deleted after a period of time
-equal to the duration of the segment plus the duration of the playlist.
-
-
-
-
23.7 ico# TOC
-
-
ICO file muxer.
-
-
Microsoft’s icon file format (ICO) has some strict limitations that should be noted:
-
-
- Size cannot exceed 256 pixels in any dimension
-
- Only BMP and PNG images can be stored
-
- If a BMP image is used, it must be one of the following pixel formats:
-
-
BMP Bit Depth FFmpeg Pixel Format
-1bit pal8
-4bit pal8
-8bit pal8
-16bit rgb555le
-24bit bgr24
-32bit bgra
- If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
-
- If a PNG image is used, it must use the rgba pixel format
-
-
-
-
23.8 image2# TOC
-
-
Image file muxer.
-
-
The image file muxer writes video frames to image files.
-
-
The output filenames are specified by a pattern, which can be used to
-produce sequentially numbered series of files.
-The pattern may contain the string "%d" or "%0N d", this string
-specifies the position of the characters representing a numbering in
-the filenames. If the form "%0N d" is used, the string
-representing the number in each filename is 0-padded to N
-digits. The literal character ’%’ can be specified in the pattern with
-the string "%%".
-
-
If the pattern contains "%d" or "%0N d", the first filename of
-the file list specified will contain the number 1, all the following
-numbers will be sequential.
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the image files to write.
-
-
For example the pattern "img-%03d.bmp" will specify a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.
-The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
-form img%-1.jpg , img%-2.jpg , ..., img%-10.jpg ,
-etc.
-
-
-
23.8.1 Examples# TOC
-
-
The following example shows how to use ffmpeg for creating a
-sequence of files img-001.jpeg , img-002.jpeg , ...,
-taking one image every second from the input video:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
-
-
-
Note that with ffmpeg, if the format is not specified with the
--f option and the output filename specifies an image file
-format, the image2 muxer is automatically selected, so the previous
-command can be written as:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
-
-
-
Note also that the pattern must not necessarily contain "%d" or
-"%0N d", for example to create a single image file
-img.jpeg from the input video you can employ the command:
-
-
ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
-
-
-
The strftime option allows you to expand the filename with
-date and time information. Check the documentation of
-the strftime() function for the syntax.
-
-
For example to generate image files from the strftime()
-"%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command
-can be used:
-
-
ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
-
-
-
-
23.8.2 Options# TOC
-
-
-start_number Start the sequence from the specified number. Default value is 1. Must
-be a non-negative number.
-
-update If set to 1, the filename will always be interpreted as just a
-filename, not a pattern, and the corresponding file will be continuously
-overwritten with new images. Default value is 0.
-
-strftime If set to 1, expand the filename with date and time information from
-strftime(). Default value is 0.
-
-
-
The image muxer supports the .Y.U.V image file format. This format is
-special in that that each image frame consists of three files, for
-each of the YUV420P components. To read or write this image file format,
-specify the name of the ’.Y’ file. The muxer will automatically open the
-’.U’ and ’.V’ files as required.
-
-
-
23.9 matroska# TOC
-
-
Matroska container muxer.
-
-
This muxer implements the matroska and webm container specs.
-
-
-
23.9.1 Metadata# TOC
-
-
The recognized metadata settings in this muxer are:
-
-
-title Set title name provided to a single track.
-
-language Specify the language of the track in the Matroska languages form.
-
-The language can be either the 3 letters bibliographic ISO-639-2 (ISO
-639-2/B) form (like "fre" for French), or a language code mixed with a
-country code for specialities in languages (like "fre-ca" for Canadian
-French).
-
-stereo_mode Set stereo 3D video layout of two views in a single video track.
-
-The following values are recognized:
-
-‘mono ’
-video is not stereo
-
‘left_right ’
-Both views are arranged side by side, Left-eye view is on the left
-
‘bottom_top ’
-Both views are arranged in top-bottom orientation, Left-eye view is at bottom
-
‘top_bottom ’
-Both views are arranged in top-bottom orientation, Left-eye view is on top
-
‘checkerboard_rl ’
-Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
-
‘checkerboard_lr ’
-Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
-
‘row_interleaved_rl ’
-Each view is constituted by a row based interleaving, Right-eye view is first row
-
‘row_interleaved_lr ’
-Each view is constituted by a row based interleaving, Left-eye view is first row
-
‘col_interleaved_rl ’
-Both views are arranged in a column based interleaving manner, Right-eye view is first column
-
‘col_interleaved_lr ’
-Both views are arranged in a column based interleaving manner, Left-eye view is first column
-
‘anaglyph_cyan_red ’
-All frames are in anaglyph format viewable through red-cyan filters
-
‘right_left ’
-Both views are arranged side by side, Right-eye view is on the left
-
‘anaglyph_green_magenta ’
-All frames are in anaglyph format viewable through green-magenta filters
-
‘block_lr ’
-Both eyes laced in one Block, Left-eye view is first
-
‘block_rl ’
-Both eyes laced in one Block, Right-eye view is first
-
-
-
-
For example a 3D WebM clip can be created using the following command line:
-
-
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
-
-
-
-
23.9.2 Options# TOC
-
-
This muxer supports the following options:
-
-
-reserve_index_space By default, this muxer writes the index for seeking (called cues in Matroska
-terms) at the end of the file, because it cannot know in advance how much space
-to leave for the index at the beginning of the file. However for some use cases
-– e.g. streaming where seeking is possible but slow – it is useful to put the
-index at the beginning of the file.
-
-If this option is set to a non-zero value, the muxer will reserve a given amount
-of space in the file header and then try to write the cues there when the muxing
-finishes. If the available space does not suffice, muxing will fail. A safe size
-for most use cases should be about 50kB per hour of video.
-
-Note that cues are only written if the output is seekable and this option will
-have no effect if it is not.
-
-
-
-
23.10 md5# TOC
-
-
MD5 testing format.
-
-
This muxer computes and prints the MD5 hash of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a single line of the form:
-MD5=MD5 , where MD5 is a hexadecimal number representing
-the computed MD5 hash.
-
-
For example to compute the MD5 hash of the input converted to raw
-audio and video, and store it in the file out.md5 :
-
-
ffmpeg -i INPUT -f md5 out.md5
-
-
-
You can print the MD5 to stdout with the command:
-
-
ffmpeg -i INPUT -f md5 -
-
-
-
See also the framemd5 muxer.
-
-
-
23.11 mov, mp4, ismv# TOC
-
-
MOV/MP4/ISMV (Smooth Streaming) muxer.
-
-
The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
-file has all the metadata about all packets stored in one location
-(written at the end of the file, it can be moved to the start for
-better playback by adding faststart to the movflags , or
-using the qt-faststart tool). A fragmented
-file consists of a number of fragments, where packets and metadata
-about these packets are stored together. Writing a fragmented
-file has the advantage that the file is decodable even if the
-writing is interrupted (while a normal MOV/MP4 is undecodable if
-it is not properly finished), and it requires less memory when writing
-very long files (since writing normal MOV/MP4 files stores info about
-every single packet in memory until the file is closed). The downside
-is that it is less compatible with other applications.
-
-
-
23.11.1 Options# TOC
-
-
Fragmentation is enabled by setting one of the AVOptions that define
-how to cut the file into fragments:
-
-
--moov_size bytes Reserves space for the moov atom at the beginning of the file instead of placing the
-moov atom at the end. If the space reserved is insufficient, muxing will fail.
-
-movflags frag_keyframe Start a new fragment at each video keyframe.
-
-frag_duration duration Create fragments that are duration microseconds long.
-
-frag_size size Create fragments that contain up to size bytes of payload data.
-
-movflags frag_custom Allow the caller to manually choose when to cut fragments, by
-calling av_write_frame(ctx, NULL) to write a fragment with
-the packets written so far. (This is only useful with other
-applications integrating libavformat, not from ffmpeg.)
-
-min_frag_duration duration Don’t create fragments that are shorter than duration microseconds long.
-
-
-
If more than one condition is specified, fragments are cut when
-one of the specified conditions is fulfilled. The exception to this is
--min_frag_duration, which has to be fulfilled for any of the other
-conditions to apply.
-
-
Additionally, the way the output file is written can be adjusted
-through a few other options:
-
-
--movflags empty_moov Write an initial moov atom directly at the start of the file, without
-describing any samples in it. Generally, an mdat/moov pair is written
-at the start of the file, as a normal MOV/MP4 file, containing only
-a short portion of the file. With this option set, there is no initial
-mdat atom, and the moov atom only describes the tracks but has
-a zero duration.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags separate_moof Write a separate moof (movie fragment) atom for each track. Normally,
-packets for all tracks are written in a moof atom (which is slightly
-more efficient), but with this option set, the muxer writes one moof/mdat
-pair for each track, making it easier to separate tracks.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags faststart Run a second pass moving the index (moov atom) to the beginning of the file.
-This operation can take a while, and will not work in various situations such
-as fragmented output, thus it is not enabled by default.
-
-movflags rtphint Add RTP hinting tracks to the output file.
-
-movflags disable_chpl Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
-and a QuickTime chapter track are written to the file. With this option
-set, only the QuickTime chapter track will be written. Nero chapters can
-cause failures when the file is reprocessed with certain tagging programs, like
-mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
-
-movflags omit_tfhd_offset Do not write any absolute base_data_offset in tfhd atoms. This avoids
-tying fragments to absolute byte positions in the file/streams.
-
-movflags default_base_moof Similarly to the omit_tfhd_offset, this flag avoids writing the
-absolute base_data_offset field in tfhd atoms, but does so by using
-the new default-base-is-moof flag instead. This flag is new from
-14496-12:2012. This may make the fragments easier to parse in certain
-circumstances (avoiding basing track fragment location calculations
-on the implicit end of the previous track fragment).
-
-
-
-
23.11.2 Example# TOC
-
-
Smooth Streaming content can be pushed in real time to a publishing
-point on IIS with this muxer. Example:
-
-
ffmpeg -re <normal input/transcoding options> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
-
-
-
-
23.12 mp3# TOC
-
-
The MP3 muxer writes a raw MP3 stream with the following optional features:
-
- An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
-2.4 are supported, the id3v2_version private option controls which one is
-used (3 or 4). Setting id3v2_version to 0 disables the ID3v2 header
-completely.
-
-The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
-The pictures are supplied to the muxer in form of a video stream with a single
-packet. There can be any number of those streams, each will correspond to a
-single APIC frame. The stream metadata tags title and comment map
-to APIC description and picture type respectively. See
-http://id3.org/id3v2.4.0-frames for allowed picture types.
-
-Note that the APIC frames must be written at the beginning, so the muxer will
-buffer the audio frames until it gets all the pictures. It is therefore advised
-to provide the pictures as soon as possible to avoid excessive buffering.
-
- A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
-default, but will be written only if the output is seekable. The
-write_xing private option can be used to disable it. The frame contains
-various information that may be useful to the decoder, like the audio duration
-or encoder delay.
-
- A legacy ID3v1 tag at the end of the file (disabled by default). It may be
-enabled with the write_id3v1 private option, but as its capabilities are
-very limited, its usage is not recommended.
-
-
-
Examples:
-
-
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
-
-
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
-
-
-
To attach a picture to an mp3 file select both the audio and the picture stream
-with map:
-
-
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
--metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
-
-
-
Write a "clean" MP3 without any extra features:
-
-
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
-
-
-
-
23.13 mpegts# TOC
-
-
MPEG transport stream muxer.
-
-
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
-
-
The recognized metadata settings in mpegts muxer are service_provider
-and service_name. If they are not set the default for
-service_provider is "FFmpeg" and the default for
-service_name is "Service01".
-
-
-
23.13.1 Options# TOC
-
-
The muxer options are:
-
-
--mpegts_original_network_id number Set the original_network_id (default 0x0001). This is unique identifier
-of a network in DVB. Its main use is in the unique identification of a
-service through the path Original_Network_ID, Transport_Stream_ID.
-
-mpegts_transport_stream_id number Set the transport_stream_id (default 0x0001). This identifies a
-transponder in DVB.
-
-mpegts_service_id number Set the service_id (default 0x0001) also known as program in DVB.
-
-mpegts_pmt_start_pid number Set the first PID for PMT (default 0x1000, max 0x1f00).
-
-mpegts_start_pid number Set the first PID for data packets (default 0x0100, max 0x0f00).
-
-mpegts_m2ts_mode number Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
-
-muxrate number Set a constant muxrate (default VBR).
-
-pcr_period numer Override the default PCR retransmission time (default 20ms), ignored
-if variable muxrate is selected.
-
-pes_payload_size number Set minimum PES packet payload in bytes.
-
-mpegts_flags flags Set flags (see below).
-
-mpegts_copyts number Preserve original timestamps, if value is set to 1. Default value is -1, which
-results in shifting timestamps so that they start from 0.
-
-tables_version number Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
-This option allows updating stream structure so that standard consumer may
-detect the change. To do so, reopen output AVFormatContext (in case of API
-usage) or restart ffmpeg instance, cyclically changing tables_version value:
-
-
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
-ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-
-
-
Option mpegts_flags may take a set of such flags:
-
-
-resend_headers Reemit PAT/PMT before writing the next packet.
-
latm Use LATM packetization for AAC.
-
-
-
-
23.13.2 Example# TOC
-
-
-
ffmpeg -i file.mpg -c copy \
- -mpegts_original_network_id 0x1122 \
- -mpegts_transport_stream_id 0x3344 \
- -mpegts_service_id 0x5566 \
- -mpegts_pmt_start_pid 0x1500 \
- -mpegts_start_pid 0x150 \
- -metadata service_provider="Some provider" \
- -metadata service_name="Some Channel" \
- -y out.ts
-
-
-
-
23.14 null# TOC
-
-
Null muxer.
-
-
This muxer does not generate any output file, it is mainly useful for
-testing or benchmarking purposes.
-
-
For example to benchmark decoding with ffmpeg you can use the
-command:
-
-
ffmpeg -benchmark -i INPUT -f null out.null
-
-
-
Note that the above command does not read or write the out.null
-file, but specifying the output file is required by the ffmpeg
-syntax.
-
-
Alternatively you can write the command as:
-
-
ffmpeg -benchmark -i INPUT -f null -
-
-
-
-
23.15 nut# TOC
-
-
--syncpoints flags Change the syncpoint usage in nut:
-
-default use the normal low-overhead seeking aids.none do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;Use of this option is not recommended, as the resulting files are very damage
- sensitive and seeking is not possible. Also in general the overhead from
- syncpoints is negligible. Note, -write_index 0 can be used to disable
- all growing data tables, allowing to mux endless streams with limited memory
- and without these disadvantages.
-
timestamped extend the syncpoint with a wallclock field.
-The none and timestamped flags are experimental.
-
-write_index bool Write index at the end, the default is to write an index.
-
-
-
-
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
-
-
-
-
23.16 ogg# TOC
-
-
Ogg container muxer.
-
-
--page_duration duration Preferred page duration, in microseconds. The muxer will attempt to create
-pages that are approximately duration microseconds long. This allows the
-user to compromise between seek granularity and container overhead. The default
-is 1 second. A value of 0 will fill all segments, making pages as large as
-possible. A value of 1 will effectively use 1 packet-per-page in most
-situations, giving a small seek granularity at the cost of additional container
-overhead.
-
-
-
-
23.17 segment, stream_segment, ssegment# TOC
-
-
Basic stream segmenter.
-
-
This muxer outputs streams to a number of separate files of nearly
-fixed duration. Output filename pattern can be set in a fashion similar to
-image2 .
-
-
stream_segment is a variant of the muxer used to write to
-streaming output formats, i.e. which do not require global headers,
-and is recommended for outputting e.g. to MPEG transport stream segments.
-ssegment is a shorter alias for stream_segment.
-
-
Every segment starts with a keyframe of the selected reference stream,
-which is set through the reference_stream option.
-
-
Note that if you want accurate splitting for a video file, you need to
-make the input key frames correspond to the exact splitting times
-expected by the segmenter, or the segment muxer will start the new
-segment with the key frame found next after the specified start
-time.
-
-
The segment muxer works best with a single constant frame rate video.
-
-
Optionally it can generate a list of the created segments, by setting
-the option segment_list . The list type is specified by the
-segment_list_type option. The entry filenames in the segment
-list are set by default to the basename of the corresponding segment
-files.
-
-
See also the hls muxer, which provides a more specific
-implementation for HLS segmentation.
-
-
-
23.17.1 Options# TOC
-
-
The segment muxer supports the following options:
-
-
-reference_stream specifier Set the reference stream, as specified by the string specifier .
-If specifier is set to auto, the reference is chosen
-automatically. Otherwise it must be a stream specifier (see the “Stream
-specifiers” chapter in the ffmpeg manual) which specifies the
-reference stream. The default value is auto.
-
-segment_format format Override the inner container format, by default it is guessed by the filename
-extension.
-
-segment_format_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing the : special character must be
-escaped.
-
-segment_list name Generate also a listfile named name . If not specified no
-listfile is generated.
-
-segment_list_flags flags Set flags affecting the segment list generation.
-
-It currently supports the following flags:
-
-‘cache ’
-Allow caching (only affects M3U8 list files).
-
-‘live ’
-Allow live-friendly file generation.
-
-
-segment_list_type type Select the listing format.
-
-flat use a simple flat list of entries.hls use a m3u8-like structure.
-
-segment_list_size size Update the list file so that it contains at most size
-segments. If 0 the list file will contain all the segments. Default
-value is 0.
-
-segment_list_entry_prefix prefix Prepend prefix to each entry. Useful to generate absolute paths.
-By default no prefix is applied.
-
-The following values are recognized:
-
-‘flat ’
-Generate a flat list for the created segments, one segment per line.
-
-‘csv, ext ’
-Generate a list for the created segments, one segment per line,
-each line matching the format (comma-separated values):
-
-
segment_filename ,segment_start_time ,segment_end_time
-segment_filename is the name of the output file generated by the
-muxer according to the provided pattern. CSV escaping (according to
-RFC4180) is applied if required.
-
-segment_start_time and segment_end_time specify
-the segment start and end time expressed in seconds.
-
-A list file with the suffix ".csv" or ".ext" will
-auto-select this format.
-
-‘ext ’ is deprecated in favor or ‘csv ’.
-
-‘ffconcat ’
-Generate an ffconcat file for the created segments. The resulting file
-can be read using the FFmpeg concat demuxer.
-
-A list file with the suffix ".ffcat" or ".ffconcat" will
-auto-select this format.
-
-‘m3u8 ’
-Generate an extended M3U8 file, version 3, compliant with
-http://tools.ietf.org/id/draft-pantos-http-live-streaming .
-
-A list file with the suffix ".m3u8" will auto-select this format.
-
-
-If not specified the type is guessed from the list file name suffix.
-
-segment_time time Set segment duration to time , the value must be a duration
-specification. Default value is "2". See also the
-segment_times option.
-
-Note that splitting may not be accurate, unless you force the
-reference stream key-frames at the given time. See the introductory
-notice and the examples below.
-
-segment_atclocktime 1|0 If set to "1" split at regular clock time intervals starting from 00:00
-o’clock. The time value specified in segment_time is
-used for setting the length of the splitting interval.
-
-For example with segment_time set to "900" this makes it possible
-to create files at 12:00 o’clock, 12:15, 12:30, etc.
-
-Default value is "0".
-
-segment_time_delta delta Specify the accuracy time when selecting the start time for a
-segment, expressed as a duration specification. Default value is "0".
-
-When delta is specified a key-frame will start a new segment if its
-PTS satisfies the relation:
-
-
PTS >= start_time - time_delta
- This option is useful when splitting video content, which is always
-split at GOP boundaries, in case a key frame is found just before the
-specified split time.
-
-In particular may be used in combination with the ffmpeg option
-force_key_frames . The key frame times specified by
-force_key_frames may not be set accurately because of rounding
-issues, with the consequence that a key frame time may result set just
-before the specified time. For constant frame rate videos a value of
-1/(2*frame_rate ) should address the worst case mismatch between
-the specified time and the time set by force_key_frames .
-
-segment_times times Specify a list of split points. times contains a list of comma
-separated duration specifications, in increasing order. See also
-the segment_time option.
-
-segment_frames frames Specify a list of split video frame numbers. frames contains a
-list of comma separated integer numbers, in increasing order.
-
-This option specifies to start a new segment whenever a reference
-stream key frame is found and the sequential number (starting from 0)
-of the frame is greater or equal to the next value in the list.
-
-segment_wrap limit Wrap around segment index once it reaches limit .
-
-segment_start_number number Set the sequence number of the first segment. Defaults to 0.
-
-reset_timestamps 1|0 Reset timestamps at the begin of each segment, so that each segment
-will start with near-zero timestamps. It is meant to ease the playback
-of the generated segments. May not work with some combinations of
-muxers/codecs. It is set to 0 by default.
-
-initial_offset offset Specify timestamp offset to apply to the output packet timestamps. The
-argument must be a time duration specification, and defaults to 0.
-
-
-
-
23.17.2 Examples# TOC
-
-
-
-
-
23.18 smoothstreaming# TOC
-
-
Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
-
-
-window_size Specify the number of fragments kept in the manifest. Default 0 (keep all).
-
-extra_window_size Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
-
-lookahead_count Specify the number of lookahead fragments. Default 2.
-
-min_frag_duration Specify the minimum fragment duration (in microseconds). Default 5000000.
-
-remove_at_exit Specify whether to remove all fragments when finished. Default 0 (do not remove).
-
-
-
-
-
23.19 tee# TOC
-
-
The tee muxer can be used to write the same data to several files or any
-other kind of muxer. It can be used, for example, to both stream a video to
-the network and save it to disk at the same time.
-
-
It is different from specifying several outputs to the ffmpeg
-command-line tool because the audio and video data will be encoded only once
-with the tee muxer; encoding can be a very expensive process. It is not
-useful when using the libavformat API directly because it is then possible
-to feed the same packets to several muxers directly.
-
-
The slave outputs are specified in the file name given to the muxer,
-separated by ’|’. If any of the slave name contains the ’|’ separator,
-leading or trailing spaces or any special character, it must be
-escaped (see (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual ).
-
-
Muxer options can be specified for each slave by prepending them as a list of
-key =value pairs separated by ’:’, between square brackets. If
-the options values contain a special character or the ’:’ separator, they
-must be escaped; note that this is a second level escaping.
-
-
The following special options are also recognized:
-
-f Specify the format name. Useful if it cannot be guessed from the
-output name suffix.
-
-bsfs[/spec ] Specify a list of bitstream filters to apply to the specified
-output.
-
-It is possible to specify to which streams a given bitstream filter
-applies, by appending a stream specifier to the option separated by
-/. spec must be a stream specifier (see Format stream specifiers ). If the stream specifier is not specified, the
-bitstream filters will be applied to all streams in the output.
-
-Several bitstream filters can be specified, separated by ",".
-
-select Select the streams that should be mapped to the slave output,
-specified by a stream specifier. If not specified, this defaults to
-all the input streams.
-
-
-
-
23.19.1 Examples# TOC
-
-
- Encode something and both archive it in a WebM file and stream it
-as MPEG-TS over UDP (the streams need to be explicitly mapped):
-
-
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
- "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Use ffmpeg to encode the input, and send the output
-to three different destinations. The dump_extra bitstream
-filter is used to add extradata information to all the output video
-keyframes packets, as requested by the MPEG-TS format. The select
-option is applied to out.aac in order to make it contain only
-audio packets.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
- As below, but select only stream a:1 for the audio output. Note
-that a second level escaping must be performed, as ":" is a special
-character used to separate options.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
-
-
-
Note: some codecs may need different options depending on the output format;
-the auto-detection of this can not work with the tee muxer. The main example
-is the global_header flag.
-
-
-
23.20 webm_dash_manifest# TOC
-
-
WebM DASH Manifest muxer.
-
-
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML.
-
-
-
23.20.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-adaptation_sets This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
-unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
-audio and video streams. Any number of adaptation sets can be added using this option.
-
-
-
-
23.20.2 Example# TOC
-
-
ffmpeg -f webm_dash_manifest -i video1.webm \
- -f webm_dash_manifest -i video2.webm \
- -f webm_dash_manifest -i audio1.webm \
- -f webm_dash_manifest -i audio2.webm \
- -map 0 -map 1 -map 2 -map 3 \
- -c copy \
- -f webm_dash_manifest \
- -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
- manifest.xml
-
-
-
-
24 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
25 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
25.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
25.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
25.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
25.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
25.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
25.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
25.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
25.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
25.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
25.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
25.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
25.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
25.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
25.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
25.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
25.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
25.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
25.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
25.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
25.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
25.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
25.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
25.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
25.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
25.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
25.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
25.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
25.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
25.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
25.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
25.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
25.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
25.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
25.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
25.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
25.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
25.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
25.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
25.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
26 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
27 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
27.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
27.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
27.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
27.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
27.3 bktr# TOC
-
-
BSD video input device.
-
-
-
27.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
27.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
27.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
27.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
27.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
27.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
27.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
27.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
27.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
27.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
27.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
27.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
27.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
27.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
27.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
27.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
27.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
27.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
27.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
27.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
27.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
27.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
27.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
27.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
27.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
27.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
27.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
27.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
27.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
27.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
27.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
27.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
27.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
28 Output Devices# TOC
-
-
Output devices are configured elements in FFmpeg that can write
-multimedia data to an output device attached to your system.
-
-
When you configure your FFmpeg build, all the supported output devices
-are enabled by default. You can list all available ones using the
-configure option "–list-outdevs".
-
-
You can disable all the output devices using the configure option
-"–disable-outdevs", and selectively enable an output device using the
-option "–enable-outdev=OUTDEV ", or you can disable a particular
-input device using the option "–disable-outdev=OUTDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-enabled output devices.
-
-
A description of the currently available output devices follows.
-
-
-
28.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) output device.
-
-
-
28.1.1 Examples# TOC
-
-
- Play a file on default ALSA device:
-
-
ffmpeg -i INPUT -f alsa default
- Play a file on soundcard 1, audio device 7:
-
-
ffmpeg -i INPUT -f alsa hw:1,7
-
-
-
-
28.2 caca# TOC
-
-
CACA output device.
-
-
This output device allows one to show a video stream in CACA window.
-Only one CACA window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need to configure FFmpeg with
---enable-libcaca.
-libcaca is a graphics library that outputs text instead of pixels.
-
-
For more information about libcaca, check:
-http://caca.zoy.org/wiki/libcaca
-
-
-
28.2.1 Options# TOC
-
-
-window_title Set the CACA window title, if not specified default to the filename
-specified for the output device.
-
-window_size Set the CACA window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video.
-
-driver Set display driver.
-
-algorithm Set dithering algorithm. Dithering is necessary
-because the picture being rendered has usually far more colours than
-the available palette.
-The accepted values are listed with -list_dither algorithms.
-
-antialias Set antialias method. Antialiasing smoothens the rendered
-image and avoids the commonly seen staircase effect.
-The accepted values are listed with -list_dither antialiases.
-
-charset Set which characters are going to be used when rendering text.
-The accepted values are listed with -list_dither charsets.
-
-color Set color to be used when rendering text.
-The accepted values are listed with -list_dither colors.
-
-list_drivers If set to true , print a list of available drivers and exit.
-
-list_dither List available dither options related to the argument.
-The argument must be one of algorithms, antialiases,
-charsets, colors.
-
-
-
-
28.2.2 Examples# TOC
-
-
- The following command shows the ffmpeg output is an
-CACA window, forcing its size to 80x25:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
- Show the list of available drivers and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
- Show the list of available dither colors and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
-
-
-
-
28.3 decklink# TOC
-
-
The decklink output device provides playback capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this output device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz.
-
-
-
28.3.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-preroll Amount of time to preroll video in seconds.
-Defaults to 0.5 .
-
-
-
-
-
28.3.2 Examples# TOC
-
-
- List output devices:
-
-
ffmpeg -i test.avi -f decklink -list_devices 1 dummy
- List supported formats:
-
-
ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
- Play video clip:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
- Play video clip with non-standard framerate or video size:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
-
-
-
-
28.4 fbdev# TOC
-
-
Linux framebuffer output device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
-
28.4.1 Options# TOC
-
-xoffset yoffset Set x/y coordinate of top left corner. Default is 0.
-
-
-
-
28.4.2 Examples# TOC
-
Play a file on framebuffer device /dev/fb0 .
-Required pixel format depends on current framebuffer settings.
-
-
ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
28.5 opengl# TOC
-
OpenGL output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-opengl.
-
-
This output device allows one to render to OpenGL context.
-Context may be provided by application or default SDL window is created.
-
-
When device renders to external context, application must implement handlers for following messages:
-AV_DEV_TO_APP_CREATE_WINDOW_BUFFER - create OpenGL context on current thread.
-AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER - make OpenGL context current.
-AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER - swap buffers.
-AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER - destroy OpenGL context.
-Application is also required to inform a device about current resolution by sending AV_APP_TO_DEV_WINDOW_SIZE message.
-
-
-
28.5.1 Options# TOC
-
-background Set background color. Black is a default.
-
no_window Disables default SDL window when set to non-zero value.
-Application must provide OpenGL context and both window_size_cb and window_swap_buffers_cb callbacks when set.
-
window_title Set the SDL window title, if not specified default to the filename specified for the output device.
-Ignored when no_window is set.
-
window_size Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.
-If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.
-Mostly usable when no_window is not set.
-
-
-
-
-
28.5.2 Examples# TOC
-
Play a file on SDL window using OpenGL rendering:
-
-
ffmpeg -i INPUT -f opengl "window title"
-
-
-
-
28.6 oss# TOC
-
-
OSS (Open Sound System) output device.
-
-
-
28.7 pulse# TOC
-
-
PulseAudio output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org
-
-
-
28.7.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is set to the specified output name.
-
-device Specify the device to use. Default device is used when not provided.
-List of output devices can be obtained with command pactl list sinks.
-
-buffer_size buffer_duration Control the size and duration of the PulseAudio buffer. A small buffer
-gives more control, but requires more frequent updates.
-
-buffer_size specifies size in bytes while
-buffer_duration specifies duration in milliseconds.
-
-When both options are provided then the highest value is used
-(duration is recalculated to bytes using stream parameters). If they
-are set to 0 (which is default), the device will use the default
-PulseAudio duration value. By default PulseAudio set buffer duration
-to around 2 seconds.
-
-prebuf Specify pre-buffering size in bytes. The server does not start with
-playback before at least prebuf bytes are available in the
-buffer. By default this option is initialized to the same value as
-buffer_size or buffer_duration (whichever is bigger).
-
-minreq Specify minimum request size in bytes. The server does not request less
-than minreq bytes from the client, instead waits until the buffer
-is free enough to request more bytes at once. It is recommended to not set
-this option, which will initialize this to a value that is deemed sensible
-by the server.
-
-
-
-
-
28.7.2 Examples# TOC
-
Play a file on default device on default server:
-
-
ffmpeg -i INPUT -f pulse "stream name"
-
-
-
-
28.8 sdl# TOC
-
-
SDL (Simple DirectMedia Layer) output device.
-
-
This output device allows one to show a video stream in an SDL
-window. Only one SDL window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need libsdl installed on your system
-when configuring your build.
-
-
For more information about SDL, check:
-http://www.libsdl.org/
-
-
-
28.8.1 Options# TOC
-
-
-window_title Set the SDL window title, if not specified default to the filename
-specified for the output device.
-
-icon_title Set the name of the iconified SDL window, if not specified it is set
-to the same value of window_title .
-
-window_size Set the SDL window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video,
-downscaled according to the aspect ratio.
-
-window_fullscreen Set fullscreen mode when non-zero value is provided.
-Default value is zero.
-
-
-
-
28.8.2 Interactive commands# TOC
-
-
The window created by the device can be controlled through the
-following interactive commands.
-
-
-q, ESC Quit the device immediately.
-
-
-
-
28.8.3 Examples# TOC
-
-
The following command shows the ffmpeg output is an
-SDL window, forcing its size to the qcif format:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
-
-
-
-
28.9 sndio# TOC
-
-
sndio audio output device.
-
-
-
28.10 xv# TOC
-
-
XV (XVideo) output device.
-
-
This output device allows one to show a video stream in a X Window System
-window.
-
-
-
28.10.1 Options# TOC
-
-
-display_name Specify the hardware display name, which determines the display and
-communications domain to be used.
-
-The display name or DISPLAY environment variable can be a string in
-the format hostname [:number [.screen_number ]].
-
-hostname specifies the name of the host machine on which the
-display is physically attached. number specifies the number of
-the display server on that host machine. screen_number specifies
-the screen to be used on that server.
-
-If unspecified, it defaults to the value of the DISPLAY environment
-variable.
-
-For example, dual-headed:0.1 would specify screen 1 of display
-0 on the machine named “dual-headed”.
-
-Check the X11 specification for more detailed information about the
-display name format.
-
-window_id When set to non-zero value then device doesn’t create new window,
-but uses existing one with provided window_id . By default
-this options is set to zero and device creates its own window.
-
-window_size Set the created window size, can be a string of the form
-width xheight or a video size abbreviation. If not
-specified it defaults to the size of the input video.
-Ignored when window_id is set.
-
-window_x window_y Set the X and Y window offsets for the created window. They are both
-set to 0 by default. The values may be ignored by the window manager.
-Ignored when window_id is set.
-
-window_title Set the window title, if not specified default to the filename
-specified for the output device. Ignored when window_id is set.
-
-
-
For more information about XVideo see http://www.x.org/ .
-
-
-
28.10.2 Examples# TOC
-
-
- Decode, display and encode video input with ffmpeg at the
-same time:
-
-
ffmpeg -i INPUT OUTPUT -f xv display
- Decode and display the input video to multiple X11 windows:
-
-
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
-
-
-
-
29 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
30 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
31 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
32 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
33 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
33.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
33.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
34 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
35 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
35.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
35.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
35.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
35.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
35.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
35.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
35.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
35.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
35.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
35.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
35.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
35.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
35.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
35.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
35.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
35.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
35.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
35.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
35.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
35.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
35.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
35.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
35.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
35.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
35.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
35.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
35.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
35.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
35.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
35.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
35.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
35.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
35.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
35.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
35.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
35.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
35.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
35.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
35.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
35.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
35.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
35.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
35.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
35.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
35.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
35.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
35.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
35.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
35.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
35.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
35.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
35.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
35.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
35.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
35.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
35.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
35.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
35.42.2 Examples# TOC
-
-
-
-
-
35.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
35.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
36 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
36.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
36.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
36.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
36.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
36.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
36.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
36.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
36.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
36.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
36.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
37 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
37.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
37.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
38 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
38.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
38.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
38.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
38.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
38.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
38.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
38.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
38.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
38.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
38.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
38.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
38.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
38.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
38.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
38.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
38.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
38.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
38.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
38.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
38.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
38.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
38.15.1 Examples# TOC
-
-
-
-
-
38.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
38.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
38.17.1 Examples# TOC
-
-
-
-
-
38.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
38.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
38.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
38.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
38.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
38.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
38.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
38.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
38.23.1 Examples# TOC
-
-
-
-
-
38.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
38.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
38.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
38.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
38.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
38.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
38.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
38.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
38.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
38.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
38.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
38.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
38.29.1 Examples# TOC
-
-
-
-
-
38.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
38.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
38.31.1 p/c/n/u/b meaning# TOC
-
-
-
38.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
38.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
38.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
38.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
38.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
38.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
38.34.1 Examples# TOC
-
-
-
-
-
38.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
38.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
38.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
38.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
38.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
38.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
38.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
38.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
38.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
38.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
38.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
38.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
38.42.1 Workflow examples# TOC
-
-
-
38.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
38.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
38.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
38.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
38.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
38.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
38.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
38.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
38.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
38.48.1 Examples# TOC
-
-
-
-
-
38.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
38.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
38.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
38.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
38.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
38.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
38.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
38.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
38.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
38.55.1 Examples# TOC
-
-
-
-
-
38.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
38.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
38.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
38.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
38.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
38.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
38.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
38.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
38.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
38.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
38.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
38.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
38.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
38.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
38.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
38.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
38.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
38.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.65.2 Examples# TOC
-
-
-
-
-
38.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
38.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.67.1 Examples# TOC
-
-
-
-
-
38.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
38.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
38.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
38.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
38.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
38.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
38.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
38.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
38.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
38.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
38.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
38.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
38.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
38.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
38.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
38.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.79.2 Examples# TOC
-
-
-
-
-
38.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
38.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
38.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
38.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
38.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
38.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
38.85.1 Examples# TOC
-
-
-
-
-
38.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
38.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
38.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
38.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
38.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
38.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
38.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
38.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
38.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
38.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
38.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
38.94.1 Examples# TOC
-
-
-
-
-
38.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
38.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
38.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
38.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
38.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
38.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
38.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
38.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
38.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
38.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
38.101.2 Examples# TOC
-
-
-
-
-
38.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
38.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
38.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
38.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
38.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
38.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
38.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
38.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
38.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
39 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
39.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
39.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
39.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
39.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
39.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
39.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
39.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
39.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
39.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
39.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
40 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
40.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
40.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
41 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
41.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
41.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
41.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
41.2.1 Examples# TOC
-
-
-
-
-
41.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
41.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
41.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
41.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
41.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
41.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
41.6.1 Examples# TOC
-
-
-
-
-
41.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
41.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
41.7.2 Examples# TOC
-
-
-
-
-
41.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
41.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
41.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
41.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
41.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
41.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
41.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
41.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
41.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
41.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
41.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
41.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
41.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
41.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
42 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
42.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
42.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
42.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
43 See Also# TOC
-
-
ffmpeg
-ffplay , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
44 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Bitstream Filters Documentation
-
-
-
- FFmpeg Bitstream Filters Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the bitstream filters provided by the
-libavcodec library.
-
-
A bitstream filter operates on the encoded stream data, and performs
-bitstream level modifications without performing decoding.
-
-
-
-
2 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
2.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
2.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
2.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
2.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
2.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
2.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
2.7 mjpega_dump_header# TOC
-
-
-
2.8 movsub# TOC
-
-
-
2.9 mp3_header_decompress# TOC
-
-
-
2.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
2.11 remove_extra# TOC
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavcodec
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Codecs Documentation
-
-
-
- FFmpeg Codecs Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the codecs (decoders and encoders) provided by
-the libavcodec library.
-
-
-
-
2 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
3 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
4 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
4.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
4.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
5 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
5.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
5.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
5.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
5.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
5.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
5.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
5.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
5.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
5.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
6 Subtitles Decoders# TOC
-
-
-
6.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
6.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
6.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
6.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
7 Encoders# TOC
-
-
Encoders are configured elements in FFmpeg which allow the encoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native encoders
-are enabled by default. Encoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available encoders using the configure option --list-encoders.
-
-
You can disable all the encoders with the configure option
---disable-encoders and selectively enable / disable single encoders
-with the options --enable-encoder=ENCODER /
---disable-encoder=ENCODER .
-
-
The option -encoders of the ff* tools will display the list of
-enabled encoders.
-
-
-
-
8 Audio Encoders# TOC
-
-
A description of some of the currently available audio encoders
-follows.
-
-
-
-
-
Advanced Audio Coding (AAC) encoder.
-
-
This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
-low complexity (AAC-LC) profile is supported. To use this encoder, you must set
-strict option to ‘experimental ’ or lower.
-
-
As this encoder is experimental, unexpected behavior may exist from time to
-time. For a more stable AAC encoder, see libvo-aacenc . However, be warned
-that it has a worse quality reported by some users.
-
-
See also libfdk_aac and libfaac .
-
-
-
8.1.1 Options# TOC
-
-
-b Set bit rate in bits/s. Setting this automatically activates constant bit rate
-(CBR) mode.
-
-q Set quality for variable bit rate (VBR) mode. This option is valid only using
-the ffmpeg command-line tool. For library interface users, use
-global_quality .
-
-stereo_mode Set stereo encoding mode. Possible values:
-
-
-‘auto ’
-Automatically selected by the encoder.
-
-‘ms_off ’
-Disable middle/side encoding. This is the default.
-
-‘ms_force ’
-Force middle/side encoding.
-
-
-aac_coder Set AAC encoder coding method. Possible values:
-
-
-‘faac ’
-FAAC-inspired method.
-
-This method is a simplified reimplementation of the method used in FAAC, which
-sets thresholds proportional to the band energies, and then decreases all the
-thresholds with quantizer steps to find the appropriate quantization with
-distortion below threshold band by band.
-
-The quality of this method is comparable to the two loop searching method
-described below, but somewhat a little better and slower.
-
-‘anmr ’
-Average noise to mask ratio (ANMR) trellis-based solution.
-
-This has a theoretic best quality out of all the coding methods, but at the
-cost of the slowest speed.
-
-‘twoloop ’
-Two loop searching (TLS) method.
-
-This method first sets quantizers depending on band thresholds and then tries
-to find an optimal combination by adding or subtracting a specific value from
-all quantizers and adjusting some individual quantizer a little.
-
-This method produces similar quality with the FAAC method and is the default.
-
-‘fast ’
-Constant quantizer method.
-
-This method sets a constant quantizer for all bands. This is the fastest of all
-the methods, yet produces the worst quality.
-
-
-
-
-
-
-
8.2 ac3 and ac3_fixed# TOC
-
-
AC-3 audio encoders.
-
-
These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
The ac3 encoder uses floating-point math, while the ac3_fixed
-encoder only uses fixed-point integer math. This does not mean that one is
-always faster, just that one or the other may be better suited to a
-particular system. The floating-point encoder will generally produce better
-quality audio for a given bitrate. The ac3_fixed encoder is not the
-default codec for any of the output formats, so it must be specified explicitly
-using the option -acodec ac3_fixed in order to use it.
-
-
-
8.2.1 AC-3 Metadata# TOC
-
-
The AC-3 metadata options are used to set parameters that describe the audio,
-but in most cases do not affect the audio encoding itself. Some of the options
-do directly affect or influence the decoding and playback of the resulting
-bitstream, while others are just for informational purposes. A few of the
-options will add bits to the output stream that could otherwise be used for
-audio data, and will thus affect the quality of the output. Those will be
-indicated accordingly with a note in the option list below.
-
-
These parameters are described in detail in several publicly-available
-documents.
-
-
-
-
8.2.1.1 Metadata Control Options# TOC
-
-
--per_frame_metadata boolean Allow Per-Frame Metadata. Specifies if the encoder should check for changing
-metadata for each frame.
-
-0 The metadata values set at initialization will be used for every frame in the
-stream. (default)
-
1 Metadata values can be changed before encoding each frame.
-
-
-
-
-
-
8.2.1.2 Downmix Levels# TOC
-
-
--center_mixlev level Center Mix Level. The amount of gain the decoder should apply to the center
-channel when downmixing to stereo. This field will only be written to the
-bitstream if a center channel is present. The value is specified as a scale
-factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6dB gain
-
-
--surround_mixlev level Surround Mix Level. The amount of gain the decoder should apply to the surround
-channel(s) when downmixing to stereo. This field will only be written to the
-bitstream if one or more surround channels are present. The value is specified
-as a scale factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.500 Apply -6dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
8.2.1.3 Audio Production Information# TOC
-
Audio Production Information is optional information describing the mixing
-environment. Either none or both of the fields are written to the bitstream.
-
-
--mixing_level number Mixing Level. Specifies peak sound pressure level (SPL) in the production
-environment when the mix was mastered. Valid values are 80 to 111, or -1 for
-unknown or not indicated. The default value is -1, but that value cannot be
-used if the Audio Production Information is written to the bitstream. Therefore,
-if the room_type option is not the default value, the mixing_level
-option must not be -1.
-
--room_type type Room Type. Describes the equalization used during the final mixing session at
-the studio or on the dubbing stage. A large room is a dubbing stage with the
-industry standard X-curve equalization; a small room has flat equalization.
-This field will not be written to the bitstream if both the mixing_level
-option and the room_type option have the default values.
-
-0 notindicated Not Indicated (default)
-
1 large Large Room
-
2 small Small Room
-
-
-
-
-
-
8.2.1.4 Other Metadata Options# TOC
-
-
--copyright boolean Copyright Indicator. Specifies whether a copyright exists for this audio.
-
-0 off No Copyright Exists (default)
-
1 on Copyright Exists
-
-
--dialnorm value Dialogue Normalization. Indicates how far the average dialogue level of the
-program is below digital 100% full scale (0 dBFS). This parameter determines a
-level shift during audio reproduction that sets the average volume of the
-dialogue to a preset level. The goal is to match volume level between program
-sources. A value of -31dB will result in no volume level change, relative to
-the source volume, during audio reproduction. Valid values are whole numbers in
-the range -31 to -1, with -31 being the default.
-
--dsur_mode mode Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
-(Pro Logic). This field will only be written to the bitstream if the audio
-stream is stereo. Using this option does NOT mean the encoder will actually
-apply Dolby Surround processing.
-
-0 notindicated Not Indicated (default)
-
1 off Not Dolby Surround Encoded
-
2 on Dolby Surround Encoded
-
-
--original boolean Original Bit Stream Indicator. Specifies whether this audio is from the
-original source and not a copy.
-
-0 off Not Original Source
-
1 on Original Source (default)
-
-
-
-
-
-
8.2.2 Extended Bitstream Information# TOC
-
The extended bitstream options are part of the Alternate Bit Stream Syntax as
-specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
-If any one parameter in a group is specified, all values in that group will be
-written to the bitstream. Default values are used for those that are written
-but have not been specified. If the mixing levels are written, the decoder
-will use these values instead of the ones specified in the center_mixlev
-and surround_mixlev options if it supports the Alternate Bit Stream
-Syntax.
-
-
-
8.2.2.1 Extended Bitstream Information - Part 1# TOC
-
-
--dmix_mode mode Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
-(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
-
-0 notindicated Not Indicated (default)
-
1 ltrt Lt/Rt Downmix Preferred
-
2 loro Lo/Ro Downmix Preferred
-
-
--ltrt_cmixlev level Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lt/Rt mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--ltrt_surmixlev level Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lt/Rt mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
--loro_cmixlev level Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lo/Ro mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--loro_surmixlev level Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lo/Ro mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
8.2.2.2 Extended Bitstream Information - Part 2# TOC
-
-
--dsurex_mode mode Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
-(7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually
-apply Dolby Surround EX processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Surround EX Off
-
2 off Dolby Surround EX On
-
-
--dheadphone_mode mode Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
-encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
-option does NOT mean the encoder will actually apply Dolby Headphone
-processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Headphone Off
-
2 off Dolby Headphone On
-
-
--ad_conv_type type A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
-conversion.
-
-0 standard Standard A/D Converter (default)
-
1 hdcd HDCD A/D Converter
-
-
-
-
-
-
8.2.3 Other AC-3 Encoding Options# TOC
-
-
--stereo_rematrixing boolean Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
-is an optional AC-3 feature that increases quality by selectively encoding
-the left/right channels as mid/side. This option is enabled by default, and it
-is highly recommended that it be left as enabled except for testing purposes.
-
-
-
-
-
8.2.4 Floating-Point-Only AC-3 Encoding Options# TOC
-
-
These options are only valid for the floating-point encoder and do not exist
-for the fixed-point encoder due to the corresponding features not being
-implemented in fixed-point.
-
-
--channel_coupling boolean Enables/Disables use of channel coupling, which is an optional AC-3 feature
-that increases quality by combining high frequency information from multiple
-channels into a single channel. The per-channel high frequency information is
-sent with less accuracy in both the frequency and time domains. This allows
-more bits to be used for lower frequencies while preserving enough information
-to reconstruct the high frequencies. This option is enabled by default for the
-floating-point encoder and should generally be left as enabled except for
-testing purposes or to increase encoding speed.
-
--1 auto Selected by Encoder (default)
-
0 off Disable Channel Coupling
-
1 on Enable Channel Coupling
-
-
--cpl_start_band number Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
-value higher than the bandwidth is used, it will be reduced to 1 less than the
-coupling end band. If auto is used, the start band will be determined by
-the encoder based on the bit rate, sample rate, and channel layout. This option
-has no effect if channel coupling is disabled.
-
--1 auto Selected by Encoder (default)
-
-
-
-
-
-
8.3 libfaac# TOC
-
-
libfaac AAC (Advanced Audio Coding) encoder wrapper.
-
-
Requires the presence of the libfaac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfaac --enable-nonfree.
-
-
This encoder is considered to be of higher quality with respect to the
-the native experimental FFmpeg AAC encoder .
-
-
For more information see the libfaac project at
-http://www.audiocoding.com/faac.html/ .
-
-
-
8.3.1 Options# TOC
-
-
The following shared FFmpeg codec options are recognized.
-
-
The following options are supported by the libfaac wrapper. The
-faac-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bit rate in bits/s for ABR (Average Bit Rate) mode. If the bit rate
-is not explicitly specified, it is automatically set to a suitable
-value depending on the selected profile. faac bitrate is
-expressed in kilobits/s.
-
-Note that libfaac does not support CBR (Constant Bit Rate) but only
-ABR (Average Bit Rate).
-
-If VBR mode is enabled this option is ignored.
-
-ar (-R ) Set audio sampling rate (in Hz).
-
-ac (-c ) Set the number of audio channels.
-
-cutoff (-C ) Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_main ’
-Main AAC (Main)
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_ssr ’
-Scalable Sample Rate (SSR)
-
-‘aac_ltp ’
-Long Term Prediction (LTP)
-
-
-If not specified it is set to ‘aac_low ’.
-
-flags +qscale Set constant quality VBR (Variable Bit Rate) mode.
-
-global_quality Set quality in VBR mode as an integer number of lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-and used to set the quality value used by libfaac. A reasonable range
-for the option value in QP units is [10-500], the higher the value the
-higher the quality.
-
-q (-q ) Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value sets the quality value used by libfaac. A reasonable range
-for the option value is [10-500], the higher the value the higher the
-quality.
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
8.3.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to ABR 128 kbps AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfaac -b:a 128k -output.m4a
- Use ffmpeg to convert an audio file to VBR AAC, using the
-LTP AAC profile:
-
-
ffmpeg -i input.wav -c:a libfaac -profile:a aac_ltp -q:a 100 output.m4a
-
-
-
-
8.4 libfdk_aac# TOC
-
-
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
-
-
The libfdk-aac library is based on the Fraunhofer FDK AAC code from
-the Android project.
-
-
Requires the presence of the libfdk-aac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfdk-aac. The library is also incompatible with GPL,
-so if you allow the use of GPL, you should configure with
---enable-gpl --enable-nonfree --enable-libfdk-aac.
-
-
This encoder is considered to be of higher quality with respect to
-both the native experimental FFmpeg AAC encoder and
-libfaac .
-
-
VBR encoding, enabled through the vbr or flags
-+qscale options, is experimental and only works with some
-combinations of parameters.
-
-
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
-higher.
-
-
For more information see the fdk-aac project at
-http://sourceforge.net/p/opencore-amr/fdk-aac/ .
-
-
-
8.4.1 Options# TOC
-
-
The following options are mapped on the shared FFmpeg codec options.
-
-
-b Set bit rate in bits/s. If the bitrate is not explicitly specified, it
-is automatically set to a suitable value depending on the selected
-profile.
-
-In case VBR mode is enabled the option is ignored.
-
-ar Set audio sampling rate (in Hz).
-
-channels Set the number of audio channels.
-
-flags +qscale Enable fixed quality, VBR (Variable Bit Rate) mode.
-Note that VBR is implicitly enabled when the vbr value is
-positive.
-
-cutoff Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_he ’
-High Efficiency AAC (HE-AAC)
-
-‘aac_he_v2 ’
-High Efficiency AAC version 2 (HE-AACv2)
-
-‘aac_ld ’
-Low Delay AAC (LD)
-
-‘aac_eld ’
-Enhanced Low Delay AAC (ELD)
-
-
-If not specified it is set to ‘aac_low ’.
-
-
-
The following are private options of the libfdk_aac encoder.
-
-
-afterburner Enable afterburner feature if set to 1, disabled if set to 0. This
-improves the quality but also the required processing power.
-
-Default value is 1.
-
-eld_sbr Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
-if set to 0.
-
-Default value is 0.
-
-signaling Set SBR/PS signaling style.
-
-It can assume one of the following values:
-
-‘default ’
-choose signaling implicitly (explicit hierarchical by default,
-implicit if global header is disabled)
-
-‘implicit ’
-implicit backwards compatible signaling
-
-‘explicit_sbr ’
-explicit SBR, implicit PS signaling
-
-‘explicit_hierarchical ’
-explicit hierarchical signaling
-
-
-Default value is ‘default ’.
-
-latm Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
-
-Default value is 0.
-
-header_period Set StreamMuxConfig and PCE repetition period (in frames) for sending
-in-band configuration buffers within LATM/LOAS transport layer.
-
-Must be a 16-bits non-negative integer.
-
-Default value is 0.
-
-vbr Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
-good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
-(Constant Bit Rate) is enabled.
-
-Currently only the ‘aac_low ’ profile supports VBR encoding.
-
-VBR modes 1-5 correspond to roughly the following average bit rates:
-
-
-‘1 ’
-32 kbps/channel
-
‘2 ’
-40 kbps/channel
-
‘3 ’
-48-56 kbps/channel
-
‘4 ’
-64 kbps/channel
-
‘5 ’
-about 80-96 kbps/channel
-
-
-Default value is 0.
-
-
-
-
8.4.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to VBR AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
- Use ffmpeg to convert an audio file to CBR 64k kbps AAC, using the
-High-Efficiency AAC profile:
-
-
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
-
-
-
-
8.5 libmp3lame# TOC
-
-
LAME (Lame Ain’t an MP3 Encoder) MP3 encoder wrapper.
-
-
Requires the presence of the libmp3lame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libmp3lame.
-
-
See libshine for a fixed-point MP3 encoder, although with a
-lower quality.
-
-
-
8.5.1 Options# TOC
-
-
The following options are supported by the libmp3lame wrapper. The
-lame-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR or ABR. LAME bitrate is
-expressed in kilobits/s.
-
-q (-V ) Set constant quality setting for VBR. This option is valid only
-using the ffmpeg command-line tool. For library interface
-users, use global_quality .
-
-compression_level (-q ) Set algorithm quality. Valid arguments are integers in the 0-9 range,
-with 0 meaning highest quality but slowest, and 9 meaning fastest
-while producing the worst quality.
-
-reservoir Enable use of bit reservoir when set to 1. Default value is 1. LAME
-has this enabled by default, but can be overridden by use
---nores option.
-
-joint_stereo (-m j ) Enable the encoder to use (on a frame by frame basis) either L/R
-stereo or mid/side stereo. Default value is 1.
-
-abr (--abr ) Enable the encoder to use ABR when set to 1. The lame
---abr sets the target bitrate, while this options only
-tells FFmpeg to use ABR still relies on b to set bitrate.
-
-
-
-
-
8.6 libopencore-amrnb# TOC
-
-
OpenCORE Adaptive Multi-Rate Narrowband encoder.
-
-
Requires the presence of the libopencore-amrnb headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopencore-amrnb --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
-but you can override it by setting strict to ‘unofficial ’ or
-lower.
-
-
-
8.6.1 Options# TOC
-
-
-b Set bitrate in bits per second. Only the following bitrates are supported,
-otherwise libavcodec will round to the nearest valid bitrate.
-
-
-4750 5150 5900 6700 7400 7950 10200 12200
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
8.7 libshine# TOC
-
-
Shine Fixed-Point MP3 encoder wrapper.
-
-
Shine is a fixed-point MP3 encoder. It has a far better performance on
-platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
-However, as it is more targeted on performance than quality, it is not on par
-with LAME and other production-grade encoders quality-wise. Also, according to
-the project’s homepage, this encoder may not be free of bugs as the code was
-written a long time ago and the project was dead for at least 5 years.
-
-
This encoder only supports stereo and mono input. This is also CBR-only.
-
-
The original project (last updated in early 2007) is at
-http://sourceforge.net/projects/libshine-fxp/ . We only support the
-updated fork by the Savonet/Liquidsoap project at https://github.com/savonet/shine .
-
-
Requires the presence of the libshine headers and library during
-configuration. You need to explicitly configure the build with
---enable-libshine.
-
-
See also libmp3lame .
-
-
-
8.7.1 Options# TOC
-
-
The following options are supported by the libshine wrapper. The
-shineenc-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. shineenc -b option
-is expressed in kilobits/s.
-
-
-
-
-
8.8 libtwolame# TOC
-
-
TwoLAME MP2 encoder wrapper.
-
-
Requires the presence of the libtwolame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtwolame.
-
-
-
8.8.1 Options# TOC
-
-
The following options are supported by the libtwolame wrapper. The
-twolame-equivalent options follow the FFmpeg ones and are in
-parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. twolame b
-option is expressed in kilobits/s. Default value is 128k.
-
-q (-V ) Set quality for experimental VBR support. Maximum value range is
-from -50 to 50, useful range is from -10 to 10. The higher the
-value, the better the quality. This option is valid only using the
-ffmpeg command-line tool. For library interface users,
-use global_quality .
-
-mode (--mode ) Set the mode of the resulting audio. Possible values:
-
-
-‘auto ’
-Choose mode automatically based on the input. This is the default.
-
‘stereo ’
-Stereo
-
‘joint_stereo ’
-Joint stereo
-
‘dual_channel ’
-Dual channel
-
‘mono ’
-Mono
-
-
-psymodel (--psyc-mode ) Set psychoacoustic model to use in encoding. The argument must be
-an integer between -1 and 4, inclusive. The higher the value, the
-better the quality. The default value is 3.
-
-energy_levels (--energy ) Enable energy levels extensions when set to 1. The default value is
-0 (disabled).
-
-error_protection (--protect ) Enable CRC error protection when set to 1. The default value is 0
-(disabled).
-
-copyright (--copyright ) Set MPEG audio copyright flag when set to 1. The default value is 0
-(disabled).
-
-original (--original ) Set MPEG audio original flag when set to 1. The default value is 0
-(disabled).
-
-
-
-
-
8.9 libvo-aacenc# TOC
-
-
VisualOn AAC encoder.
-
-
Requires the presence of the libvo-aacenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-aacenc --enable-version3.
-
-
This encoder is considered to be worse than the
-native experimental FFmpeg AAC encoder , according to
-multiple sources.
-
-
-
8.9.1 Options# TOC
-
-
The VisualOn AAC encoder only support encoding AAC-LC and up to 2
-channels. It is also CBR-only.
-
-
-b Set bit rate in bits/s.
-
-
-
-
-
8.10 libvo-amrwbenc# TOC
-
-
VisualOn Adaptive Multi-Rate Wideband encoder.
-
-
Requires the presence of the libvo-amrwbenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-amrwbenc --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 16000Hz sample
-rate, but you can override it by setting strict to
-‘unofficial ’ or lower.
-
-
-
8.10.1 Options# TOC
-
-
-b Set bitrate in bits/s. Only the following bitrates are supported, otherwise
-libavcodec will round to the nearest valid bitrate.
-
-
-‘6600 ’
-‘8850 ’
-‘12650 ’
-‘14250 ’
-‘15850 ’
-‘18250 ’
-‘19850 ’
-‘23050 ’
-‘23850 ’
-
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
8.11 libopus# TOC
-
-
libopus Opus Interactive Audio Codec encoder wrapper.
-
-
Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
-
8.11.1 Option Mapping# TOC
-
-
Most libopus options are modelled after the opusenc utility from
-opus-tools. The following is an option mapping chart describing options
-supported by the libopus wrapper, and their opusenc-equivalent
-in parentheses.
-
-
-b (bitrate ) Set the bit rate in bits/s. FFmpeg’s b option is
-expressed in bits/s, while opusenc’s bitrate in
-kilobits/s.
-
-vbr (vbr , hard-cbr , and cvbr ) Set VBR mode. The FFmpeg vbr option has the following
-valid arguments, with the their opusenc equivalent options
-in parentheses:
-
-
-‘off (hard-cbr ) ’
-Use constant bit rate encoding.
-
-‘on (vbr ) ’
-Use variable bit rate encoding (the default).
-
-‘constrained (cvbr ) ’
-Use constrained variable bit rate encoding.
-
-
-compression_level (comp ) Set encoding algorithm complexity. Valid options are integers in
-the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
-gives the highest quality but slowest encoding. The default is 10.
-
-frame_duration (framesize ) Set maximum frame size, or duration of a frame in milliseconds. The
-argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
-frame sizes achieve lower latency but less quality at a given bitrate.
-Sizes greater than 20ms are only interesting at fairly low bitrates.
-The default is 20ms.
-
-packet_loss (expect-loss ) Set expected packet loss percentage. The default is 0.
-
-application (N.A.) Set intended application type. Valid options are listed below:
-
-
-‘voip ’
-Favor improved speech intelligibility.
-
‘audio ’
-Favor faithfulness to the input (the default).
-
‘lowdelay ’
-Restrict to only the lowest delay modes.
-
-
-cutoff (N.A.) Set cutoff bandwidth in Hz. The argument must be exactly one of the
-following: 4000, 6000, 8000, 12000, or 20000, corresponding to
-narrowband, mediumband, wideband, super wideband, and fullband
-respectively. The default is 0 (cutoff disabled).
-
-
-
-
-
8.12 libvorbis# TOC
-
-
libvorbis encoder wrapper.
-
-
Requires the presence of the libvorbisenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvorbis.
-
-
-
8.12.1 Options# TOC
-
-
The following options are supported by the libvorbis wrapper. The
-oggenc-equivalent of the options are listed in parentheses.
-
-
To get a more accurate and extensive documentation of the libvorbis
-options, consult the libvorbisenc’s and oggenc’s documentations.
-See http://xiph.org/vorbis/ ,
-http://wiki.xiph.org/Vorbis-tools , and oggenc(1).
-
-
-b (-b ) Set bitrate expressed in bits/s for ABR. oggenc -b is
-expressed in kilobits/s.
-
-q (-q ) Set constant quality setting for VBR. The value should be a float
-number in the range of -1.0 to 10.0. The higher the value, the better
-the quality. The default value is ‘3.0 ’.
-
-This option is valid only using the ffmpeg command-line tool.
-For library interface users, use global_quality .
-
-cutoff (--advanced-encode-option lowpass_frequency=N ) Set cutoff bandwidth in Hz, a value of 0 disables cutoff. oggenc’s
-related option is expressed in kHz. The default value is ‘0 ’ (cutoff
-disabled).
-
-minrate (-m ) Set minimum bitrate expressed in bits/s. oggenc -m is
-expressed in kilobits/s.
-
-maxrate (-M ) Set maximum bitrate expressed in bits/s. oggenc -M is
-expressed in kilobits/s. This only has effect on ABR mode.
-
-iblock (--advanced-encode-option impulse_noisetune=N ) Set noise floor bias for impulse blocks. The value is a float number from
--15.0 to 0.0. A negative bias instructs the encoder to pay special attention
-to the crispness of transients in the encoded audio. The tradeoff for better
-transient response is a higher bitrate.
-
-
-
-
-
8.13 libwavpack# TOC
-
-
A wrapper providing WavPack encoding through libwavpack.
-
-
Only lossless mode using 32-bit integer samples is supported currently.
-
-
Requires the presence of the libwavpack headers and library during
-configuration. You need to explicitly configure the build with
---enable-libwavpack.
-
-
Note that a libavcodec-native encoder for the WavPack codec exists so users can
-encode audios with this codec without using this encoder. See wavpackenc .
-
-
-
8.13.1 Options# TOC
-
-
wavpack command line utility’s corresponding options are listed in
-parentheses, if any.
-
-
-frame_size (--blocksize ) Default is 32768.
-
-compression_level Set speed vs. compression tradeoff. Acceptable arguments are listed below:
-
-
-‘0 (-f ) ’
-Fast mode.
-
-‘1 ’
-Normal (default) settings.
-
-‘2 (-h ) ’
-High quality.
-
-‘3 (-hh ) ’
-Very high quality.
-
-‘4-8 (-hh -x EXTRAPROC ) ’
-Same as ‘3 ’, but with extra processing enabled.
-
-‘4 ’ is the same as -x2 and ‘8 ’ is the same as -x6 .
-
-
-
-
-
-
8.14 wavpack# TOC
-
-
WavPack lossless audio encoder.
-
-
This is a libavcodec-native WavPack encoder. There is also an encoder based on
-libwavpack, but there is virtually no reason to use that encoder.
-
-
See also libwavpack .
-
-
-
8.14.1 Options# TOC
-
-
The equivalent options for wavpack command line utility are listed in
-parentheses.
-
-
-
8.14.1.1 Shared options# TOC
-
-
The following shared options are effective for this encoder. Only special notes
-about this particular encoder will be documented here. For the general meaning
-of the options, see the Codec Options chapter .
-
-
-frame_size (--blocksize ) For this encoder, the range for this option is between 128 and 131072. Default
-is automatically decided based on sample rate and number of channel.
-
-For the complete formula of calculating default, see
-libavcodec/wavpackenc.c .
-
-compression_level (-f , -h , -hh , and -x ) This option’s syntax is consistent with libwavpack ’s.
-
-
-
-
8.14.1.2 Private options# TOC
-
-
-joint_stereo (-j ) Set whether to enable joint stereo. Valid values are:
-
-
-‘on (1 ) ’
-Force mid/side audio encoding.
-
‘off (0 ) ’
-Force left/right audio encoding.
-
‘auto ’
-Let the encoder decide automatically.
-
-
-optimize_mono Set whether to enable optimization for mono. This option is only effective for
-non-mono streams. Available values:
-
-
-‘on ’
-enabled
-
‘off ’
-disabled
-
-
-
-
-
-
-
9 Video Encoders# TOC
-
-
A description of some of the currently available video encoders
-follows.
-
-
-
9.1 libtheora# TOC
-
-
libtheora Theora encoder wrapper.
-
-
Requires the presence of the libtheora headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtheora.
-
-
For more information about the libtheora project see
-http://www.theora.org/ .
-
-
-
9.1.1 Options# TOC
-
-
The following global options are mapped to internal libtheora options
-which affect the quality and the bitrate of the encoded stream.
-
-
-b Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
-case VBR (Variable Bit Rate) mode is enabled this option is ignored.
-
-flags Used to enable constant quality mode (VBR) encoding through the
-qscale flag, and to enable the pass1 and pass2
-modes.
-
-g Set the GOP size.
-
-global_quality Set the global quality as an integer in lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
-value in the native libtheora range [0-63]. A higher value corresponds
-to a higher quality.
-
-q Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value is clipped in the [0-10] range, and then multiplied by 6.3
-to get a value in the native libtheora range [0-63].
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
9.1.2 Examples# TOC
-
-
- Set maximum constant quality (VBR) encoding with ffmpeg:
-
-
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
- Use ffmpeg to convert a CBR 1000 kbps Theora video stream:
-
-
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
-
-
-
-
9.2 libvpx# TOC
-
-
VP8/VP9 format supported through libvpx.
-
-
Requires the presence of the libvpx headers and library during configuration.
-You need to explicitly configure the build with --enable-libvpx.
-
-
-
9.2.1 Options# TOC
-
-
Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
-
-
-threads g_threads
-
-profile g_profile
-
-vb rc_target_bitrate
-
-g kf_max_dist
-
-keyint_min kf_min_dist
-
-qmin rc_min_quantizer
-
-qmax rc_max_quantizer
-
-bufsize, vb rc_buf_sz
-(bufsize * 1000 / vb)
-
-rc_buf_optimal_sz
-(bufsize * 1000 / vb * 5 / 6)
-
-rc_init_occupancy, vb rc_buf_initial_sz
-(rc_init_occupancy * 1000 / vb)
-
-rc_buffer_aggressivity rc_undershoot_pct
-
-skip_threshold rc_dropframe_thresh
-
-qcomp rc_2pass_vbr_bias_pct
-
-maxrate, vb rc_2pass_vbr_maxsection_pct
-(maxrate * 100 / vb)
-
-minrate, vb rc_2pass_vbr_minsection_pct
-(minrate * 100 / vb)
-
-minrate, maxrate, vb VPX_CBR
-(minrate == maxrate == vb)
-
-crf VPX_CQ, VP8E_SET_CQ_LEVEL
-
-quality
-best VPX_DL_BEST_QUALITY
-
good VPX_DL_GOOD_QUALITY
-
realtime VPX_DL_REALTIME
-
-
-speed VP8E_SET_CPUUSED
-
-nr VP8E_SET_NOISE_SENSITIVITY
-
-mb_threshold VP8E_SET_STATIC_THRESHOLD
-
-slices VP8E_SET_TOKEN_PARTITIONS
-
-max-intra-rate VP8E_SET_MAX_INTRA_BITRATE_PCT
-
-force_key_frames VPX_EFLAG_FORCE_KF
-
-Alternate reference frame related
-vp8flags altref VP8E_SET_ENABLEAUTOALTREF
-
arnr_max_frames VP8E_SET_ARNR_MAXFRAMES
-
arnr_type VP8E_SET_ARNR_TYPE
-
arnr_strength VP8E_SET_ARNR_STRENGTH
-
rc_lookahead g_lag_in_frames
-
-
-vp8flags error_resilient g_error_resilient
-
-aq_mode VP9E_SET_AQ_MODE
-
-
-
-
For more information about libvpx see:
-http://www.webmproject.org/
-
-
-
-
9.3 libwebp# TOC
-
-
libwebp WebP Image encoder wrapper
-
-
libwebp is Google’s official encoder for WebP images. It can encode in either
-lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
-frame. Lossless images are a separate codec developed by Google.
-
-
-
9.3.1 Pixel Format# TOC
-
-
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
-to limitations of the format and libwebp. Alpha is supported for either mode.
-Because of API limitations, if RGB is passed in when encoding lossy or YUV is
-passed in for encoding lossless, the pixel format will automatically be
-converted using functions from libwebp. This is not ideal and is done only for
-convenience.
-
-
-
9.3.2 Options# TOC
-
-
--lossless boolean Enables/Disables use of lossless mode. Default is 0.
-
--compression_level integer For lossy, this is a quality/speed tradeoff. Higher values give better quality
-for a given size at the cost of increased encoding time. For lossless, this is
-a size/speed tradeoff. Higher values give smaller size at the cost of increased
-encoding time. More specifically, it controls the number of extra algorithms
-and compression tools used, and varies the combination of these tools. This
-maps to the method option in libwebp. The valid range is 0 to 6.
-Default is 4.
-
--qscale float For lossy encoding, this controls image quality, 0 to 100. For lossless
-encoding, this controls the effort and time spent at compressing more. The
-default value is 75. Note that for usage via libavcodec, this option is called
-global_quality and must be multiplied by FF_QP2LAMBDA .
-
--preset type Configuration preset. This does some automatic settings based on the general
-type of the image.
-
-none Do not use a preset.
-
default Use the encoder default.
-
picture Digital picture, like portrait, inner shot
-
photo Outdoor photograph, with natural lighting
-
drawing Hand or line drawing, with high-contrast details
-
icon Small-sized colorful images
-
text Text-like
-
-
-
-
-
-
9.4 libx264, libx264rgb# TOC
-
-
x264 H.264/MPEG-4 AVC encoder wrapper.
-
-
This encoder requires the presence of the libx264 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx264.
-
-
libx264 supports an impressive number of features, including 8x8 and
-4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
-entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
-for detail retention (adaptive quantization, psy-RD, psy-trellis).
-
-
Many libx264 encoder options are mapped to FFmpeg global codec
-options, while unique encoder options are provided through private
-options. Additionally the x264opts and x264-params
-private options allows one to pass a list of key=value tuples as accepted
-by the libx264 x264_param_parse function.
-
-
The x264 project website is at
-http://www.videolan.org/developers/x264.html .
-
-
The libx264rgb encoder is the same as libx264, except it accepts packed RGB
-pixel formats as input instead of YUV.
-
-
-
9.4.1 Supported Pixel Formats# TOC
-
-
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
-x264’s configure time. FFmpeg only supports one bit depth in one particular
-build. In other words, it is not possible to build one FFmpeg with multiple
-versions of x264 with different bit depths.
-
-
-
9.4.2 Options# TOC
-
-
The following options are supported by the libx264 wrapper. The
-x264-equivalent options or values are listed in parentheses
-for easy migration.
-
-
To reduce the duplication of documentation, only the private options
-and some others requiring special attention are documented here. For
-the documentation of the undocumented generic options, see
-the Codec Options chapter .
-
-
To get a more accurate and extensive documentation of the libx264
-options, invoke the command x264 --full-help or consult
-the libx264 documentation.
-
-
-b (bitrate ) Set bitrate in bits/s. Note that FFmpeg’s b option is
-expressed in bits/s, while x264’s bitrate is in
-kilobits/s.
-
-bf (bframes ) g (keyint ) qmin (qpmin ) Minimum quantizer scale.
-
-qmax (qpmax ) Maximum quantizer scale.
-
-qdiff (qpstep ) Maximum difference between quantizer scales.
-
-qblur (qblur ) Quantizer curve blur
-
-qcomp (qcomp ) Quantizer curve compression factor
-
-refs (ref ) Number of reference frames each P-frame can use. The range is from 0-16 .
-
-sc_threshold (scenecut ) Sets the threshold for the scene change detection.
-
-trellis (trellis ) Performs Trellis quantization to increase efficiency. Enabled by default.
-
-nr (nr ) me_range (merange ) Maximum range of the motion search in pixels.
-
-me_method (me ) Set motion estimation method. Possible values in the decreasing order
-of speed:
-
-
-‘dia (dia ) ’
-‘epzs (dia ) ’
-Diamond search with radius 1 (fastest). ‘epzs ’ is an alias for
-‘dia ’.
-
‘hex (hex ) ’
-Hexagonal search with radius 2.
-
‘umh (umh ) ’
-Uneven multi-hexagon search.
-
‘esa (esa ) ’
-Exhaustive search.
-
‘tesa (tesa ) ’
-Hadamard exhaustive search (slowest).
-
-
-subq (subme ) Sub-pixel motion estimation method.
-
-b_strategy (b-adapt ) Adaptive B-frame placement decision algorithm. Use only on first-pass.
-
-keyint_min (min-keyint ) Minimum GOP size.
-
-coder Set entropy encoder. Possible values:
-
-
-‘ac ’
-Enable CABAC.
-
-‘vlc ’
-Enable CAVLC and disable CABAC. It generates the same effect as
-x264’s --no-cabac option.
-
-
-cmp Set full pixel motion estimation comparation algorithm. Possible values:
-
-
-‘chroma ’
-Enable chroma in motion estimation.
-
-‘sad ’
-Ignore chroma in motion estimation. It generates the same effect as
-x264’s --no-chroma-me option.
-
-
-threads (threads ) Number of encoding threads.
-
-thread_type Set multithreading technique. Possible values:
-
-
-‘slice ’
-Slice-based multithreading. It generates the same effect as
-x264’s --sliced-threads option.
-
‘frame ’
-Frame-based multithreading.
-
-
-flags Set encoding flags. It can be used to disable closed GOP and enable
-open GOP by setting it to -cgop. The result is similar to
-the behavior of x264’s --open-gop option.
-
-rc_init_occupancy (vbv-init ) preset (preset ) Set the encoding preset.
-
-tune (tune ) Set tuning of the encoding params.
-
-profile (profile ) Set profile restrictions.
-
-fastfirstpass Enable fast settings when encoding first pass, when set to 1. When set
-to 0, it has the same effect of x264’s
---slow-firstpass option.
-
-crf (crf ) Set the quality for constant quality mode.
-
-crf_max (crf-max ) In CRF mode, prevents VBV from lowering quality beyond this point.
-
-qp (qp ) Set constant quantization rate control method parameter.
-
-aq-mode (aq-mode ) Set AQ method. Possible values:
-
-
-‘none (0 ) ’
-Disabled.
-
-‘variance (1 ) ’
-Variance AQ (complexity mask).
-
-‘autovariance (2 ) ’
-Auto-variance AQ (experimental).
-
-
-aq-strength (aq-strength ) Set AQ strength, reduce blocking and blurring in flat and textured areas.
-
-psy Use psychovisual optimizations when set to 1. When set to 0, it has the
-same effect as x264’s --no-psy option.
-
-psy-rd (psy-rd ) Set strength of psychovisual optimization, in
-psy-rd :psy-trellis format.
-
-rc-lookahead (rc-lookahead ) Set number of frames to look ahead for frametype and ratecontrol.
-
-weightb Enable weighted prediction for B-frames when set to 1. When set to 0,
-it has the same effect as x264’s --no-weightb option.
-
-weightp (weightp ) Set weighted prediction method for P-frames. Possible values:
-
-
-‘none (0 ) ’
-Disabled
-
‘simple (1 ) ’
-Enable only weighted refs
-
‘smart (2 ) ’
-Enable both weighted refs and duplicates
-
-
-ssim (ssim ) Enable calculation and printing SSIM stats after the encoding.
-
-intra-refresh (intra-refresh ) Enable the use of Periodic Intra Refresh instead of IDR frames when set
-to 1.
-
-avcintra-class (class ) Configure the encoder to generate AVC-Intra.
-Valid values are 50,100 and 200
-
-bluray-compat (bluray-compat ) Configure the encoder to be compatible with the bluray standard.
-It is a shorthand for setting "bluray-compat=1 force-cfr=1".
-
-b-bias (b-bias ) Set the influence on how often B-frames are used.
-
-b-pyramid (b-pyramid ) Set method for keeping of some B-frames as references. Possible values:
-
-
-‘none (none ) ’
-Disabled.
-
‘strict (strict ) ’
-Strictly hierarchical pyramid.
-
‘normal (normal ) ’
-Non-strict (not Blu-ray compatible).
-
-
-mixed-refs Enable the use of one reference per partition, as opposed to one
-reference per macroblock when set to 1. When set to 0, it has the
-same effect as x264’s --no-mixed-refs option.
-
-8x8dct Enable adaptive spatial transform (high profile 8x8 transform)
-when set to 1. When set to 0, it has the same effect as
-x264’s --no-8x8dct option.
-
-fast-pskip Enable early SKIP detection on P-frames when set to 1. When set
-to 0, it has the same effect as x264’s
---no-fast-pskip option.
-
-aud (aud ) Enable use of access unit delimiters when set to 1.
-
-mbtree Enable use macroblock tree ratecontrol when set to 1. When set
-to 0, it has the same effect as x264’s
---no-mbtree option.
-
-deblock (deblock ) Set loop filter parameters, in alpha :beta form.
-
-cplxblur (cplxblur ) Set fluctuations reduction in QP (before curve compression).
-
-partitions (partitions ) Set partitions to consider as a comma-separated list of. Possible
-values in the list:
-
-
-‘p8x8 ’
-8x8 P-frame partition.
-
‘p4x4 ’
-4x4 P-frame partition.
-
‘b8x8 ’
-4x4 B-frame partition.
-
‘i8x8 ’
-8x8 I-frame partition.
-
‘i4x4 ’
-4x4 I-frame partition.
-(Enabling ‘p4x4 ’ requires ‘p8x8 ’ to be enabled. Enabling
-‘i8x8 ’ requires adaptive spatial transform (8x8dct
-option) to be enabled.)
-
‘none (none ) ’
-Do not consider any partitions.
-
‘all (all ) ’
-Consider every partition.
-
-
-direct-pred (direct ) Set direct MV prediction mode. Possible values:
-
-
-‘none (none ) ’
-Disable MV prediction.
-
‘spatial (spatial ) ’
-Enable spatial predicting.
-
‘temporal (temporal ) ’
-Enable temporal predicting.
-
‘auto (auto ) ’
-Automatically decided.
-
-
-slice-max-size (slice-max-size ) Set the limit of the size of each slice in bytes. If not specified
-but RTP payload size (ps ) is specified, that is used.
-
-stats (stats ) Set the file name for multi-pass stats.
-
-nal-hrd (nal-hrd ) Set signal HRD information (requires vbv-bufsize to be set).
-Possible values:
-
-
-‘none (none ) ’
-Disable HRD information signaling.
-
‘vbr (vbr ) ’
-Variable bit rate.
-
‘cbr (cbr ) ’
-Constant bit rate (not allowed in MP4 container).
-
-
-x264opts (N.A.) Set any x264 option, see x264 --fullhelp for a list.
-
-Argument is a list of key =value couples separated by
-":". In filter and psy-rd options that use ":" as a separator
-themselves, use "," instead. They accept it as well since long ago but this
-is kept undocumented for some reason.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
- x264-params (N.A.) Override the x264 configuration using a :-separated list of key=value
-parameters.
-
-This option is functionally the same as the x264opts , but is
-duplicated for compatibility with the Libav fork.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
-cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
-no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
-
-
-
Encoding ffpresets for common usages are provided so they can be used with the
-general presets system (e.g. passing the pre option).
-
-
-
9.5 libx265# TOC
-
-
x265 H.265/HEVC encoder wrapper.
-
-
This encoder requires the presence of the libx265 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx265 .
-
-
-
9.5.1 Options# TOC
-
-
-preset Set the x265 preset.
-
-tune Set the x265 tune parameter.
-
-x265-params Set x265 options using a list of key =value couples separated
-by ":". See x265 --help for a list of options.
-
-For example to specify libx265 encoding options with -x265-params :
-
-
-
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
-
-
-
-
9.6 libxvid# TOC
-
-
Xvid MPEG-4 Part 2 encoder wrapper.
-
-
This encoder requires the presence of the libxvidcore headers and library
-during configuration. You need to explicitly configure the build with
---enable-libxvid --enable-gpl.
-
-
The native mpeg4 encoder supports the MPEG-4 Part 2 format, so
-users can encode to this format without this library.
-
-
-
9.6.1 Options# TOC
-
-
The following options are supported by the libxvid wrapper. Some of
-the following options are listed but are not documented, and
-correspond to shared codec options. See the Codec
-Options chapter for their documentation. The other shared options
-which are not listed have no effect for the libxvid encoder.
-
-
-b g qmin qmax mpeg_quant threads bf b_qfactor b_qoffset flags Set specific encoding flags. Possible values:
-
-
-‘mv4 ’
-Use four motion vector by macroblock.
-
-‘aic ’
-Enable high quality AC prediction.
-
-‘gray ’
-Only encode grayscale.
-
-‘gmc ’
-Enable the use of global motion compensation (GMC).
-
-‘qpel ’
-Enable quarter-pixel motion compensation.
-
-‘cgop ’
-Enable closed GOP.
-
-‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
-
-
-trellis me_method Set motion estimation method. Possible values in decreasing order of
-speed and increasing order of quality:
-
-
-‘zero ’
-Use no motion estimation (default).
-
-‘phods ’
-‘x1 ’
-‘log ’
-Enable advanced diamond zonal search for 16x16 blocks and half-pixel
-refinement for 16x16 blocks. ‘x1 ’ and ‘log ’ are aliases for
-‘phods ’.
-
-‘epzs ’
-Enable all of the things described above, plus advanced diamond zonal
-search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
-estimation on chroma planes.
-
-‘full ’
-Enable all of the things described above, plus extended 16x16 and 8x8
-blocks search.
-
-
-mbd Set macroblock decision algorithm. Possible values in the increasing
-order of quality:
-
-
-‘simple ’
-Use macroblock comparing function algorithm (default).
-
-‘bits ’
-Enable rate distortion-based half pixel and quarter pixel refinement for
-16x16 blocks.
-
-‘rd ’
-Enable all of the things described above, plus rate distortion-based
-half pixel and quarter pixel refinement for 8x8 blocks, and rate
-distortion-based search using square pattern.
-
-
-lumi_aq Enable lumi masking adaptive quantization when set to 1. Default is 0
-(disabled).
-
-variance_aq Enable variance adaptive quantization when set to 1. Default is 0
-(disabled).
-
-When combined with lumi_aq , the resulting quality will not
-be better than any of the two specified individually. In other
-words, the resulting quality will be the worse one of the two
-effects.
-
-ssim Set structural similarity (SSIM) displaying method. Possible values:
-
-
-‘off ’
-Disable displaying of SSIM information.
-
-‘avg ’
-Output average SSIM at the end of encoding to stdout. The format of
-showing the average SSIM is:
-
-
-
-For users who are not familiar with C, %f means a float number, or
-a decimal (e.g. 0.939232).
-
-‘frame ’
-Output both per-frame SSIM data during encoding and average SSIM at
-the end of encoding to stdout. The format of per-frame information
-is:
-
-
-
SSIM: avg: %1.3f min: %1.3f max: %1.3f
- For users who are not familiar with C, %1.3f means a float number
-rounded to 3 digits after the dot (e.g. 0.932).
-
-
-
-ssim_acc Set SSIM accuracy. Valid options are integers within the range of
-0-4, while 0 gives the most accurate result and 4 computes the
-fastest.
-
-
-
-
-
9.7 mpeg2# TOC
-
-
MPEG-2 video encoder.
-
-
-
9.7.1 Options# TOC
-
-
-seq_disp_ext integer Specifies if the encoder should write a sequence_display_extension to the
-output.
-
--1 auto Decide automatically to write it or not (this is the default) by checking if
-the data to be written is different from the default or unspecified values.
-
0 never Never write it.
-
1 always Always write it.
-
-
-
-
-
-
-
PNG image encoder.
-
-
-
9.8.1 Private options# TOC
-
-
-dpi integer Set physical density of pixels, in dots per inch, unset by default
-
dpm integer Set physical density of pixels, in dots per meter, unset by default
-
-
-
-
9.9 ProRes# TOC
-
-
Apple ProRes encoder.
-
-
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
-The used encoder can be chosen with the -vcodec option.
-
-
-
9.9.1 Private Options for prores-ks# TOC
-
-
-profile integer Select the ProRes profile to encode
-
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-‘4444 ’
-
-
-quant_mat integer Select quantization matrix.
-
-‘auto ’
-‘default ’
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-
-If set to auto , the matrix matching the profile will be picked.
-If not set, the matrix providing the highest quality, default , will be
-picked.
-
-bits_per_mb integer How many bits to allot for coding one macroblock. Different profiles use
-between 200 and 2400 bits per macroblock, the maximum is 8000.
-
-mbs_per_slice integer Number of macroblocks in each slice (1-8); the default value (8)
-should be good in almost all situations.
-
-vendor string Override the 4-byte vendor ID.
-A custom vendor ID like apl0 would claim the stream was produced by
-the Apple encoder.
-
-alpha_bits integer Specify number of bits for alpha component.
-Possible values are 0 , 8 and 16 .
-Use 0 to disable alpha plane coding.
-
-
-
-
-
9.9.2 Speed considerations# TOC
-
-
In the default mode of operation the encoder has to honor frame constraints
-(i.e. not produce frames with size bigger than requested) while still making
-output picture as good as possible.
-A frame containing a lot of small details is harder to compress and the encoder
-would spend more time searching for appropriate quantizers for each slice.
-
-
Setting a higher bits_per_mb limit will improve the speed.
-
-
For the fastest encoding speed set the qscale parameter (4 is the
-recommended value) and do not set a size constraint.
-
-
-
-
10 Subtitles Encoders# TOC
-
-
-
10.1 dvdsub# TOC
-
-
This codec encodes the bitmap subtitle format that is used in DVDs.
-Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
-and they can also be used in Matroska files.
-
-
-
10.1.1 Options# TOC
-
-
-even_rows_fix When set to 1, enable a work-around that makes the number of pixel rows
-even in all subtitles. This fixes a problem with some players that
-cut off the bottom row if the number is odd. The work-around just adds
-a fully transparent row if needed. The overhead is low, typically
-one byte per subtitle on average.
-
-By default, this work-around is disabled.
-
-
-
-
-
11 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavcodec
-
-
-
-
12 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Devices Documentation
-
-
-
- FFmpeg Devices Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the input and output devices provided by the
-libavdevice library.
-
-
-
-
2 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
3 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
3.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
3.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
3.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
3.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
3.3 bktr# TOC
-
-
BSD video input device.
-
-
-
3.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
3.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
3.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
3.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
3.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
3.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
3.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
3.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
3.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
3.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
3.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
3.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
3.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
3.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
3.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
3.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
3.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
3.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
3.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
3.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
3.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
3.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
3.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
3.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
3.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
3.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
3.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
3.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
3.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
3.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
3.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
3.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
3.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
4 Output Devices# TOC
-
-
Output devices are configured elements in FFmpeg that can write
-multimedia data to an output device attached to your system.
-
-
When you configure your FFmpeg build, all the supported output devices
-are enabled by default. You can list all available ones using the
-configure option "–list-outdevs".
-
-
You can disable all the output devices using the configure option
-"–disable-outdevs", and selectively enable an output device using the
-option "–enable-outdev=OUTDEV ", or you can disable a particular
-input device using the option "–disable-outdev=OUTDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-enabled output devices.
-
-
A description of the currently available output devices follows.
-
-
-
4.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) output device.
-
-
-
4.1.1 Examples# TOC
-
-
- Play a file on default ALSA device:
-
-
ffmpeg -i INPUT -f alsa default
- Play a file on soundcard 1, audio device 7:
-
-
ffmpeg -i INPUT -f alsa hw:1,7
-
-
-
-
4.2 caca# TOC
-
-
CACA output device.
-
-
This output device allows one to show a video stream in CACA window.
-Only one CACA window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need to configure FFmpeg with
---enable-libcaca.
-libcaca is a graphics library that outputs text instead of pixels.
-
-
For more information about libcaca, check:
-http://caca.zoy.org/wiki/libcaca
-
-
-
4.2.1 Options# TOC
-
-
-window_title Set the CACA window title, if not specified default to the filename
-specified for the output device.
-
-window_size Set the CACA window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video.
-
-driver Set display driver.
-
-algorithm Set dithering algorithm. Dithering is necessary
-because the picture being rendered has usually far more colours than
-the available palette.
-The accepted values are listed with -list_dither algorithms.
-
-antialias Set antialias method. Antialiasing smoothens the rendered
-image and avoids the commonly seen staircase effect.
-The accepted values are listed with -list_dither antialiases.
-
-charset Set which characters are going to be used when rendering text.
-The accepted values are listed with -list_dither charsets.
-
-color Set color to be used when rendering text.
-The accepted values are listed with -list_dither colors.
-
-list_drivers If set to true , print a list of available drivers and exit.
-
-list_dither List available dither options related to the argument.
-The argument must be one of algorithms, antialiases,
-charsets, colors.
-
-
-
-
4.2.2 Examples# TOC
-
-
- The following command shows the ffmpeg output is an
-CACA window, forcing its size to 80x25:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
- Show the list of available drivers and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
- Show the list of available dither colors and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
-
-
-
-
4.3 decklink# TOC
-
-
The decklink output device provides playback capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this output device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz.
-
-
-
4.3.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-preroll Amount of time to preroll video in seconds.
-Defaults to 0.5 .
-
-
-
-
-
4.3.2 Examples# TOC
-
-
- List output devices:
-
-
ffmpeg -i test.avi -f decklink -list_devices 1 dummy
- List supported formats:
-
-
ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
- Play video clip:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
- Play video clip with non-standard framerate or video size:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
-
-
-
-
4.4 fbdev# TOC
-
-
Linux framebuffer output device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
-
4.4.1 Options# TOC
-
-xoffset yoffset Set x/y coordinate of top left corner. Default is 0.
-
-
-
-
4.4.2 Examples# TOC
-
Play a file on framebuffer device /dev/fb0 .
-Required pixel format depends on current framebuffer settings.
-
-
ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
4.5 opengl# TOC
-
OpenGL output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-opengl.
-
-
This output device allows one to render to OpenGL context.
-Context may be provided by application or default SDL window is created.
-
-
When device renders to external context, application must implement handlers for following messages:
-AV_DEV_TO_APP_CREATE_WINDOW_BUFFER - create OpenGL context on current thread.
-AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER - make OpenGL context current.
-AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER - swap buffers.
-AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER - destroy OpenGL context.
-Application is also required to inform a device about current resolution by sending AV_APP_TO_DEV_WINDOW_SIZE message.
-
-
-
4.5.1 Options# TOC
-
-background Set background color. Black is a default.
-
no_window Disables default SDL window when set to non-zero value.
-Application must provide OpenGL context and both window_size_cb and window_swap_buffers_cb callbacks when set.
-
window_title Set the SDL window title, if not specified default to the filename specified for the output device.
-Ignored when no_window is set.
-
window_size Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.
-If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.
-Mostly usable when no_window is not set.
-
-
-
-
-
4.5.2 Examples# TOC
-
Play a file on SDL window using OpenGL rendering:
-
-
ffmpeg -i INPUT -f opengl "window title"
-
-
-
-
-
-
OSS (Open Sound System) output device.
-
-
-
4.7 pulse# TOC
-
-
PulseAudio output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org
-
-
-
4.7.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is set to the specified output name.
-
-device Specify the device to use. Default device is used when not provided.
-List of output devices can be obtained with command pactl list sinks.
-
-buffer_size buffer_duration Control the size and duration of the PulseAudio buffer. A small buffer
-gives more control, but requires more frequent updates.
-
-buffer_size specifies size in bytes while
-buffer_duration specifies duration in milliseconds.
-
-When both options are provided then the highest value is used
-(duration is recalculated to bytes using stream parameters). If they
-are set to 0 (which is default), the device will use the default
-PulseAudio duration value. By default PulseAudio set buffer duration
-to around 2 seconds.
-
-prebuf Specify pre-buffering size in bytes. The server does not start with
-playback before at least prebuf bytes are available in the
-buffer. By default this option is initialized to the same value as
-buffer_size or buffer_duration (whichever is bigger).
-
-minreq Specify minimum request size in bytes. The server does not request less
-than minreq bytes from the client, instead waits until the buffer
-is free enough to request more bytes at once. It is recommended to not set
-this option, which will initialize this to a value that is deemed sensible
-by the server.
-
-
-
-
-
4.7.2 Examples# TOC
-
Play a file on default device on default server:
-
-
ffmpeg -i INPUT -f pulse "stream name"
-
-
-
-
-
-
SDL (Simple DirectMedia Layer) output device.
-
-
This output device allows one to show a video stream in an SDL
-window. Only one SDL window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need libsdl installed on your system
-when configuring your build.
-
-
For more information about SDL, check:
-http://www.libsdl.org/
-
-
-
4.8.1 Options# TOC
-
-
-window_title Set the SDL window title, if not specified default to the filename
-specified for the output device.
-
-icon_title Set the name of the iconified SDL window, if not specified it is set
-to the same value of window_title .
-
-window_size Set the SDL window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video,
-downscaled according to the aspect ratio.
-
-window_fullscreen Set fullscreen mode when non-zero value is provided.
-Default value is zero.
-
-
-
-
4.8.2 Interactive commands# TOC
-
-
The window created by the device can be controlled through the
-following interactive commands.
-
-
-q, ESC Quit the device immediately.
-
-
-
-
4.8.3 Examples# TOC
-
-
The following command shows the ffmpeg output is an
-SDL window, forcing its size to the qcif format:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
-
-
-
-
4.9 sndio# TOC
-
-
sndio audio output device.
-
-
-
-
-
XV (XVideo) output device.
-
-
This output device allows one to show a video stream in a X Window System
-window.
-
-
-
4.10.1 Options# TOC
-
-
-display_name Specify the hardware display name, which determines the display and
-communications domain to be used.
-
-The display name or DISPLAY environment variable can be a string in
-the format hostname [:number [.screen_number ]].
-
-hostname specifies the name of the host machine on which the
-display is physically attached. number specifies the number of
-the display server on that host machine. screen_number specifies
-the screen to be used on that server.
-
-If unspecified, it defaults to the value of the DISPLAY environment
-variable.
-
-For example, dual-headed:0.1 would specify screen 1 of display
-0 on the machine named “dual-headed”.
-
-Check the X11 specification for more detailed information about the
-display name format.
-
-window_id When set to non-zero value then device doesn’t create new window,
-but uses existing one with provided window_id . By default
-this options is set to zero and device creates its own window.
-
-window_size Set the created window size, can be a string of the form
-width xheight or a video size abbreviation. If not
-specified it defaults to the size of the input video.
-Ignored when window_id is set.
-
-window_x window_y Set the X and Y window offsets for the created window. They are both
-set to 0 by default. The values may be ignored by the window manager.
-Ignored when window_id is set.
-
-window_title Set the window title, if not specified default to the filename
-specified for the output device. Ignored when window_id is set.
-
-
-
For more information about XVideo see http://www.x.org/ .
-
-
-
4.10.2 Examples# TOC
-
-
- Decode, display and encode video input with ffmpeg at the
-same time:
-
-
ffmpeg -i INPUT OUTPUT -f xv display
- Decode and display the input video to multiple X11 windows:
-
-
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
-
-
-
-
-
5 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavdevice
-
-
-
-
6 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Filters Documentation
-
-
-
- FFmpeg Filters Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes filters, sources, and sinks provided by the
-libavfilter library.
-
-
-
-
2 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
3 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
4 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
4.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
4.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
5 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
6 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
6.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
6.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
6.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
6.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
6.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
6.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
6.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
6.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
6.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
6.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
6.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
6.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
6.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
6.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
6.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
6.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
6.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
6.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
6.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
6.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
6.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
6.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
6.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
6.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
6.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
6.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
6.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
6.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
6.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
6.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
6.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
6.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
6.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
6.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
6.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
6.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
6.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
6.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
6.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
6.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
6.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
6.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
6.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
6.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
6.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
6.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
6.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
6.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
6.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
6.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
6.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
6.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
6.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
6.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
6.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
6.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
6.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
6.42.2 Examples# TOC
-
-
-
-
-
6.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
6.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
7 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
7.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
7.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
7.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
7.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
7.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
7.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
7.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
7.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
7.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
7.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
8 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
8.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
8.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
9 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
9.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
9.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
9.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
9.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
9.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
9.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
9.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
9.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
9.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
9.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
9.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
9.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
9.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
9.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
9.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
9.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
9.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
9.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
9.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
9.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
9.15.1 Examples# TOC
-
-
-
-
-
9.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
9.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
9.17.1 Examples# TOC
-
-
-
-
-
9.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
9.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
9.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
9.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
9.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
9.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
9.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
9.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
9.23.1 Examples# TOC
-
-
-
-
-
9.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
9.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
9.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
9.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
9.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
9.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
9.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
9.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
9.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
9.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
9.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
9.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
9.29.1 Examples# TOC
-
-
-
-
-
9.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
9.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
9.31.1 p/c/n/u/b meaning# TOC
-
-
-
9.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
9.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
9.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
9.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
9.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
9.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
9.34.1 Examples# TOC
-
-
-
-
-
9.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
9.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
9.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
9.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
9.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
9.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
9.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
9.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
9.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
9.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
9.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
9.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
9.42.1 Workflow examples# TOC
-
-
-
9.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
9.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
9.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
9.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
9.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
9.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
9.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
9.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
9.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
9.48.1 Examples# TOC
-
-
-
-
-
9.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
9.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
9.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
9.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
9.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
9.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
9.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
9.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
9.55.1 Examples# TOC
-
-
-
-
-
9.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
9.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
9.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
9.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
9.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
9.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
9.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
9.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
9.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
9.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
9.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
9.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
9.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
9.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
9.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
9.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
9.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.65.2 Examples# TOC
-
-
-
-
-
9.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
9.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.67.1 Examples# TOC
-
-
-
-
-
9.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
9.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
9.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
9.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
9.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
9.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
9.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
9.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
9.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
9.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
9.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
9.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
9.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
9.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.79.2 Examples# TOC
-
-
-
-
-
9.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
9.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
9.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
9.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
9.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
9.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
9.85.1 Examples# TOC
-
-
-
-
-
9.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
9.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
9.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
9.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
9.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
9.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
9.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
9.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
9.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
9.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
9.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
9.94.1 Examples# TOC
-
-
-
-
-
9.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
9.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
9.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
9.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
9.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
9.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
9.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
9.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
9.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
9.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
9.101.2 Examples# TOC
-
-
-
-
-
9.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
9.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
9.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
9.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
9.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
9.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
9.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
9.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
9.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
10 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
10.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
10.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
10.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
10.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
10.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
10.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
10.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
10.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
10.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
10.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
11 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
11.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
11.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
12 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
12.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
12.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
12.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
12.2.1 Examples# TOC
-
-
-
-
-
12.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
12.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
12.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
12.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
12.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
12.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
12.6.1 Examples# TOC
-
-
-
-
-
12.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
12.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
12.7.2 Examples# TOC
-
-
-
-
-
12.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
12.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
12.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
12.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
12.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
12.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
12.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
12.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
12.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
12.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
12.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
12.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
12.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
12.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
13 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
13.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
13.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
13.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
14 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavfilter
-
-
-
-
15 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Formats Documentation
-
-
-
- FFmpeg Formats Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the supported formats (muxers and demuxers)
-provided by the libavformat library.
-
-
-
-
2 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
2.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
3 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
3.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
3.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
3.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
3.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
3.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
3.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
3.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
3.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
3.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
3.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
3.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
3.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
3.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
4 Muxers# TOC
-
-
Muxers are configured elements in FFmpeg which allow writing
-multimedia streams to a particular type of file.
-
-
When you configure your FFmpeg build, all the supported muxers
-are enabled by default. You can list all available muxers using the
-configure option --list-muxers.
-
-
You can disable all the muxers with the configure option
---disable-muxers and selectively enable / disable single muxers
-with the options --enable-muxer=MUXER /
---disable-muxer=MUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled muxers.
-
-
A description of some of the currently available muxers follows.
-
-
-
4.1 aiff# TOC
-
-
Audio Interchange File Format muxer.
-
-
-
4.1.1 Options# TOC
-
-
It accepts the following options:
-
-
-write_id3v2 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
-
-id3v2_version Select ID3v2 version to write. Currently only version 3 and 4 (aka.
-ID3v2.3 and ID3v2.4) are supported. The default is version 4.
-
-
-
-
-
-
-
CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a single line of the form:
-CRC=0xCRC , where CRC is a hexadecimal number 0-padded to
-8 digits containing the CRC for all the decoded input frames.
-
-
See also the framecrc muxer.
-
-
-
4.2.1 Examples# TOC
-
-
For example to compute the CRC of the input, and store it in the file
-out.crc :
-
-
ffmpeg -i INPUT -f crc out.crc
-
-
-
You can print the CRC to stdout with the command:
-
-
ffmpeg -i INPUT -f crc -
-
-
-
You can select the output format of each frame with ffmpeg by
-specifying the audio and video codec and format. For example to
-compute the CRC of the input audio converted to PCM unsigned 8-bit
-and the input video converted to MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
-
-
-
-
4.3 framecrc# TOC
-
-
Per-packet CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , 0xCRC
-
-
-
CRC is a hexadecimal number 0-padded to 8 digits containing the
-CRC of the packet.
-
-
-
4.3.1 Examples# TOC
-
-
For example to compute the CRC of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.crc :
-
-
ffmpeg -i INPUT -f framecrc out.crc
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framecrc -
-
-
-
With ffmpeg, you can select the output format to which the
-audio and video frames are encoded before computing the CRC for each
-packet by specifying the audio and video codec. For example, to
-compute the CRC of each decoded input audio frame converted to PCM
-unsigned 8-bit and of each decoded input video frame converted to
-MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
-
-
-
See also the crc muxer.
-
-
-
4.4 framemd5# TOC
-
-
Per-packet MD5 testing format.
-
-
This muxer computes and prints the MD5 hash for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , MD5
-
-
-
MD5 is a hexadecimal number representing the computed MD5 hash
-for the packet.
-
-
-
4.4.1 Examples# TOC
-
-
For example to compute the MD5 of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.md5 :
-
-
ffmpeg -i INPUT -f framemd5 out.md5
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framemd5 -
-
-
-
See also the md5 muxer.
-
-
-
-
-
Animated GIF muxer.
-
-
It accepts the following options:
-
-
-loop Set the number of times to loop the output. Use -1 for no loop, 0
-for looping indefinitely (default).
-
-final_delay Force the delay (expressed in centiseconds) after the last frame. Each frame
-ends with a delay until the next frame. The default is -1, which is a
-special value to tell the muxer to re-use the previous delay. In case of a
-loop, you might want to customize this value to mark a pause for instance.
-
-
-
For example, to encode a gif looping 10 times, with a 5 seconds delay between
-the loops:
-
-
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
-
-
-
Note 1: if you wish to extract the frames in separate GIF files, you need to
-force the image2 muxer:
-
-
ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
-
-
-
Note 2: the GIF format has a very small time base: the delay between two frames
-can not be smaller than one centi second.
-
-
-
-
-
Apple HTTP Live Streaming muxer that segments MPEG-TS according to
-the HTTP Live Streaming (HLS) specification.
-
-
It creates a playlist file, and one or more segment files. The output filename
-specifies the playlist filename.
-
-
By default, the muxer creates a file for each segment produced. These files
-have the same name as the playlist, followed by a sequential number and a
-.ts extension.
-
-
For example, to convert an input file with ffmpeg:
-
-
ffmpeg -i in.nut out.m3u8
-
-
This example will produce the playlist, out.m3u8 , and segment files:
-out0.ts , out1.ts , out2.ts , etc.
-
-
See also the segment muxer, which provides a more generic and
-flexible implementation of a segmenter, and can be used to perform HLS
-segmentation.
-
-
-
4.6.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-hls_time seconds Set the segment length in seconds. Default value is 2.
-
-hls_list_size size Set the maximum number of playlist entries. If set to 0 the list file
-will contain all the segments. Default value is 5.
-
-hls_ts_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing : special characters must be
-escaped.
-
-hls_wrap wrap Set the number after which the segment filename number (the number
-specified in each segment file) wraps. If set to 0 the number will be
-never wrapped. Default value is 0.
-
-This option is useful to avoid to fill the disk with many segment
-files, and limits the maximum number of segment files written to disk
-to wrap .
-
-start_number number Start the playlist sequence number from number . Default value is
-0.
-
-hls_allow_cache allowcache Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
-
-hls_base_url baseurl Append baseurl to every entry in the playlist.
-Useful to generate playlists with absolute paths.
-
-Note that the playlist sequence number must be unique for each segment
-and it is not to be confused with the segment filename sequence number
-which can be cyclic, for example if the wrap option is
-specified.
-
-hls_segment_filename filename Set the segment filename. Unless hls_flags single_file is set filename
-is used as a string format with the segment number:
-
-
ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
- This example will produce the playlist, out.m3u8 , and segment files:
-file000.ts , file001.ts , file002.ts , etc.
-
-hls_flags single_file If this flag is set, the muxer will store all segments in a single MPEG-TS
-file, and will use byte ranges in the playlist. HLS playlists generated with
-this way will have the version number 4.
-For example:
-
-
ffmpeg -i in.nut -hls_flags single_file out.m3u8
- Will produce the playlist, out.m3u8 , and a single segment file,
-out.ts .
-
-hls_flags delete_segments Segment files removed from the playlist are deleted after a period of time
-equal to the duration of the segment plus the duration of the playlist.
-
-
-
-
-
-
ICO file muxer.
-
-
Microsoft’s icon file format (ICO) has some strict limitations that should be noted:
-
-
- Size cannot exceed 256 pixels in any dimension
-
- Only BMP and PNG images can be stored
-
- If a BMP image is used, it must be one of the following pixel formats:
-
-
BMP Bit Depth FFmpeg Pixel Format
-1bit pal8
-4bit pal8
-8bit pal8
-16bit rgb555le
-24bit bgr24
-32bit bgra
- If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
-
- If a PNG image is used, it must use the rgba pixel format
-
-
-
-
4.8 image2# TOC
-
-
Image file muxer.
-
-
The image file muxer writes video frames to image files.
-
-
The output filenames are specified by a pattern, which can be used to
-produce sequentially numbered series of files.
-The pattern may contain the string "%d" or "%0N d", this string
-specifies the position of the characters representing a numbering in
-the filenames. If the form "%0N d" is used, the string
-representing the number in each filename is 0-padded to N
-digits. The literal character ’%’ can be specified in the pattern with
-the string "%%".
-
-
If the pattern contains "%d" or "%0N d", the first filename of
-the file list specified will contain the number 1, all the following
-numbers will be sequential.
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the image files to write.
-
-
For example the pattern "img-%03d.bmp" will specify a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.
-The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
-form img%-1.jpg , img%-2.jpg , ..., img%-10.jpg ,
-etc.
-
-
-
4.8.1 Examples# TOC
-
-
The following example shows how to use ffmpeg for creating a
-sequence of files img-001.jpeg , img-002.jpeg , ...,
-taking one image every second from the input video:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
-
-
-
Note that with ffmpeg, if the format is not specified with the
--f option and the output filename specifies an image file
-format, the image2 muxer is automatically selected, so the previous
-command can be written as:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
-
-
-
Note also that the pattern must not necessarily contain "%d" or
-"%0N d", for example to create a single image file
-img.jpeg from the input video you can employ the command:
-
-
ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
-
-
-
The strftime option allows you to expand the filename with
-date and time information. Check the documentation of
-the strftime() function for the syntax.
-
-
For example to generate image files from the strftime()
-"%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command
-can be used:
-
-
ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
-
-
-
-
4.8.2 Options# TOC
-
-
-start_number Start the sequence from the specified number. Default value is 1. Must
-be a non-negative number.
-
-update If set to 1, the filename will always be interpreted as just a
-filename, not a pattern, and the corresponding file will be continuously
-overwritten with new images. Default value is 0.
-
-strftime If set to 1, expand the filename with date and time information from
-strftime(). Default value is 0.
-
-
-
The image muxer supports the .Y.U.V image file format. This format is
-special in that that each image frame consists of three files, for
-each of the YUV420P components. To read or write this image file format,
-specify the name of the ’.Y’ file. The muxer will automatically open the
-’.U’ and ’.V’ files as required.
-
-
-
4.9 matroska# TOC
-
-
Matroska container muxer.
-
-
This muxer implements the matroska and webm container specs.
-
-
-
4.9.1 Metadata# TOC
-
-
The recognized metadata settings in this muxer are:
-
-
-title Set title name provided to a single track.
-
-language Specify the language of the track in the Matroska languages form.
-
-The language can be either the 3 letters bibliographic ISO-639-2 (ISO
-639-2/B) form (like "fre" for French), or a language code mixed with a
-country code for specialities in languages (like "fre-ca" for Canadian
-French).
-
-stereo_mode Set stereo 3D video layout of two views in a single video track.
-
-The following values are recognized:
-
-‘mono ’
-video is not stereo
-
‘left_right ’
-Both views are arranged side by side, Left-eye view is on the left
-
‘bottom_top ’
-Both views are arranged in top-bottom orientation, Left-eye view is at bottom
-
‘top_bottom ’
-Both views are arranged in top-bottom orientation, Left-eye view is on top
-
‘checkerboard_rl ’
-Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
-
‘checkerboard_lr ’
-Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
-
‘row_interleaved_rl ’
-Each view is constituted by a row based interleaving, Right-eye view is first row
-
‘row_interleaved_lr ’
-Each view is constituted by a row based interleaving, Left-eye view is first row
-
‘col_interleaved_rl ’
-Both views are arranged in a column based interleaving manner, Right-eye view is first column
-
‘col_interleaved_lr ’
-Both views are arranged in a column based interleaving manner, Left-eye view is first column
-
‘anaglyph_cyan_red ’
-All frames are in anaglyph format viewable through red-cyan filters
-
‘right_left ’
-Both views are arranged side by side, Right-eye view is on the left
-
‘anaglyph_green_magenta ’
-All frames are in anaglyph format viewable through green-magenta filters
-
‘block_lr ’
-Both eyes laced in one Block, Left-eye view is first
-
‘block_rl ’
-Both eyes laced in one Block, Right-eye view is first
-
-
-
-
For example a 3D WebM clip can be created using the following command line:
-
-
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
-
-
-
-
4.9.2 Options# TOC
-
-
This muxer supports the following options:
-
-
-reserve_index_space By default, this muxer writes the index for seeking (called cues in Matroska
-terms) at the end of the file, because it cannot know in advance how much space
-to leave for the index at the beginning of the file. However for some use cases
-– e.g. streaming where seeking is possible but slow – it is useful to put the
-index at the beginning of the file.
-
-If this option is set to a non-zero value, the muxer will reserve a given amount
-of space in the file header and then try to write the cues there when the muxing
-finishes. If the available space does not suffice, muxing will fail. A safe size
-for most use cases should be about 50kB per hour of video.
-
-Note that cues are only written if the output is seekable and this option will
-have no effect if it is not.
-
-
-
-
4.10 md5# TOC
-
-
MD5 testing format.
-
-
This muxer computes and prints the MD5 hash of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a single line of the form:
-MD5=MD5 , where MD5 is a hexadecimal number representing
-the computed MD5 hash.
-
-
For example to compute the MD5 hash of the input converted to raw
-audio and video, and store it in the file out.md5 :
-
-
ffmpeg -i INPUT -f md5 out.md5
-
-
-
You can print the MD5 to stdout with the command:
-
-
ffmpeg -i INPUT -f md5 -
-
-
-
See also the framemd5 muxer.
-
-
-
4.11 mov, mp4, ismv# TOC
-
-
MOV/MP4/ISMV (Smooth Streaming) muxer.
-
-
The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
-file has all the metadata about all packets stored in one location
-(written at the end of the file, it can be moved to the start for
-better playback by adding faststart to the movflags , or
-using the qt-faststart tool). A fragmented
-file consists of a number of fragments, where packets and metadata
-about these packets are stored together. Writing a fragmented
-file has the advantage that the file is decodable even if the
-writing is interrupted (while a normal MOV/MP4 is undecodable if
-it is not properly finished), and it requires less memory when writing
-very long files (since writing normal MOV/MP4 files stores info about
-every single packet in memory until the file is closed). The downside
-is that it is less compatible with other applications.
-
-
-
4.11.1 Options# TOC
-
-
Fragmentation is enabled by setting one of the AVOptions that define
-how to cut the file into fragments:
-
-
--moov_size bytes Reserves space for the moov atom at the beginning of the file instead of placing the
-moov atom at the end. If the space reserved is insufficient, muxing will fail.
-
-movflags frag_keyframe Start a new fragment at each video keyframe.
-
-frag_duration duration Create fragments that are duration microseconds long.
-
-frag_size size Create fragments that contain up to size bytes of payload data.
-
-movflags frag_custom Allow the caller to manually choose when to cut fragments, by
-calling av_write_frame(ctx, NULL) to write a fragment with
-the packets written so far. (This is only useful with other
-applications integrating libavformat, not from ffmpeg.)
-
-min_frag_duration duration Don’t create fragments that are shorter than duration microseconds long.
-
-
-
If more than one condition is specified, fragments are cut when
-one of the specified conditions is fulfilled. The exception to this is
--min_frag_duration, which has to be fulfilled for any of the other
-conditions to apply.
-
-
Additionally, the way the output file is written can be adjusted
-through a few other options:
-
-
--movflags empty_moov Write an initial moov atom directly at the start of the file, without
-describing any samples in it. Generally, an mdat/moov pair is written
-at the start of the file, as a normal MOV/MP4 file, containing only
-a short portion of the file. With this option set, there is no initial
-mdat atom, and the moov atom only describes the tracks but has
-a zero duration.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags separate_moof Write a separate moof (movie fragment) atom for each track. Normally,
-packets for all tracks are written in a moof atom (which is slightly
-more efficient), but with this option set, the muxer writes one moof/mdat
-pair for each track, making it easier to separate tracks.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags faststart Run a second pass moving the index (moov atom) to the beginning of the file.
-This operation can take a while, and will not work in various situations such
-as fragmented output, thus it is not enabled by default.
-
-movflags rtphint Add RTP hinting tracks to the output file.
-
-movflags disable_chpl Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
-and a QuickTime chapter track are written to the file. With this option
-set, only the QuickTime chapter track will be written. Nero chapters can
-cause failures when the file is reprocessed with certain tagging programs, like
-mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
-
-movflags omit_tfhd_offset Do not write any absolute base_data_offset in tfhd atoms. This avoids
-tying fragments to absolute byte positions in the file/streams.
-
-movflags default_base_moof Similarly to the omit_tfhd_offset, this flag avoids writing the
-absolute base_data_offset field in tfhd atoms, but does so by using
-the new default-base-is-moof flag instead. This flag is new from
-14496-12:2012. This may make the fragments easier to parse in certain
-circumstances (avoiding basing track fragment location calculations
-on the implicit end of the previous track fragment).
-
-
-
-
4.11.2 Example# TOC
-
-
Smooth Streaming content can be pushed in real time to a publishing
-point on IIS with this muxer. Example:
-
-
ffmpeg -re <normal input/transcoding options> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
-
-
-
-
4.12 mp3# TOC
-
-
The MP3 muxer writes a raw MP3 stream with the following optional features:
-
- An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
-2.4 are supported, the id3v2_version private option controls which one is
-used (3 or 4). Setting id3v2_version to 0 disables the ID3v2 header
-completely.
-
-The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
-The pictures are supplied to the muxer in form of a video stream with a single
-packet. There can be any number of those streams, each will correspond to a
-single APIC frame. The stream metadata tags title and comment map
-to APIC description and picture type respectively. See
-http://id3.org/id3v2.4.0-frames for allowed picture types.
-
-Note that the APIC frames must be written at the beginning, so the muxer will
-buffer the audio frames until it gets all the pictures. It is therefore advised
-to provide the pictures as soon as possible to avoid excessive buffering.
-
- A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
-default, but will be written only if the output is seekable. The
-write_xing private option can be used to disable it. The frame contains
-various information that may be useful to the decoder, like the audio duration
-or encoder delay.
-
- A legacy ID3v1 tag at the end of the file (disabled by default). It may be
-enabled with the write_id3v1 private option, but as its capabilities are
-very limited, its usage is not recommended.
-
-
-
Examples:
-
-
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
-
-
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
-
-
-
To attach a picture to an mp3 file select both the audio and the picture stream
-with map:
-
-
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
--metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
-
-
-
Write a "clean" MP3 without any extra features:
-
-
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
-
-
-
-
4.13 mpegts# TOC
-
-
MPEG transport stream muxer.
-
-
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
-
-
The recognized metadata settings in mpegts muxer are service_provider
-and service_name. If they are not set the default for
-service_provider is "FFmpeg" and the default for
-service_name is "Service01".
-
-
-
4.13.1 Options# TOC
-
-
The muxer options are:
-
-
--mpegts_original_network_id number Set the original_network_id (default 0x0001). This is unique identifier
-of a network in DVB. Its main use is in the unique identification of a
-service through the path Original_Network_ID, Transport_Stream_ID.
-
-mpegts_transport_stream_id number Set the transport_stream_id (default 0x0001). This identifies a
-transponder in DVB.
-
-mpegts_service_id number Set the service_id (default 0x0001) also known as program in DVB.
-
-mpegts_pmt_start_pid number Set the first PID for PMT (default 0x1000, max 0x1f00).
-
-mpegts_start_pid number Set the first PID for data packets (default 0x0100, max 0x0f00).
-
-mpegts_m2ts_mode number Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
-
-muxrate number Set a constant muxrate (default VBR).
-
-pcr_period numer Override the default PCR retransmission time (default 20ms), ignored
-if variable muxrate is selected.
-
-pes_payload_size number Set minimum PES packet payload in bytes.
-
-mpegts_flags flags Set flags (see below).
-
-mpegts_copyts number Preserve original timestamps, if value is set to 1. Default value is -1, which
-results in shifting timestamps so that they start from 0.
-
-tables_version number Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
-This option allows updating stream structure so that standard consumer may
-detect the change. To do so, reopen output AVFormatContext (in case of API
-usage) or restart ffmpeg instance, cyclically changing tables_version value:
-
-
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
-ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-
-
-
Option mpegts_flags may take a set of such flags:
-
-
-resend_headers Reemit PAT/PMT before writing the next packet.
-
latm Use LATM packetization for AAC.
-
-
-
-
4.13.2 Example# TOC
-
-
-
ffmpeg -i file.mpg -c copy \
- -mpegts_original_network_id 0x1122 \
- -mpegts_transport_stream_id 0x3344 \
- -mpegts_service_id 0x5566 \
- -mpegts_pmt_start_pid 0x1500 \
- -mpegts_start_pid 0x150 \
- -metadata service_provider="Some provider" \
- -metadata service_name="Some Channel" \
- -y out.ts
-
-
-
-
4.14 null# TOC
-
-
Null muxer.
-
-
This muxer does not generate any output file, it is mainly useful for
-testing or benchmarking purposes.
-
-
For example to benchmark decoding with ffmpeg you can use the
-command:
-
-
ffmpeg -benchmark -i INPUT -f null out.null
-
-
-
Note that the above command does not read or write the out.null
-file, but specifying the output file is required by the ffmpeg
-syntax.
-
-
Alternatively you can write the command as:
-
-
ffmpeg -benchmark -i INPUT -f null -
-
-
-
-
4.15 nut# TOC
-
-
--syncpoints flags Change the syncpoint usage in nut:
-
-default use the normal low-overhead seeking aids.none do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;Use of this option is not recommended, as the resulting files are very damage
- sensitive and seeking is not possible. Also in general the overhead from
- syncpoints is negligible. Note, -write_index 0 can be used to disable
- all growing data tables, allowing to mux endless streams with limited memory
- and without these disadvantages.
-
timestamped extend the syncpoint with a wallclock field.
-The none and timestamped flags are experimental.
-
-write_index bool Write index at the end, the default is to write an index.
-
-
-
-
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
-
-
-
-
4.16 ogg# TOC
-
-
Ogg container muxer.
-
-
--page_duration duration Preferred page duration, in microseconds. The muxer will attempt to create
-pages that are approximately duration microseconds long. This allows the
-user to compromise between seek granularity and container overhead. The default
-is 1 second. A value of 0 will fill all segments, making pages as large as
-possible. A value of 1 will effectively use 1 packet-per-page in most
-situations, giving a small seek granularity at the cost of additional container
-overhead.
-
-
-
-
4.17 segment, stream_segment, ssegment# TOC
-
-
Basic stream segmenter.
-
-
This muxer outputs streams to a number of separate files of nearly
-fixed duration. Output filename pattern can be set in a fashion similar to
-image2 .
-
-
stream_segment is a variant of the muxer used to write to
-streaming output formats, i.e. which do not require global headers,
-and is recommended for outputting e.g. to MPEG transport stream segments.
-ssegment is a shorter alias for stream_segment.
-
-
Every segment starts with a keyframe of the selected reference stream,
-which is set through the reference_stream option.
-
-
Note that if you want accurate splitting for a video file, you need to
-make the input key frames correspond to the exact splitting times
-expected by the segmenter, or the segment muxer will start the new
-segment with the key frame found next after the specified start
-time.
-
-
The segment muxer works best with a single constant frame rate video.
-
-
Optionally it can generate a list of the created segments, by setting
-the option segment_list . The list type is specified by the
-segment_list_type option. The entry filenames in the segment
-list are set by default to the basename of the corresponding segment
-files.
-
-
See also the hls muxer, which provides a more specific
-implementation for HLS segmentation.
-
-
-
4.17.1 Options# TOC
-
-
The segment muxer supports the following options:
-
-
-reference_stream specifier Set the reference stream, as specified by the string specifier .
-If specifier is set to auto, the reference is chosen
-automatically. Otherwise it must be a stream specifier (see the “Stream
-specifiers” chapter in the ffmpeg manual) which specifies the
-reference stream. The default value is auto.
-
-segment_format format Override the inner container format, by default it is guessed by the filename
-extension.
-
-segment_format_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing the : special character must be
-escaped.
-
-segment_list name Generate also a listfile named name . If not specified no
-listfile is generated.
-
-segment_list_flags flags Set flags affecting the segment list generation.
-
-It currently supports the following flags:
-
-‘cache ’
-Allow caching (only affects M3U8 list files).
-
-‘live ’
-Allow live-friendly file generation.
-
-
-segment_list_type type Select the listing format.
-
-flat use a simple flat list of entries.hls use a m3u8-like structure.
-
-segment_list_size size Update the list file so that it contains at most size
-segments. If 0 the list file will contain all the segments. Default
-value is 0.
-
-segment_list_entry_prefix prefix Prepend prefix to each entry. Useful to generate absolute paths.
-By default no prefix is applied.
-
-The following values are recognized:
-
-‘flat ’
-Generate a flat list for the created segments, one segment per line.
-
-‘csv, ext ’
-Generate a list for the created segments, one segment per line,
-each line matching the format (comma-separated values):
-
-
segment_filename ,segment_start_time ,segment_end_time
-segment_filename is the name of the output file generated by the
-muxer according to the provided pattern. CSV escaping (according to
-RFC4180) is applied if required.
-
-segment_start_time and segment_end_time specify
-the segment start and end time expressed in seconds.
-
-A list file with the suffix ".csv" or ".ext" will
-auto-select this format.
-
-‘ext ’ is deprecated in favor or ‘csv ’.
-
-‘ffconcat ’
-Generate an ffconcat file for the created segments. The resulting file
-can be read using the FFmpeg concat demuxer.
-
-A list file with the suffix ".ffcat" or ".ffconcat" will
-auto-select this format.
-
-‘m3u8 ’
-Generate an extended M3U8 file, version 3, compliant with
-http://tools.ietf.org/id/draft-pantos-http-live-streaming .
-
-A list file with the suffix ".m3u8" will auto-select this format.
-
-
-If not specified the type is guessed from the list file name suffix.
-
-segment_time time Set segment duration to time , the value must be a duration
-specification. Default value is "2". See also the
-segment_times option.
-
-Note that splitting may not be accurate, unless you force the
-reference stream key-frames at the given time. See the introductory
-notice and the examples below.
-
-segment_atclocktime 1|0 If set to "1" split at regular clock time intervals starting from 00:00
-o’clock. The time value specified in segment_time is
-used for setting the length of the splitting interval.
-
-For example with segment_time set to "900" this makes it possible
-to create files at 12:00 o’clock, 12:15, 12:30, etc.
-
-Default value is "0".
-
-segment_time_delta delta Specify the accuracy time when selecting the start time for a
-segment, expressed as a duration specification. Default value is "0".
-
-When delta is specified a key-frame will start a new segment if its
-PTS satisfies the relation:
-
-
PTS >= start_time - time_delta
- This option is useful when splitting video content, which is always
-split at GOP boundaries, in case a key frame is found just before the
-specified split time.
-
-In particular may be used in combination with the ffmpeg option
-force_key_frames . The key frame times specified by
-force_key_frames may not be set accurately because of rounding
-issues, with the consequence that a key frame time may result set just
-before the specified time. For constant frame rate videos a value of
-1/(2*frame_rate ) should address the worst case mismatch between
-the specified time and the time set by force_key_frames .
-
-segment_times times Specify a list of split points. times contains a list of comma
-separated duration specifications, in increasing order. See also
-the segment_time option.
-
-segment_frames frames Specify a list of split video frame numbers. frames contains a
-list of comma separated integer numbers, in increasing order.
-
-This option specifies to start a new segment whenever a reference
-stream key frame is found and the sequential number (starting from 0)
-of the frame is greater or equal to the next value in the list.
-
-segment_wrap limit Wrap around segment index once it reaches limit .
-
-segment_start_number number Set the sequence number of the first segment. Defaults to 0.
-
-reset_timestamps 1|0 Reset timestamps at the begin of each segment, so that each segment
-will start with near-zero timestamps. It is meant to ease the playback
-of the generated segments. May not work with some combinations of
-muxers/codecs. It is set to 0 by default.
-
-initial_offset offset Specify timestamp offset to apply to the output packet timestamps. The
-argument must be a time duration specification, and defaults to 0.
-
-
-
-
4.17.2 Examples# TOC
-
-
-
-
-
4.18 smoothstreaming# TOC
-
-
Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
-
-
-window_size Specify the number of fragments kept in the manifest. Default 0 (keep all).
-
-extra_window_size Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
-
-lookahead_count Specify the number of lookahead fragments. Default 2.
-
-min_frag_duration Specify the minimum fragment duration (in microseconds). Default 5000000.
-
-remove_at_exit Specify whether to remove all fragments when finished. Default 0 (do not remove).
-
-
-
-
-
4.19 tee# TOC
-
-
The tee muxer can be used to write the same data to several files or any
-other kind of muxer. It can be used, for example, to both stream a video to
-the network and save it to disk at the same time.
-
-
It is different from specifying several outputs to the ffmpeg
-command-line tool because the audio and video data will be encoded only once
-with the tee muxer; encoding can be a very expensive process. It is not
-useful when using the libavformat API directly because it is then possible
-to feed the same packets to several muxers directly.
-
-
The slave outputs are specified in the file name given to the muxer,
-separated by ’|’. If any of the slave name contains the ’|’ separator,
-leading or trailing spaces or any special character, it must be
-escaped (see (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual ).
-
-
Muxer options can be specified for each slave by prepending them as a list of
-key =value pairs separated by ’:’, between square brackets. If
-the options values contain a special character or the ’:’ separator, they
-must be escaped; note that this is a second level escaping.
-
-
The following special options are also recognized:
-
-f Specify the format name. Useful if it cannot be guessed from the
-output name suffix.
-
-bsfs[/spec ] Specify a list of bitstream filters to apply to the specified
-output.
-
-It is possible to specify to which streams a given bitstream filter
-applies, by appending a stream specifier to the option separated by
-/. spec must be a stream specifier (see Format stream specifiers ). If the stream specifier is not specified, the
-bitstream filters will be applied to all streams in the output.
-
-Several bitstream filters can be specified, separated by ",".
-
-select Select the streams that should be mapped to the slave output,
-specified by a stream specifier. If not specified, this defaults to
-all the input streams.
-
-
-
-
4.19.1 Examples# TOC
-
-
- Encode something and both archive it in a WebM file and stream it
-as MPEG-TS over UDP (the streams need to be explicitly mapped):
-
-
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
- "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Use ffmpeg to encode the input, and send the output
-to three different destinations. The dump_extra bitstream
-filter is used to add extradata information to all the output video
-keyframes packets, as requested by the MPEG-TS format. The select
-option is applied to out.aac in order to make it contain only
-audio packets.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
- As below, but select only stream a:1 for the audio output. Note
-that a second level escaping must be performed, as ":" is a special
-character used to separate options.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
-
-
-
Note: some codecs may need different options depending on the output format;
-the auto-detection of this can not work with the tee muxer. The main example
-is the global_header flag.
-
-
-
4.20 webm_dash_manifest# TOC
-
-
WebM DASH Manifest muxer.
-
-
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML.
-
-
-
4.20.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-adaptation_sets This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
-unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
-audio and video streams. Any number of adaptation sets can be added using this option.
-
-
-
-
4.20.2 Example# TOC
-
-
ffmpeg -f webm_dash_manifest -i video1.webm \
- -f webm_dash_manifest -i video2.webm \
- -f webm_dash_manifest -i audio1.webm \
- -f webm_dash_manifest -i audio2.webm \
- -map 0 -map 1 -map 2 -map 3 \
- -c copy \
- -f webm_dash_manifest \
- -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
- manifest.xml
-
-
-
-
5 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
-
6 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavformat
-
-
-
-
7 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Protocols Documentation
-
-
-
- FFmpeg Protocols Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the input and output protocols provided by the
-libavformat library.
-
-
-
-
2 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
2.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
2.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
2.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
2.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
2.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
2.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
2.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
2.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
2.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
2.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
2.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
2.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
2.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
2.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
2.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
2.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
2.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
2.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
2.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
2.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
2.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
2.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
2.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
2.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
2.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
2.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
2.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
2.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
2.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
2.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
2.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
2.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
2.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
2.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
2.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
2.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
2.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavformat
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Resampler Documentation
-
-
-
- FFmpeg Resampler Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The FFmpeg resampler provides a high-level interface to the
-libswresample library audio resampling utilities. In particular it
-allows one to perform audio resampling, audio channel layout rematrixing,
-and convert audio format and packing layout.
-
-
-
-
2 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libswresample
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Scaler Documentation
-
-
-
- FFmpeg Scaler Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The FFmpeg rescaler provides a high-level interface to the libswscale
-library image conversion utilities. In particular it allows one to perform
-image rescaling and pixel format conversion.
-
-
-
-
2 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libswscale
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Utilities Documentation
-
-
-
- FFmpeg Utilities Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes some generic features and utilities provided
-by the libavutil library.
-
-
-
-
2 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
2.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
2.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
2.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
2.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
2.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
2.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
2.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
2.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
2.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
2.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
3 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
4 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
-
5 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavutil
-
-
-
-
6 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffmpeg Documentation
-
-
-
- ffmpeg Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffmpeg [global_options ] {[input_file_options ] -i input_file } ... {[output_file_options ] output_file } ...
-
-
-
2 Description# TOC
-
-
ffmpeg is a very fast video and audio converter that can also grab from
-a live audio/video source. It can also convert between arbitrary sample
-rates and resize video on the fly with a high quality polyphase filter.
-
-
ffmpeg reads from an arbitrary number of input "files" (which can be regular
-files, pipes, network streams, grabbing devices, etc.), specified by the
--i option, and writes to an arbitrary number of output "files", which are
-specified by a plain output filename. Anything found on the command line which
-cannot be interpreted as an option is considered to be an output filename.
-
-
Each input or output file can, in principle, contain any number of streams of
-different types (video/audio/subtitle/attachment/data). The allowed number and/or
-types of streams may be limited by the container format. Selecting which
-streams from which inputs will go into which output is either done automatically
-or with the -map option (see the Stream selection chapter).
-
-
To refer to input files in options, you must use their indices (0-based). E.g.
-the first input file is 0, the second is 1, etc. Similarly, streams
-within a file are referred to by their indices. E.g. 2:3 refers to the
-fourth stream in the third input file. Also see the Stream specifiers chapter.
-
-
As a general rule, options are applied to the next specified
-file. Therefore, order is important, and you can have the same
-option on the command line multiple times. Each occurrence is
-then applied to the next input or output file.
-Exceptions from this rule are the global options (e.g. verbosity level),
-which should be specified first.
-
-
Do not mix input and output files – first specify all input files, then all
-output files. Also do not mix options which belong to different files. All
-options apply ONLY to the next input or output file and are reset between files.
-
-
- To set the video bitrate of the output file to 64 kbit/s:
-
-
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
- To force the frame rate of the output file to 24 fps:
-
-
ffmpeg -i input.avi -r 24 output.avi
- To force the frame rate of the input file (valid for raw formats only)
-to 1 fps and the frame rate of the output file to 24 fps:
-
-
ffmpeg -r 1 -i input.m2v -r 24 output.avi
-
-
-
The format option may be needed for raw input files.
-
-
-
-
3 Detailed description# TOC
-
-
The transcoding process in ffmpeg for each output can be described by
-the following diagram:
-
-
-
_______ ______________
-| | | |
-| input | demuxer | encoded data | decoder
-| file | ---------> | packets | -----+
-|_______| |______________| |
- v
- _________
- | |
- | decoded |
- | frames |
- |_________|
- ________ ______________ |
-| | | | |
-| output | <-------- | encoded data | <----+
-| file | muxer | packets | encoder
-|________| |______________|
-
-
-
-
-
ffmpeg calls the libavformat library (containing demuxers) to read
-input files and get packets containing encoded data from them. When there are
-multiple input files, ffmpeg tries to keep them synchronized by
-tracking lowest timestamp on any active input stream.
-
-
Encoded packets are then passed to the decoder (unless streamcopy is selected
-for the stream, see further for a description). The decoder produces
-uncompressed frames (raw video/PCM audio/...) which can be processed further by
-filtering (see next section). After filtering, the frames are passed to the
-encoder, which encodes them and outputs encoded packets. Finally those are
-passed to the muxer, which writes the encoded packets to the output file.
-
-
-
3.1 Filtering# TOC
-
Before encoding, ffmpeg can process raw audio and video frames using
-filters from the libavfilter library. Several chained filters form a filter
-graph. ffmpeg distinguishes between two types of filtergraphs:
-simple and complex.
-
-
-
3.1.1 Simple filtergraphs# TOC
-
Simple filtergraphs are those that have exactly one input and output, both of
-the same type. In the above diagram they can be represented by simply inserting
-an additional step between decoding and encoding:
-
-
-
_________ ______________
-| | | |
-| decoded | | encoded data |
-| frames |\ _ | packets |
-|_________| \ /||______________|
- \ __________ /
- simple _\|| | / encoder
- filtergraph | filtered |/
- | frames |
- |__________|
-
-
-
-
Simple filtergraphs are configured with the per-stream -filter option
-(with -vf and -af aliases for video and audio respectively).
-A simple filtergraph for video can look for example like this:
-
-
-
_______ _____________ _______ ________
-| | | | | | | |
-| input | ---> | deinterlace | ---> | scale | ---> | output |
-|_______| |_____________| |_______| |________|
-
-
-
-
Note that some filters change frame properties but not frame contents. E.g. the
-fps filter in the example above changes number of frames, but does not
-touch the frame contents. Another example is the setpts filter, which
-only sets timestamps and otherwise passes the frames unchanged.
-
-
-
3.1.2 Complex filtergraphs# TOC
-
Complex filtergraphs are those which cannot be described as simply a linear
-processing chain applied to one stream. This is the case, for example, when the graph has
-more than one input and/or output, or when output stream type is different from
-input. They can be represented with the following diagram:
-
-
-
_________
-| |
-| input 0 |\ __________
-|_________| \ | |
- \ _________ /| output 0 |
- \ | | / |__________|
- _________ \| complex | /
-| | | |/
-| input 1 |---->| filter |\
-|_________| | | \ __________
- /| graph | \ | |
- / | | \| output 1 |
- _________ / |_________| |__________|
-| | /
-| input 2 |/
-|_________|
-
-
-
-
Complex filtergraphs are configured with the -filter_complex option.
-Note that this option is global, since a complex filtergraph, by its nature,
-cannot be unambiguously associated with a single stream or file.
-
-
The -lavfi option is equivalent to -filter_complex .
-
-
A trivial example of a complex filtergraph is the overlay filter, which
-has two video inputs and one video output, containing one video overlaid on top
-of the other. Its audio counterpart is the amix filter.
-
-
-
3.2 Stream copy# TOC
-
Stream copy is a mode selected by supplying the copy parameter to the
--codec option. It makes ffmpeg omit the decoding and encoding
-step for the specified stream, so it does only demuxing and muxing. It is useful
-for changing the container format or modifying container-level metadata. The
-diagram above will, in this case, simplify to this:
-
-
-
_______ ______________ ________
-| | | | | |
-| input | demuxer | encoded data | muxer | output |
-| file | ---------> | packets | -------> | file |
-|_______| |______________| |________|
-
-
-
-
Since there is no decoding or encoding, it is very fast and there is no quality
-loss. However, it might not work in some cases because of many factors. Applying
-filters is obviously also impossible, since filters work on uncompressed data.
-
-
-
-
4 Stream selection# TOC
-
-
By default, ffmpeg includes only one stream of each type (video, audio, subtitle)
-present in the input files and adds them to each output file. It picks the
-"best" of each based upon the following criteria: for video, it is the stream
-with the highest resolution, for audio, it is the stream with the most channels, for
-subtitles, it is the first subtitle stream. In the case where several streams of
-the same type rate equally, the stream with the lowest index is chosen.
-
-
You can disable some of those defaults by using the -vn/-an/-sn options. For
-full manual control, use the -map option, which disables the defaults just
-described.
-
-
-
-
5 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
5.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
5.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
5.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
5.4 Main options# TOC
-
-
--f fmt (input/output ) Force input or output file format. The format is normally auto detected for input
-files and guessed from the file extension for output files, so this option is not
-needed in most cases.
-
--i filename (input ) input file name
-
--y (global ) Overwrite output files without asking.
-
--n (global ) Do not overwrite output files, and exit immediately if a specified
-output file already exists.
-
--c[:stream_specifier ] codec (input/output,per-stream ) -codec[:stream_specifier ] codec (input/output,per-stream ) Select an encoder (when used before an output file) or a decoder (when used
-before an input file) for one or more streams. codec is the name of a
-decoder/encoder or a special value copy (output only) to indicate that
-the stream is not to be re-encoded.
-
-For example
-
-
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
- encodes all video streams with libx264 and copies all audio streams.
-
-For each stream, the last matching c option is applied, so
-
-
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
- will copy all the streams except the second video, which will be encoded with
-libx264, and the 138th audio, which will be encoded with libvorbis.
-
--t duration (input/output ) When used as an input option (before -i), limit the duration of
-data read from the input file.
-
-When used as an output option (before an output filename), stop writing the
-output after its duration reaches duration .
-
-duration may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--to position (output ) Stop writing the output at position .
-position may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--fs limit_size (output ) Set the file size limit, expressed in bytes.
-
--ss position (input/output ) When used as an input option (before -i), seeks in this input file to
-position . Note the in most formats it is not possible to seek exactly, so
-ffmpeg will seek to the closest seek point before position .
-When transcoding and -accurate_seek is enabled (the default), this
-extra segment between the seek point and position will be decoded and
-discarded. When doing stream copy or when -noaccurate_seek is used, it
-will be preserved.
-
-When used as an output option (before an output filename), decodes but discards
-input until the timestamps reach position .
-
-position may be either in seconds or in hh:mm:ss[.xxx] form.
-
--itsoffset offset (input ) Set the input time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added to the timestamps of the input files. Specifying
-a positive offset means that the corresponding streams are delayed by
-the time duration specified in offset .
-
--timestamp date (output ) Set the recording timestamp in the container.
-
-date must be a time duration specification,
-see (ffmpeg-utils)the Date section in the ffmpeg-utils(1) manual .
-
--metadata[:metadata_specifier] key =value (output,per-metadata ) Set a metadata key/value pair.
-
-An optional metadata_specifier may be given to set metadata
-on streams or chapters. See -map_metadata documentation for
-details.
-
-This option overrides metadata set with -map_metadata. It is
-also possible to delete metadata by using an empty value.
-
-For example, for setting the title in the output file:
-
-
ffmpeg -i in.avi -metadata title="my title" out.flv
- To set the language of the first audio stream:
-
-
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
- -target type (output ) Specify target file type (vcd, svcd, dvd, dv,
-dv50). type may be prefixed with pal-, ntsc- or
-film- to use the corresponding standard. All the format options
-(bitrate, codecs, buffer sizes) are then set automatically. You can just type:
-
-
-
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
- Nevertheless you can specify additional options as long as you know
-they do not conflict with the standard, as in:
-
-
-
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
- -dframes number (output ) Set the number of data frames to output. This is an alias for -frames:d.
-
--frames[:stream_specifier ] framecount (output,per-stream ) Stop writing to the stream after framecount frames.
-
--q[:stream_specifier ] q (output,per-stream ) -qscale[:stream_specifier ] q (output,per-stream ) Use fixed quality scale (VBR). The meaning of q /qscale is
-codec-dependent.
-If qscale is used without a stream_specifier then it applies only
-to the video stream, this is to maintain compatibility with previous behavior
-and as specifying the same codec specific value to 2 different codecs that is
-audio and video generally is not what is intended when no stream_specifier is
-used.
-
--filter[:stream_specifier ] filtergraph (output,per-stream ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single input and a single output of the
-same type of the stream. In the filtergraph, the input is associated
-to the label in, and the output to the label out. See
-the ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-See the -filter_complex option if you
-want to create filtergraphs with multiple inputs and/or outputs.
-
--filter_script[:stream_specifier ] filename (output,per-stream ) This option is similar to -filter , the only difference is that its
-argument is the name of the file from which a filtergraph description is to be
-read.
-
--pre[:stream_specifier ] preset_name (output,per-stream ) Specify the preset for matching stream(s).
-
--stats (global ) Print encoding progress/statistics. It is on by default, to explicitly
-disable it you need to specify -nostats.
-
--progress url (global ) Send program-friendly progress information to url .
-
-Progress information is written approximately every second and at the end of
-the encoding process. It is made of "key =value " lines. key
-consists of only alphanumeric characters. The last key of a sequence of
-progress information is always "progress".
-
--stdin Enable interaction on standard input. On by default unless standard input is
-used as an input. To explicitly disable interaction you need to specify
--nostdin.
-
-Disabling interaction on standard input is useful, for example, if
-ffmpeg is in the background process group. Roughly the same result can
-be achieved with ffmpeg ... < /dev/null but it requires a
-shell.
-
--debug_ts (global ) Print timestamp information. It is off by default. This option is
-mostly useful for testing and debugging purposes, and the output
-format may change from one version to another, so it should not be
-employed by portable scripts.
-
-See also the option -fdebug ts.
-
--attach filename (output ) Add an attachment to the output file. This is supported by a few formats
-like Matroska for e.g. fonts used in rendering subtitles. Attachments
-are implemented as a specific type of stream, so this option will add
-a new stream to the file. It is then possible to use per-stream options
-on this stream in the usual way. Attachment streams created with this
-option will be created after all the other streams (i.e. those created
-with -map or automatic mappings).
-
-Note that for Matroska you also have to set the mimetype metadata tag:
-
-
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
- (assuming that the attachment stream will be third in the output file).
-
--dump_attachment[:stream_specifier ] filename (input,per-stream ) Extract the matching attachment stream into a file named filename . If
-filename is empty, then the value of the filename metadata tag
-will be used.
-
-E.g. to extract the first attachment to a file named ’out.ttf’:
-
-
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
- To extract all attachments to files determined by the filename tag:
-
-
ffmpeg -dump_attachment:t "" -i INPUT
- Technical note – attachments are implemented as codec extradata, so this
-option can actually be used to extract extradata from any stream, not just
-attachments.
-
-
-
-
-
5.5 Video Options# TOC
-
-
--vframes number (output ) Set the number of video frames to output. This is an alias for -frames:v.
-
-r[:stream_specifier ] fps (input/output,per-stream ) Set frame rate (Hz value, fraction or abbreviation).
-
-As an input option, ignore any timestamps stored in the file and instead
-generate timestamps assuming constant frame rate fps .
-This is not the same as the -framerate option used for some input formats
-like image2 or v4l2 (it used to be the same in older versions of FFmpeg).
-If in doubt use -framerate instead of the input option -r .
-
-As an output option, duplicate or drop input frames to achieve constant output
-frame rate fps .
-
--s[:stream_specifier ] size (input/output,per-stream ) Set frame size.
-
-As an input option, this is a shortcut for the video_size private
-option, recognized by some demuxers for which the frame size is either not
-stored in the file or is configurable – e.g. raw video or video grabbers.
-
-As an output option, this inserts the scale video filter to the
-end of the corresponding filtergraph. Please use the scale filter
-directly to insert it at the beginning or some other place.
-
-The format is ‘wxh ’ (default - same as source).
-
--aspect[:stream_specifier ] aspect (output,per-stream ) Set the video display aspect ratio specified by aspect .
-
-aspect can be a floating point number string, or a string of the
-form num :den , where num and den are the
-numerator and denominator of the aspect ratio. For example "4:3",
-"16:9", "1.3333", and "1.7777" are valid argument values.
-
-If used together with -vcodec copy , it will affect the aspect ratio
-stored at container level, but not the aspect ratio stored in encoded
-frames, if it exists.
-
--vn (output ) Disable video recording.
-
--vcodec codec (output ) Set the video codec. This is an alias for -codec:v.
-
--pass[:stream_specifier ] n (output,per-stream ) Select the pass number (1 or 2). It is used to do two-pass
-video encoding. The statistics of the video are recorded in the first
-pass into a log file (see also the option -passlogfile),
-and in the second pass that log file is used to generate the video
-at the exact requested bitrate.
-On pass 1, you may just deactivate audio and set output to null,
-examples for Windows and Unix:
-
-
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
-ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
- -passlogfile[:stream_specifier ] prefix (output,per-stream ) Set two-pass log file name prefix to prefix , the default file name
-prefix is “ffmpeg2pass”. The complete file name will be
-PREFIX-N.log , where N is a number specific to the output
-stream
-
--vf filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:v, see the -filter option .
-
-
-
-
5.6 Advanced Video options# TOC
-
-
--pix_fmt[:stream_specifier ] format (input/output,per-stream ) Set pixel format. Use -pix_fmts to show all the supported
-pixel formats.
-If the selected pixel format can not be selected, ffmpeg will print a
-warning and select the best pixel format supported by the encoder.
-If pix_fmt is prefixed by a +, ffmpeg will exit with an error
-if the requested pixel format can not be selected, and automatic conversions
-inside filtergraphs are disabled.
-If pix_fmt is a single +, ffmpeg selects the same pixel format
-as the input (or graph output) and automatic conversions are disabled.
-
--sws_flags flags (input/output ) Set SwScaler flags.
-
-vdt n Discard threshold.
-
--rc_override[:stream_specifier ] override (output,per-stream ) Rate control override for specific intervals, formatted as "int,int,int"
-list separated with slashes. Two first values are the beginning and
-end frame numbers, last one is quantizer to use if positive, or quality
-factor if negative.
-
--ilme Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
-Use this option if your input file is interlaced and you want
-to keep the interlaced format for minimum losses.
-The alternative is to deinterlace the input stream with
--deinterlace , but deinterlacing introduces losses.
-
-psnr Calculate PSNR of compressed frames.
-
-vstats Dump video coding statistics to vstats_HHMMSS.log .
-
-vstats_file file Dump video coding statistics to file .
-
-top[:stream_specifier ] n (output,per-stream ) top=1/bottom=0/auto=-1 field first
-
-dc precision Intra_dc_precision.
-
-vtag fourcc/tag (output ) Force video tag/fourcc. This is an alias for -tag:v.
-
-qphist (global ) Show QP histogram
-
-vbsf bitstream_filter Deprecated see -bsf
-
--force_key_frames[:stream_specifier ] time [,time ...] (output,per-stream ) -force_key_frames[:stream_specifier ] expr:expr (output,per-stream ) Force key frames at the specified timestamps, more precisely at the first
-frames after each specified time.
-
-If the argument is prefixed with expr:, the string expr
-is interpreted like an expression and is evaluated for each frame. A
-key frame is forced in case the evaluation is non-zero.
-
-If one of the times is "chapters[delta ]", it is expanded into
-the time of the beginning of all chapters in the file, shifted by
-delta , expressed as a time in seconds.
-This option can be useful to ensure that a seek point is present at a
-chapter mark or any other designated place in the output file.
-
-For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
-before the beginning of every chapter:
-
-
-force_key_frames 0:05:00,chapters-0.1
- The expression in expr can contain the following constants:
-
-n the number of current processed frame, starting from 0
-
n_forced the number of forced frames
-
prev_forced_n the number of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
prev_forced_t the time of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
t the time of the current processed frame
-
-
-For example to force a key frame every 5 seconds, you can specify:
-
-
-force_key_frames expr:gte(t,n_forced*5)
- To force a key frame 5 seconds after the time of the last forced one,
-starting from second 13:
-
-
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
- Note that forcing too many keyframes is very harmful for the lookahead
-algorithms of certain encoders: using fixed-GOP options or similar
-would be more efficient.
-
--copyinkf[:stream_specifier ] (output,per-stream ) When doing stream copy, copy also non-key frames found at the
-beginning.
-
--hwaccel[:stream_specifier ] hwaccel (input,per-stream ) Use hardware acceleration to decode the matching stream(s). The allowed values
-of hwaccel are:
-
-none Do not use any hardware acceleration (the default).
-
-auto Automatically select the hardware acceleration method.
-
-vda Use Apple VDA hardware acceleration.
-
-vdpau Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
-
-dxva2 Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
-
-
-This option has no effect if the selected hwaccel is not available or not
-supported by the chosen decoder.
-
-Note that most acceleration methods are intended for playback and will not be
-faster than software decoding on modern CPUs. Additionally, ffmpeg
-will usually need to copy the decoded frames from the GPU memory into the system
-memory, resulting in further performance loss. This option is thus mainly
-useful for testing.
-
--hwaccel_device[:stream_specifier ] hwaccel_device (input,per-stream ) Select a device to use for hardware acceleration.
-
-This option only makes sense when the -hwaccel option is also
-specified. Its exact meaning depends on the specific hardware acceleration
-method chosen.
-
-
-vdpau For VDPAU, this option specifies the X11 display/screen to use. If this option
-is not specified, the value of the DISPLAY environment variable is used
-
-dxva2 For DXVA2, this option should contain the number of the display adapter to use.
-If this option is not specified, the default adapter is used.
-
-
-
-
-
5.7 Audio Options# TOC
-
-
--aframes number (output ) Set the number of audio frames to output. This is an alias for -frames:a.
-
-ar[:stream_specifier ] freq (input/output,per-stream ) Set the audio sampling frequency. For output streams it is set by
-default to the frequency of the corresponding input stream. For input
-streams this option only makes sense for audio grabbing devices and raw
-demuxers and is mapped to the corresponding demuxer options.
-
-aq q (output ) Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
-
-ac[:stream_specifier ] channels (input/output,per-stream ) Set the number of audio channels. For output streams it is set by
-default to the number of input audio channels. For input streams
-this option only makes sense for audio grabbing devices and raw demuxers
-and is mapped to the corresponding demuxer options.
-
-an (output ) Disable audio recording.
-
-acodec codec (input/output ) Set the audio codec. This is an alias for -codec:a.
-
-sample_fmt[:stream_specifier ] sample_fmt (output,per-stream ) Set the audio sample format. Use -sample_fmts to get a list
-of supported sample formats.
-
--af filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:a, see the -filter option .
-
-
-
-
5.8 Advanced Audio options# TOC
-
-
--atag fourcc/tag (output ) Force audio tag/fourcc. This is an alias for -tag:a.
-
-absf bitstream_filter Deprecated, see -bsf
-
-guess_layout_max channels (input,per-stream ) If some input channel layout is not known, try to guess only if it
-corresponds to at most the specified number of channels. For example, 2
-tells to ffmpeg to recognize 1 channel as mono and 2 channels as
-stereo but not 6 channels as 5.1. The default is to always try to guess. Use
-0 to disable all guessing.
-
-
-
-
5.9 Subtitle options# TOC
-
-
--scodec codec (input/output ) Set the subtitle codec. This is an alias for -codec:s.
-
-sn (output ) Disable subtitle recording.
-
-sbsf bitstream_filter Deprecated, see -bsf
-
-
-
-
5.10 Advanced Subtitle options# TOC
-
-
--fix_sub_duration Fix subtitles durations. For each subtitle, wait for the next packet in the
-same stream and adjust the duration of the first to avoid overlap. This is
-necessary with some subtitles codecs, especially DVB subtitles, because the
-duration in the original packet is only a rough estimate and the end is
-actually marked by an empty subtitle frame. Failing to use this option when
-necessary can result in exaggerated durations or muxing failures due to
-non-monotonic timestamps.
-
-Note that this option will delay the output of all data until the next
-subtitle packet is decoded: it may increase memory consumption and latency a
-lot.
-
--canvas_size size Set the size of the canvas used to render subtitles.
-
-
-
-
-
5.11 Advanced options# TOC
-
-
--map [-]input_file_id [:stream_specifier ][,sync_file_id [:stream_specifier ]] | [linklabel] (output )
-Designate one or more input streams as a source for the output file. Each input
-stream is identified by the input file index input_file_id and
-the input stream index input_stream_id within the input
-file. Both indices start at 0. If specified,
-sync_file_id :stream_specifier sets which input stream
-is used as a presentation sync reference.
-
-The first -map option on the command line specifies the
-source for output stream 0, the second -map option specifies
-the source for output stream 1, etc.
-
-A - character before the stream identifier creates a "negative" mapping.
-It disables matching streams from already created mappings.
-
-An alternative [linklabel] form will map outputs from complex filter
-graphs (see the -filter_complex option) to the output file.
-linklabel must correspond to a defined output link label in the graph.
-
-For example, to map ALL streams from the first input file to output
-
-
ffmpeg -i INPUT -map 0 output
- For example, if you have two audio streams in the first input file,
-these streams are identified by "0:0" and "0:1". You can use
--map to select which streams to place in an output file. For
-example:
-
-
ffmpeg -i INPUT -map 0:1 out.wav
- will map the input stream in INPUT identified by "0:1" to
-the (single) output stream in out.wav .
-
-For example, to select the stream with index 2 from input file
-a.mov (specified by the identifier "0:2"), and stream with
-index 6 from input b.mov (specified by the identifier "1:6"),
-and copy them to the output file out.mov :
-
-
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
- To select all video and the third audio stream from an input file:
-
-
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
- To map all the streams except the second audio, use negative mappings
-
-
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
- To pick the English audio stream:
-
-
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
- Note that using this option disables the default mappings for this output file.
-
-
--map_channel [input_file_id .stream_specifier .channel_id |-1][:output_file_id .stream_specifier ] Map an audio channel from a given input to an output. If
-output_file_id .stream_specifier is not set, the audio channel will
-be mapped on all the audio streams.
-
-Using "-1" instead of
-input_file_id .stream_specifier .channel_id will map a muted
-channel.
-
-For example, assuming INPUT is a stereo audio file, you can switch the
-two audio channels with the following command:
-
-
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
- If you want to mute the first channel and keep the second:
-
-
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
- The order of the "-map_channel" option specifies the order of the channels in
-the output stream. The output channel layout is guessed from the number of
-channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
-in combination of "-map_channel" makes the channel gain levels to be updated if
-input and output channel layouts don’t match (for instance two "-map_channel"
-options and "-ac 6").
-
-You can also extract each channel of an input to specific outputs; the following
-command extracts two channels of the INPUT audio stream (file 0, stream 0)
-to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:
-
-
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
- The following example splits the channels of a stereo input into two separate
-streams, which are put into the same output file:
-
-
ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
- Note that currently each output stream can only contain channels from a single
-input stream; you can’t for example use "-map_channel" to pick multiple input
-audio channels contained in different streams (from the same or different files)
-and merge them into a single output stream. It is therefore not currently
-possible, for example, to turn two separate mono streams into a single stereo
-stream. However splitting a stereo stream into two single channel mono streams
-is possible.
-
-If you need this feature, a possible workaround is to use the amerge
-filter. For example, if you need to merge a media (here input.mkv ) with 2
-mono audio streams into one single stereo channel audio stream (and keep the
-video stream), you can use the following command:
-
-
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
- -map_metadata[:metadata_spec_out ] infile [:metadata_spec_in ] (output,per-metadata ) Set metadata information of the next output file from infile . Note that
-those are file indices (zero-based), not filenames.
-Optional metadata_spec_in/out parameters specify, which metadata to copy.
-A metadata specifier can have the following forms:
-
-g global metadata, i.e. metadata that applies to the whole file
-
-s [:stream_spec ]per-stream metadata. stream_spec is a stream specifier as described
-in the Stream specifiers chapter. In an input metadata specifier, the first
-matching stream is copied from. In an output metadata specifier, all matching
-streams are copied to.
-
-c :chapter_index per-chapter metadata. chapter_index is the zero-based chapter index.
-
-p :program_index per-program metadata. program_index is the zero-based program index.
-
-If metadata specifier is omitted, it defaults to global.
-
-By default, global metadata is copied from the first input file,
-per-stream and per-chapter metadata is copied along with streams/chapters. These
-default mappings are disabled by creating any mapping of the relevant type. A negative
-file index can be used to create a dummy mapping that just disables automatic copying.
-
-For example to copy metadata from the first stream of the input file to global metadata
-of the output file:
-
-
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
- To do the reverse, i.e. copy global metadata to all audio streams:
-
-
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
- Note that simple 0 would work as well in this example, since global
-metadata is assumed by default.
-
--map_chapters input_file_index (output ) Copy chapters from input file with index input_file_index to the next
-output file. If no chapter mapping is specified, then chapters are copied from
-the first input file with at least one chapter. Use a negative file index to
-disable any chapter copying.
-
--benchmark (global ) Show benchmarking information at the end of an encode.
-Shows CPU time used and maximum memory consumption.
-Maximum memory consumption is not supported on all systems,
-it will usually display as 0 if not supported.
-
-benchmark_all (global ) Show benchmarking information during the encode.
-Shows CPU time used in various steps (audio/video encode/decode).
-
-timelimit duration (global ) Exit after ffmpeg has been running for duration seconds.
-
-dump (global ) Dump each input packet to stderr.
-
-hex (global ) When dumping packets, also dump the payload.
-
-re (input ) Read input at native frame rate. Mainly used to simulate a grab device.
-or live input stream (e.g. when reading from a file). Should not be used
-with actual grab devices or live input streams (where it can cause packet
-loss).
-By default ffmpeg attempts to read the input(s) as fast as possible.
-This option will slow down the reading of the input(s) to the native frame rate
-of the input(s). It is useful for real-time output (e.g. live streaming).
-
-loop_input Loop over the input stream. Currently it works only for image
-streams. This option is used for automatic FFserver testing.
-This option is deprecated, use -loop 1.
-
-loop_output number_of_times Repeatedly loop output for formats that support looping such as animated GIF
-(0 will loop the output infinitely).
-This option is deprecated, use -loop.
-
-vsync parameter Video sync method.
-For compatibility reasons old values can be specified as numbers.
-Newly added values will have to be specified as strings always.
-
-
-0, passthrough Each frame is passed with its timestamp from the demuxer to the muxer.
-
1, cfr Frames will be duplicated and dropped to achieve exactly the requested
-constant frame rate.
-
2, vfr Frames are passed through with their timestamp or dropped so as to
-prevent 2 frames from having the same timestamp.
-
drop As passthrough but destroys all timestamps, making the muxer generate
-fresh timestamps based on frame-rate.
-
-1, auto Chooses between 1 and 2 depending on muxer capabilities. This is the
-default method.
-
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-With -map you can select from which stream the timestamps should be
-taken. You can leave either video or audio unchanged and sync the
-remaining stream(s) to the unchanged one.
-
--async samples_per_second Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
-the parameter is the maximum samples per second by which the audio is changed.
--async 1 is a special case where only the start of the audio stream is corrected
-without any later correction.
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-This option has been deprecated. Use the aresample audio filter instead.
-
--copyts Do not process input timestamps, but keep their values without trying
-to sanitize them. In particular, do not remove the initial start time
-offset value.
-
-Note that, depending on the vsync option or on specific muxer
-processing (e.g. in case the format option avoid_negative_ts
-is enabled) the output timestamps may mismatch with the input
-timestamps even when this option is selected.
-
--start_at_zero When used with copyts , shift input timestamps so they start at zero.
-
-This means that using e.g. -ss 50 will make output timestamps start at
-50 seconds, regardless of what timestamp the input file started at.
-
--copytb mode Specify how to set the encoder timebase when stream copying. mode is an
-integer numeric value, and can assume one of the following values:
-
-
-1 Use the demuxer timebase.
-
-The time base is copied to the output encoder from the corresponding input
-demuxer. This is sometimes required to avoid non monotonically increasing
-timestamps when copying video streams with variable frame rate.
-
-0 Use the decoder timebase.
-
-The time base is copied to the output encoder from the corresponding input
-decoder.
-
--1 Try to make the choice automatically, in order to generate a sane output.
-
-
-Default value is -1.
-
--shortest (output ) Finish encoding when the shortest input stream ends.
-
-dts_delta_threshold Timestamp discontinuity delta threshold.
-
-muxdelay seconds (input ) Set the maximum demux-decode delay.
-
-muxpreload seconds (input ) Set the initial demux-decode delay.
-
-streamid output-stream-index :new-value (output ) Assign a new stream-id value to an output stream. This option should be
-specified prior to the output filename to which it applies.
-For the situation where multiple output files exist, a streamid
-may be reassigned to a different value.
-
-For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
-an output mpegts file:
-
-
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
- -bsf[:stream_specifier ] bitstream_filters (output,per-stream ) Set bitstream filters for matching streams. bitstream_filters is
-a comma-separated list of bitstream filters. Use the -bsfs option
-to get the list of bitstream filters.
-
-
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
-
-
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
- -tag[:stream_specifier ] codec_tag (input/output,per-stream ) Force a tag/fourcc for matching streams.
-
--timecode hh :mm :ss SEPff Specify Timecode for writing. SEP is ’:’ for non drop timecode and ’;’
-(or ’.’) for drop.
-
-
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
- -filter_complex filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. For simple graphs – those with one input and one output of the same
-type – see the -filter options. filtergraph is a description of
-the filtergraph, as described in the “Filtergraph syntax” section of the
-ffmpeg-filters manual.
-
-Input link labels must refer to input streams using the
-[file_index:stream_specifier] syntax (i.e. the same as -map
-uses). If stream_specifier matches multiple streams, the first one will be
-used. An unlabeled input will be connected to the first unused input stream of
-the matching type.
-
-Output link labels are referred to with -map . Unlabeled outputs are
-added to the first output file.
-
-Note that with this option it is possible to use only lavfi sources without
-normal input files.
-
-For example, to overlay an image over video
-
-
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
-'[out]' out.mkv
- Here [0:v] refers to the first video stream in the first input file,
-which is linked to the first (main) input of the overlay filter. Similarly the
-first video stream in the second input is linked to the second (overlay) input
-of overlay.
-
-Assuming there is only one video stream in each input file, we can omit input
-labels, so the above is equivalent to
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
-'[out]' out.mkv
- Furthermore we can omit the output label and the single output from the filter
-graph will be added to the output file automatically, so we can simply write
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
- To generate 5 seconds of pure red video using lavfi color source:
-
-
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
- -lavfi filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. Equivalent to -filter_complex .
-
--filter_complex_script filename (global ) This option is similar to -filter_complex , the only difference is that
-its argument is the name of the file from which a complex filtergraph
-description is to be read.
-
--accurate_seek (input ) This option enables or disables accurate seeking in input files with the
--ss option. It is enabled by default, so seeking is accurate when
-transcoding. Use -noaccurate_seek to disable it, which may be useful
-e.g. when copying some streams and transcoding the others.
-
--override_ffserver (global ) Overrides the input specifications from ffserver. Using this
-option you can map any input stream to ffserver and control
-many aspects of the encoding from ffmpeg. Without this
-option ffmpeg will transmit to ffserver what is
-requested by ffserver.
-
-The option is intended for cases where features are needed that cannot be
-specified to ffserver but can be to ffmpeg.
-
--sdp_file file (global ) Print sdp information to file .
-This allows dumping sdp information when at least one output isn’t an
-rtp stream.
-
--discard (input ) Allows discarding specific streams or frames of streams at the demuxer.
-Not all demuxers support this.
-
-
-none Discard no frame.
-
-default Default, which discards no frames.
-
-noref Discard all non-reference frames.
-
-bidir Discard all bidirectional frames.
-
-nokey Discard all frames excepts keyframes.
-
-all Discard all frames.
-
-
-
-
-
As a special exception, you can use a bitmap subtitle stream as input: it
-will be converted into a video with the same size as the largest video in
-the file, or 720x576 if no video is present. Note that this is an
-experimental and temporary solution. It will be removed once libavfilter has
-proper support for subtitles.
-
-
For example, to hardcode subtitles on top of a DVB-T recording stored in
-MPEG-TS format, delaying the subtitles by 1 second:
-
-
ffmpeg -i input.ts -filter_complex \
- '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
- -sn -map '#0x2dc' output.mkv
-
-
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
-audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
-
-
-
5.12 Preset files# TOC
-
A preset file contains a sequence of option =value pairs,
-one for each line, specifying a sequence of options which would be
-awkward to specify on the command line. Lines starting with the hash
-(’#’) character are ignored and are used to provide comments. Check
-the presets directory in the FFmpeg source tree for examples.
-
-
There are two types of preset files: ffpreset and avpreset files.
-
-
-
5.12.1 ffpreset files# TOC
-
ffpreset files are specified with the vpre, apre,
-spre, and fpre options. The fpre option takes the
-filename of the preset instead of a preset name as input and can be
-used for any kind of codec. For the vpre, apre, and
-spre options, the options specified in a preset file are
-applied to the currently selected codec of the same type as the preset
-option.
-
-
The argument passed to the vpre, apre, and spre
-preset options identifies the preset file to use according to the
-following rules:
-
-
First ffmpeg searches for a file named arg .ffpreset in the
-directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg , and in
-the datadir defined at configuration time (usually PREFIX/share/ffmpeg )
-or in a ffpresets folder along the executable on win32,
-in that order. For example, if the argument is libvpx-1080p, it will
-search for the file libvpx-1080p.ffpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-codec_name -arg .ffpreset in the above-mentioned
-directories, where codec_name is the name of the codec to which
-the preset file options will be applied. For example, if you select
-the video codec with -vcodec libvpx and use -vpre 1080p,
-then it will search for the file libvpx-1080p.ffpreset .
-
-
-
5.12.2 avpreset files# TOC
-
avpreset files are specified with the pre option. They work similar to
-ffpreset files, but they only allow encoder- specific options. Therefore, an
-option =value pair specifying an encoder cannot be used.
-
-
When the pre option is specified, ffmpeg will look for files with the
-suffix .avpreset in the directories $AVCONV_DATADIR (if set), and
-$HOME/.avconv , and in the datadir defined at configuration time (usually
-PREFIX/share/ffmpeg ), in that order.
-
-
First ffmpeg searches for a file named codec_name -arg .avpreset in
-the above-mentioned directories, where codec_name is the name of the codec
-to which the preset file options will be applied. For example, if you select the
-video codec with -vcodec libvpx and use -pre 1080p, then it will
-search for the file libvpx-1080p.avpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-arg .avpreset in the same directories.
-
-
-
-
-
-
- For streaming at very low bitrates, use a low frame rate
-and a small GOP size. This is especially true for RealVideo where
-the Linux player does not seem to be very fast, so it can miss
-frames. An example is:
-
-
-
ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
- The parameter ’q’ which is displayed while encoding is the current
-quantizer. The value 1 indicates that a very good quality could
-be achieved. The value 31 indicates the worst quality. If q=31 appears
-too often, it means that the encoder cannot compress enough to meet
-your bitrate. You must either increase the bitrate, decrease the
-frame rate or decrease the frame size.
-
- If your computer is not fast enough, you can speed up the
-compression at the expense of the compression ratio. You can use
-’-me zero’ to speed up motion estimation, and ’-g 0’ to disable
-motion estimation completely (you have only I-frames, which means it
-is about as good as JPEG compression).
-
- To have very low audio bitrates, reduce the sampling frequency
-(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
-
- To have a constant quality (but a variable bitrate), use the option
-’-qscale n’ when ’n’ is between 1 (excellent quality) and 31 (worst
-quality).
-
-
-
-
-
7 Examples# TOC
-
-
-
7.1 Video and Audio grabbing# TOC
-
-
If you specify the input format and device then ffmpeg can grab video
-and audio directly.
-
-
-
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
-
-
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Note that you must activate the right video source and channel before
-launching ffmpeg with any TV viewer such as
-xawtv by Gerd Knorr. You also
-have to set the audio recording levels correctly with a
-standard mixer.
-
-
-
7.2 X11 grabbing# TOC
-
-
Grab the X11 display with ffmpeg via
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as
-the DISPLAY environment variable.
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
-variable. 10 is the x-offset and 20 the y-offset for the grabbing.
-
-
-
7.3 Video and Audio file format conversion# TOC
-
-
Any supported file format and protocol can serve as input to ffmpeg:
-
-
Examples:
-
- You can use YUV files as input:
-
-
-
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
- It will use the files:
-
-
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
-/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
- The Y files use twice the resolution of the U and V files. They are
-raw files, without header. They can be generated by all decent video
-decoders. You must specify the size of the image with the -s option
-if ffmpeg cannot guess it.
-
- You can input from a raw YUV420P file:
-
-
-
ffmpeg -i /tmp/test.yuv /tmp/out.avi
- test.yuv is a file containing raw YUV planar data. Each frame is composed
-of the Y plane followed by the U and V planes at half vertical and
-horizontal resolution.
-
- You can output to a raw YUV420P file:
-
-
-
ffmpeg -i mydivx.avi hugefile.yuv
- You can set several input files and output files:
-
-
-
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
- Converts the audio file a.wav and the raw YUV video file a.yuv
-to MPEG file a.mpg.
-
- You can also do audio and video conversions at the same time:
-
-
-
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
- Converts a.wav to MPEG audio at 22050 Hz sample rate.
-
- You can encode to several formats at the same time and define a
-mapping from input stream to output streams:
-
-
-
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
- Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map
-file:index’ specifies which input stream is used for each output
-stream, in the order of the definition of output streams.
-
- You can transcode decrypted VOBs:
-
-
-
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
- This is a typical DVD ripping example; the input is a VOB file, the
-output an AVI file with MPEG-4 video and MP3 audio. Note that in this
-command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
-GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
-input video. Furthermore, the audio stream is MP3-encoded so you need
-to enable LAME support by passing --enable-libmp3lame to configure.
-The mapping is particularly useful for DVD transcoding
-to get the desired audio language.
-
-NOTE: To see the supported input formats, use ffmpeg -formats.
-
- You can extract images from a video, or create a video from many images:
-
-For extracting images from a video:
-
-
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
- This will extract one video frame per second from the video and will
-output them in files named foo-001.jpeg , foo-002.jpeg ,
-etc. Images will be rescaled to fit the new WxH values.
-
-If you want to extract just a limited number of frames, you can use the
-above command in combination with the -vframes or -t option, or in
-combination with -ss to start extracting from a certain point in time.
-
-For creating a video from many images:
-
-
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
- The syntax foo-%03d.jpeg specifies to use a decimal number
-composed of three digits padded with zeroes to express the sequence
-number. It is the same syntax supported by the C printf function, but
-only formats accepting a normal integer are suitable.
-
-When importing an image sequence, -i also supports expanding
-shell-like wildcard patterns (globbing) internally, by selecting the
-image2-specific -pattern_type glob option.
-
-For example, for creating a video from filenames matching the glob pattern
-foo-*.jpeg:
-
-
ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
- You can put many streams of the same type in the output:
-
-
-
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
- The resulting output file test12.nut will contain the first four streams
-from the input files in reverse order.
-
- To force CBR video output:
-
-
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
- The four options lmin, lmax, mblmin and mblmax use ’lambda’ units,
-but you may use the QP2LAMBDA constant to easily convert from ’q’ units:
-
-
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
-
-
-
-
-
8 See Also# TOC
-
-
ffmpeg-all ,
-ffplay , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
9 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffplay Documentation
-
-
-
- ffplay Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffplay [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
FFplay is a very simple and portable media player using the FFmpeg
-libraries and the SDL library. It is mostly used as a testbed for the
-various FFmpeg APIs.
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--x width Force displayed width.
-
-y height Force displayed height.
-
-s size Set frame size (WxH or abbreviation), needed for videos which do
-not contain a header with the frame size like raw YUV. This option
-has been deprecated in favor of private options, try -video_size.
-
-fs Start in fullscreen mode.
-
-an Disable audio.
-
-vn Disable video.
-
-sn Disable subtitles.
-
-ss pos Seek to a given position in seconds.
-
-t duration play <duration> seconds of audio/video
-
-bytes Seek by bytes.
-
-nodisp Disable graphical display.
-
-f fmt Force format.
-
-window_title title Set window title (default is the input filename).
-
-loop number Loops movie playback <number> times. 0 means forever.
-
-showmode mode Set the show mode to use.
-Available values for mode are:
-
-‘0, video ’
-show video
-
‘1, waves ’
-show audio waves
-
‘2, rdft ’
-show audio frequency band using RDFT ((Inverse) Real Discrete Fourier Transform)
-
-
-Default value is "video", if video is not present or cannot be played
-"rdft" is automatically selected.
-
-You can interactively cycle through the available show modes by
-pressing the key w .
-
--vf filtergraph Create the filtergraph specified by filtergraph and use it to
-filter the video stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single video input and a single video
-output. In the filtergraph, the input is associated to the label
-in, and the output to the label out. See the
-ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-You can specify this parameter multiple times and cycle through the specified
-filtergraphs along with the show modes by pressing the key w .
-
--af filtergraph filtergraph is a description of the filtergraph to apply to
-the input audio.
-Use the option "-filters" to show all the available filters (including
-sources and sinks).
-
--i input_file Read input_file .
-
-
-
-
3.5 Advanced options# TOC
-
--pix_fmt format Set pixel format.
-This option has been deprecated in favor of private options, try -pixel_format.
-
--stats Print several playback statistics, in particular show the stream
-duration, the codec parameters, the current position in the stream and
-the audio/video synchronisation drift. It is on by default, to
-explicitly disable it you need to specify -nostats.
-
--fast Non-spec-compliant optimizations.
-
-genpts Generate pts.
-
-sync type Set the master clock to audio (type=audio), video
-(type=video) or external (type=ext). Default is audio. The
-master clock is used to control audio-video synchronization. Most media
-players use audio as master clock, but in some cases (streaming or high
-quality broadcast) it is necessary to change that. This option is mainly
-used for debugging purposes.
-
-ast audio_stream_specifier Select the desired audio stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" audio stream is selected in the program of the
-already selected video stream.
-
-vst video_stream_specifier Select the desired video stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" video stream is selected.
-
-sst subtitle_stream_specifier Select the desired subtitle stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" subtitle stream is selected in the program of the
-already selected video or audio stream.
-
-autoexit Exit when video is done playing.
-
-exitonkeydown Exit if any key is pressed.
-
-exitonmousedown Exit if any mouse button is pressed.
-
--codec:media_specifier codec_name Force a specific decoder implementation for the stream identified by
-media_specifier , which can assume the values a (audio),
-v (video), and s subtitle.
-
--acodec codec_name Force a specific audio decoder.
-
--vcodec codec_name Force a specific video decoder.
-
--scodec codec_name Force a specific subtitle decoder.
-
--autorotate Automatically rotate the video according to presentation metadata. Enabled by
-default, use -noautorotate to disable it.
-
--framedrop Drop video frames if video is out of sync. Enabled by default if the master
-clock is not set to video. Use this option to enable frame dropping for all
-master clock sources, use -noframedrop to disable it.
-
--infbuf Do not limit the input buffer size, read as much data as possible from the
-input as soon as possible. Enabled by default for realtime streams, where data
-may be dropped if not read in time. Use this option to enable infinite buffers
-for all inputs, use -noinfbuf to disable it.
-
-
-
-
-
3.6 While playing# TOC
-
-
-q, ESC Quit.
-
-f Toggle full screen.
-
-p, SPC Pause.
-
-a Cycle audio channel in the current program.
-
-v Cycle video channel.
-
-t Cycle subtitle channel in the current program.
-
-c Cycle program.
-
-w Cycle video filters or show modes.
-
-s Step to the next frame.
-
-Pause if the stream is not already paused, step to the next video
-frame, and pause.
-
-left/right Seek backward/forward 10 seconds.
-
-down/up Seek backward/forward 1 minute.
-
-page down/page up Seek to the previous/next chapter.
-or if there are no chapters
-Seek backward/forward 10 minutes.
-
-mouse click Seek to percentage in file corresponding to fraction of width.
-
-
-
-
-
-
4 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
4.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
4.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
4.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
4.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
4.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
4.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
4.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
4.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
4.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
4.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
5 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
6 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
7 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
8 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
9 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
9.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
9.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
10 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
10.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
10.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
10.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
10.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
10.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
10.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
10.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
10.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
10.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
10.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
11 Subtitles Decoders# TOC
-
-
-
11.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
11.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
11.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
11.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
12 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
12.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
12.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
12.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
12.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
12.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
12.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
12.7 mjpega_dump_header# TOC
-
-
-
12.8 movsub# TOC
-
-
-
12.9 mp3_header_decompress# TOC
-
-
-
12.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
12.11 remove_extra# TOC
-
-
-
13 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
13.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
14 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
14.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
14.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
14.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
14.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
14.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
14.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
14.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
14.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
14.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
14.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
14.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
14.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
14.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
14.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
14.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
14.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
15 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
16 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
16.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
16.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
16.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
16.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
16.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
16.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
16.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
16.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
16.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
16.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
16.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
16.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
16.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
16.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
16.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
16.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
16.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
16.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
16.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
16.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
16.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
16.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
16.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
16.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
16.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
16.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
16.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
16.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
16.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
16.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
16.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
16.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
16.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
16.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
16.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
16.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
16.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
16.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
16.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
17 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
18 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
18.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
18.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
18.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
18.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
18.3 bktr# TOC
-
-
BSD video input device.
-
-
-
18.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
18.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
18.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
18.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
18.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
18.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
18.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
18.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
18.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
18.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
18.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
18.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
18.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
18.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
18.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
18.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
18.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
18.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
18.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
18.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
18.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
18.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
18.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
18.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
18.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
18.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
18.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
18.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
18.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
18.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
18.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
18.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
18.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
19 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
20 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
21 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
22 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
23 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
23.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
23.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
24 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
25 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
25.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
25.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
25.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
25.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
25.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
25.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
25.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
25.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
25.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
25.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
25.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
25.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
25.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
25.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
25.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
25.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
25.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
25.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
25.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
25.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
25.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
25.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
25.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
25.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
25.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
25.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
25.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
25.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
25.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
25.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
25.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
25.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
25.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
25.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
25.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
25.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
25.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
25.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
25.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
25.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
25.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
25.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
25.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
25.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
25.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
25.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
25.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
25.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
25.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
25.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
25.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
25.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
25.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
25.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
25.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
25.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
25.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
25.42.2 Examples# TOC
-
-
-
-
-
25.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
25.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
26 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
26.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
26.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
26.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
26.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
26.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
26.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
26.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
26.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
26.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
26.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
27 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
27.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
27.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
28 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
28.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
28.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
28.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
28.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
28.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
28.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
28.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
28.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
28.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
28.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
28.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
28.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
28.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
28.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
28.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
28.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
28.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
28.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
28.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
28.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
28.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
28.15.1 Examples# TOC
-
-
-
-
-
28.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
28.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
28.17.1 Examples# TOC
-
-
-
-
-
28.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
28.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
28.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
28.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
28.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
28.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
28.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
28.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
28.23.1 Examples# TOC
-
-
-
-
-
28.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
28.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
28.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
28.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
28.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
28.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
28.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
28.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
28.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
28.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
28.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
28.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
28.29.1 Examples# TOC
-
-
-
-
-
28.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
28.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
28.31.1 p/c/n/u/b meaning# TOC
-
-
-
28.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
28.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
28.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
28.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
28.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
28.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
28.34.1 Examples# TOC
-
-
-
-
-
28.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
28.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
28.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
28.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
28.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
28.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
28.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
28.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
28.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
28.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
28.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
28.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
28.42.1 Workflow examples# TOC
-
-
-
28.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
28.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
28.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
28.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
28.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
28.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
28.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
28.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
28.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
28.48.1 Examples# TOC
-
-
-
-
-
28.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
28.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
28.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
28.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
28.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
28.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
28.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
28.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
28.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
28.55.1 Examples# TOC
-
-
-
-
-
28.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
28.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
28.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
28.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
28.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
28.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
28.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
28.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
28.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
28.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
28.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
28.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
28.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
28.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
28.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
28.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
28.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
28.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.65.2 Examples# TOC
-
-
-
-
-
28.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
28.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.67.1 Examples# TOC
-
-
-
-
-
28.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
28.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
28.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
28.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
28.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
28.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
28.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
28.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
28.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
28.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
28.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
28.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
28.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
28.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
28.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
28.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.79.2 Examples# TOC
-
-
-
-
-
28.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
28.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
28.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
28.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
28.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
28.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
28.85.1 Examples# TOC
-
-
-
-
-
28.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
28.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
28.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
28.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
28.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
28.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
28.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
28.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
28.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
28.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
28.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
28.94.1 Examples# TOC
-
-
-
-
-
28.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
28.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
28.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
28.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
28.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
28.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
28.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
28.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
28.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
28.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
28.101.2 Examples# TOC
-
-
-
-
-
28.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
28.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
28.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
28.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
28.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
28.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
28.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
28.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
28.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
29 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
29.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
29.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
29.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
29.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
29.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
29.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
29.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
29.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
29.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
29.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
30 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
30.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
30.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
31 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
31.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
31.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
31.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
31.2.1 Examples# TOC
-
-
-
-
-
31.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
31.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
31.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
31.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
31.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
31.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
31.6.1 Examples# TOC
-
-
-
-
-
31.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
31.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
31.7.2 Examples# TOC
-
-
-
-
-
31.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
31.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
31.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
31.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
31.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
31.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
31.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
31.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
31.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
31.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
31.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
31.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
31.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
31.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
32 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
32.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
32.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
32.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
33 See Also# TOC
-
-
ffplay ,
-ffmpeg , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
34 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffplay Documentation
-
-
-
- ffplay Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffplay [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
FFplay is a very simple and portable media player using the FFmpeg
-libraries and the SDL library. It is mostly used as a testbed for the
-various FFmpeg APIs.
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--x width Force displayed width.
-
-y height Force displayed height.
-
-s size Set frame size (WxH or abbreviation), needed for videos which do
-not contain a header with the frame size like raw YUV. This option
-has been deprecated in favor of private options, try -video_size.
-
-fs Start in fullscreen mode.
-
-an Disable audio.
-
-vn Disable video.
-
-sn Disable subtitles.
-
-ss pos Seek to a given position in seconds.
-
-t duration play <duration> seconds of audio/video
-
-bytes Seek by bytes.
-
-nodisp Disable graphical display.
-
-f fmt Force format.
-
-window_title title Set window title (default is the input filename).
-
-loop number Loops movie playback <number> times. 0 means forever.
-
-showmode mode Set the show mode to use.
-Available values for mode are:
-
-‘0, video ’
-show video
-
‘1, waves ’
-show audio waves
-
‘2, rdft ’
-show audio frequency band using RDFT ((Inverse) Real Discrete Fourier Transform)
-
-
-Default value is "video", if video is not present or cannot be played
-"rdft" is automatically selected.
-
-You can interactively cycle through the available show modes by
-pressing the key w .
-
--vf filtergraph Create the filtergraph specified by filtergraph and use it to
-filter the video stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single video input and a single video
-output. In the filtergraph, the input is associated to the label
-in, and the output to the label out. See the
-ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-You can specify this parameter multiple times and cycle through the specified
-filtergraphs along with the show modes by pressing the key w .
-
--af filtergraph filtergraph is a description of the filtergraph to apply to
-the input audio.
-Use the option "-filters" to show all the available filters (including
-sources and sinks).
-
--i input_file Read input_file .
-
-
-
-
3.5 Advanced options# TOC
-
--pix_fmt format Set pixel format.
-This option has been deprecated in favor of private options, try -pixel_format.
-
--stats Print several playback statistics, in particular show the stream
-duration, the codec parameters, the current position in the stream and
-the audio/video synchronisation drift. It is on by default, to
-explicitly disable it you need to specify -nostats.
-
--fast Non-spec-compliant optimizations.
-
-genpts Generate pts.
-
-sync type Set the master clock to audio (type=audio), video
-(type=video) or external (type=ext). Default is audio. The
-master clock is used to control audio-video synchronization. Most media
-players use audio as master clock, but in some cases (streaming or high
-quality broadcast) it is necessary to change that. This option is mainly
-used for debugging purposes.
-
-ast audio_stream_specifier Select the desired audio stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" audio stream is selected in the program of the
-already selected video stream.
-
-vst video_stream_specifier Select the desired video stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" video stream is selected.
-
-sst subtitle_stream_specifier Select the desired subtitle stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" subtitle stream is selected in the program of the
-already selected video or audio stream.
-
-autoexit Exit when video is done playing.
-
-exitonkeydown Exit if any key is pressed.
-
-exitonmousedown Exit if any mouse button is pressed.
-
--codec:media_specifier codec_name Force a specific decoder implementation for the stream identified by
-media_specifier , which can assume the values a (audio),
-v (video), and s subtitle.
-
--acodec codec_name Force a specific audio decoder.
-
--vcodec codec_name Force a specific video decoder.
-
--scodec codec_name Force a specific subtitle decoder.
-
--autorotate Automatically rotate the video according to presentation metadata. Enabled by
-default, use -noautorotate to disable it.
-
--framedrop Drop video frames if video is out of sync. Enabled by default if the master
-clock is not set to video. Use this option to enable frame dropping for all
-master clock sources, use -noframedrop to disable it.
-
--infbuf Do not limit the input buffer size, read as much data as possible from the
-input as soon as possible. Enabled by default for realtime streams, where data
-may be dropped if not read in time. Use this option to enable infinite buffers
-for all inputs, use -noinfbuf to disable it.
-
-
-
-
-
3.6 While playing# TOC
-
-
-q, ESC Quit.
-
-f Toggle full screen.
-
-p, SPC Pause.
-
-a Cycle audio channel in the current program.
-
-v Cycle video channel.
-
-t Cycle subtitle channel in the current program.
-
-c Cycle program.
-
-w Cycle video filters or show modes.
-
-s Step to the next frame.
-
-Pause if the stream is not already paused, step to the next video
-frame, and pause.
-
-left/right Seek backward/forward 10 seconds.
-
-down/up Seek backward/forward 1 minute.
-
-page down/page up Seek to the previous/next chapter.
-or if there are no chapters
-Seek backward/forward 10 minutes.
-
-mouse click Seek to percentage in file corresponding to fraction of width.
-
-
-
-
-
-
-
4 See Also# TOC
-
-
ffmpeg-all ,
-ffmpeg , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
5 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffprobe Documentation
-
-
-
- ffprobe Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffprobe [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
ffprobe gathers information from multimedia streams and prints it in
-human- and machine-readable fashion.
-
-
For example it can be used to check the format of the container used
-by a multimedia stream and the format and type of each media stream
-contained in it.
-
-
If a filename is specified in input, ffprobe will try to open and
-probe the file content. If the file cannot be opened or recognized as
-a multimedia file, a positive exit code is returned.
-
-
ffprobe may be employed both as a standalone application or in
-combination with a textual filter, which may perform more
-sophisticated processing, e.g. statistical processing or plotting.
-
-
Options are used to list some of the formats supported by ffprobe or
-for specifying which information to display, and for setting how
-ffprobe will show it.
-
-
ffprobe output is designed to be easily parsable by a textual filter,
-and consists of one or more sections of a form defined by the selected
-writer, which is specified by the print_format option.
-
-
Sections may contain other nested sections, and are identified by a
-name (which may be shared by other sections), and an unique
-name. See the output of sections .
-
-
Metadata tags stored in the container or in the streams are recognized
-and printed in the corresponding "FORMAT", "STREAM" or "PROGRAM_STREAM"
-section.
-
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--f format Force format to use.
-
--unit Show the unit of the displayed values.
-
--prefix Use SI prefixes for the displayed values.
-Unless the "-byte_binary_prefix" option is used all the prefixes
-are decimal.
-
--byte_binary_prefix Force the use of binary prefixes for byte values.
-
--sexagesimal Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.
-
--pretty Prettify the format of the displayed values, it corresponds to the
-options "-unit -prefix -byte_binary_prefix -sexagesimal".
-
--of, -print_format writer_name [=writer_options ] Set the output printing format.
-
-writer_name specifies the name of the writer, and
-writer_options specifies the options to be passed to the writer.
-
-For example for printing the output in JSON format, specify:
-
-
-For more details on the available output printing formats, see the
-Writers section below.
-
--sections Print sections structure and section information, and exit. The output
-is not meant to be parsed by a machine.
-
--select_streams stream_specifier Select only the streams specified by stream_specifier . This
-option affects only the options related to streams
-(e.g. show_streams, show_packets, etc.).
-
-For example to show only audio streams, you can use the command:
-
-
ffprobe -show_streams -select_streams a INPUT
- To show only video packets belonging to the video stream with index 1:
-
-
ffprobe -show_packets -select_streams v:1 INPUT
- -show_data Show payload data, as a hexadecimal and ASCII dump. Coupled with
--show_packets , it will dump the packets’ data. Coupled with
--show_streams , it will dump the codec extradata.
-
-The dump is printed as the "data" field. It may contain newlines.
-
--show_data_hash algorithm Show a hash of payload data, for packets with -show_packets and for
-codec extradata with -show_streams .
-
--show_error Show information about the error found when trying to probe the input.
-
-The error information is printed within a section with name "ERROR".
-
--show_format Show information about the container format of the input multimedia
-stream.
-
-All the container format information is printed within a section with
-name "FORMAT".
-
--show_format_entry name Like -show_format , but only prints the specified entry of the
-container format information, rather than all. This option may be given more
-than once, then all specified entries will be shown.
-
-This option is deprecated, use show_entries instead.
-
--show_entries section_entries Set list of entries to show.
-
-Entries are specified according to the following
-syntax. section_entries contains a list of section entries
-separated by :. Each section entry is composed by a section
-name (or unique name), optionally followed by a list of entries local
-to that section, separated by ,.
-
-If section name is specified but is followed by no =, all
-entries are printed to output, together with all the contained
-sections. Otherwise only the entries specified in the local section
-entries list are printed. In particular, if = is specified but
-the list of local entries is empty, then no entries will be shown for
-that section.
-
-Note that the order of specification of the local section entries is
-not honored in the output, and the usual display order will be
-retained.
-
-The formal syntax is given by:
-
-
LOCAL_SECTION_ENTRIES ::= SECTION_ENTRY_NAME [,LOCAL_SECTION_ENTRIES ]
-SECTION_ENTRY ::= SECTION_NAME [=[LOCAL_SECTION_ENTRIES ]]
-SECTION_ENTRIES ::= SECTION_ENTRY [:SECTION_ENTRIES ]
-For example, to show only the index and type of each stream, and the PTS
-time, duration time, and stream index of the packets, you can specify
-the argument:
-
-
packet=pts_time,duration_time,stream_index : stream=index,codec_type
- To show all the entries in the section "format", but only the codec
-type in the section "stream", specify the argument:
-
-
format : stream=codec_type
- To show all the tags in the stream and format sections:
-
-
stream_tags : format_tags
- To show only the title tag (if available) in the stream
-sections:
-
-
--show_packets Show information about each packet contained in the input multimedia
-stream.
-
-The information for each single packet is printed within a dedicated
-section with name "PACKET".
-
--show_frames Show information about each frame and subtitle contained in the input
-multimedia stream.
-
-The information for each single frame is printed within a dedicated
-section with name "FRAME" or "SUBTITLE".
-
--show_streams Show information about each media stream contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "STREAM".
-
--show_programs Show information about programs and their streams contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "PROGRAM_STREAM".
-
--show_chapters Show information about chapters stored in the format.
-
-Each chapter is printed within a dedicated section with name "CHAPTER".
-
--count_frames Count the number of frames per stream and report it in the
-corresponding stream section.
-
--count_packets Count the number of packets per stream and report it in the
-corresponding stream section.
-
--read_intervals read_intervals
-Read only the specified intervals. read_intervals must be a
-sequence of interval specifications separated by ",".
-ffprobe will seek to the interval starting point, and will
-continue reading from that.
-
-Each interval is specified by two optional parts, separated by "%".
-
-The first part specifies the interval start position. It is
-interpreted as an abolute position, or as a relative offset from the
-current position if it is preceded by the "+" character. If this first
-part is not specified, no seeking will be performed when reading this
-interval.
-
-The second part specifies the interval end position. It is interpreted
-as an absolute position, or as a relative offset from the current
-position if it is preceded by the "+" character. If the offset
-specification starts with "#", it is interpreted as the number of
-packets to read (not including the flushing packets) from the interval
-start. If no second part is specified, the program will read until the
-end of the input.
-
-Note that seeking is not accurate, thus the actual interval start
-point may be different from the specified position. Also, when an
-interval duration is specified, the absolute end time will be computed
-by adding the duration to the interval start point found by seeking
-the file, rather than to the specified start value.
-
-The formal syntax is given by:
-
-
INTERVAL ::= [START |+START_OFFSET ][%[END |+END_OFFSET ]]
-INTERVALS ::= INTERVAL [,INTERVALS ]
-A few examples follow.
-
- Seek to time 10, read packets until 20 seconds after the found seek
-point, then seek to position 01:30 (1 minute and thirty
-seconds) and read packets until position 01:45.
-
-
- Read only 42 packets after seeking to position 01:23:
-
-
- Read only the first 20 seconds from the start:
-
-
- Read from the start until position 02:30:
-
-
-
-
--show_private_data, -private Show private data, that is data depending on the format of the
-particular shown element.
-This option is enabled by default, but you may need to disable it
-for specific uses, for example when creating XSD-compliant XML output.
-
--show_program_version Show information related to program version.
-
-Version information is printed within a section with name
-"PROGRAM_VERSION".
-
--show_library_versions Show information related to library versions.
-
-Version information for each library is printed within a section with
-name "LIBRARY_VERSION".
-
--show_versions Show information related to program and library versions. This is the
-equivalent of setting both -show_program_version and
--show_library_versions options.
-
--show_pixel_formats Show information about all pixel formats supported by FFmpeg.
-
-Pixel format information for each format is printed within a section
-with name "PIXEL_FORMAT".
-
--bitexact Force bitexact output, useful to produce output which is not dependent
-on the specific build.
-
--i input_file Read input_file .
-
-
-
-
-
4 Writers# TOC
-
-
A writer defines the output format adopted by ffprobe, and will be
-used for printing all the parts of the output.
-
-
A writer may accept one or more arguments, which specify the options
-to adopt. The options are specified as a list of key =value
-pairs, separated by ":".
-
-
All writers support the following options:
-
-
-string_validation, sv Set string validation mode.
-
-The following values are accepted.
-
-‘fail ’
-The writer will fail immediately in case an invalid string (UTF-8)
-sequence or code point is found in the input. This is especially
-useful to validate input metadata.
-
-‘ignore ’
-Any validation error will be ignored. This will result in possibly
-broken output, especially with the json or xml writer.
-
-‘replace ’
-The writer will substitute invalid UTF-8 sequences or code points with
-the string specified with the string_validation_replacement .
-
-
-Default value is ‘replace ’.
-
-string_validation_replacement, svr Set replacement string to use in case string_validation is
-set to ‘replace ’.
-
-In case the option is not specified, the writer will assume the empty
-string, that is it will remove the invalid sequences from the input
-strings.
-
-
-
A description of the currently available writers follows.
-
-
-
4.1 default# TOC
-
Default format.
-
-
Print each section in the form:
-
-
[SECTION]
-key1=val1
-...
-keyN=valN
-[/SECTION]
-
-
-
Metadata tags are printed as a line in the corresponding FORMAT, STREAM or
-PROGRAM_STREAM section, and are prefixed by the string "TAG:".
-
-
A description of the accepted options follows.
-
-
-nokey, nk If set to 1 specify not to print the key of each field. Default value
-is 0.
-
-noprint_wrappers, nw If set to 1 specify not to print the section header and footer.
-Default value is 0.
-
-
-
-
4.2 compact, csv# TOC
-
Compact and CSV format.
-
-
The csv writer is equivalent to compact, but supports
-different defaults.
-
-
Each section is printed on a single line.
-If no option is specifid, the output has the form:
-
-
section|key1=val1| ... |keyN=valN
-
-
-
Metadata tags are printed in the corresponding "format" or "stream"
-section. A metadata tag key, if printed, is prefixed by the string
-"tag:".
-
-
The description of the accepted options follows.
-
-
-item_sep, s Specify the character to use for separating fields in the output line.
-It must be a single printable character, it is "|" by default ("," for
-the csv writer).
-
-nokey, nk If set to 1 specify not to print the key of each field. Its default
-value is 0 (1 for the csv writer).
-
-escape, e Set the escape mode to use, default to "c" ("csv" for the csv
-writer).
-
-It can assume one of the following values:
-
-c Perform C-like escaping. Strings containing a newline (’\n’), carriage
-return (’\r’), a tab (’\t’), a form feed (’\f’), the escaping
-character (’\’) or the item separator character SEP are escaped using C-like fashioned
-escaping, so that a newline is converted to the sequence "\n", a
-carriage return to "\r", ’\’ to "\\" and the separator SEP is
-converted to "\SEP ".
-
-csv Perform CSV-like escaping, as described in RFC4180. Strings
-containing a newline (’\n’), a carriage return (’\r’), a double quote
-(’"’), or SEP are enclosed in double-quotes.
-
-none Perform no escaping.
-
-
-print_section, p Print the section name at the begin of each line if the value is
-1, disable it with value set to 0. Default value is
-1.
-
-
-
-
-
4.3 flat# TOC
-
Flat format.
-
-
A free-form output where each line contains an explicit key=value, such as
-"streams.stream.3.tags.foo=bar". The output is shell escaped, so it can be
-directly embedded in sh scripts as long as the separator character is an
-alphanumeric character or an underscore (see sep_char option).
-
-
The description of the accepted options follows.
-
-
-sep_char, s Separator character used to separate the chapter, the section name, IDs and
-potential tags in the printed field key.
-
-Default value is ’.’.
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
-
INI format output.
-
-
Print output in an INI based format.
-
-
The following conventions are adopted:
-
-
- all key and values are UTF-8
- ’.’ is the subgroup separator
- newline, ’\t’, ’\f’, ’\b’ and the following characters are escaped
- ’\’ is the escape character
- ’#’ is the comment indicator
- ’=’ is the key/value separator
- ’:’ is not used but usually parsed as key/value separator
-
-
-
This writer accepts options as a list of key =value pairs,
-separated by ":".
-
-
The description of the accepted options follows.
-
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
4.5 json# TOC
-
JSON based format.
-
-
Each section is printed using JSON notation.
-
-
The description of the accepted options follows.
-
-
-compact, c If set to 1 enable compact output, that is each section will be
-printed on a single line. Default value is 0.
-
-
-
For more information about JSON, see http://www.json.org/ .
-
-
-
-
XML based format.
-
-
The XML output is described in the XML schema description file
-ffprobe.xsd installed in the FFmpeg datadir.
-
-
An updated version of the schema can be retrieved at the url
-http://www.ffmpeg.org/schema/ffprobe.xsd , which redirects to the
-latest schema committed into the FFmpeg development source code tree.
-
-
Note that the output issued will be compliant to the
-ffprobe.xsd schema only when no special global output options
-(unit , prefix , byte_binary_prefix ,
-sexagesimal etc.) are specified.
-
-
The description of the accepted options follows.
-
-
-fully_qualified, q If set to 1 specify if the output should be fully qualified. Default
-value is 0.
-This is required for generating an XML file which can be validated
-through an XSD file.
-
-xsd_compliant, x If set to 1 perform more checks for ensuring that the output is XSD
-compliant. Default value is 0.
-This option automatically sets fully_qualified to 1.
-
-
-
For more information about the XML format, see
-http://www.w3.org/XML/ .
-
-
-
5 Timecode# TOC
-
-
ffprobe supports Timecode extraction:
-
-
- MPEG1/2 timecode is extracted from the GOP, and is available in the video
-stream details (-show_streams , see timecode ).
-
- MOV timecode is extracted from tmcd track, so is available in the tmcd
-stream metadata (-show_streams , see TAG:timecode ).
-
- DV, GXF and AVI timecodes are available in format metadata
-(-show_format , see TAG:timecode ).
-
-
-
-
-
6 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
6.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
6.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
6.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
6.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
6.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
6.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
6.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
6.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
6.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
6.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
7 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
8 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
9 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
10 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
11 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
11.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
11.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
12 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
12.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
12.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
12.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
12.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
12.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
12.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
12.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
12.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
12.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
12.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
13 Subtitles Decoders# TOC
-
-
-
13.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
13.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
13.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
13.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
14 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
14.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
14.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
14.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
14.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
14.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
14.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
14.7 mjpega_dump_header# TOC
-
-
-
14.8 movsub# TOC
-
-
-
14.9 mp3_header_decompress# TOC
-
-
-
14.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
14.11 remove_extra# TOC
-
-
-
15 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
15.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
16 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
16.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
16.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
16.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
16.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
16.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
16.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
16.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
16.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
16.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
16.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
16.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
16.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
16.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
16.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
16.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
16.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
17 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
18 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
18.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
18.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
18.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
18.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
18.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
18.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
18.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
18.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
18.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
18.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
18.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
18.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
18.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
18.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
18.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
18.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
18.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
18.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
18.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
18.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
18.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
18.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
18.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
18.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
18.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
18.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
18.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
18.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
18.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
18.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
18.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
18.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
18.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
18.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
18.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
18.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
18.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
18.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
18.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
19 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
20 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
20.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
20.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
20.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
20.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
20.3 bktr# TOC
-
-
BSD video input device.
-
-
-
20.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
20.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
20.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
20.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
20.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
20.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
20.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
20.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
20.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
20.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
20.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
20.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
20.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
20.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
20.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
20.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
20.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
20.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
20.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
20.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
20.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
20.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
20.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
20.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
20.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
20.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
20.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
20.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
20.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
20.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
20.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
20.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
20.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
21 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
22 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
23 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
24 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
25 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
25.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
25.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
26 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
27 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
27.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
27.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
27.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
27.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
27.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
27.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
27.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
27.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
27.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
27.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
27.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
27.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
27.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
27.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
27.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
27.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
27.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
27.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
27.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
27.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
27.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
27.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
27.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
27.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
27.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
27.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
27.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
27.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
27.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
27.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
27.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
27.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
27.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
27.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
27.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
27.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
27.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
27.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
27.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
27.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
27.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
27.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
27.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
27.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
27.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
27.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
27.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
27.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
27.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
27.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
27.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
27.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
27.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
27.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
27.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
27.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
27.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
27.42.2 Examples# TOC
-
-
-
-
-
27.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
27.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
28 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
28.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
28.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
28.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
28.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
28.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
28.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
28.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
28.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
28.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
28.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
29 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
29.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
29.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
30 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
30.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
30.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
30.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
30.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
30.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
30.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
30.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
30.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
30.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
30.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
30.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
30.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
30.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
30.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
30.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
30.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
30.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
30.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
30.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
30.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
30.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
30.15.1 Examples# TOC
-
-
-
-
-
30.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
30.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
30.17.1 Examples# TOC
-
-
-
-
-
30.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
30.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
30.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
30.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
30.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
30.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
30.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
30.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
30.23.1 Examples# TOC
-
-
-
-
-
30.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
30.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
30.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
30.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
30.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
30.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
30.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
30.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
30.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
30.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
30.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
30.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
30.29.1 Examples# TOC
-
-
-
-
-
30.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
30.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
30.31.1 p/c/n/u/b meaning# TOC
-
-
-
30.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
30.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
30.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
30.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
30.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
30.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
30.34.1 Examples# TOC
-
-
-
-
-
30.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
30.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
30.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
30.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
30.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
30.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
30.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
30.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
30.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
30.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
30.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
30.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
30.42.1 Workflow examples# TOC
-
-
-
30.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
30.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
30.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
30.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
30.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
30.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
30.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
30.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
30.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
30.48.1 Examples# TOC
-
-
-
-
-
30.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
30.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
30.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
30.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
30.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
30.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
30.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
30.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
30.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
30.55.1 Examples# TOC
-
-
-
-
-
30.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
30.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
30.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
30.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
30.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
30.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
30.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
30.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
30.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
30.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
30.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
30.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
30.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
30.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
30.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
30.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
30.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
30.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.65.2 Examples# TOC
-
-
-
-
-
30.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
30.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.67.1 Examples# TOC
-
-
-
-
-
30.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
30.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
30.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
30.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
30.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
30.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
30.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
30.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
30.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
30.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
30.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
30.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
30.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
30.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
30.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
30.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.79.2 Examples# TOC
-
-
-
-
-
30.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
30.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
30.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
30.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
30.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
30.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
30.85.1 Examples# TOC
-
-
-
-
-
30.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
30.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
30.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
30.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
30.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
30.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
30.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
30.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
30.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
30.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
30.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
30.94.1 Examples# TOC
-
-
-
-
-
30.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
30.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
30.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
30.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
30.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
30.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
30.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
30.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
30.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
30.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
30.101.2 Examples# TOC
-
-
-
-
-
30.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
30.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
30.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
30.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
30.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
30.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
30.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
30.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
30.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
31 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
31.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
31.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
31.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
31.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
31.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
31.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
31.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
31.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
31.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
31.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
32 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
32.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
32.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
33 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
33.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
33.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
33.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
33.2.1 Examples# TOC
-
-
-
-
-
33.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
33.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
33.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
33.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
33.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
33.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
33.6.1 Examples# TOC
-
-
-
-
-
33.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
33.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
33.7.2 Examples# TOC
-
-
-
-
-
33.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
33.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
33.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
33.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
33.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
33.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
33.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
33.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
33.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
33.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
33.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
33.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
33.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
33.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
34 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
34.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
34.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
34.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
35 See Also# TOC
-
-
ffprobe ,
-ffmpeg , ffplay , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
36 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffprobe Documentation
-
-
-
- ffprobe Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffprobe [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
ffprobe gathers information from multimedia streams and prints it in
-human- and machine-readable fashion.
-
-
For example it can be used to check the format of the container used
-by a multimedia stream and the format and type of each media stream
-contained in it.
-
-
If a filename is specified in input, ffprobe will try to open and
-probe the file content. If the file cannot be opened or recognized as
-a multimedia file, a positive exit code is returned.
-
-
ffprobe may be employed both as a standalone application or in
-combination with a textual filter, which may perform more
-sophisticated processing, e.g. statistical processing or plotting.
-
-
Options are used to list some of the formats supported by ffprobe or
-for specifying which information to display, and for setting how
-ffprobe will show it.
-
-
ffprobe output is designed to be easily parsable by a textual filter,
-and consists of one or more sections of a form defined by the selected
-writer, which is specified by the print_format option.
-
-
Sections may contain other nested sections, and are identified by a
-name (which may be shared by other sections), and an unique
-name. See the output of sections .
-
-
Metadata tags stored in the container or in the streams are recognized
-and printed in the corresponding "FORMAT", "STREAM" or "PROGRAM_STREAM"
-section.
-
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--f format Force format to use.
-
--unit Show the unit of the displayed values.
-
--prefix Use SI prefixes for the displayed values.
-Unless the "-byte_binary_prefix" option is used all the prefixes
-are decimal.
-
--byte_binary_prefix Force the use of binary prefixes for byte values.
-
--sexagesimal Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.
-
--pretty Prettify the format of the displayed values, it corresponds to the
-options "-unit -prefix -byte_binary_prefix -sexagesimal".
-
--of, -print_format writer_name [=writer_options ] Set the output printing format.
-
-writer_name specifies the name of the writer, and
-writer_options specifies the options to be passed to the writer.
-
-For example for printing the output in JSON format, specify:
-
-
-For more details on the available output printing formats, see the
-Writers section below.
-
--sections Print sections structure and section information, and exit. The output
-is not meant to be parsed by a machine.
-
--select_streams stream_specifier Select only the streams specified by stream_specifier . This
-option affects only the options related to streams
-(e.g. show_streams, show_packets, etc.).
-
-For example to show only audio streams, you can use the command:
-
-
ffprobe -show_streams -select_streams a INPUT
- To show only video packets belonging to the video stream with index 1:
-
-
ffprobe -show_packets -select_streams v:1 INPUT
- -show_data Show payload data, as a hexadecimal and ASCII dump. Coupled with
--show_packets , it will dump the packets’ data. Coupled with
--show_streams , it will dump the codec extradata.
-
-The dump is printed as the "data" field. It may contain newlines.
-
--show_data_hash algorithm Show a hash of payload data, for packets with -show_packets and for
-codec extradata with -show_streams .
-
--show_error Show information about the error found when trying to probe the input.
-
-The error information is printed within a section with name "ERROR".
-
--show_format Show information about the container format of the input multimedia
-stream.
-
-All the container format information is printed within a section with
-name "FORMAT".
-
--show_format_entry name Like -show_format , but only prints the specified entry of the
-container format information, rather than all. This option may be given more
-than once, then all specified entries will be shown.
-
-This option is deprecated, use show_entries instead.
-
--show_entries section_entries Set list of entries to show.
-
-Entries are specified according to the following
-syntax. section_entries contains a list of section entries
-separated by :. Each section entry is composed by a section
-name (or unique name), optionally followed by a list of entries local
-to that section, separated by ,.
-
-If section name is specified but is followed by no =, all
-entries are printed to output, together with all the contained
-sections. Otherwise only the entries specified in the local section
-entries list are printed. In particular, if = is specified but
-the list of local entries is empty, then no entries will be shown for
-that section.
-
-Note that the order of specification of the local section entries is
-not honored in the output, and the usual display order will be
-retained.
-
-The formal syntax is given by:
-
-
LOCAL_SECTION_ENTRIES ::= SECTION_ENTRY_NAME [,LOCAL_SECTION_ENTRIES ]
-SECTION_ENTRY ::= SECTION_NAME [=[LOCAL_SECTION_ENTRIES ]]
-SECTION_ENTRIES ::= SECTION_ENTRY [:SECTION_ENTRIES ]
-For example, to show only the index and type of each stream, and the PTS
-time, duration time, and stream index of the packets, you can specify
-the argument:
-
-
packet=pts_time,duration_time,stream_index : stream=index,codec_type
- To show all the entries in the section "format", but only the codec
-type in the section "stream", specify the argument:
-
-
format : stream=codec_type
- To show all the tags in the stream and format sections:
-
-
stream_tags : format_tags
- To show only the title tag (if available) in the stream
-sections:
-
-
--show_packets Show information about each packet contained in the input multimedia
-stream.
-
-The information for each single packet is printed within a dedicated
-section with name "PACKET".
-
--show_frames Show information about each frame and subtitle contained in the input
-multimedia stream.
-
-The information for each single frame is printed within a dedicated
-section with name "FRAME" or "SUBTITLE".
-
--show_streams Show information about each media stream contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "STREAM".
-
--show_programs Show information about programs and their streams contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "PROGRAM_STREAM".
-
--show_chapters Show information about chapters stored in the format.
-
-Each chapter is printed within a dedicated section with name "CHAPTER".
-
--count_frames Count the number of frames per stream and report it in the
-corresponding stream section.
-
--count_packets Count the number of packets per stream and report it in the
-corresponding stream section.
-
--read_intervals read_intervals
-Read only the specified intervals. read_intervals must be a
-sequence of interval specifications separated by ",".
-ffprobe will seek to the interval starting point, and will
-continue reading from that.
-
-Each interval is specified by two optional parts, separated by "%".
-
-The first part specifies the interval start position. It is
-interpreted as an abolute position, or as a relative offset from the
-current position if it is preceded by the "+" character. If this first
-part is not specified, no seeking will be performed when reading this
-interval.
-
-The second part specifies the interval end position. It is interpreted
-as an absolute position, or as a relative offset from the current
-position if it is preceded by the "+" character. If the offset
-specification starts with "#", it is interpreted as the number of
-packets to read (not including the flushing packets) from the interval
-start. If no second part is specified, the program will read until the
-end of the input.
-
-Note that seeking is not accurate, thus the actual interval start
-point may be different from the specified position. Also, when an
-interval duration is specified, the absolute end time will be computed
-by adding the duration to the interval start point found by seeking
-the file, rather than to the specified start value.
-
-The formal syntax is given by:
-
-
INTERVAL ::= [START |+START_OFFSET ][%[END |+END_OFFSET ]]
-INTERVALS ::= INTERVAL [,INTERVALS ]
-A few examples follow.
-
- Seek to time 10, read packets until 20 seconds after the found seek
-point, then seek to position 01:30 (1 minute and thirty
-seconds) and read packets until position 01:45.
-
-
- Read only 42 packets after seeking to position 01:23:
-
-
- Read only the first 20 seconds from the start:
-
-
- Read from the start until position 02:30:
-
-
-
-
--show_private_data, -private Show private data, that is data depending on the format of the
-particular shown element.
-This option is enabled by default, but you may need to disable it
-for specific uses, for example when creating XSD-compliant XML output.
-
--show_program_version Show information related to program version.
-
-Version information is printed within a section with name
-"PROGRAM_VERSION".
-
--show_library_versions Show information related to library versions.
-
-Version information for each library is printed within a section with
-name "LIBRARY_VERSION".
-
--show_versions Show information related to program and library versions. This is the
-equivalent of setting both -show_program_version and
--show_library_versions options.
-
--show_pixel_formats Show information about all pixel formats supported by FFmpeg.
-
-Pixel format information for each format is printed within a section
-with name "PIXEL_FORMAT".
-
--bitexact Force bitexact output, useful to produce output which is not dependent
-on the specific build.
-
--i input_file Read input_file .
-
-
-
-
-
4 Writers# TOC
-
-
A writer defines the output format adopted by ffprobe, and will be
-used for printing all the parts of the output.
-
-
A writer may accept one or more arguments, which specify the options
-to adopt. The options are specified as a list of key =value
-pairs, separated by ":".
-
-
All writers support the following options:
-
-
-string_validation, sv Set string validation mode.
-
-The following values are accepted.
-
-‘fail ’
-The writer will fail immediately in case an invalid string (UTF-8)
-sequence or code point is found in the input. This is especially
-useful to validate input metadata.
-
-‘ignore ’
-Any validation error will be ignored. This will result in possibly
-broken output, especially with the json or xml writer.
-
-‘replace ’
-The writer will substitute invalid UTF-8 sequences or code points with
-the string specified with the string_validation_replacement .
-
-
-Default value is ‘replace ’.
-
-string_validation_replacement, svr Set replacement string to use in case string_validation is
-set to ‘replace ’.
-
-In case the option is not specified, the writer will assume the empty
-string, that is it will remove the invalid sequences from the input
-strings.
-
-
-
A description of the currently available writers follows.
-
-
-
4.1 default# TOC
-
Default format.
-
-
Print each section in the form:
-
-
[SECTION]
-key1=val1
-...
-keyN=valN
-[/SECTION]
-
-
-
Metadata tags are printed as a line in the corresponding FORMAT, STREAM or
-PROGRAM_STREAM section, and are prefixed by the string "TAG:".
-
-
A description of the accepted options follows.
-
-
-nokey, nk If set to 1 specify not to print the key of each field. Default value
-is 0.
-
-noprint_wrappers, nw If set to 1 specify not to print the section header and footer.
-Default value is 0.
-
-
-
-
4.2 compact, csv# TOC
-
Compact and CSV format.
-
-
The csv writer is equivalent to compact, but supports
-different defaults.
-
-
Each section is printed on a single line.
-If no option is specifid, the output has the form:
-
-
section|key1=val1| ... |keyN=valN
-
-
-
Metadata tags are printed in the corresponding "format" or "stream"
-section. A metadata tag key, if printed, is prefixed by the string
-"tag:".
-
-
The description of the accepted options follows.
-
-
-item_sep, s Specify the character to use for separating fields in the output line.
-It must be a single printable character, it is "|" by default ("," for
-the csv writer).
-
-nokey, nk If set to 1 specify not to print the key of each field. Its default
-value is 0 (1 for the csv writer).
-
-escape, e Set the escape mode to use, default to "c" ("csv" for the csv
-writer).
-
-It can assume one of the following values:
-
-c Perform C-like escaping. Strings containing a newline (’\n’), carriage
-return (’\r’), a tab (’\t’), a form feed (’\f’), the escaping
-character (’\’) or the item separator character SEP are escaped using C-like fashioned
-escaping, so that a newline is converted to the sequence "\n", a
-carriage return to "\r", ’\’ to "\\" and the separator SEP is
-converted to "\SEP ".
-
-csv Perform CSV-like escaping, as described in RFC4180. Strings
-containing a newline (’\n’), a carriage return (’\r’), a double quote
-(’"’), or SEP are enclosed in double-quotes.
-
-none Perform no escaping.
-
-
-print_section, p Print the section name at the begin of each line if the value is
-1, disable it with value set to 0. Default value is
-1.
-
-
-
-
-
4.3 flat# TOC
-
Flat format.
-
-
A free-form output where each line contains an explicit key=value, such as
-"streams.stream.3.tags.foo=bar". The output is shell escaped, so it can be
-directly embedded in sh scripts as long as the separator character is an
-alphanumeric character or an underscore (see sep_char option).
-
-
The description of the accepted options follows.
-
-
-sep_char, s Separator character used to separate the chapter, the section name, IDs and
-potential tags in the printed field key.
-
-Default value is ’.’.
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
-
INI format output.
-
-
Print output in an INI based format.
-
-
The following conventions are adopted:
-
-
- all key and values are UTF-8
- ’.’ is the subgroup separator
- newline, ’\t’, ’\f’, ’\b’ and the following characters are escaped
- ’\’ is the escape character
- ’#’ is the comment indicator
- ’=’ is the key/value separator
- ’:’ is not used but usually parsed as key/value separator
-
-
-
This writer accepts options as a list of key =value pairs,
-separated by ":".
-
-
The description of the accepted options follows.
-
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
4.5 json# TOC
-
JSON based format.
-
-
Each section is printed using JSON notation.
-
-
The description of the accepted options follows.
-
-
-compact, c If set to 1 enable compact output, that is each section will be
-printed on a single line. Default value is 0.
-
-
-
For more information about JSON, see http://www.json.org/ .
-
-
-
-
XML based format.
-
-
The XML output is described in the XML schema description file
-ffprobe.xsd installed in the FFmpeg datadir.
-
-
An updated version of the schema can be retrieved at the url
-http://www.ffmpeg.org/schema/ffprobe.xsd , which redirects to the
-latest schema committed into the FFmpeg development source code tree.
-
-
Note that the output issued will be compliant to the
-ffprobe.xsd schema only when no special global output options
-(unit , prefix , byte_binary_prefix ,
-sexagesimal etc.) are specified.
-
-
The description of the accepted options follows.
-
-
-fully_qualified, q If set to 1 specify if the output should be fully qualified. Default
-value is 0.
-This is required for generating an XML file which can be validated
-through an XSD file.
-
-xsd_compliant, x If set to 1 perform more checks for ensuring that the output is XSD
-compliant. Default value is 0.
-This option automatically sets fully_qualified to 1.
-
-
-
For more information about the XML format, see
-http://www.w3.org/XML/ .
-
-
-
5 Timecode# TOC
-
-
ffprobe supports Timecode extraction:
-
-
- MPEG1/2 timecode is extracted from the GOP, and is available in the video
-stream details (-show_streams , see timecode ).
-
- MOV timecode is extracted from tmcd track, so is available in the tmcd
-stream metadata (-show_streams , see TAG:timecode ).
-
- DV, GXF and AVI timecodes are available in format metadata
-(-show_format , see TAG:timecode ).
-
-
-
-
-
-
6 See Also# TOC
-
-
ffprobe-all ,
-ffmpeg , ffplay , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
7 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- General Documentation
-
-
-
- General Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 External libraries# TOC
-
-
FFmpeg can be hooked up with a number of external libraries to add support
-for more formats. None of them are used by default, their use has to be
-explicitly requested by passing the appropriate flags to
-./configure.
-
-
-
1.1 OpenJPEG# TOC
-
-
FFmpeg can use the OpenJPEG libraries for encoding/decoding J2K videos. Go to
-http://www.openjpeg.org/ to get the libraries and follow the installation
-instructions. To enable using OpenJPEG in FFmpeg, pass --enable-libopenjpeg to
-./configure .
-
-
-
-
1.2 OpenCORE, VisualOn, and Fraunhofer libraries# TOC
-
-
Spun off Google Android sources, OpenCore, VisualOn and Fraunhofer
-libraries provide encoders for a number of audio codecs.
-
-
-
OpenCORE and VisualOn libraries are under the Apache License 2.0
-(see http://www.apache.org/licenses/LICENSE-2.0 for details), which is
-incompatible to the LGPL version 2.1 and GPL version 2. You have to
-upgrade FFmpeg’s license to LGPL version 3 (or if you have enabled
-GPL components, GPL version 3) by passing --enable-version3 to configure in
-order to use it.
-
-
The Fraunhofer AAC library is licensed under a license incompatible to the GPL
-and is not known to be compatible to the LGPL. Therefore, you have to pass
---enable-nonfree to configure to use it.
-
-
-
1.2.1 OpenCORE AMR# TOC
-
-
FFmpeg can make use of the OpenCORE libraries for AMR-NB
-decoding/encoding and AMR-WB decoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the libraries.
-Then pass --enable-libopencore-amrnb and/or
---enable-libopencore-amrwb to configure to enable them.
-
-
-
1.2.2 VisualOn AAC encoder library# TOC
-
-
FFmpeg can make use of the VisualOn AACenc library for AAC encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libvo-aacenc to configure to enable it.
-
-
-
1.2.3 VisualOn AMR-WB encoder library# TOC
-
-
FFmpeg can make use of the VisualOn AMR-WBenc library for AMR-WB encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libvo-amrwbenc to configure to enable it.
-
-
-
1.2.4 Fraunhofer AAC library# TOC
-
-
FFmpeg can make use of the Fraunhofer AAC library for AAC encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libfdk-aac to configure to enable it.
-
-
-
1.3 LAME# TOC
-
-
FFmpeg can make use of the LAME library for MP3 encoding.
-
-
Go to http://lame.sourceforge.net/ and follow the
-instructions for installing the library.
-Then pass --enable-libmp3lame to configure to enable it.
-
-
-
1.4 TwoLAME# TOC
-
-
FFmpeg can make use of the TwoLAME library for MP2 encoding.
-
-
Go to http://www.twolame.org/ and follow the
-instructions for installing the library.
-Then pass --enable-libtwolame to configure to enable it.
-
-
-
1.5 libvpx# TOC
-
-
FFmpeg can make use of the libvpx library for VP8/VP9 encoding.
-
-
Go to http://www.webmproject.org/ and follow the instructions for
-installing the library. Then pass --enable-libvpx to configure to
-enable it.
-
-
-
1.6 libwavpack# TOC
-
-
FFmpeg can make use of the libwavpack library for WavPack encoding.
-
-
Go to http://www.wavpack.com/ and follow the instructions for
-installing the library. Then pass --enable-libwavpack to configure to
-enable it.
-
-
-
1.7 OpenH264# TOC
-
-
FFmpeg can make use of the OpenH264 library for H.264 encoding.
-
-
Go to http://www.openh264.org/ and follow the instructions for
-installing the library. Then pass --enable-libopenh264 to configure to
-enable it.
-
-
-
1.8 x264# TOC
-
-
FFmpeg can make use of the x264 library for H.264 encoding.
-
-
Go to http://www.videolan.org/developers/x264.html and follow the
-instructions for installing the library. Then pass --enable-libx264 to
-configure to enable it.
-
-
-
-
1.9 x265# TOC
-
-
FFmpeg can make use of the x265 library for HEVC encoding.
-
-
Go to http://x265.org/developers.html and follow the instructions
-for installing the library. Then pass --enable-libx265 to configure
-to enable it.
-
-
-
-
1.10 libilbc# TOC
-
-
iLBC is a narrowband speech codec that has been made freely available
-by Google as part of the WebRTC project. libilbc is a packaging friendly
-copy of the iLBC codec. FFmpeg can make use of the libilbc library for
-iLBC encoding and decoding.
-
-
Go to https://github.com/TimothyGu/libilbc and follow the instructions for
-installing the library. Then pass --enable-libilbc to configure to
-enable it.
-
-
-
1.11 libzvbi# TOC
-
-
libzvbi is a VBI decoding library which can be used by FFmpeg to decode DVB
-teletext pages and DVB teletext subtitles.
-
-
Go to http://sourceforge.net/projects/zapping/ and follow the instructions for
-installing the library. Then pass --enable-libzvbi to configure to
-enable it.
-
-
-
-
1.12 AviSynth# TOC
-
-
FFmpeg can read AviSynth scripts as input. To enable support, pass
---enable-avisynth to configure. The correct headers are
-included in compat/avisynth/, which allows the user to enable support
-without needing to search for these headers themselves.
-
-
For Windows, supported AviSynth variants are
-AviSynth 2.5 or 2.6 for 32-bit builds and
-AviSynth+ 0.1 for 32-bit and 64-bit builds.
-
-
For Linux and OS X, the supported AviSynth variant is
-AvxSynth .
-
-
-
AviSynth and AvxSynth are loaded dynamically. Distributors can build FFmpeg
-with --enable-avisynth, and the binaries will work regardless of the
-end user having AviSynth or AvxSynth installed - they’ll only need to be
-installed to use AviSynth scripts (obviously).
-
-
-
-
2 Supported File Formats, Codecs or Features# TOC
-
-
You can use the -formats and -codecs options to have an exhaustive list.
-
-
-
2.1 File Formats# TOC
-
-
FFmpeg supports the following file formats through the libavformat
-library:
-
-
-Name Encoding Decoding Comments 4xm X 4X Technologies format, used in some games. 8088flex TMV X ACT Voice X contains G.729 audio Adobe Filmstrip X X Audio IFF (AIFF) X X American Laser Games MM X Multimedia format used in games like Mad Dog McCree. 3GPP AMR X X Amazing Studio Packed Animation File X Multimedia format used in game Heart Of Darkness. Apple HTTP Live Streaming X Artworx Data Format X ADP X Audio format used on the Nintendo Gamecube. AFC X Audio format used on the Nintendo Gamecube. ASF X X AST X X Audio format used on the Nintendo Wii. AVI X X AviSynth X AVR X Audio format used on Mac. AVS X Multimedia format used by the Creature Shock game. Beam Software SIFF X Audio and video format used in some games by Beam Software. Bethesda Softworks VID X Used in some games from Bethesda Softworks. Binary text X Bink X Multimedia format used by many games. Bitmap Brothers JV X Used in Z and Z95 games. Brute Force & Ignorance X Used in the game Flash Traffic: City of Angels. BRSTM X Audio format used on the Nintendo Wii. BWF X X CRI ADX X X Audio-only format used in console video games. Discworld II BMV X Interplay C93 X Used in the game Cyberia from Interplay. Delphine Software International CIN X Multimedia format used by Delphine Software games. CD+G X Video format used by CD+G karaoke disks Phantom Cine X Commodore CDXL X Amiga CD video format Core Audio Format X X Apple Core Audio Format CRC testing format X Creative Voice X X Created for the Sound Blaster Pro. CRYO APC X Audio format used in some games by CRYO Interactive Entertainment. D-Cinema audio X X Deluxe Paint Animation X DFA X This format is used in Chronomaster game DSD Stream File (DSF) X DV video X X DXA X This format is used in the non-Windows version of the Feeble Files
- game and different game cutscenes repacked for use with ScummVM. Electronic Arts cdata X Electronic Arts Multimedia X Used in various EA games; files have extensions like WVE and UV2. Ensoniq Paris Audio File X FFM (FFserver live feed) X X Flash (SWF) X X Flash 9 (AVM2) X X Only embedded audio is decoded. FLI/FLC/FLX animation X .fli/.flc files Flash Video (FLV) X X Macromedia Flash video files framecrc testing format X FunCom ISS X Audio format used in various games from FunCom like The Longest Journey. G.723.1 X X G.729 BIT X X G.729 raw X GIF Animation X X GXF X X General eXchange Format SMPTE 360M, used by Thomson Grass Valley
- playout servers. HNM X Only version 4 supported, used in some games from Cryo Interactive iCEDraw File X ICO X X Microsoft Windows ICO id Quake II CIN video X id RoQ X X Used in Quake III, Jedi Knight 2 and other computer games. IEC61937 encapsulation X X IFF X Interchange File Format iLBC X X Interplay MVE X Format used in various Interplay computer games. IV8 X A format generated by IndigoVision 8000 video server. IVF (On2) X X A format used by libvpx IRCAM X X LATM X X LMLM4 X Used by Linux Media Labs MPEG-4 PCI boards LOAS X contains LATM multiplexed AAC audio LRC X X LVF X LXF X VR native stream format, used by Leitch/Harris’ video servers. Magic Lantern Video (MLV) X Matroska X X Matroska audio X FFmpeg metadata X X Metadata in text format. MAXIS XA X Used in Sim City 3000; file extension .xa. MD Studio X Metal Gear Solid: The Twin Snakes X Megalux Frame X Used by Megalux Ultimate Paint Mobotix .mxg X Monkey’s Audio X Motion Pixels MVI X MOV/QuickTime/MP4 X X 3GP, 3GP2, PSP, iPod variants supported MP2 X X MP3 X X MPEG-1 System X X muxed audio and video, VCD format supported MPEG-PS (program stream) X X also known as VOB file, SVCD and DVD format supported MPEG-TS (transport stream) X X also known as DVB Transport Stream MPEG-4 X X MPEG-4 is a variant of QuickTime. Mirillis FIC video X No cursor rendering. MIME multipart JPEG X MSN TCP webcam X Used by MSN Messenger webcam streams. MTV X Musepack X Musepack SV8 X Material eXchange Format (MXF) X X SMPTE 377M, used by D-Cinema, broadcast industry. Material eXchange Format (MXF), D-10 Mapping X X SMPTE 386M, D-10/IMX Mapping. NC camera feed X NC (AVIP NC4600) camera streams NIST SPeech HEader REsources X NTT TwinVQ (VQF) X Nippon Telegraph and Telephone Corporation TwinVQ. Nullsoft Streaming Video X NuppelVideo X NUT X X NUT Open Container Format Ogg X X Playstation Portable PMP X Portable Voice Format X TechnoTrend PVA X Used by TechnoTrend DVB PCI boards. QCP X raw ADTS (AAC) X X raw AC-3 X X raw Chinese AVS video X X raw CRI ADX X X raw Dirac X X raw DNxHD X X raw DTS X X raw DTS-HD X raw E-AC-3 X X raw FLAC X X raw GSM X raw H.261 X X raw H.263 X X raw H.264 X X raw HEVC X X raw Ingenient MJPEG X raw MJPEG X X raw MLP X raw MPEG X raw MPEG-1 X raw MPEG-2 X raw MPEG-4 X X raw NULL X raw video X X raw id RoQ X raw Shorten X raw TAK X raw TrueHD X X raw VC-1 X X raw PCM A-law X X raw PCM mu-law X X raw PCM signed 8 bit X X raw PCM signed 16 bit big-endian X X raw PCM signed 16 bit little-endian X X raw PCM signed 24 bit big-endian X X raw PCM signed 24 bit little-endian X X raw PCM signed 32 bit big-endian X X raw PCM signed 32 bit little-endian X X raw PCM unsigned 8 bit X X raw PCM unsigned 16 bit big-endian X X raw PCM unsigned 16 bit little-endian X X raw PCM unsigned 24 bit big-endian X X raw PCM unsigned 24 bit little-endian X X raw PCM unsigned 32 bit big-endian X X raw PCM unsigned 32 bit little-endian X X raw PCM floating-point 32 bit big-endian X X raw PCM floating-point 32 bit little-endian X X raw PCM floating-point 64 bit big-endian X X raw PCM floating-point 64 bit little-endian X X RDT X REDCODE R3D X File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio. RealMedia X X Redirector X RedSpark X Renderware TeXture Dictionary X RL2 X Audio and video format used in some games by Entertainment Software Partners. RPL/ARMovie X Lego Mindstorms RSO X X RSD X RTMP X X Output is performed by publishing stream to RTMP server RTP X X RTSP X X SAP X X SBG X SDP X Sega FILM/CPK X Used in many Sega Saturn console games. Silicon Graphics Movie X Sierra SOL X .sol files used in Sierra Online games. Sierra VMD X Used in Sierra CD-ROM games. Smacker X Multimedia format used by many games. SMJPEG X X Used in certain Loki game ports. Smush X Multimedia format used in some LucasArts games. Sony OpenMG (OMA) X X Audio format used in Sony Sonic Stage and Sony Vegas. Sony PlayStation STR X Sony Wave64 (W64) X X SoX native format X X SUN AU format X X SUP raw PGS subtitles X Text files X THP X Used on the Nintendo GameCube. Tiertex Limited SEQ X Tiertex .seq files used in the DOS CD-ROM version of the game Flashback. True Audio X VC-1 test bitstream X X Vivo X WAV X X WavPack X X WebM X X Windows Televison (WTV) X X Wing Commander III movie X Multimedia format used in Origin’s Wing Commander III computer game. Westwood Studios audio X Multimedia format used in Westwood Studios games. Westwood Studios VQA X Multimedia format used in Westwood Studios games. XMV X Microsoft video container used in Xbox games. xWMA X Microsoft audio container used by XAudio 2. eXtended BINary text (XBIN) X YUV4MPEG pipe X X Psygnosis YOP X
-
-
X means that encoding (resp. decoding) is supported.
-
-
-
2.2 Image Formats# TOC
-
-
FFmpeg can read and write images for each frame of a video sequence. The
-following image formats are supported:
-
-
-Name Encoding Decoding Comments .Y.U.V X X one raw file per component Alias PIX X X Alias/Wavefront PIX image format animated GIF X X BMP X X Microsoft BMP image BRender PIX X Argonaut BRender 3D engine image format. DPX X X Digital Picture Exchange EXR X OpenEXR JPEG X X Progressive JPEG is not supported. JPEG 2000 X X JPEG-LS X X LJPEG X Lossless JPEG PAM X X PAM is a PNM extension with alpha support. PBM X X Portable BitMap image PCX X X PC Paintbrush PGM X X Portable GrayMap image PGMYUV X X PGM with U and V components in YUV 4:2:0 PIC X Pictor/PC Paint PNG X X PPM X X Portable PixelMap image PTX X V.Flash PTX format SGI X X SGI RGB image format Sun Rasterfile X X Sun RAS image format TIFF X X YUV, JPEG and some extension is not supported yet. Truevision Targa X X Targa (.TGA) image format WebP E X WebP image format, encoding supported through external library libwebp XBM X X X BitMap image format XFace X X X-Face image format XWD X X X Window Dump image format
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.3 Video Codecs# TOC
-
-
-Name Encoding Decoding Comments 4X Movie X Used in certain computer games. 8088flex TMV X A64 multicolor X Creates video suitable to be played on a commodore 64 (multicolor mode). Amazing Studio PAF Video X American Laser Games MM X Used in games like Mad Dog McCree. AMV Video X X Used in Chinese MP3 players. ANSI/ASCII art X Apple Intermediate Codec X Apple MJPEG-B X Apple ProRes X X Apple QuickDraw X fourcc: qdrw Asus v1 X X fourcc: ASV1 Asus v2 X X fourcc: ASV2 ATI VCR1 X fourcc: VCR1 ATI VCR2 X fourcc: VCR2 Auravision Aura X Auravision Aura 2 X Autodesk Animator Flic video X Autodesk RLE X fourcc: AASC Avid 1:1 10-bit RGB Packer X X fourcc: AVrp AVS (Audio Video Standard) video X Video encoding used by the Creature Shock game. AYUV X X Microsoft uncompressed packed 4:4:4:4 Beam Software VB X Bethesda VID video X Used in some games from Bethesda Softworks. Bink Video X Bitmap Brothers JV video X y41p Brooktree uncompressed 4:1:1 12-bit X X Brute Force & Ignorance X Used in the game Flash Traffic: City of Angels. C93 video X Codec used in Cyberia game. CamStudio X fourcc: CSCD CD+G X Video codec for CD+G karaoke disks CDXL X Amiga CD video codec Chinese AVS video E X AVS1-P2, JiZhun profile, encoding through external library libxavs Delphine Software International CIN video X Codec used in Delphine Software International games. Discworld II BMV Video X Canopus Lossless Codec X Cinepak X Cirrus Logic AccuPak X X fourcc: CLJR CPiA Video Format X Creative YUV (CYUV) X DFA X Codec used in Chronomaster game. Dirac E X supported through external library libschroedinger Deluxe Paint Animation X DNxHD X X aka SMPTE VC3 Duck TrueMotion 1.0 X fourcc: DUCK Duck TrueMotion 2.0 X fourcc: TM20 DV (Digital Video) X X Dxtory capture format X Feeble Files/ScummVM DXA X Codec originally used in Feeble Files game. Electronic Arts CMV video X Used in NHL 95 game. Electronic Arts Madcow video X Electronic Arts TGV video X Electronic Arts TGQ video X Electronic Arts TQI video X Escape 124 X Escape 130 X FFmpeg video codec #1 X X lossless codec (fourcc: FFV1) Flash Screen Video v1 X X fourcc: FSV1 Flash Screen Video v2 X X Flash Video (FLV) X X Sorenson H.263 used in Flash Forward Uncompressed X Fraps X Go2Webinar X fourcc: G2M4 H.261 X X H.263 / H.263-1996 X X H.263+ / H.263-1998 / H.263 version 2 X X H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 E X encoding supported through external library libx264 and OpenH264 HEVC X X encoding supported through the external library libx265 HNM version 4 X HuffYUV X X HuffYUV FFmpeg variant X X IBM Ultimotion X fourcc: ULTI id Cinematic video X Used in Quake II. id RoQ video X X Used in Quake III, Jedi Knight 2, other computer games. IFF ILBM X IFF interleaved bitmap IFF ByteRun1 X IFF run length encoded bitmap Intel H.263 X Intel Indeo 2 X Intel Indeo 3 X Intel Indeo 4 X Intel Indeo 5 X Interplay C93 X Used in the game Cyberia from Interplay. Interplay MVE video X Used in Interplay .MVE files. J2K X X Karl Morton’s video codec X Codec used in Worms games. Kega Game Video (KGV1) X Kega emulator screen capture codec. Lagarith X LCL (LossLess Codec Library) MSZH X LCL (LossLess Codec Library) ZLIB E E LOCO X LucasArts SANM/Smush X Used in LucasArts games / SMUSH animations. lossless MJPEG X X Microsoft ATC Screen X Also known as Microsoft Screen 3. Microsoft Expression Encoder Screen X Also known as Microsoft Titanium Screen 2. Microsoft RLE X Microsoft Screen 1 X Also known as Windows Media Video V7 Screen. Microsoft Screen 2 X Also known as Windows Media Video V9 Screen. Microsoft Video 1 X Mimic X Used in MSN Messenger Webcam streams. Miro VideoXL X fourcc: VIXL MJPEG (Motion JPEG) X X Mobotix MxPEG video X Motion Pixels video X MPEG-1 video X X MPEG-2 video X X MPEG-4 part 2 X X libxvidcore can be used alternatively for encoding. MPEG-4 part 2 Microsoft variant version 1 X MPEG-4 part 2 Microsoft variant version 2 X X MPEG-4 part 2 Microsoft variant version 3 X X Nintendo Gamecube THP video X NuppelVideo/RTjpeg X Video encoding used in NuppelVideo files. On2 VP3 X still experimental On2 VP5 X fourcc: VP50 On2 VP6 X fourcc: VP60,VP61,VP62 On2 VP7 X fourcc: VP70,VP71 VP8 E X fourcc: VP80, encoding supported through external library libvpx VP9 E X encoding supported through external library libvpx Pinnacle TARGA CineWave YUV16 X fourcc: Y216 Prores X fourcc: apch,apcn,apcs,apco Q-team QPEG X fourccs: QPEG, Q1.0, Q1.1 QuickTime 8BPS video X QuickTime Animation (RLE) video X X fourcc: ’rle ’ QuickTime Graphics (SMC) X fourcc: ’smc ’ QuickTime video (RPZA) X fourcc: rpza R10K AJA Kona 10-bit RGB Codec X X R210 Quicktime Uncompressed RGB 10-bit X X Raw Video X X RealVideo 1.0 X X RealVideo 2.0 X X RealVideo 3.0 X still far from ideal RealVideo 4.0 X Renderware TXD (TeXture Dictionary) X Texture dictionaries used by the Renderware Engine. RL2 video X used in some games by Entertainment Software Partners Sierra VMD video X Used in Sierra VMD files. Silicon Graphics Motion Video Compressor 1 (MVC1) X Silicon Graphics Motion Video Compressor 2 (MVC2) X Silicon Graphics RLE 8-bit video X Smacker video X Video encoding used in Smacker. SMPTE VC-1 X Snow X X experimental wavelet codec (fourcc: SNOW) Sony PlayStation MDEC (Motion DECoder) X Sorenson Vector Quantizer 1 X X fourcc: SVQ1 Sorenson Vector Quantizer 3 X fourcc: SVQ3 Sunplus JPEG (SP5X) X fourcc: SP5X TechSmith Screen Capture Codec X fourcc: TSCC TechSmith Screen Capture Codec 2 X fourcc: TSC2 Theora E X encoding supported through external library libtheora Tiertex Limited SEQ video X Codec used in DOS CD-ROM FlashBack game. Ut Video X X v210 QuickTime uncompressed 4:2:2 10-bit X X v308 QuickTime uncompressed 4:4:4 X X v408 QuickTime uncompressed 4:4:4:4 X X v410 QuickTime uncompressed 4:4:4 10-bit X X VBLE Lossless Codec X VMware Screen Codec / VMware Video X Codec used in videos captured by VMware. Westwood Studios VQA (Vector Quantized Animation) video X Windows Media Image X Windows Media Video 7 X X Windows Media Video 8 X X Windows Media Video 9 X not completely working Wing Commander III / Xan X Used in Wing Commander III .MVE files. Wing Commander IV / Xan X Used in Wing Commander IV. Winnov WNV1 X WMV7 X X YAMAHA SMAF X X Psygnosis YOP Video X yuv4 X X libquicktime uncompressed packed 4:2:0 ZeroCodec Lossless Video X ZLIB X X part of LCL, encoder experimental Zip Motion Blocks Video X X Encoder works only in PAL8.
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.4 Audio Codecs# TOC
-
-
-Name Encoding Decoding Comments 8SVX exponential X 8SVX fibonacci X AAC+ E X encoding supported through external library libaacplus AAC E X encoding supported through external library libfaac and libvo-aacenc AC-3 IX IX ADPCM 4X Movie X ADPCM CDROM XA X ADPCM Creative Technology X 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2 ADPCM Electronic Arts X Used in various EA titles. ADPCM Electronic Arts Maxis CDROM XS X Used in Sim City 3000. ADPCM Electronic Arts R1 X ADPCM Electronic Arts R2 X ADPCM Electronic Arts R3 X ADPCM Electronic Arts XAS X ADPCM G.722 X X ADPCM G.726 X X ADPCM IMA AMV X Used in AMV files ADPCM IMA Electronic Arts EACS X ADPCM IMA Electronic Arts SEAD X ADPCM IMA Funcom X ADPCM IMA QuickTime X X ADPCM IMA Loki SDL MJPEG X ADPCM IMA WAV X X ADPCM IMA Westwood X ADPCM ISS IMA X Used in FunCom games. ADPCM IMA Dialogic X ADPCM IMA Duck DK3 X Used in some Sega Saturn console games. ADPCM IMA Duck DK4 X Used in some Sega Saturn console games. ADPCM IMA Radical X ADPCM Microsoft X X ADPCM MS IMA X X ADPCM Nintendo Gamecube AFC X ADPCM Nintendo Gamecube DTK X ADPCM Nintendo Gamecube THP X ADPCM QT IMA X X ADPCM SEGA CRI ADX X X Used in Sega Dreamcast games. ADPCM Shockwave Flash X X ADPCM Sound Blaster Pro 2-bit X ADPCM Sound Blaster Pro 2.6-bit X ADPCM Sound Blaster Pro 4-bit X ADPCM VIMA Used in LucasArts SMUSH animations. ADPCM Westwood Studios IMA X Used in Westwood Studios games like Command and Conquer. ADPCM Yamaha X X AMR-NB E X encoding supported through external library libopencore-amrnb AMR-WB E X encoding supported through external library libvo-amrwbenc Amazing Studio PAF Audio X Apple lossless audio X X QuickTime fourcc ’alac’ ATRAC1 X ATRAC3 X ATRAC3+ X Bink Audio X Used in Bink and Smacker files in many games. CELT E decoding supported through external library libcelt Delphine Software International CIN audio X Codec used in Delphine Software International games. Discworld II BMV Audio X COOK X All versions except 5.1 are supported. DCA (DTS Coherent Acoustics) X X DPCM id RoQ X X Used in Quake III, Jedi Knight 2 and other computer games. DPCM Interplay X Used in various Interplay computer games. DPCM Sierra Online X Used in Sierra Online game audio files. DPCM Sol X DPCM Xan X Used in Origin’s Wing Commander IV AVI files. DSD (Direct Stream Digitial), least significant bit first X DSD (Direct Stream Digitial), most significant bit first X DSD (Direct Stream Digitial), least significant bit first, planar X DSD (Direct Stream Digitial), most significant bit first, planar X DSP Group TrueSpeech X DV audio X Enhanced AC-3 X X EVRC (Enhanced Variable Rate Codec) X FLAC (Free Lossless Audio Codec) X IX G.723.1 X X G.729 X GSM E X encoding supported through external library libgsm GSM Microsoft variant E X encoding supported through external library libgsm IAC (Indeo Audio Coder) X iLBC (Internet Low Bitrate Codec) E E encoding and decoding supported through external library libilbc IMC (Intel Music Coder) X MACE (Macintosh Audio Compression/Expansion) 3:1 X MACE (Macintosh Audio Compression/Expansion) 6:1 X MLP (Meridian Lossless Packing) X Used in DVD-Audio discs. Monkey’s Audio X MP1 (MPEG audio layer 1) IX MP2 (MPEG audio layer 2) IX IX encoding supported also through external library TwoLAME MP3 (MPEG audio layer 3) E IX encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported MPEG-4 Audio Lossless Coding (ALS) X Musepack SV7 X Musepack SV8 X Nellymoser Asao X X On2 AVC (Audio for Video Codec) X Opus E E supported through external library libopus PCM A-law X X PCM mu-law X X PCM signed 8-bit planar X X PCM signed 16-bit big-endian planar X X PCM signed 16-bit little-endian planar X X PCM signed 24-bit little-endian planar X X PCM signed 32-bit little-endian planar X X PCM 32-bit floating point big-endian X X PCM 32-bit floating point little-endian X X PCM 64-bit floating point big-endian X X PCM 64-bit floating point little-endian X X PCM D-Cinema audio signed 24-bit X X PCM signed 8-bit X X PCM signed 16-bit big-endian X X PCM signed 16-bit little-endian X X PCM signed 24-bit big-endian X X PCM signed 24-bit little-endian X X PCM signed 32-bit big-endian X X PCM signed 32-bit little-endian X X PCM signed 16/20/24-bit big-endian in MPEG-TS X PCM unsigned 8-bit X X PCM unsigned 16-bit big-endian X X PCM unsigned 16-bit little-endian X X PCM unsigned 24-bit big-endian X X PCM unsigned 24-bit little-endian X X PCM unsigned 32-bit big-endian X X PCM unsigned 32-bit little-endian X X PCM Zork X QCELP / PureVoice X QDesign Music Codec 2 X There are still some distortions. RealAudio 1.0 (14.4K) X X Real 14400 bit/s codec RealAudio 2.0 (28.8K) X Real 28800 bit/s codec RealAudio 3.0 (dnet) IX X Real low bitrate AC-3 codec RealAudio Lossless X RealAudio SIPR / ACELP.NET X Shorten X Sierra VMD audio X Used in Sierra VMD files. Smacker audio X SMPTE 302M AES3 audio X X Sonic X X experimental codec Sonic lossless X X experimental codec Speex E E supported through external library libspeex TAK (Tom’s lossless Audio Kompressor) X True Audio (TTA) X X TrueHD X Used in HD-DVD and Blu-Ray discs. TwinVQ (VQF flavor) X VIMA X Used in LucasArts SMUSH animations. Vorbis E X A native but very primitive encoder exists. Voxware MetaSound X WavPack X X Westwood Audio (SND1) X Windows Media Audio 1 X X Windows Media Audio 2 X X Windows Media Audio Lossless X Windows Media Audio Pro X Windows Media Audio Voice X
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
I means that an integer-only version is available, too (ensures high
-performance on systems without hardware floating point support).
-
-
-
2.5 Subtitle Formats# TOC
-
-
-Name Muxing Demuxing Encoding Decoding 3GPP Timed Text X X AQTitle X X DVB X X X X DVB teletext X E DVD X X X X JACOsub X X X MicroDVD X X X MPL2 X X MPsub (MPlayer) X X PGS X PJS (Phoenix) X X RealText X X SAMI X X Spruce format (STL) X X SSA/ASS X X X X SubRip (SRT) X X X X SubViewer v1 X X SubViewer X X TED Talks captions X X VobSub (IDX+SUB) X X VPlayer X X WebVTT X X X X XSUB X X
-
-
X means that the feature is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.6 Network Protocols# TOC
-
-
-Name Support file X FTP X Gopher X HLS X HTTP X HTTPS X Icecast X MMSH X MMST X pipe X RTMP X RTMPE X RTMPS X RTMPT X RTMPTE X RTMPTS X RTP X SAMBA E SCTP X SFTP E TCP X TLS X UDP X
-
-
X means that the protocol is supported.
-
-
E means that support is provided through an external library.
-
-
-
-
2.7 Input/Output Devices# TOC
-
-
-Name Input Output ALSA X X BKTR X caca X DV1394 X Lavfi virtual device X Linux framebuffer X X JACK X LIBCDIO X LIBDC1394 X OpenAL X OpenGL X OSS X X PulseAudio X X SDL X Video4Linux2 X X VfW capture X X11 grabbing X Win32 grabbing X
-
-
X means that input/output is supported.
-
-
-
2.8 Timecode# TOC
-
-
-Codec/format Read Write AVI X X DV X X GXF X X MOV X X MPEG1/2 X X MXF X X
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Using git to develop FFmpeg
-
-
-
- Using git to develop FFmpeg
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Introduction# TOC
-
-
This document aims in giving some quick references on a set of useful git
-commands. You should always use the extensive and detailed documentation
-provided directly by git:
-
-
-
-
shows you the available subcommands,
-
-
-
git <command> --help
-man git-<command>
-
-
-
shows information about the subcommand <command>.
-
-
Additional information could be found on the
-Git Reference website
-
-
For more information about the Git project, visit the
-
-
Git website
-
-
Consult these resources whenever you have problems, they are quite exhaustive.
-
-
What follows now is a basic introduction to Git and some FFmpeg-specific
-guidelines to ease the contribution to the project
-
-
-
2 Basics Usage# TOC
-
-
-
2.1 Get GIT# TOC
-
-
You can get git from http://git-scm.com/
-Most distribution and operating system provide a package for it.
-
-
-
-
2.2 Cloning the source tree# TOC
-
-
-
git clone git://source.ffmpeg.org/ffmpeg <target>
-
-
-
This will put the FFmpeg sources into the directory <target> .
-
-
-
git clone git@source.ffmpeg.org:ffmpeg <target>
-
-
-
This will put the FFmpeg sources into the directory <target> and let
-you push back your changes to the remote repository.
-
-
Make sure that you do not have Windows line endings in your checkouts,
-otherwise you may experience spurious compilation failures. One way to
-achieve this is to run
-
-
-
git config --global core.autocrlf false
-
-
-
-
-
2.3 Updating the source tree to the latest revision# TOC
-
-
-
-
pulls in the latest changes from the tracked branch. The tracked branch
-can be remote. By default the master branch tracks the branch master in
-the remote origin.
-
-
-
--rebase (see below) is recommended.
-
-
-
2.4 Rebasing your local branches# TOC
-
-
-
-
fetches the changes from the main repository and replays your local commits
-over it. This is required to keep all your local changes at the top of
-FFmpeg’s master tree. The master tree will reject pushes with merge commits.
-
-
-
-
2.5 Adding/removing files/directories# TOC
-
-
-
git add [-A] <filename/dirname>
-git rm [-r] <filename/dirname>
-
-
-
GIT needs to get notified of all changes you make to your working
-directory that makes files appear or disappear.
-Line moves across files are automatically tracked.
-
-
-
-
2.6 Showing modifications# TOC
-
-
-
git diff <filename(s)>
-
-
-
will show all local modifications in your working directory as unified diff.
-
-
-
-
2.7 Inspecting the changelog# TOC
-
-
-
-
You may also use the graphical tools like gitview or gitk or the web
-interface available at http://source.ffmpeg.org/
-
-
-
2.8 Checking source tree status# TOC
-
-
-
-
detects all the changes you made and lists what actions will be taken in case
-of a commit (additions, modifications, deletions, etc.).
-
-
-
-
2.9 Committing# TOC
-
-
-
-
to double check your changes before committing them to avoid trouble later
-on. All experienced developers do this on each and every commit, no matter
-how small.
-Every one of them has been saved from looking like a fool by this many times.
-It’s very easy for stray debug output or cosmetic modifications to slip in,
-please avoid problems through this extra level of scrutiny.
-
-
For cosmetics-only commits you should get (almost) empty output from
-
-
-
git diff -w -b <filename(s)>
-
-
-
Also check the output of
-
-
-
-
to make sure you don’t have untracked files or deletions.
-
-
-
git add [-i|-p|-A] <filenames/dirnames>
-
-
-
Make sure you have told git your name and email address
-
-
-
git config --global user.name "My Name"
-git config --global user.email my@email.invalid
-
-
-
Use –global to set the global configuration for all your git checkouts.
-
-
Git will select the changes to the files for commit. Optionally you can use
-the interactive or the patch mode to select hunk by hunk what should be
-added to the commit.
-
-
-
-
-
Git will commit the selected changes to your current local branch.
-
-
You will be prompted for a log message in an editor, which is either
-set in your personal configuration file through
-
-
-
git config --global core.editor
-
-
-
or set by one of the following environment variables:
-GIT_EDITOR , VISUAL or EDITOR .
-
-
Log messages should be concise but descriptive. Explain why you made a change,
-what you did will be obvious from the changes themselves most of the time.
-Saying just "bug fix" or "10l" is bad. Remember that people of varying skill
-levels look at and educate themselves while reading through your code. Don’t
-include filenames in log messages, Git provides that information.
-
-
Possibly make the commit message have a terse, descriptive first line, an
-empty line and then a full description. The first line will be used to name
-the patch by git format-patch.
-
-
-
2.10 Preparing a patchset# TOC
-
-
-
git format-patch <commit> [-o directory]
-
-
-
will generate a set of patches for each commit between <commit> and
-current HEAD . E.g.
-
-
-
git format-patch origin/master
-
-
-
will generate patches for all commits on current branch which are not
-present in upstream.
-A useful shortcut is also
-
-
-
-
which will generate patches from last n commits.
-By default the patches are created in the current directory.
-
-
-
2.11 Sending patches for review# TOC
-
-
-
git send-email <commit list|directory>
-
-
-
will send the patches created by git format-patch or directly
-generates them. All the email fields can be configured in the global/local
-configuration or overridden by command line.
-Note that this tool must often be installed separately (e.g. git-email
-package on Debian-based distros).
-
-
-
-
2.12 Renaming/moving/copying files or contents of files# TOC
-
-
Git automatically tracks such changes, making those normal commits.
-
-
-
mv/cp path/file otherpath/otherfile
-git add [-A] .
-git commit
-
-
-
-
-
3 Git configuration# TOC
-
-
In order to simplify a few workflows, it is advisable to configure both
-your personal Git installation and your local FFmpeg repository.
-
-
-
3.1 Personal Git installation# TOC
-
-
Add the following to your ~/.gitconfig to help git send-email
-and git format-patch detect renames:
-
-
-
[diff]
- renames = copy
-
-
-
-
3.2 Repository configuration# TOC
-
-
In order to have git send-email automatically send patches
-to the ffmpeg-devel mailing list, add the following stanza
-to /path/to/ffmpeg/repository/.git/config :
-
-
-
[sendemail]
- to = ffmpeg-devel@ffmpeg.org
-
-
-
-
4 FFmpeg specific# TOC
-
-
-
4.1 Reverting broken commits# TOC
-
-
-
-
git reset will uncommit the changes till <commit> rewriting
-the current branch history.
-
-
-
-
allows one to amend the last commit details quickly.
-
-
-
git rebase -i origin/master
-
-
-
will replay local commits over the main repository allowing to edit, merge
-or remove some of them in the process.
-
-
-
git reset, git commit --amend and git rebase
-rewrite history, so you should use them ONLY on your local or topic branches.
-The main repository will reject those changes.
-
-
-
-
git revert will generate a revert commit. This will not make the
-faulty commit disappear from the history.
-
-
-
4.2 Pushing changes to remote trees# TOC
-
-
-
-
Will push the changes to the default remote (origin ).
-Git will prevent you from pushing changes if the local and remote trees are
-out of sync. Refer to and to sync the local tree.
-
-
-
git remote add <name> <url>
-
-
-
Will add additional remote with a name reference, it is useful if you want
-to push your local branch for review on a remote host.
-
-
-
git push <remote> <refspec>
-
-
-
Will push the changes to the <remote> repository.
-Omitting <refspec> makes git push update all the remote
-branches matching the local ones.
-
-
-
4.3 Finding a specific svn revision# TOC
-
-
Since version 1.7.1 git supports :/foo syntax for specifying commits
-based on a regular expression. see man gitrevisions
-
-
-
git show :/'as revision 23456'
-
-
-
will show the svn changeset r23456 . With older git versions searching in
-the git log output is the easiest option (especially if a pager with
-search capabilities is used).
-This commit can be checked out with
-
-
-
git checkout -b svn_23456 :/'as revision 23456'
-
-
-
or for git < 1.7.1 with
-
-
-
git checkout -b svn_23456 $SHA1
-
-
-
where $SHA1 is the commit hash from the git log output.
-
-
-
-
5 pre-push checklist# TOC
-
-
Once you have a set of commits that you feel are ready for pushing,
-work through the following checklist to doublecheck everything is in
-proper order. This list tries to be exhaustive. In case you are just
-pushing a typo in a comment, some of the steps may be unnecessary.
-Apply your common sense, but if in doubt, err on the side of caution.
-
-
First, make sure that the commits and branches you are going to push
-match what you want pushed and that nothing is missing, extraneous or
-wrong. You can see what will be pushed by running the git push command
-with –dry-run first. And then inspecting the commits listed with
-git log -p 1234567..987654. The git status command
-may help in finding local changes that have been forgotten to be added.
-
-
Next let the code pass through a full run of our testsuite.
-
-
- make distclean
- /path/to/ffmpeg/configure
- make check
- if fate fails due to missing samples run make fate-rsync and retry
-
-
-
Make sure all your changes have been checked before pushing them, the
-testsuite only checks against regressions and that only to some extend. It does
-obviously not check newly added features/code to be working unless you have
-added a test for that (which is recommended).
-
-
Also note that every single commit should pass the test suite, not just
-the result of a series of patches.
-
-
Once everything passed, push the changes to your public ffmpeg clone and post a
-merge request to ffmpeg-devel. You can also push them directly but this is not
-recommended.
-
-
-
6 Server Issues# TOC
-
-
Contact the project admins root@ffmpeg.org if you have technical
-problems with the GIT server.
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavcodec Documentation
-
-
-
- Libavcodec Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavcodec library provides a generic encoding/decoding framework
-and contains multiple decoders and encoders for audio, video and
-subtitle streams, and several bitstream filters.
-
-
The shared architecture provides various services ranging from bit
-stream I/O to DSP optimizations, and makes it suitable for
-implementing robust and fast codecs as well as for experimentation.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-codecs , bitstream-filters ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavdevice Documentation
-
-
-
- Libavdevice Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavdevice library provides a generic framework for grabbing from
-and rendering to many common multimedia input/output devices, and
-supports several input and output devices, including Video4Linux2,
-VfW, DShow, and ALSA.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-devices ,
-libavutil , libavcodec , libavformat
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavfilter Documentation
-
-
-
- Libavfilter Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavfilter library provides a generic audio/video filtering
-framework containing several filters, sources and sinks.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-filters ,
-libavutil , libswscale , libswresample ,
-libavcodec , libavformat , libavdevice
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavformat Documentation
-
-
-
- Libavformat Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavformat library provides a generic framework for multiplexing
-and demultiplexing (muxing and demuxing) audio, video and subtitle
-streams. It encompasses multiple muxers and demuxers for multimedia
-container formats.
-
-
It also supports several input and output protocols to access a media
-resource.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-formats , ffmpeg-protocols ,
-libavutil , libavcodec
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavutil Documentation
-
-
-
- Libavutil Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavutil library is a utility library to aid portable
-multimedia programming. It contains safe portable string functions,
-random number generators, data structures, additional mathematics
-functions, cryptography and multimedia related functionality (like
-enumerations for pixel and sample formats). It is not a library for
-code needed by both libavcodec and libavformat.
-
-
The goals for this library is to be:
-
-
-Modular It should have few interdependencies and the possibility of disabling individual
-parts during ./configure.
-
-Small Both sources and objects should be small.
-
-Efficient It should have low CPU and memory usage.
-
-Useful It should avoid useless features that almost no one needs.
-
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-utils
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libswresample Documentation
-
-
-
- Libswresample Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libswresample library performs highly optimized audio resampling,
-rematrixing and sample format conversion operations.
-
-
Specifically, this library performs the following conversions:
-
-
- Resampling : is the process of changing the audio rate, for
-example from a high sample rate of 44100Hz to 8000Hz. Audio
-conversion from high to low sample rate is a lossy process. Several
-resampling options and algorithms are available.
-
- Format conversion : is the process of converting the type of
-samples, for example from 16-bit signed samples to unsigned 8-bit or
-float samples. It also handles packing conversion, when passing from
-packed layout (all samples belonging to distinct channels interleaved
-in the same buffer), to planar layout (all samples belonging to the
-same channel stored in a dedicated buffer or "plane").
-
- Rematrixing : is the process of changing the channel layout, for
-example from stereo to mono. When the input channels cannot be mapped
-to the output streams, the process is lossy, since it involves
-different gain factors and mixing.
-
-
-
Various other audio conversions (e.g. stretching and padding) are
-enabled through dedicated options.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-resampler ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libswscale Documentation
-
-
-
- Libswscale Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libswscale library performs highly optimized image scaling and
-colorspace and pixel format conversion operations.
-
-
Specifically, this library performs the following conversions:
-
-
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-scaler ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- NUT
-
-
-
- NUT
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
NUT is a low overhead generic container format. It stores audio, video,
-subtitle and user-defined streams in a simple, yet efficient, way.
-
-
It was created by a group of FFmpeg and MPlayer developers in 2003
-and was finalized in 2008.
-
-
The official nut specification is at svn://svn.mplayerhq.hu/nut
-In case of any differences between this text and the official specification,
-the official specification shall prevail.
-
-
-
-
NUT has some variants signaled by using the flags field in its main header.
-
-
-BROADCAST Extend the syncpoint to report the sender wallclock PIPE Omit completely the syncpoint
-
-
-
2.1 BROADCAST# TOC
-
-
The BROADCAST variant provides a secondary time reference to facilitate
-detecting endpoint latency and network delays.
-It assumes all the endpoint clocks are syncronized.
-To be used in real-time scenarios.
-
-
-
2.2 PIPE# TOC
-
-
The PIPE variant assumes NUT is used as non-seekable intermediate container,
-by not using syncpoint removes unneeded overhead and reduces the overall
-memory usage.
-
-
-
3 Container-specific codec tags# TOC
-
-
-
3.1 Generic raw YUVA formats# TOC
-
-
Since many exotic planar YUVA pixel formats are not considered by
-the AVI/QuickTime FourCC lists, the following scheme is adopted for
-representing them.
-
-
The first two bytes can contain the values:
-Y1 = only Y
-Y2 = Y+A
-Y3 = YUV
-Y4 = YUVA
-
-
The third byte represents the width and height chroma subsampling
-values for the UV planes, that is the amount to shift the luma
-width/height right to find the chroma width/height.
-
-
The fourth byte is the number of bits used (8, 16, ...).
-
-
If the order of bytes is inverted, that means that each component has
-to be read big-endian.
-
-
-
3.2 Raw Audio# TOC
-
-
-ALAW A-LAW ULAW MU-LAW P<type><interleaving><bits> little-endian PCM <bits><interleaving><type>P big-endian PCM
-
-
<type> is S for signed integer, U for unsigned integer, F for IEEE float
-<interleaving> is D for default, P is for planar.
-<bits> is 8/16/24/32
-
-
-
PFD[32] would for example be signed 32 bit little-endian IEEE float
-
-
-
-
3.3 Subtitles# TOC
-
-
-UTF8 Raw UTF-8 SSA[0] SubStation Alpha DVDS DVD subtitles DVBS DVB subtitles
-
-
-
3.4 Raw Data# TOC
-
-
-
-
-
3.5 Codecs# TOC
-
-
-3IV1 non-compliant MPEG-4 generated by old 3ivx ASV1 Asus Video ASV2 Asus Video 2 CVID Cinepak CYUV Creative YUV DIVX non-compliant MPEG-4 generated by old DivX DUCK Truemotion 1 FFV1 FFmpeg video 1 FFVH FFmpeg Huffyuv H261 ITU H.261 H262 ITU H.262 H263 ITU H.263 H264 ITU H.264 HFYU Huffyuv I263 Intel H.263 IV31 Indeo 3.1 IV32 Indeo 3.2 IV50 Indeo 5.0 LJPG ITU JPEG (lossless) MJLS ITU JPEG-LS MJPG ITU JPEG MPG4 MS MPEG-4v1 (not ISO MPEG-4) MP42 MS MPEG-4v2 MP43 MS MPEG-4v3 MP4V ISO MPEG-4 Part 2 Video (from old encoders) mpg1 ISO MPEG-1 Video mpg2 ISO MPEG-2 Video MRLE MS RLE MSVC MS Video 1 RT21 Indeo 2.1 RV10 RealVideo 1.0 RV20 RealVideo 2.0 RV30 RealVideo 3.0 RV40 RealVideo 4.0 SNOW FFmpeg Snow SVQ1 Sorenson Video 1 SVQ3 Sorenson Video 3 theo Xiph Theora TM20 Truemotion 2.0 UMP4 non-compliant MPEG-4 generated by UB Video MPEG-4 VCR1 ATI VCR1 VP30 VP 3.0 VP31 VP 3.1 VP50 VP 5.0 VP60 VP 6.0 VP61 VP 6.1 VP62 VP 6.2 VP70 VP 7.0 WMV1 MS WMV7 WMV2 MS WMV8 WMV3 MS WMV9 WV1F non-compliant MPEG-4 generated by ? WVC1 VC-1 XVID non-compliant MPEG-4 generated by old Xvid XVIX non-compliant MPEG-4 generated by old Xvid with interlacing bug
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Platform Specific Information
-
-
-
- Platform Specific Information
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Unix-like# TOC
-
-
Some parts of FFmpeg cannot be built with version 2.15 of the GNU
-assembler which is still provided by a few AMD64 distributions. To
-make sure your compiler really uses the required version of gas
-after a binutils upgrade, run:
-
-
-
$(gcc -print-prog-name=as) --version
-
-
-
If not, then you should install a different compiler that has no
-hard-coded path to gas. In the worst case pass --disable-asm
-to configure.
-
-
-
1.1 Advanced linking configuration# TOC
-
-
If you compiled FFmpeg libraries statically and you want to use them to
-build your own shared library, you may need to force PIC support (with
---enable-pic during FFmpeg configure) and add the following option
-to your project LDFLAGS:
-
-
-
-
If your target platform requires position independent binaries, you should
-pass the correct linking flag (e.g. -pie) to --extra-ldexeflags.
-
-
-
-
-
BSD make will not build FFmpeg, you need to install and use GNU Make
-(gmake).
-
-
-
1.3 (Open)Solaris# TOC
-
-
GNU Make is required to build FFmpeg, so you have to invoke (gmake),
-standard Solaris Make will not work. When building with a non-c99 front-end
-(gcc, generic suncc) add either --extra-libs=/usr/lib/values-xpg6.o
-or --extra-libs=/usr/lib/64/values-xpg6.o to the configure options
-since the libc is not c99-compliant by default. The probes performed by
-configure may raise an exception leading to the death of configure itself
-due to a bug in the system shell. Simply invoke a different shell such as
-bash directly to work around this:
-
-
-
-
-
1.4 Darwin (Mac OS X, iPhone)# TOC
-
-
The toolchain provided with Xcode is sufficient to build the basic
-unacelerated code.
-
-
Mac OS X on PowerPC or ARM (iPhone) requires a preprocessor from
-https://github.com/FFmpeg/gas-preprocessor or
-https://github.com/yuvi/gas-preprocessor (currently outdated) to build the optimized
-assembly functions. Put the Perl script somewhere
-in your PATH, FFmpeg’s configure will pick it up automatically.
-
-
Mac OS X on amd64 and x86 requires yasm to build most of the
-optimized assembly functions. Fink ,
-Gentoo Prefix ,
-Homebrew
-or MacPorts can easily provide it.
-
-
-
-
-
-
Using a cross-compiler is preferred for various reasons.
-http://www.delorie.com/howto/djgpp/linux-x-djgpp.html
-
-
-
-
-
-
For information about compiling FFmpeg on OS/2 see
-http://www.edm2.com/index.php/FFmpeg .
-
-
-
-
4 Windows# TOC
-
-
To get help and instructions for building FFmpeg under Windows, check out
-the FFmpeg Windows Help Forum at http://ffmpeg.zeranoe.com/forum/ .
-
-
-
4.1 Native Windows compilation using MinGW or MinGW-w64# TOC
-
-
FFmpeg can be built to run natively on Windows using the MinGW or MinGW-w64
-toolchains. Install the latest versions of MSYS and MinGW or MinGW-w64 from
-http://www.mingw.org/ or http://mingw-w64.sourceforge.net/ .
-You can find detailed installation instructions in the download section and
-the FAQ.
-
-
Notes:
-
-
- Building natively using MSYS can be sped up by disabling implicit rules
-in the Makefile by calling make -r instead of plain make. This
-speed up is close to non-existent for normal one-off builds and is only
-noticeable when running make for a second time (for example during
-make install).
-
- In order to compile FFplay, you must have the MinGW development library
-of SDL and pkg-config installed.
-
- By using ./configure --enable-shared when configuring FFmpeg,
-you can build the FFmpeg libraries (e.g. libavutil, libavcodec,
-libavformat) as DLLs.
-
-
-
-
-
4.2 Microsoft Visual C++ or Intel C++ Compiler for Windows# TOC
-
-
FFmpeg can be built with MSVC 2012 or earlier using a C99-to-C89 conversion utility
-and wrapper, or with MSVC 2013 and ICL natively.
-
-
You will need the following prerequisites:
-
-
-
-
To set up a proper environment in MSYS, you need to run msys.bat from
-the Visual Studio or Intel Compiler command prompt.
-
-
Place yasm.exe somewhere in your PATH. If using MSVC 2012 or
-earlier, place c99wrap.exe and c99conv.exe somewhere in your
-PATH as well.
-
-
Next, make sure any other headers and libs you want to use, such as zlib, are
-located in a spot that the compiler can see. Do so by modifying the LIB
-and INCLUDE environment variables to include the Windows-style
-paths to these directories. Alternatively, you can try and use the
---extra-cflags/--extra-ldflags configure options. If using MSVC
-2012 or earlier, place inttypes.h somewhere the compiler can see too.
-
-
Finally, run:
-
-
-
For MSVC:
-./configure --toolchain=msvc
-
-For ICL:
-./configure --toolchain=icl
-
-make
-make install
-
-
-
If you wish to compile shared libraries, add --enable-shared to your
-configure options. Note that due to the way MSVC and ICL handle DLL imports and
-exports, you cannot compile static and shared libraries at the same time, and
-enabling shared libraries will automatically disable the static ones.
-
-
Notes:
-
-
-
-
-
4.2.1 Linking to FFmpeg with Microsoft Visual C++# TOC
-
-
If you plan to link with MSVC-built static libraries, you will need
-to make sure you have Runtime Library set to
-Multi-threaded (/MT) in your project’s settings.
-
-
You will need to define inline to something MSVC understands:
-
-
#define inline __inline
-
-
-
Also note, that as stated in Microsoft Visual C++ , you will need
-an MSVC-compatible inttypes.h .
-
-
If you plan on using import libraries created by dlltool, you must
-set References to No (/OPT:NOREF) under the linker optimization
-settings, otherwise the resulting binaries will fail during runtime.
-This is not required when using import libraries generated by lib.exe.
-This issue is reported upstream at
-http://sourceware.org/bugzilla/show_bug.cgi?id=12633 .
-
-
To create import libraries that work with the /OPT:REF option
-(which is enabled by default in Release mode), follow these steps:
-
-
- Open the Visual Studio Command Prompt .
-
-Alternatively, in a normal command line prompt, call vcvars32.bat
-which sets up the environment variables for the Visual C++ tools
-(the standard location for this file is something like
-C:\Program Files (x86_\Microsoft Visual Studio 10.0\VC\bin\vcvars32.bat ).
-
- Enter the bin directory where the created LIB and DLL files
-are stored.
-
- Generate new import libraries with lib.exe:
-
-
-
lib /machine:i386 /def:..\lib\foo-version.def /out:foo.lib
- Replace foo-version and foo with the respective library names.
-
-
-
-
-
4.3 Cross compilation for Windows with Linux# TOC
-
-
You must use the MinGW cross compilation tools available at
-http://www.mingw.org/ .
-
-
Then configure FFmpeg with the following options:
-
-
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
-
-
(you can change the cross-prefix according to the prefix chosen for the
-MinGW tools).
-
-
Then you can easily test FFmpeg with Wine .
-
-
-
4.4 Compilation under Cygwin# TOC
-
-
Please use Cygwin 1.7.x as the obsolete 1.5.x Cygwin versions lack
-llrint() in its C library.
-
-
Install your Cygwin with all the "Base" packages, plus the
-following "Devel" ones:
-
-
binutils, gcc4-core, make, git, mingw-runtime, texinfo
-
-
-
In order to run FATE you will also need the following "Utils" packages:
-
-
-
If you want to build FFmpeg with additional libraries, download Cygwin
-"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
-
-
libogg-devel, libvorbis-devel
-
-
-
These library packages are only available from
-Cygwin Ports :
-
-
-
yasm, libSDL-devel, libfaac-devel, libaacplus-devel, libgsm-devel, libmp3lame-devel,
-libschroedinger1.0-devel, speex-devel, libtheora-devel, libxvidcore-devel
-
-
-
The recommendation for x264 is to build it from source, as it evolves too
-quickly for Cygwin Ports to be up to date.
-
-
-
4.5 Crosscompilation for Windows under Cygwin# TOC
-
-
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
-
-
Just install your Cygwin as explained before, plus these additional
-"Devel" packages:
-
-
gcc-mingw-core, mingw-runtime, mingw-zlib
-
-
-
and add some special flags to your configure invocation.
-
-
For a static build run
-
-
./configure --target-os=mingw32 --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-
-
-
and for a build with shared libraries
-
-
./configure --target-os=mingw32 --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-
-
-
-
5 Plan 9# TOC
-
-
The native Plan 9 compiler
-does not implement all the C99 features needed by FFmpeg so the gcc
-port must be used. Furthermore, a few items missing from the C
-library and shell environment need to be fixed.
-
-
- GNU awk, grep, make, and sed
-
-Working packages of these tools can be found at
-ports2plan9 .
-They can be installed with 9front’s pkg
-utility by setting pkgpath to
-http://ports2plan9.googlecode.com/files/.
-
- Missing/broken head and printf commands
-
-Replacements adequate for building FFmpeg can be found in the
-compat/plan9 directory. Place these somewhere they will be
-found by the shell. These are not full implementations of the
-commands and are not suitable for general use.
-
- Missing C99 stdint.h and inttypes.h
-
-Replacement headers are available from
-http://code.google.com/p/plan9front/issues/detail?id=152 .
-
- Missing or non-standard library functions
-
-Some functions in the C library are missing or incomplete. The
-gcc-apelibs-1207 ports2plan9
-includes an updated C library, but installing the full package gives
-unusable executables. Instead, keep the files from gccbin.tgz
-under /386/lib/gnu. From the libc.a archive in the
-gcc-apelibs-1207 package, extract the following object files and
-turn them into a library:
-
-
- strerror.o
- strtoll.o
- snprintf.o
- vsnprintf.o
- vfprintf.o
- _IO_getc.o
- _IO_putc.o
-
-
-Use the --extra-libs option of configure to inform the
-build system of this library.
-
- FPU exceptions enabled by default
-
-Unlike most other systems, Plan 9 enables FPU exceptions by default.
-These must be disabled before calling any FFmpeg functions. While the
-included tools will do this automatically, other users of the
-libraries must do it themselves.
-
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
-
-#include "libavutil/attributes.h"
-#include "libavutil/avutil.h"
-#include "libavutil/dict.h"
-#include "libavutil/frame.h"
-#include "libavutil/log.h"
-#include "libavutil/samplefmt.h"
-#include "libavutil/pixfmt.h"
-#include "libavutil/rational.h"
-
-#include "libavfilter/version.h"
-
-/**
- * Return the LIBAVFILTER_VERSION_INT constant.
- */
-unsigned avfilter_version(void);
-
-/**
- * Return the libavfilter build-time configuration.
- */
-const char *avfilter_configuration(void);
-
-/**
- * Return the libavfilter license.
- */
-const char *avfilter_license(void);
-
-typedef struct AVFilterContext AVFilterContext;
-typedef struct AVFilterLink AVFilterLink;
-typedef struct AVFilterPad AVFilterPad;
-typedef struct AVFilterFormats AVFilterFormats;
-
-#if FF_API_AVFILTERBUFFER
-/**
- * A reference-counted buffer data type used by the filter system. Filters
- * should not store pointers to this structure directly, but instead use the
- * AVFilterBufferRef structure below.
- */
-typedef struct AVFilterBuffer {
- uint8_t *data[8]; ///< buffer data for each plane/channel
-
- /**
- * pointers to the data planes/channels.
- *
- * For video, this should simply point to data[].
- *
- * For planar audio, each channel has a separate data pointer, and
- * linesize[0] contains the size of each channel buffer.
- * For packed audio, there is just one data pointer, and linesize[0]
- * contains the total size of the buffer for all channels.
- *
- * Note: Both data and extended_data will always be set, but for planar
- * audio with more channels that can fit in data, extended_data must be used
- * in order to access all channels.
- */
- uint8_t **extended_data;
- int linesize[8]; ///< number of bytes per line
-
- /** private data to be used by a custom free function */
- void *priv;
- /**
- * A pointer to the function to deallocate this buffer if the default
- * function is not sufficient. This could, for example, add the memory
- * back into a memory pool to be reused later without the overhead of
- * reallocating it from scratch.
- */
- void (*free)(struct AVFilterBuffer *buf);
-
- int format; ///< media format
- int w, h; ///< width and height of the allocated buffer
- unsigned refcount; ///< number of references to this buffer
-} AVFilterBuffer;
-
-#define AV_PERM_READ 0x01 ///< can read from the buffer
-#define AV_PERM_WRITE 0x02 ///< can write to the buffer
-#define AV_PERM_PRESERVE 0x04 ///< nobody else can overwrite the buffer
-#define AV_PERM_REUSE 0x08 ///< can output the buffer multiple times, with the same contents each time
-#define AV_PERM_REUSE2 0x10 ///< can output the buffer multiple times, modified each time
-#define AV_PERM_NEG_LINESIZES 0x20 ///< the buffer requested can have negative linesizes
-#define AV_PERM_ALIGN 0x40 ///< the buffer must be aligned
-
-#define AVFILTER_ALIGN 16 //not part of ABI
-
-/**
- * Audio specific properties in a reference to an AVFilterBuffer. Since
- * AVFilterBufferRef is common to different media formats, audio specific
- * per reference properties must be separated out.
- */
-typedef struct AVFilterBufferRefAudioProps {
- uint64_t channel_layout; ///< channel layout of audio buffer
- int nb_samples; ///< number of audio samples per channel
- int sample_rate; ///< audio buffer sample rate
- int channels; ///< number of channels (do not access directly)
-} AVFilterBufferRefAudioProps;
-
-/**
- * Video specific properties in a reference to an AVFilterBuffer. Since
- * AVFilterBufferRef is common to different media formats, video specific
- * per reference properties must be separated out.
- */
-typedef struct AVFilterBufferRefVideoProps {
- int w; ///< image width
- int h; ///< image height
- AVRational sample_aspect_ratio; ///< sample aspect ratio
- int interlaced; ///< is frame interlaced
- int top_field_first; ///< field order
- enum AVPictureType pict_type; ///< picture type of the frame
- int key_frame; ///< 1 -> keyframe, 0-> not
- int qp_table_linesize; ///< qp_table stride
- int qp_table_size; ///< qp_table size
- int8_t *qp_table; ///< array of Quantization Parameters
-} AVFilterBufferRefVideoProps;
-
-/**
- * A reference to an AVFilterBuffer. Since filters can manipulate the origin of
- * a buffer to, for example, crop image without any memcpy, the buffer origin
- * and dimensions are per-reference properties. Linesize is also useful for
- * image flipping, frame to field filters, etc, and so is also per-reference.
- *
- * TODO: add anything necessary for frame reordering
- */
-typedef struct AVFilterBufferRef {
- AVFilterBuffer *buf; ///< the buffer that this is a reference to
- uint8_t *data[8]; ///< picture/audio data for each plane
- /**
- * pointers to the data planes/channels.
- *
- * For video, this should simply point to data[].
- *
- * For planar audio, each channel has a separate data pointer, and
- * linesize[0] contains the size of each channel buffer.
- * For packed audio, there is just one data pointer, and linesize[0]
- * contains the total size of the buffer for all channels.
- *
- * Note: Both data and extended_data will always be set, but for planar
- * audio with more channels that can fit in data, extended_data must be used
- * in order to access all channels.
- */
- uint8_t **extended_data;
- int linesize[8]; ///< number of bytes per line
-
- AVFilterBufferRefVideoProps *video; ///< video buffer specific properties
- AVFilterBufferRefAudioProps *audio; ///< audio buffer specific properties
-
- /**
- * presentation timestamp. The time unit may change during
- * filtering, as it is specified in the link and the filter code
- * may need to rescale the PTS accordingly.
- */
- int64_t pts;
- int64_t pos; ///< byte position in stream, -1 if unknown
-
- int format; ///< media format
-
- int perms; ///< permissions, see the AV_PERM_* flags
-
- enum AVMediaType type; ///< media type of buffer data
-
- AVDictionary *metadata; ///< dictionary containing metadata key=value tags
-} AVFilterBufferRef;
-
-/**
- * Copy properties of src to dst, without copying the actual data
- */
-attribute_deprecated
-void avfilter_copy_buffer_ref_props(AVFilterBufferRef *dst, const AVFilterBufferRef *src);
-
-/**
- * Add a new reference to a buffer.
- *
- * @param ref an existing reference to the buffer
- * @param pmask a bitmask containing the allowable permissions in the new
- * reference
- * @return a new reference to the buffer with the same properties as the
- * old, excluding any permissions denied by pmask
- */
-attribute_deprecated
-AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask);
-
-/**
- * Remove a reference to a buffer. If this is the last reference to the
- * buffer, the buffer itself is also automatically freed.
- *
- * @param ref reference to the buffer, may be NULL
- *
- * @note it is recommended to use avfilter_unref_bufferp() instead of this
- * function
- */
-attribute_deprecated
-void avfilter_unref_buffer(AVFilterBufferRef *ref);
-
-/**
- * Remove a reference to a buffer and set the pointer to NULL.
- * If this is the last reference to the buffer, the buffer itself
- * is also automatically freed.
- *
- * @param ref pointer to the buffer reference
- */
-attribute_deprecated
-void avfilter_unref_bufferp(AVFilterBufferRef **ref);
-#endif
-
-/**
- * Get the number of channels of a buffer reference.
- */
-attribute_deprecated
-int avfilter_ref_get_channels(AVFilterBufferRef *ref);
-
-#if FF_API_AVFILTERPAD_PUBLIC
-/**
- * A filter pad used for either input or output.
- *
- * See doc/filter_design.txt for details on how to implement the methods.
- *
- * @warning this struct might be removed from public API.
- * users should call avfilter_pad_get_name() and avfilter_pad_get_type()
- * to access the name and type fields; there should be no need to access
- * any other fields from outside of libavfilter.
- */
-struct AVFilterPad {
- /**
- * Pad name. The name is unique among inputs and among outputs, but an
- * input may have the same name as an output. This may be NULL if this
- * pad has no need to ever be referenced by name.
- */
- const char *name;
-
- /**
- * AVFilterPad type.
- */
- enum AVMediaType type;
-
- /**
- * Input pads:
- * Minimum required permissions on incoming buffers. Any buffer with
- * insufficient permissions will be automatically copied by the filter
- * system to a new buffer which provides the needed access permissions.
- *
- * Output pads:
- * Guaranteed permissions on outgoing buffers. Any buffer pushed on the
- * link must have at least these permissions; this fact is checked by
- * asserts. It can be used to optimize buffer allocation.
- */
- attribute_deprecated int min_perms;
-
- /**
- * Input pads:
- * Permissions which are not accepted on incoming buffers. Any buffer
- * which has any of these permissions set will be automatically copied
- * by the filter system to a new buffer which does not have those
- * permissions. This can be used to easily disallow buffers with
- * AV_PERM_REUSE.
- *
- * Output pads:
- * Permissions which are automatically removed on outgoing buffers. It
- * can be used to optimize buffer allocation.
- */
- attribute_deprecated int rej_perms;
-
- /**
- * @deprecated unused
- */
- int (*start_frame)(AVFilterLink *link, AVFilterBufferRef *picref);
-
- /**
- * Callback function to get a video buffer. If NULL, the filter system will
- * use ff_default_get_video_buffer().
- *
- * Input video pads only.
- */
- AVFrame *(*get_video_buffer)(AVFilterLink *link, int w, int h);
-
- /**
- * Callback function to get an audio buffer. If NULL, the filter system will
- * use ff_default_get_audio_buffer().
- *
- * Input audio pads only.
- */
- AVFrame *(*get_audio_buffer)(AVFilterLink *link, int nb_samples);
-
- /**
- * @deprecated unused
- */
- int (*end_frame)(AVFilterLink *link);
-
- /**
- * @deprecated unused
- */
- int (*draw_slice)(AVFilterLink *link, int y, int height, int slice_dir);
-
- /**
- * Filtering callback. This is where a filter receives a frame with
- * audio/video data and should do its processing.
- *
- * Input pads only.
- *
- * @return >= 0 on success, a negative AVERROR on error. This function
- * must ensure that frame is properly unreferenced on error if it
- * hasn't been passed on to another filter.
- */
- int (*filter_frame)(AVFilterLink *link, AVFrame *frame);
-
- /**
- * Frame poll callback. This returns the number of immediately available
- * samples. It should return a positive value if the next request_frame()
- * is guaranteed to return one frame (with no delay).
- *
- * Defaults to just calling the source poll_frame() method.
- *
- * Output pads only.
- */
- int (*poll_frame)(AVFilterLink *link);
-
- /**
- * Frame request callback. A call to this should result in at least one
- * frame being output over the given link. This should return zero on
- * success, and another value on error.
- * See ff_request_frame() for the error codes with a specific
- * meaning.
- *
- * Output pads only.
- */
- int (*request_frame)(AVFilterLink *link);
-
- /**
- * Link configuration callback.
- *
- * For output pads, this should set the following link properties:
- * video: width, height, sample_aspect_ratio, time_base
- * audio: sample_rate.
- *
- * This should NOT set properties such as format, channel_layout, etc which
- * are negotiated between filters by the filter system using the
- * query_formats() callback before this function is called.
- *
- * For input pads, this should check the properties of the link, and update
- * the filter's internal state as necessary.
- *
- * For both input and output pads, this should return zero on success,
- * and another value on error.
- */
- int (*config_props)(AVFilterLink *link);
-
- /**
- * The filter expects a fifo to be inserted on its input link,
- * typically because it has a delay.
- *
- * input pads only.
- */
- int needs_fifo;
-
- /**
- * The filter expects writable frames from its input link,
- * duplicating data buffers if needed.
- *
- * input pads only.
- */
- int needs_writable;
-};
-#endif
-
-/**
- * Get the number of elements in a NULL-terminated array of AVFilterPads (e.g.
- * AVFilter.inputs/outputs).
- */
-int avfilter_pad_count(const AVFilterPad *pads);
-
-/**
- * Get the name of an AVFilterPad.
- *
- * @param pads an array of AVFilterPads
- * @param pad_idx index of the pad in the array it; is the caller's
- * responsibility to ensure the index is valid
- *
- * @return name of the pad_idx'th pad in pads
- */
-const char *avfilter_pad_get_name(const AVFilterPad *pads, int pad_idx);
-
-/**
- * Get the type of an AVFilterPad.
- *
- * @param pads an array of AVFilterPads
- * @param pad_idx index of the pad in the array; it is the caller's
- * responsibility to ensure the index is valid
- *
- * @return type of the pad_idx'th pad in pads
- */
-enum AVMediaType avfilter_pad_get_type(const AVFilterPad *pads, int pad_idx);
-
-/**
- * The number of the filter inputs is not determined just by AVFilter.inputs.
- * The filter might add additional inputs during initialization depending on the
- * options supplied to it.
- */
-#define AVFILTER_FLAG_DYNAMIC_INPUTS (1 << 0)
-/**
- * The number of the filter outputs is not determined just by AVFilter.outputs.
- * The filter might add additional outputs during initialization depending on
- * the options supplied to it.
- */
-#define AVFILTER_FLAG_DYNAMIC_OUTPUTS (1 << 1)
-/**
- * The filter supports multithreading by splitting frames into multiple parts
- * and processing them concurrently.
- */
-#define AVFILTER_FLAG_SLICE_THREADS (1 << 2)
-/**
- * Some filters support a generic "enable" expression option that can be used
- * to enable or disable a filter in the timeline. Filters supporting this
- * option have this flag set. When the enable expression is false, the default
- * no-op filter_frame() function is called in place of the filter_frame()
- * callback defined on each input pad, thus the frame is passed unchanged to
- * the next filters.
- */
-#define AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC (1 << 16)
-/**
- * Same as AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC, except that the filter will
- * have its filter_frame() callback(s) called as usual even when the enable
- * expression is false. The filter will disable filtering within the
- * filter_frame() callback(s) itself, for example executing code depending on
- * the AVFilterContext->is_disabled value.
- */
-#define AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL (1 << 17)
-/**
- * Handy mask to test whether the filter supports or no the timeline feature
- * (internally or generically).
- */
-#define AVFILTER_FLAG_SUPPORT_TIMELINE (AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL)
-
-/**
- * Filter definition. This defines the pads a filter contains, and all the
- * callback functions used to interact with the filter.
- */
-typedef struct AVFilter {
- /**
- * Filter name. Must be non-NULL and unique among filters.
- */
- const char *name;
-
- /**
- * A description of the filter. May be NULL.
- *
- * You should use the NULL_IF_CONFIG_SMALL() macro to define it.
- */
- const char *description;
-
- /**
- * List of inputs, terminated by a zeroed element.
- *
- * NULL if there are no (static) inputs. Instances of filters with
- * AVFILTER_FLAG_DYNAMIC_INPUTS set may have more inputs than present in
- * this list.
- */
- const AVFilterPad *inputs;
- /**
- * List of outputs, terminated by a zeroed element.
- *
- * NULL if there are no (static) outputs. Instances of filters with
- * AVFILTER_FLAG_DYNAMIC_OUTPUTS set may have more outputs than present in
- * this list.
- */
- const AVFilterPad *outputs;
-
- /**
- * A class for the private data, used to declare filter private AVOptions.
- * This field is NULL for filters that do not declare any options.
- *
- * If this field is non-NULL, the first member of the filter private data
- * must be a pointer to AVClass, which will be set by libavfilter generic
- * code to this class.
- */
- const AVClass *priv_class;
-
- /**
- * A combination of AVFILTER_FLAG_*
- */
- int flags;
-
- /*****************************************************************
- * All fields below this line are not part of the public API. They
- * may not be used outside of libavfilter and can be changed and
- * removed at will.
- * New public fields should be added right above.
- *****************************************************************
- */
-
- /**
- * Filter initialization function.
- *
- * This callback will be called only once during the filter lifetime, after
- * all the options have been set, but before links between filters are
- * established and format negotiation is done.
- *
- * Basic filter initialization should be done here. Filters with dynamic
- * inputs and/or outputs should create those inputs/outputs here based on
- * provided options. No more changes to this filter's inputs/outputs can be
- * done after this callback.
- *
- * This callback must not assume that the filter links exist or frame
- * parameters are known.
- *
- * @ref AVFilter.uninit "uninit" is guaranteed to be called even if
- * initialization fails, so this callback does not have to clean up on
- * failure.
- *
- * @return 0 on success, a negative AVERROR on failure
- */
- int (*init)(AVFilterContext *ctx);
-
- /**
- * Should be set instead of @ref AVFilter.init "init" by the filters that
- * want to pass a dictionary of AVOptions to nested contexts that are
- * allocated during init.
- *
- * On return, the options dict should be freed and replaced with one that
- * contains all the options which could not be processed by this filter (or
- * with NULL if all the options were processed).
- *
- * Otherwise the semantics is the same as for @ref AVFilter.init "init".
- */
- int (*init_dict)(AVFilterContext *ctx, AVDictionary **options);
-
- /**
- * Filter uninitialization function.
- *
- * Called only once right before the filter is freed. Should deallocate any
- * memory held by the filter, release any buffer references, etc. It does
- * not need to deallocate the AVFilterContext.priv memory itself.
- *
- * This callback may be called even if @ref AVFilter.init "init" was not
- * called or failed, so it must be prepared to handle such a situation.
- */
- void (*uninit)(AVFilterContext *ctx);
-
- /**
- * Query formats supported by the filter on its inputs and outputs.
- *
- * This callback is called after the filter is initialized (so the inputs
- * and outputs are fixed), shortly before the format negotiation. This
- * callback may be called more than once.
- *
- * This callback must set AVFilterLink.out_formats on every input link and
- * AVFilterLink.in_formats on every output link to a list of pixel/sample
- * formats that the filter supports on that link. For audio links, this
- * filter must also set @ref AVFilterLink.in_samplerates "in_samplerates" /
- * @ref AVFilterLink.out_samplerates "out_samplerates" and
- * @ref AVFilterLink.in_channel_layouts "in_channel_layouts" /
- * @ref AVFilterLink.out_channel_layouts "out_channel_layouts" analogously.
- *
- * This callback may be NULL for filters with one input, in which case
- * libavfilter assumes that it supports all input formats and preserves
- * them on output.
- *
- * @return zero on success, a negative value corresponding to an
- * AVERROR code otherwise
- */
- int (*query_formats)(AVFilterContext *);
-
- int priv_size; ///< size of private data to allocate for the filter
-
- /**
- * Used by the filter registration system. Must not be touched by any other
- * code.
- */
- struct AVFilter *next;
-
- /**
- * Make the filter instance process a command.
- *
- * @param cmd the command to process, for handling simplicity all commands must be alphanumeric only
- * @param arg the argument for the command
- * @param res a buffer with size res_size where the filter(s) can return a response. This must not change when the command is not supported.
- * @param flags if AVFILTER_CMD_FLAG_FAST is set and the command would be
- * time consuming then a filter should treat it like an unsupported command
- *
- * @returns >=0 on success otherwise an error code.
- * AVERROR(ENOSYS) on unsupported commands
- */
- int (*process_command)(AVFilterContext *, const char *cmd, const char *arg, char *res, int res_len, int flags);
-
- /**
- * Filter initialization function, alternative to the init()
- * callback. Args contains the user-supplied parameters, opaque is
- * used for providing binary data.
- */
- int (*init_opaque)(AVFilterContext *ctx, void *opaque);
-} AVFilter;
-
-/**
- * Process multiple parts of the frame concurrently.
- */
-#define AVFILTER_THREAD_SLICE (1 << 0)
-
-typedef struct AVFilterInternal AVFilterInternal;
-
-/** An instance of a filter */
-struct AVFilterContext {
- const AVClass *av_class; ///< needed for av_log() and filters common options
-
- const AVFilter *filter; ///< the AVFilter of which this is an instance
-
- char *name; ///< name of this filter instance
-
- AVFilterPad *input_pads; ///< array of input pads
- AVFilterLink **inputs; ///< array of pointers to input links
-#if FF_API_FOO_COUNT
- attribute_deprecated unsigned input_count; ///< @deprecated use nb_inputs
-#endif
- unsigned nb_inputs; ///< number of input pads
-
- AVFilterPad *output_pads; ///< array of output pads
- AVFilterLink **outputs; ///< array of pointers to output links
-#if FF_API_FOO_COUNT
- attribute_deprecated unsigned output_count; ///< @deprecated use nb_outputs
-#endif
- unsigned nb_outputs; ///< number of output pads
-
- void *priv; ///< private data for use by the filter
-
- struct AVFilterGraph *graph; ///< filtergraph this filter belongs to
-
- /**
- * Type of multithreading being allowed/used. A combination of
- * AVFILTER_THREAD_* flags.
- *
- * May be set by the caller before initializing the filter to forbid some
- * or all kinds of multithreading for this filter. The default is allowing
- * everything.
- *
- * When the filter is initialized, this field is combined using bit AND with
- * AVFilterGraph.thread_type to get the final mask used for determining
- * allowed threading types. I.e. a threading type needs to be set in both
- * to be allowed.
- *
- * After the filter is initialized, libavfilter sets this field to the
- * threading type that is actually used (0 for no multithreading).
- */
- int thread_type;
-
- /**
- * An opaque struct for libavfilter internal use.
- */
- AVFilterInternal *internal;
-
- struct AVFilterCommand *command_queue;
-
- char *enable_str; ///< enable expression string
- void *enable; ///< parsed expression (AVExpr*)
- double *var_values; ///< variable values for the enable expression
- int is_disabled; ///< the enabled state from the last expression evaluation
-};
-
-/**
- * A link between two filters. This contains pointers to the source and
- * destination filters between which this link exists, and the indexes of
- * the pads involved. In addition, this link also contains the parameters
- * which have been negotiated and agreed upon between the filter, such as
- * image dimensions, format, etc.
- */
-struct AVFilterLink {
- AVFilterContext *src; ///< source filter
- AVFilterPad *srcpad; ///< output pad on the source filter
-
- AVFilterContext *dst; ///< dest filter
- AVFilterPad *dstpad; ///< input pad on the dest filter
-
- enum AVMediaType type; ///< filter media type
-
- /* These parameters apply only to video */
- int w; ///< agreed upon image width
- int h; ///< agreed upon image height
- AVRational sample_aspect_ratio; ///< agreed upon sample aspect ratio
- /* These parameters apply only to audio */
- uint64_t channel_layout; ///< channel layout of current buffer (see libavutil/channel_layout.h)
- int sample_rate; ///< samples per second
-
- int format; ///< agreed upon media format
-
- /**
- * Define the time base used by the PTS of the frames/samples
- * which will pass through this link.
- * During the configuration stage, each filter is supposed to
- * change only the output timebase, while the timebase of the
- * input link is assumed to be an unchangeable property.
- */
- AVRational time_base;
-
- /*****************************************************************
- * All fields below this line are not part of the public API. They
- * may not be used outside of libavfilter and can be changed and
- * removed at will.
- * New public fields should be added right above.
- *****************************************************************
- */
- /**
- * Lists of formats and channel layouts supported by the input and output
- * filters respectively. These lists are used for negotiating the format
- * to actually be used, which will be loaded into the format and
- * channel_layout members, above, when chosen.
- *
- */
- AVFilterFormats *in_formats;
- AVFilterFormats *out_formats;
-
- /**
- * Lists of channel layouts and sample rates used for automatic
- * negotiation.
- */
- AVFilterFormats *in_samplerates;
- AVFilterFormats *out_samplerates;
- struct AVFilterChannelLayouts *in_channel_layouts;
- struct AVFilterChannelLayouts *out_channel_layouts;
-
- /**
- * Audio only, the destination filter sets this to a non-zero value to
- * request that buffers with the given number of samples should be sent to
- * it. AVFilterPad.needs_fifo must also be set on the corresponding input
- * pad.
- * Last buffer before EOF will be padded with silence.
- */
- int request_samples;
-
- /** stage of the initialization of the link properties (dimensions, etc) */
- enum {
- AVLINK_UNINIT = 0, ///< not started
- AVLINK_STARTINIT, ///< started, but incomplete
- AVLINK_INIT ///< complete
- } init_state;
-
- struct AVFilterPool *pool;
-
- /**
- * Graph the filter belongs to.
- */
- struct AVFilterGraph *graph;
-
- /**
- * Current timestamp of the link, as defined by the most recent
- * frame(s), in AV_TIME_BASE units.
- */
- int64_t current_pts;
-
- /**
- * Index in the age array.
- */
- int age_index;
-
- /**
- * Frame rate of the stream on the link, or 1/0 if unknown;
- * if left to 0/0, will be automatically be copied from the first input
- * of the source filter if it exists.
- *
- * Sources should set it to the best estimation of the real frame rate.
- * Filters should update it if necessary depending on their function.
- * Sinks can use it to set a default output frame rate.
- * It is similar to the r_frame_rate field in AVStream.
- */
- AVRational frame_rate;
-
- /**
- * Buffer partially filled with samples to achieve a fixed/minimum size.
- */
- AVFrame *partial_buf;
-
- /**
- * Size of the partial buffer to allocate.
- * Must be between min_samples and max_samples.
- */
- int partial_buf_size;
-
- /**
- * Minimum number of samples to filter at once. If filter_frame() is
- * called with fewer samples, it will accumulate them in partial_buf.
- * This field and the related ones must not be changed after filtering
- * has started.
- * If 0, all related fields are ignored.
- */
- int min_samples;
-
- /**
- * Maximum number of samples to filter at once. If filter_frame() is
- * called with more samples, it will split them.
- */
- int max_samples;
-
- /**
- * The buffer reference currently being received across the link by the
- * destination filter. This is used internally by the filter system to
- * allow automatic copying of buffers which do not have sufficient
- * permissions for the destination. This should not be accessed directly
- * by the filters.
- */
- AVFilterBufferRef *cur_buf_copy;
-
- /**
- * True if the link is closed.
- * If set, all attempts of start_frame, filter_frame or request_frame
- * will fail with AVERROR_EOF, and if necessary the reference will be
- * destroyed.
- * If request_frame returns AVERROR_EOF, this flag is set on the
- * corresponding link.
- * It can be set also be set by either the source or the destination
- * filter.
- */
- int closed;
-
- /**
- * Number of channels.
- */
- int channels;
-
- /**
- * True if a frame is being requested on the link.
- * Used internally by the framework.
- */
- unsigned frame_requested;
-
- /**
- * Link processing flags.
- */
- unsigned flags;
-
- /**
- * Number of past frames sent through the link.
- */
- int64_t frame_count;
-};
-
-/**
- * Link two filters together.
- *
- * @param src the source filter
- * @param srcpad index of the output pad on the source filter
- * @param dst the destination filter
- * @param dstpad index of the input pad on the destination filter
- * @return zero on success
- */
-int avfilter_link(AVFilterContext *src, unsigned srcpad,
- AVFilterContext *dst, unsigned dstpad);
-
-/**
- * Free the link in *link, and set its pointer to NULL.
- */
-void avfilter_link_free(AVFilterLink **link);
-
-/**
- * Get the number of channels of a link.
- */
-int avfilter_link_get_channels(AVFilterLink *link);
-
-/**
- * Set the closed field of a link.
- */
-void avfilter_link_set_closed(AVFilterLink *link, int closed);
-
-/**
- * Negotiate the media format, dimensions, etc of all inputs to a filter.
- *
- * @param filter the filter to negotiate the properties for its inputs
- * @return zero on successful negotiation
- */
-int avfilter_config_links(AVFilterContext *filter);
-
-#if FF_API_AVFILTERBUFFER
-/**
- * Create a buffer reference wrapped around an already allocated image
- * buffer.
- *
- * @param data pointers to the planes of the image to reference
- * @param linesize linesizes for the planes of the image to reference
- * @param perms the required access permissions
- * @param w the width of the image specified by the data and linesize arrays
- * @param h the height of the image specified by the data and linesize arrays
- * @param format the pixel format of the image specified by the data and linesize arrays
- */
-attribute_deprecated
-AVFilterBufferRef *
-avfilter_get_video_buffer_ref_from_arrays(uint8_t * const data[4], const int linesize[4], int perms,
- int w, int h, enum AVPixelFormat format);
-
-/**
- * Create an audio buffer reference wrapped around an already
- * allocated samples buffer.
- *
- * See avfilter_get_audio_buffer_ref_from_arrays_channels() for a version
- * that can handle unknown channel layouts.
- *
- * @param data pointers to the samples plane buffers
- * @param linesize linesize for the samples plane buffers
- * @param perms the required access permissions
- * @param nb_samples number of samples per channel
- * @param sample_fmt the format of each sample in the buffer to allocate
- * @param channel_layout the channel layout of the buffer
- */
-attribute_deprecated
-AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays(uint8_t **data,
- int linesize,
- int perms,
- int nb_samples,
- enum AVSampleFormat sample_fmt,
- uint64_t channel_layout);
-/**
- * Create an audio buffer reference wrapped around an already
- * allocated samples buffer.
- *
- * @param data pointers to the samples plane buffers
- * @param linesize linesize for the samples plane buffers
- * @param perms the required access permissions
- * @param nb_samples number of samples per channel
- * @param sample_fmt the format of each sample in the buffer to allocate
- * @param channels the number of channels of the buffer
- * @param channel_layout the channel layout of the buffer,
- * must be either 0 or consistent with channels
- */
-attribute_deprecated
-AVFilterBufferRef *avfilter_get_audio_buffer_ref_from_arrays_channels(uint8_t **data,
- int linesize,
- int perms,
- int nb_samples,
- enum AVSampleFormat sample_fmt,
- int channels,
- uint64_t channel_layout);
-
-#endif
-
-
-#define AVFILTER_CMD_FLAG_ONE 1 ///< Stop once a filter understood the command (for target=all for example), fast filters are favored automatically
-#define AVFILTER_CMD_FLAG_FAST 2 ///< Only execute command when its fast (like a video out that supports contrast adjustment in hw)
-
-/**
- * Make the filter instance process a command.
- * It is recommended to use avfilter_graph_send_command().
- */
-int avfilter_process_command(AVFilterContext *filter, const char *cmd, const char *arg, char *res, int res_len, int flags);
-
-/** Initialize the filter system. Register all builtin filters. */
-void avfilter_register_all(void);
-
-#if FF_API_OLD_FILTER_REGISTER
-/** Uninitialize the filter system. Unregister all filters. */
-attribute_deprecated
-void avfilter_uninit(void);
-#endif
-
-/**
- * Register a filter. This is only needed if you plan to use
- * avfilter_get_by_name later to lookup the AVFilter structure by name. A
- * filter can still by instantiated with avfilter_graph_alloc_filter even if it
- * is not registered.
- *
- * @param filter the filter to register
- * @return 0 if the registration was successful, a negative value
- * otherwise
- */
-int avfilter_register(AVFilter *filter);
-
-/**
- * Get a filter definition matching the given name.
- *
- * @param name the filter name to find
- * @return the filter definition, if any matching one is registered.
- * NULL if none found.
- */
-#if !FF_API_NOCONST_GET_NAME
-const
-#endif
-AVFilter *avfilter_get_by_name(const char *name);
-
-/**
- * Iterate over all registered filters.
- * @return If prev is non-NULL, next registered filter after prev or NULL if
- * prev is the last filter. If prev is NULL, return the first registered filter.
- */
-const AVFilter *avfilter_next(const AVFilter *prev);
-
-#if FF_API_OLD_FILTER_REGISTER
-/**
- * If filter is NULL, returns a pointer to the first registered filter pointer,
- * if filter is non-NULL, returns the next pointer after filter.
- * If the returned pointer points to NULL, the last registered filter
- * was already reached.
- * @deprecated use avfilter_next()
- */
-attribute_deprecated
-AVFilter **av_filter_next(AVFilter **filter);
-#endif
-
-#if FF_API_AVFILTER_OPEN
-/**
- * Create a filter instance.
- *
- * @param filter_ctx put here a pointer to the created filter context
- * on success, NULL on failure
- * @param filter the filter to create an instance of
- * @param inst_name Name to give to the new instance. Can be NULL for none.
- * @return >= 0 in case of success, a negative error code otherwise
- * @deprecated use avfilter_graph_alloc_filter() instead
- */
-attribute_deprecated
-int avfilter_open(AVFilterContext **filter_ctx, AVFilter *filter, const char *inst_name);
-#endif
-
-
-#if FF_API_AVFILTER_INIT_FILTER
-/**
- * Initialize a filter.
- *
- * @param filter the filter to initialize
- * @param args A string of parameters to use when initializing the filter.
- * The format and meaning of this string varies by filter.
- * @param opaque Any extra non-string data needed by the filter. The meaning
- * of this parameter varies by filter.
- * @return zero on success
- */
-attribute_deprecated
-int avfilter_init_filter(AVFilterContext *filter, const char *args, void *opaque);
-#endif
-
-/**
- * Initialize a filter with the supplied parameters.
- *
- * @param ctx uninitialized filter context to initialize
- * @param args Options to initialize the filter with. This must be a
- * ':'-separated list of options in the 'key=value' form.
- * May be NULL if the options have been set directly using the
- * AVOptions API or there are no options that need to be set.
- * @return 0 on success, a negative AVERROR on failure
- */
-int avfilter_init_str(AVFilterContext *ctx, const char *args);
-
-/**
- * Initialize a filter with the supplied dictionary of options.
- *
- * @param ctx uninitialized filter context to initialize
- * @param options An AVDictionary filled with options for this filter. On
- * return this parameter will be destroyed and replaced with
- * a dict containing options that were not found. This dictionary
- * must be freed by the caller.
- * May be NULL, then this function is equivalent to
- * avfilter_init_str() with the second parameter set to NULL.
- * @return 0 on success, a negative AVERROR on failure
- *
- * @note This function and avfilter_init_str() do essentially the same thing,
- * the difference is in manner in which the options are passed. It is up to the
- * calling code to choose whichever is more preferable. The two functions also
- * behave differently when some of the provided options are not declared as
- * supported by the filter. In such a case, avfilter_init_str() will fail, but
- * this function will leave those extra options in the options AVDictionary and
- * continue as usual.
- */
-int avfilter_init_dict(AVFilterContext *ctx, AVDictionary **options);
-
-/**
- * Free a filter context. This will also remove the filter from its
- * filtergraph's list of filters.
- *
- * @param filter the filter to free
- */
-void avfilter_free(AVFilterContext *filter);
-
-/**
- * Insert a filter in the middle of an existing link.
- *
- * @param link the link into which the filter should be inserted
- * @param filt the filter to be inserted
- * @param filt_srcpad_idx the input pad on the filter to connect
- * @param filt_dstpad_idx the output pad on the filter to connect
- * @return zero on success
- */
-int avfilter_insert_filter(AVFilterLink *link, AVFilterContext *filt,
- unsigned filt_srcpad_idx, unsigned filt_dstpad_idx);
-
-#if FF_API_AVFILTERBUFFER
-/**
- * Copy the frame properties of src to dst, without copying the actual
- * image data.
- *
- * @return 0 on success, a negative number on error.
- */
-attribute_deprecated
-int avfilter_copy_frame_props(AVFilterBufferRef *dst, const AVFrame *src);
-
-/**
- * Copy the frame properties and data pointers of src to dst, without copying
- * the actual data.
- *
- * @return 0 on success, a negative number on error.
- */
-attribute_deprecated
-int avfilter_copy_buf_props(AVFrame *dst, const AVFilterBufferRef *src);
-#endif
-
-/**
- * @return AVClass for AVFilterContext.
- *
- * @see av_opt_find().
- */
-const AVClass *avfilter_get_class(void);
-
-typedef struct AVFilterGraphInternal AVFilterGraphInternal;
-
-/**
- * A function pointer passed to the @ref AVFilterGraph.execute callback to be
- * executed multiple times, possibly in parallel.
- *
- * @param ctx the filter context the job belongs to
- * @param arg an opaque parameter passed through from @ref
- * AVFilterGraph.execute
- * @param jobnr the index of the job being executed
- * @param nb_jobs the total number of jobs
- *
- * @return 0 on success, a negative AVERROR on error
- */
-typedef int (avfilter_action_func)(AVFilterContext *ctx, void *arg, int jobnr, int nb_jobs);
-
-/**
- * A function executing multiple jobs, possibly in parallel.
- *
- * @param ctx the filter context to which the jobs belong
- * @param func the function to be called multiple times
- * @param arg the argument to be passed to func
- * @param ret a nb_jobs-sized array to be filled with return values from each
- * invocation of func
- * @param nb_jobs the number of jobs to execute
- *
- * @return 0 on success, a negative AVERROR on error
- */
-typedef int (avfilter_execute_func)(AVFilterContext *ctx, avfilter_action_func *func,
- void *arg, int *ret, int nb_jobs);
-
-typedef struct AVFilterGraph {
- const AVClass *av_class;
-#if FF_API_FOO_COUNT
- attribute_deprecated
- unsigned filter_count_unused;
-#endif
- AVFilterContext **filters;
-#if !FF_API_FOO_COUNT
- unsigned nb_filters;
-#endif
-
- char *scale_sws_opts; ///< sws options to use for the auto-inserted scale filters
- char *resample_lavr_opts; ///< libavresample options to use for the auto-inserted resample filters
-#if FF_API_FOO_COUNT
- unsigned nb_filters;
-#endif
-
- /**
- * Type of multithreading allowed for filters in this graph. A combination
- * of AVFILTER_THREAD_* flags.
- *
- * May be set by the caller at any point, the setting will apply to all
- * filters initialized after that. The default is allowing everything.
- *
- * When a filter in this graph is initialized, this field is combined using
- * bit AND with AVFilterContext.thread_type to get the final mask used for
- * determining allowed threading types. I.e. a threading type needs to be
- * set in both to be allowed.
- */
- int thread_type;
-
- /**
- * Maximum number of threads used by filters in this graph. May be set by
- * the caller before adding any filters to the filtergraph. Zero (the
- * default) means that the number of threads is determined automatically.
- */
- int nb_threads;
-
- /**
- * Opaque object for libavfilter internal use.
- */
- AVFilterGraphInternal *internal;
-
- /**
- * Opaque user data. May be set by the caller to an arbitrary value, e.g. to
- * be used from callbacks like @ref AVFilterGraph.execute.
- * Libavfilter will not touch this field in any way.
- */
- void *opaque;
-
- /**
- * This callback may be set by the caller immediately after allocating the
- * graph and before adding any filters to it, to provide a custom
- * multithreading implementation.
- *
- * If set, filters with slice threading capability will call this callback
- * to execute multiple jobs in parallel.
- *
- * If this field is left unset, libavfilter will use its internal
- * implementation, which may or may not be multithreaded depending on the
- * platform and build options.
- */
- avfilter_execute_func *execute;
-
- char *aresample_swr_opts; ///< swr options to use for the auto-inserted aresample filters, Access ONLY through AVOptions
-
- /**
- * Private fields
- *
- * The following fields are for internal use only.
- * Their type, offset, number and semantic can change without notice.
- */
-
- AVFilterLink **sink_links;
- int sink_links_count;
-
- unsigned disable_auto_convert;
-} AVFilterGraph;
-
-/**
- * Allocate a filter graph.
- */
-AVFilterGraph *avfilter_graph_alloc(void);
-
-/**
- * Create a new filter instance in a filter graph.
- *
- * @param graph graph in which the new filter will be used
- * @param filter the filter to create an instance of
- * @param name Name to give to the new instance (will be copied to
- * AVFilterContext.name). This may be used by the caller to identify
- * different filters, libavfilter itself assigns no semantics to
- * this parameter. May be NULL.
- *
- * @return the context of the newly created filter instance (note that it is
- * also retrievable directly through AVFilterGraph.filters or with
- * avfilter_graph_get_filter()) on success or NULL on failure.
- */
-AVFilterContext *avfilter_graph_alloc_filter(AVFilterGraph *graph,
- const AVFilter *filter,
- const char *name);
-
-/**
- * Get a filter instance identified by instance name from graph.
- *
- * @param graph filter graph to search through.
- * @param name filter instance name (should be unique in the graph).
- * @return the pointer to the found filter instance or NULL if it
- * cannot be found.
- */
-AVFilterContext *avfilter_graph_get_filter(AVFilterGraph *graph, const char *name);
-
-#if FF_API_AVFILTER_OPEN
-/**
- * Add an existing filter instance to a filter graph.
- *
- * @param graphctx the filter graph
- * @param filter the filter to be added
- *
- * @deprecated use avfilter_graph_alloc_filter() to allocate a filter in a
- * filter graph
- */
-attribute_deprecated
-int avfilter_graph_add_filter(AVFilterGraph *graphctx, AVFilterContext *filter);
-#endif
-
-/**
- * Create and add a filter instance into an existing graph.
- * The filter instance is created from the filter filt and inited
- * with the parameters args and opaque.
- *
- * In case of success put in *filt_ctx the pointer to the created
- * filter instance, otherwise set *filt_ctx to NULL.
- *
- * @param name the instance name to give to the created filter instance
- * @param graph_ctx the filter graph
- * @return a negative AVERROR error code in case of failure, a non
- * negative value otherwise
- */
-int avfilter_graph_create_filter(AVFilterContext **filt_ctx, const AVFilter *filt,
- const char *name, const char *args, void *opaque,
- AVFilterGraph *graph_ctx);
-
-/**
- * Enable or disable automatic format conversion inside the graph.
- *
- * Note that format conversion can still happen inside explicitly inserted
- * scale and aresample filters.
- *
- * @param flags any of the AVFILTER_AUTO_CONVERT_* constants
- */
-void avfilter_graph_set_auto_convert(AVFilterGraph *graph, unsigned flags);
-
-enum {
- AVFILTER_AUTO_CONVERT_ALL = 0, /**< all automatic conversions enabled */
- AVFILTER_AUTO_CONVERT_NONE = -1, /**< all automatic conversions disabled */
-};
-
-/**
- * Check validity and configure all the links and formats in the graph.
- *
- * @param graphctx the filter graph
- * @param log_ctx context used for logging
- * @return >= 0 in case of success, a negative AVERROR code otherwise
- */
-int avfilter_graph_config(AVFilterGraph *graphctx, void *log_ctx);
-
-/**
- * Free a graph, destroy its links, and set *graph to NULL.
- * If *graph is NULL, do nothing.
- */
-void avfilter_graph_free(AVFilterGraph **graph);
-
-/**
- * A linked-list of the inputs/outputs of the filter chain.
- *
- * This is mainly useful for avfilter_graph_parse() / avfilter_graph_parse2(),
- * where it is used to communicate open (unlinked) inputs and outputs from and
- * to the caller.
- * This struct specifies, per each not connected pad contained in the graph, the
- * filter context and the pad index required for establishing a link.
- */
-typedef struct AVFilterInOut {
- /** unique name for this input/output in the list */
- char *name;
-
- /** filter context associated to this input/output */
- AVFilterContext *filter_ctx;
-
- /** index of the filt_ctx pad to use for linking */
- int pad_idx;
-
- /** next input/input in the list, NULL if this is the last */
- struct AVFilterInOut *next;
-} AVFilterInOut;
-
-/**
- * Allocate a single AVFilterInOut entry.
- * Must be freed with avfilter_inout_free().
- * @return allocated AVFilterInOut on success, NULL on failure.
- */
-AVFilterInOut *avfilter_inout_alloc(void);
-
-/**
- * Free the supplied list of AVFilterInOut and set *inout to NULL.
- * If *inout is NULL, do nothing.
- */
-void avfilter_inout_free(AVFilterInOut **inout);
-
-#if AV_HAVE_INCOMPATIBLE_LIBAV_ABI || !FF_API_OLD_GRAPH_PARSE
-/**
- * Add a graph described by a string to a graph.
- *
- * @note The caller must provide the lists of inputs and outputs,
- * which therefore must be known before calling the function.
- *
- * @note The inputs parameter describes inputs of the already existing
- * part of the graph; i.e. from the point of view of the newly created
- * part, they are outputs. Similarly the outputs parameter describes
- * outputs of the already existing filters, which are provided as
- * inputs to the parsed filters.
- *
- * @param graph the filter graph where to link the parsed graph context
- * @param filters string to be parsed
- * @param inputs linked list to the inputs of the graph
- * @param outputs linked list to the outputs of the graph
- * @return zero on success, a negative AVERROR code on error
- */
-int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
- AVFilterInOut *inputs, AVFilterInOut *outputs,
- void *log_ctx);
-#else
-/**
- * Add a graph described by a string to a graph.
- *
- * @param graph the filter graph where to link the parsed graph context
- * @param filters string to be parsed
- * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
- * If non-NULL, *inputs is updated to contain the list of open inputs
- * after the parsing, should be freed with avfilter_inout_free().
- * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
- * If non-NULL, *outputs is updated to contain the list of open outputs
- * after the parsing, should be freed with avfilter_inout_free().
- * @return non negative on success, a negative AVERROR code on error
- * @deprecated Use avfilter_graph_parse_ptr() instead.
- */
-attribute_deprecated
-int avfilter_graph_parse(AVFilterGraph *graph, const char *filters,
- AVFilterInOut **inputs, AVFilterInOut **outputs,
- void *log_ctx);
-#endif
-
-/**
- * Add a graph described by a string to a graph.
- *
- * @param graph the filter graph where to link the parsed graph context
- * @param filters string to be parsed
- * @param inputs pointer to a linked list to the inputs of the graph, may be NULL.
- * If non-NULL, *inputs is updated to contain the list of open inputs
- * after the parsing, should be freed with avfilter_inout_free().
- * @param outputs pointer to a linked list to the outputs of the graph, may be NULL.
- * If non-NULL, *outputs is updated to contain the list of open outputs
- * after the parsing, should be freed with avfilter_inout_free().
- * @return non negative on success, a negative AVERROR code on error
- */
-int avfilter_graph_parse_ptr(AVFilterGraph *graph, const char *filters,
- AVFilterInOut **inputs, AVFilterInOut **outputs,
- void *log_ctx);
-
-/**
- * Add a graph described by a string to a graph.
- *
- * @param[in] graph the filter graph where to link the parsed graph context
- * @param[in] filters string to be parsed
- * @param[out] inputs a linked list of all free (unlinked) inputs of the
- * parsed graph will be returned here. It is to be freed
- * by the caller using avfilter_inout_free().
- * @param[out] outputs a linked list of all free (unlinked) outputs of the
- * parsed graph will be returned here. It is to be freed by the
- * caller using avfilter_inout_free().
- * @return zero on success, a negative AVERROR code on error
- *
- * @note This function returns the inputs and outputs that are left
- * unlinked after parsing the graph and the caller then deals with
- * them.
- * @note This function makes no reference whatsoever to already
- * existing parts of the graph and the inputs parameter will on return
- * contain inputs of the newly parsed part of the graph. Analogously
- * the outputs parameter will contain outputs of the newly created
- * filters.
- */
-int avfilter_graph_parse2(AVFilterGraph *graph, const char *filters,
- AVFilterInOut **inputs,
- AVFilterInOut **outputs);
-
-/**
- * Send a command to one or more filter instances.
- *
- * @param graph the filter graph
- * @param target the filter(s) to which the command should be sent
- * "all" sends to all filters
- * otherwise it can be a filter or filter instance name
- * which will send the command to all matching filters.
- * @param cmd the command to send, for handling simplicity all commands must be alphanumeric only
- * @param arg the argument for the command
- * @param res a buffer with size res_size where the filter(s) can return a response.
- *
- * @returns >=0 on success otherwise an error code.
- * AVERROR(ENOSYS) on unsupported commands
- */
-int avfilter_graph_send_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, char *res, int res_len, int flags);
-
-/**
- * Queue a command for one or more filter instances.
- *
- * @param graph the filter graph
- * @param target the filter(s) to which the command should be sent
- * "all" sends to all filters
- * otherwise it can be a filter or filter instance name
- * which will send the command to all matching filters.
- * @param cmd the command to sent, for handling simplicity all commands must be alphanumeric only
- * @param arg the argument for the command
- * @param ts time at which the command should be sent to the filter
- *
- * @note As this executes commands after this function returns, no return code
- * from the filter is provided, also AVFILTER_CMD_FLAG_ONE is not supported.
- */
-int avfilter_graph_queue_command(AVFilterGraph *graph, const char *target, const char *cmd, const char *arg, int flags, double ts);
-
-
-/**
- * Dump a graph into a human-readable string representation.
- *
- * @param graph the graph to dump
- * @param options formatting options; currently ignored
- * @return a string, or NULL in case of memory allocation failure;
- * the string must be freed using av_free
- */
-char *avfilter_graph_dump(AVFilterGraph *graph, const char *options);
-
-/**
- * Request a frame on the oldest sink link.
- *
- * If the request returns AVERROR_EOF, try the next.
- *
- * Note that this function is not meant to be the sole scheduling mechanism
- * of a filtergraph, only a convenience function to help drain a filtergraph
- * in a balanced way under normal circumstances.
- *
- * Also note that AVERROR_EOF does not mean that frames did not arrive on
- * some of the sinks during the process.
- * When there are multiple sink links, in case the requested link
- * returns an EOF, this may cause a filter to flush pending frames
- * which are sent to another sink link, although unrequested.
- *
- * @return the return value of ff_request_frame(),
- * or AVERROR_EOF if all links returned AVERROR_EOF
- */
-int avfilter_graph_request_oldest(AVFilterGraph *graph);
-
-/**
- * @}
- */
-
-#endif /* AVFILTER_AVFILTER_H */
diff --git a/Externals/ffmpeg/dev/include/libavfilter/avfiltergraph.h b/Externals/ffmpeg/dev/include/libavfilter/avfiltergraph.h
deleted file mode 100644
index b31d581ca0..0000000000
--- a/Externals/ffmpeg/dev/include/libavfilter/avfiltergraph.h
+++ /dev/null
@@ -1,28 +0,0 @@
-/*
- * Filter graphs
- * copyright (c) 2007 Bobby Bingham
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef AVFILTER_AVFILTERGRAPH_H
-#define AVFILTER_AVFILTERGRAPH_H
-
-#include "avfilter.h"
-#include "libavutil/log.h"
-
-#endif /* AVFILTER_AVFILTERGRAPH_H */
diff --git a/Externals/ffmpeg/dev/include/libavfilter/buffersink.h b/Externals/ffmpeg/dev/include/libavfilter/buffersink.h
deleted file mode 100644
index 24cd2feac7..0000000000
--- a/Externals/ffmpeg/dev/include/libavfilter/buffersink.h
+++ /dev/null
@@ -1,204 +0,0 @@
-/*
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef AVFILTER_BUFFERSINK_H
-#define AVFILTER_BUFFERSINK_H
-
-/**
- * @file
- * @ingroup lavfi_buffersink
- * memory buffer sink API for audio and video
- */
-
-#include "avfilter.h"
-
-/**
- * @defgroup lavfi_buffersink Buffer sink API
- * @ingroup lavfi
- * @{
- */
-
-#if FF_API_AVFILTERBUFFER
-/**
- * Get an audio/video buffer data from buffer_sink and put it in bufref.
- *
- * This function works with both audio and video buffer sinks.
- *
- * @param buffer_sink pointer to a buffersink or abuffersink context
- * @param flags a combination of AV_BUFFERSINK_FLAG_* flags
- * @return >= 0 in case of success, a negative AVERROR code in case of
- * failure
- */
-attribute_deprecated
-int av_buffersink_get_buffer_ref(AVFilterContext *buffer_sink,
- AVFilterBufferRef **bufref, int flags);
-
-/**
- * Get the number of immediately available frames.
- */
-attribute_deprecated
-int av_buffersink_poll_frame(AVFilterContext *ctx);
-
-/**
- * Get a buffer with filtered data from sink and put it in buf.
- *
- * @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
- * @param buf pointer to the buffer will be written here if buf is non-NULL. buf
- * must be freed by the caller using avfilter_unref_buffer().
- * Buf may also be NULL to query whether a buffer is ready to be
- * output.
- *
- * @return >= 0 in case of success, a negative AVERROR code in case of
- * failure.
- */
-attribute_deprecated
-int av_buffersink_read(AVFilterContext *ctx, AVFilterBufferRef **buf);
-
-/**
- * Same as av_buffersink_read, but with the ability to specify the number of
- * samples read. This function is less efficient than av_buffersink_read(),
- * because it copies the data around.
- *
- * @param ctx pointer to a context of the abuffersink AVFilter.
- * @param buf pointer to the buffer will be written here if buf is non-NULL. buf
- * must be freed by the caller using avfilter_unref_buffer(). buf
- * will contain exactly nb_samples audio samples, except at the end
- * of stream, when it can contain less than nb_samples.
- * Buf may also be NULL to query whether a buffer is ready to be
- * output.
- *
- * @warning do not mix this function with av_buffersink_read(). Use only one or
- * the other with a single sink, not both.
- */
-attribute_deprecated
-int av_buffersink_read_samples(AVFilterContext *ctx, AVFilterBufferRef **buf,
- int nb_samples);
-#endif
-
-/**
- * Get a frame with filtered data from sink and put it in frame.
- *
- * @param ctx pointer to a buffersink or abuffersink filter context.
- * @param frame pointer to an allocated frame that will be filled with data.
- * The data must be freed using av_frame_unref() / av_frame_free()
- * @param flags a combination of AV_BUFFERSINK_FLAG_* flags
- *
- * @return >= 0 in for success, a negative AVERROR code for failure.
- */
-int av_buffersink_get_frame_flags(AVFilterContext *ctx, AVFrame *frame, int flags);
-
-/**
- * Tell av_buffersink_get_buffer_ref() to read video/samples buffer
- * reference, but not remove it from the buffer. This is useful if you
- * need only to read a video/samples buffer, without to fetch it.
- */
-#define AV_BUFFERSINK_FLAG_PEEK 1
-
-/**
- * Tell av_buffersink_get_buffer_ref() not to request a frame from its input.
- * If a frame is already buffered, it is read (and removed from the buffer),
- * but if no frame is present, return AVERROR(EAGAIN).
- */
-#define AV_BUFFERSINK_FLAG_NO_REQUEST 2
-
-/**
- * Struct to use for initializing a buffersink context.
- */
-typedef struct {
- const enum AVPixelFormat *pixel_fmts; ///< list of allowed pixel formats, terminated by AV_PIX_FMT_NONE
-} AVBufferSinkParams;
-
-/**
- * Create an AVBufferSinkParams structure.
- *
- * Must be freed with av_free().
- */
-AVBufferSinkParams *av_buffersink_params_alloc(void);
-
-/**
- * Struct to use for initializing an abuffersink context.
- */
-typedef struct {
- const enum AVSampleFormat *sample_fmts; ///< list of allowed sample formats, terminated by AV_SAMPLE_FMT_NONE
- const int64_t *channel_layouts; ///< list of allowed channel layouts, terminated by -1
- const int *channel_counts; ///< list of allowed channel counts, terminated by -1
- int all_channel_counts; ///< if not 0, accept any channel count or layout
- int *sample_rates; ///< list of allowed sample rates, terminated by -1
-} AVABufferSinkParams;
-
-/**
- * Create an AVABufferSinkParams structure.
- *
- * Must be freed with av_free().
- */
-AVABufferSinkParams *av_abuffersink_params_alloc(void);
-
-/**
- * Set the frame size for an audio buffer sink.
- *
- * All calls to av_buffersink_get_buffer_ref will return a buffer with
- * exactly the specified number of samples, or AVERROR(EAGAIN) if there is
- * not enough. The last buffer at EOF will be padded with 0.
- */
-void av_buffersink_set_frame_size(AVFilterContext *ctx, unsigned frame_size);
-
-/**
- * Get the frame rate of the input.
- */
-AVRational av_buffersink_get_frame_rate(AVFilterContext *ctx);
-
-/**
- * Get a frame with filtered data from sink and put it in frame.
- *
- * @param ctx pointer to a context of a buffersink or abuffersink AVFilter.
- * @param frame pointer to an allocated frame that will be filled with data.
- * The data must be freed using av_frame_unref() / av_frame_free()
- *
- * @return
- * - >= 0 if a frame was successfully returned.
- * - AVERROR(EAGAIN) if no frames are available at this point; more
- * input frames must be added to the filtergraph to get more output.
- * - AVERROR_EOF if there will be no more output frames on this sink.
- * - A different negative AVERROR code in other failure cases.
- */
-int av_buffersink_get_frame(AVFilterContext *ctx, AVFrame *frame);
-
-/**
- * Same as av_buffersink_get_frame(), but with the ability to specify the number
- * of samples read. This function is less efficient than
- * av_buffersink_get_frame(), because it copies the data around.
- *
- * @param ctx pointer to a context of the abuffersink AVFilter.
- * @param frame pointer to an allocated frame that will be filled with data.
- * The data must be freed using av_frame_unref() / av_frame_free()
- * frame will contain exactly nb_samples audio samples, except at
- * the end of stream, when it can contain less than nb_samples.
- *
- * @return The return codes have the same meaning as for
- * av_buffersink_get_samples().
- *
- * @warning do not mix this function with av_buffersink_get_frame(). Use only one or
- * the other with a single sink, not both.
- */
-int av_buffersink_get_samples(AVFilterContext *ctx, AVFrame *frame, int nb_samples);
-
-/**
- * @}
- */
-
-#endif /* AVFILTER_BUFFERSINK_H */
diff --git a/Externals/ffmpeg/dev/include/libavfilter/buffersrc.h b/Externals/ffmpeg/dev/include/libavfilter/buffersrc.h
deleted file mode 100644
index ea34c04ee9..0000000000
--- a/Externals/ffmpeg/dev/include/libavfilter/buffersrc.h
+++ /dev/null
@@ -1,160 +0,0 @@
-/*
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef AVFILTER_BUFFERSRC_H
-#define AVFILTER_BUFFERSRC_H
-
-/**
- * @file
- * @ingroup lavfi_buffersrc
- * Memory buffer source API.
- */
-
-#include "libavcodec/avcodec.h"
-#include "avfilter.h"
-
-/**
- * @defgroup lavfi_buffersrc Buffer source API
- * @ingroup lavfi
- * @{
- */
-
-enum {
-
- /**
- * Do not check for format changes.
- */
- AV_BUFFERSRC_FLAG_NO_CHECK_FORMAT = 1,
-
-#if FF_API_AVFILTERBUFFER
- /**
- * Ignored
- */
- AV_BUFFERSRC_FLAG_NO_COPY = 2,
-#endif
-
- /**
- * Immediately push the frame to the output.
- */
- AV_BUFFERSRC_FLAG_PUSH = 4,
-
- /**
- * Keep a reference to the frame.
- * If the frame if reference-counted, create a new reference; otherwise
- * copy the frame data.
- */
- AV_BUFFERSRC_FLAG_KEEP_REF = 8,
-
-};
-
-/**
- * Add buffer data in picref to buffer_src.
- *
- * @param buffer_src pointer to a buffer source context
- * @param picref a buffer reference, or NULL to mark EOF
- * @param flags a combination of AV_BUFFERSRC_FLAG_*
- * @return >= 0 in case of success, a negative AVERROR code
- * in case of failure
- */
-int av_buffersrc_add_ref(AVFilterContext *buffer_src,
- AVFilterBufferRef *picref, int flags);
-
-/**
- * Get the number of failed requests.
- *
- * A failed request is when the request_frame method is called while no
- * frame is present in the buffer.
- * The number is reset when a frame is added.
- */
-unsigned av_buffersrc_get_nb_failed_requests(AVFilterContext *buffer_src);
-
-#if FF_API_AVFILTERBUFFER
-/**
- * Add a buffer to a filtergraph.
- *
- * @param ctx an instance of the buffersrc filter
- * @param buf buffer containing frame data to be passed down the filtergraph.
- * This function will take ownership of buf, the user must not free it.
- * A NULL buf signals EOF -- i.e. no more frames will be sent to this filter.
- *
- * @deprecated use av_buffersrc_write_frame() or av_buffersrc_add_frame()
- */
-attribute_deprecated
-int av_buffersrc_buffer(AVFilterContext *ctx, AVFilterBufferRef *buf);
-#endif
-
-/**
- * Add a frame to the buffer source.
- *
- * @param ctx an instance of the buffersrc filter
- * @param frame frame to be added. If the frame is reference counted, this
- * function will make a new reference to it. Otherwise the frame data will be
- * copied.
- *
- * @return 0 on success, a negative AVERROR on error
- *
- * This function is equivalent to av_buffersrc_add_frame_flags() with the
- * AV_BUFFERSRC_FLAG_KEEP_REF flag.
- */
-int av_buffersrc_write_frame(AVFilterContext *ctx, const AVFrame *frame);
-
-/**
- * Add a frame to the buffer source.
- *
- * @param ctx an instance of the buffersrc filter
- * @param frame frame to be added. If the frame is reference counted, this
- * function will take ownership of the reference(s) and reset the frame.
- * Otherwise the frame data will be copied. If this function returns an error,
- * the input frame is not touched.
- *
- * @return 0 on success, a negative AVERROR on error.
- *
- * @note the difference between this function and av_buffersrc_write_frame() is
- * that av_buffersrc_write_frame() creates a new reference to the input frame,
- * while this function takes ownership of the reference passed to it.
- *
- * This function is equivalent to av_buffersrc_add_frame_flags() without the
- * AV_BUFFERSRC_FLAG_KEEP_REF flag.
- */
-int av_buffersrc_add_frame(AVFilterContext *ctx, AVFrame *frame);
-
-/**
- * Add a frame to the buffer source.
- *
- * By default, if the frame is reference-counted, this function will take
- * ownership of the reference(s) and reset the frame. This can be controlled
- * using the flags.
- *
- * If this function returns an error, the input frame is not touched.
- *
- * @param buffer_src pointer to a buffer source context
- * @param frame a frame, or NULL to mark EOF
- * @param flags a combination of AV_BUFFERSRC_FLAG_*
- * @return >= 0 in case of success, a negative AVERROR code
- * in case of failure
- */
-int av_buffersrc_add_frame_flags(AVFilterContext *buffer_src,
- AVFrame *frame, int flags);
-
-
-/**
- * @}
- */
-
-#endif /* AVFILTER_BUFFERSRC_H */
diff --git a/Externals/ffmpeg/dev/include/libavfilter/version.h b/Externals/ffmpeg/dev/include/libavfilter/version.h
deleted file mode 100644
index 383eb55ef4..0000000000
--- a/Externals/ffmpeg/dev/include/libavfilter/version.h
+++ /dev/null
@@ -1,80 +0,0 @@
-/*
- * Version macros.
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef AVFILTER_VERSION_H
-#define AVFILTER_VERSION_H
-
-/**
- * @file
- * @ingroup lavfi
- * Libavfilter version macros
- */
-
-#include "libavutil/version.h"
-
-#define LIBAVFILTER_VERSION_MAJOR 5
-#define LIBAVFILTER_VERSION_MINOR 7
-#define LIBAVFILTER_VERSION_MICRO 101
-
-#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
- LIBAVFILTER_VERSION_MINOR, \
- LIBAVFILTER_VERSION_MICRO)
-#define LIBAVFILTER_VERSION AV_VERSION(LIBAVFILTER_VERSION_MAJOR, \
- LIBAVFILTER_VERSION_MINOR, \
- LIBAVFILTER_VERSION_MICRO)
-#define LIBAVFILTER_BUILD LIBAVFILTER_VERSION_INT
-
-#define LIBAVFILTER_IDENT "Lavfi" AV_STRINGIFY(LIBAVFILTER_VERSION)
-
-/**
- * FF_API_* defines may be placed below to indicate public API that will be
- * dropped at a future version bump. The defines themselves are not part of
- * the public API and may change, break or disappear at any time.
- */
-
-#ifndef FF_API_AVFILTERPAD_PUBLIC
-#define FF_API_AVFILTERPAD_PUBLIC (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_FOO_COUNT
-#define FF_API_FOO_COUNT (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_AVFILTERBUFFER
-#define FF_API_AVFILTERBUFFER (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_OLD_FILTER_OPTS
-#define FF_API_OLD_FILTER_OPTS (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_AVFILTER_OPEN
-#define FF_API_AVFILTER_OPEN (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_AVFILTER_INIT_FILTER
-#define FF_API_AVFILTER_INIT_FILTER (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_OLD_FILTER_REGISTER
-#define FF_API_OLD_FILTER_REGISTER (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-#ifndef FF_API_OLD_GRAPH_PARSE
-#define FF_API_OLD_GRAPH_PARSE (LIBAVFILTER_VERSION_MAJOR < 5)
-#endif
-#ifndef FF_API_NOCONST_GET_NAME
-#define FF_API_NOCONST_GET_NAME (LIBAVFILTER_VERSION_MAJOR < 6)
-#endif
-
-#endif /* AVFILTER_VERSION_H */
diff --git a/Externals/ffmpeg/dev/include/libpostproc/postprocess.h b/Externals/ffmpeg/dev/include/libpostproc/postprocess.h
deleted file mode 100644
index e00ed968d7..0000000000
--- a/Externals/ffmpeg/dev/include/libpostproc/postprocess.h
+++ /dev/null
@@ -1,107 +0,0 @@
-/*
- * Copyright (C) 2001-2003 Michael Niedermayer (michaelni@gmx.at)
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or modify
- * it under the terms of the GNU General Public License as published by
- * the Free Software Foundation; either version 2 of the License, or
- * (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU General Public License
- * along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef POSTPROC_POSTPROCESS_H
-#define POSTPROC_POSTPROCESS_H
-
-/**
- * @file
- * @ingroup lpp
- * external API header
- */
-
-/**
- * @defgroup lpp Libpostproc
- * @{
- */
-
-#include "libpostproc/version.h"
-
-/**
- * Return the LIBPOSTPROC_VERSION_INT constant.
- */
-unsigned postproc_version(void);
-
-/**
- * Return the libpostproc build-time configuration.
- */
-const char *postproc_configuration(void);
-
-/**
- * Return the libpostproc license.
- */
-const char *postproc_license(void);
-
-#define PP_QUALITY_MAX 6
-
-#define QP_STORE_T int8_t
-
-#include
-
-typedef void pp_context;
-typedef void pp_mode;
-
-#if LIBPOSTPROC_VERSION_INT < (52<<16)
-typedef pp_context pp_context_t;
-typedef pp_mode pp_mode_t;
-extern const char *const pp_help; ///< a simple help text
-#else
-extern const char pp_help[]; ///< a simple help text
-#endif
-
-void pp_postprocess(const uint8_t * src[3], const int srcStride[3],
- uint8_t * dst[3], const int dstStride[3],
- int horizontalSize, int verticalSize,
- const QP_STORE_T *QP_store, int QP_stride,
- pp_mode *mode, pp_context *ppContext, int pict_type);
-
-
-/**
- * Return a pp_mode or NULL if an error occurred.
- *
- * @param name the string after "-pp" on the command line
- * @param quality a number from 0 to PP_QUALITY_MAX
- */
-pp_mode *pp_get_mode_by_name_and_quality(const char *name, int quality);
-void pp_free_mode(pp_mode *mode);
-
-pp_context *pp_get_context(int width, int height, int flags);
-void pp_free_context(pp_context *ppContext);
-
-#define PP_CPU_CAPS_MMX 0x80000000
-#define PP_CPU_CAPS_MMX2 0x20000000
-#define PP_CPU_CAPS_3DNOW 0x40000000
-#define PP_CPU_CAPS_ALTIVEC 0x10000000
-#define PP_CPU_CAPS_AUTO 0x00080000
-
-#define PP_FORMAT 0x00000008
-#define PP_FORMAT_420 (0x00000011|PP_FORMAT)
-#define PP_FORMAT_422 (0x00000001|PP_FORMAT)
-#define PP_FORMAT_411 (0x00000002|PP_FORMAT)
-#define PP_FORMAT_444 (0x00000000|PP_FORMAT)
-#define PP_FORMAT_440 (0x00000010|PP_FORMAT)
-
-#define PP_PICT_TYPE_QP2 0x00000010 ///< MPEG2 style QScale
-
-/**
- * @}
- */
-
-#endif /* POSTPROC_POSTPROCESS_H */
diff --git a/Externals/ffmpeg/dev/include/libpostproc/version.h b/Externals/ffmpeg/dev/include/libpostproc/version.h
deleted file mode 100644
index 59c24660f8..0000000000
--- a/Externals/ffmpeg/dev/include/libpostproc/version.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Version macros.
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef POSTPROC_POSTPROCESS_VERSION_H
-#define POSTPROC_POSTPROCESS_VERSION_H
-
-/**
- * @file
- * Libpostproc version macros
- */
-
-#include "libavutil/avutil.h"
-
-#define LIBPOSTPROC_VERSION_MAJOR 53
-#define LIBPOSTPROC_VERSION_MINOR 3
-#define LIBPOSTPROC_VERSION_MICRO 100
-
-#define LIBPOSTPROC_VERSION_INT AV_VERSION_INT(LIBPOSTPROC_VERSION_MAJOR, \
- LIBPOSTPROC_VERSION_MINOR, \
- LIBPOSTPROC_VERSION_MICRO)
-#define LIBPOSTPROC_VERSION AV_VERSION(LIBPOSTPROC_VERSION_MAJOR, \
- LIBPOSTPROC_VERSION_MINOR, \
- LIBPOSTPROC_VERSION_MICRO)
-#define LIBPOSTPROC_BUILD LIBPOSTPROC_VERSION_INT
-
-#define LIBPOSTPROC_IDENT "postproc" AV_STRINGIFY(LIBPOSTPROC_VERSION)
-
-#endif /* POSTPROC_POSTPROCESS_VERSION_H */
diff --git a/Externals/ffmpeg/dev/include/libswresample/swresample.h b/Externals/ffmpeg/dev/include/libswresample/swresample.h
deleted file mode 100644
index 37656a667d..0000000000
--- a/Externals/ffmpeg/dev/include/libswresample/swresample.h
+++ /dev/null
@@ -1,534 +0,0 @@
-/*
- * Copyright (C) 2011-2013 Michael Niedermayer (michaelni@gmx.at)
- *
- * This file is part of libswresample
- *
- * libswresample is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * libswresample is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with libswresample; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef SWRESAMPLE_SWRESAMPLE_H
-#define SWRESAMPLE_SWRESAMPLE_H
-
-/**
- * @file
- * @ingroup lswr
- * libswresample public header
- */
-
-/**
- * @defgroup lswr Libswresample
- * @{
- *
- * Libswresample (lswr) is a library that handles audio resampling, sample
- * format conversion and mixing.
- *
- * Interaction with lswr is done through SwrContext, which is
- * allocated with swr_alloc() or swr_alloc_set_opts(). It is opaque, so all parameters
- * must be set with the @ref avoptions API.
- *
- * The first thing you will need to do in order to use lswr is to allocate
- * SwrContext. This can be done with swr_alloc() or swr_alloc_set_opts(). If you
- * are using the former, you must set options through the @ref avoptions API.
- * The latter function provides the same feature, but it allows you to set some
- * common options in the same statement.
- *
- * For example the following code will setup conversion from planar float sample
- * format to interleaved signed 16-bit integer, downsampling from 48kHz to
- * 44.1kHz and downmixing from 5.1 channels to stereo (using the default mixing
- * matrix). This is using the swr_alloc() function.
- * @code
- * SwrContext *swr = swr_alloc();
- * av_opt_set_channel_layout(swr, "in_channel_layout", AV_CH_LAYOUT_5POINT1, 0);
- * av_opt_set_channel_layout(swr, "out_channel_layout", AV_CH_LAYOUT_STEREO, 0);
- * av_opt_set_int(swr, "in_sample_rate", 48000, 0);
- * av_opt_set_int(swr, "out_sample_rate", 44100, 0);
- * av_opt_set_sample_fmt(swr, "in_sample_fmt", AV_SAMPLE_FMT_FLTP, 0);
- * av_opt_set_sample_fmt(swr, "out_sample_fmt", AV_SAMPLE_FMT_S16, 0);
- * @endcode
- *
- * The same job can be done using swr_alloc_set_opts() as well:
- * @code
- * SwrContext *swr = swr_alloc_set_opts(NULL, // we're allocating a new context
- * AV_CH_LAYOUT_STEREO, // out_ch_layout
- * AV_SAMPLE_FMT_S16, // out_sample_fmt
- * 44100, // out_sample_rate
- * AV_CH_LAYOUT_5POINT1, // in_ch_layout
- * AV_SAMPLE_FMT_FLTP, // in_sample_fmt
- * 48000, // in_sample_rate
- * 0, // log_offset
- * NULL); // log_ctx
- * @endcode
- *
- * Once all values have been set, it must be initialized with swr_init(). If
- * you need to change the conversion parameters, you can change the parameters
- * using @ref AVOptions, as described above in the first example; or by using
- * swr_alloc_set_opts(), but with the first argument the allocated context.
- * You must then call swr_init() again.
- *
- * The conversion itself is done by repeatedly calling swr_convert().
- * Note that the samples may get buffered in swr if you provide insufficient
- * output space or if sample rate conversion is done, which requires "future"
- * samples. Samples that do not require future input can be retrieved at any
- * time by using swr_convert() (in_count can be set to 0).
- * At the end of conversion the resampling buffer can be flushed by calling
- * swr_convert() with NULL in and 0 in_count.
- *
- * The samples used in the conversion process can be managed with the libavutil
- * @ref lavu_sampmanip "samples manipulation" API, including av_samples_alloc()
- * function used in the following example.
- *
- * The delay between input and output, can at any time be found by using
- * swr_get_delay().
- *
- * The following code demonstrates the conversion loop assuming the parameters
- * from above and caller-defined functions get_input() and handle_output():
- * @code
- * uint8_t **input;
- * int in_samples;
- *
- * while (get_input(&input, &in_samples)) {
- * uint8_t *output;
- * int out_samples = av_rescale_rnd(swr_get_delay(swr, 48000) +
- * in_samples, 44100, 48000, AV_ROUND_UP);
- * av_samples_alloc(&output, NULL, 2, out_samples,
- * AV_SAMPLE_FMT_S16, 0);
- * out_samples = swr_convert(swr, &output, out_samples,
- * input, in_samples);
- * handle_output(output, out_samples);
- * av_freep(&output);
- * }
- * @endcode
- *
- * When the conversion is finished, the conversion
- * context and everything associated with it must be freed with swr_free().
- * A swr_close() function is also available, but it exists mainly for
- * compatibility with libavresample, and is not required to be called.
- *
- * There will be no memory leak if the data is not completely flushed before
- * swr_free().
- */
-
-#include
-#include "libavutil/frame.h"
-#include "libavutil/samplefmt.h"
-
-#include "libswresample/version.h"
-
-#if LIBSWRESAMPLE_VERSION_MAJOR < 1
-#define SWR_CH_MAX 32 ///< Maximum number of channels
-#endif
-
-/**
- * @name Option constants
- * These constants are used for the @ref avoptions interface for lswr.
- * @{
- *
- */
-
-#define SWR_FLAG_RESAMPLE 1 ///< Force resampling even if equal sample rate
-//TODO use int resample ?
-//long term TODO can we enable this dynamically?
-
-/** Dithering algorithms */
-enum SwrDitherType {
- SWR_DITHER_NONE = 0,
- SWR_DITHER_RECTANGULAR,
- SWR_DITHER_TRIANGULAR,
- SWR_DITHER_TRIANGULAR_HIGHPASS,
-
- SWR_DITHER_NS = 64, ///< not part of API/ABI
- SWR_DITHER_NS_LIPSHITZ,
- SWR_DITHER_NS_F_WEIGHTED,
- SWR_DITHER_NS_MODIFIED_E_WEIGHTED,
- SWR_DITHER_NS_IMPROVED_E_WEIGHTED,
- SWR_DITHER_NS_SHIBATA,
- SWR_DITHER_NS_LOW_SHIBATA,
- SWR_DITHER_NS_HIGH_SHIBATA,
- SWR_DITHER_NB, ///< not part of API/ABI
-};
-
-/** Resampling Engines */
-enum SwrEngine {
- SWR_ENGINE_SWR, /**< SW Resampler */
- SWR_ENGINE_SOXR, /**< SoX Resampler */
- SWR_ENGINE_NB, ///< not part of API/ABI
-};
-
-/** Resampling Filter Types */
-enum SwrFilterType {
- SWR_FILTER_TYPE_CUBIC, /**< Cubic */
- SWR_FILTER_TYPE_BLACKMAN_NUTTALL, /**< Blackman Nuttall Windowed Sinc */
- SWR_FILTER_TYPE_KAISER, /**< Kaiser Windowed Sinc */
-};
-
-/**
- * @}
- */
-
-/**
- * The libswresample context. Unlike libavcodec and libavformat, this structure
- * is opaque. This means that if you would like to set options, you must use
- * the @ref avoptions API and cannot directly set values to members of the
- * structure.
- */
-typedef struct SwrContext SwrContext;
-
-/**
- * Get the AVClass for SwrContext. It can be used in combination with
- * AV_OPT_SEARCH_FAKE_OBJ for examining options.
- *
- * @see av_opt_find().
- * @return the AVClass of SwrContext
- */
-const AVClass *swr_get_class(void);
-
-/**
- * @name SwrContext constructor functions
- * @{
- */
-
-/**
- * Allocate SwrContext.
- *
- * If you use this function you will need to set the parameters (manually or
- * with swr_alloc_set_opts()) before calling swr_init().
- *
- * @see swr_alloc_set_opts(), swr_init(), swr_free()
- * @return NULL on error, allocated context otherwise
- */
-struct SwrContext *swr_alloc(void);
-
-/**
- * Initialize context after user parameters have been set.
- * @note The context must be configured using the AVOption API.
- *
- * @see av_opt_set_int()
- * @see av_opt_set_dict()
- *
- * @param[in,out] s Swr context to initialize
- * @return AVERROR error code in case of failure.
- */
-int swr_init(struct SwrContext *s);
-
-/**
- * Check whether an swr context has been initialized or not.
- *
- * @param[in] s Swr context to check
- * @see swr_init()
- * @return positive if it has been initialized, 0 if not initialized
- */
-int swr_is_initialized(struct SwrContext *s);
-
-/**
- * Allocate SwrContext if needed and set/reset common parameters.
- *
- * This function does not require s to be allocated with swr_alloc(). On the
- * other hand, swr_alloc() can use swr_alloc_set_opts() to set the parameters
- * on the allocated context.
- *
- * @param s existing Swr context if available, or NULL if not
- * @param out_ch_layout output channel layout (AV_CH_LAYOUT_*)
- * @param out_sample_fmt output sample format (AV_SAMPLE_FMT_*).
- * @param out_sample_rate output sample rate (frequency in Hz)
- * @param in_ch_layout input channel layout (AV_CH_LAYOUT_*)
- * @param in_sample_fmt input sample format (AV_SAMPLE_FMT_*).
- * @param in_sample_rate input sample rate (frequency in Hz)
- * @param log_offset logging level offset
- * @param log_ctx parent logging context, can be NULL
- *
- * @see swr_init(), swr_free()
- * @return NULL on error, allocated context otherwise
- */
-struct SwrContext *swr_alloc_set_opts(struct SwrContext *s,
- int64_t out_ch_layout, enum AVSampleFormat out_sample_fmt, int out_sample_rate,
- int64_t in_ch_layout, enum AVSampleFormat in_sample_fmt, int in_sample_rate,
- int log_offset, void *log_ctx);
-
-/**
- * @}
- *
- * @name SwrContext destructor functions
- * @{
- */
-
-/**
- * Free the given SwrContext and set the pointer to NULL.
- *
- * @param[in] s a pointer to a pointer to Swr context
- */
-void swr_free(struct SwrContext **s);
-
-/**
- * Closes the context so that swr_is_initialized() returns 0.
- *
- * The context can be brought back to life by running swr_init(),
- * swr_init() can also be used without swr_close().
- * This function is mainly provided for simplifying the usecase
- * where one tries to support libavresample and libswresample.
- *
- * @param[in,out] s Swr context to be closed
- */
-void swr_close(struct SwrContext *s);
-
-/**
- * @}
- *
- * @name Core conversion functions
- * @{
- */
-
-/** Convert audio.
- *
- * in and in_count can be set to 0 to flush the last few samples out at the
- * end.
- *
- * If more input is provided than output space then the input will be buffered.
- * You can avoid this buffering by providing more output space than input.
- * Conversion will run directly without copying whenever possible.
- *
- * @param s allocated Swr context, with parameters set
- * @param out output buffers, only the first one need be set in case of packed audio
- * @param out_count amount of space available for output in samples per channel
- * @param in input buffers, only the first one need to be set in case of packed audio
- * @param in_count number of input samples available in one channel
- *
- * @return number of samples output per channel, negative value on error
- */
-int swr_convert(struct SwrContext *s, uint8_t **out, int out_count,
- const uint8_t **in , int in_count);
-
-/**
- * Convert the next timestamp from input to output
- * timestamps are in 1/(in_sample_rate * out_sample_rate) units.
- *
- * @note There are 2 slightly differently behaving modes.
- * @li When automatic timestamp compensation is not used, (min_compensation >= FLT_MAX)
- * in this case timestamps will be passed through with delays compensated
- * @li When automatic timestamp compensation is used, (min_compensation < FLT_MAX)
- * in this case the output timestamps will match output sample numbers.
- * See ffmpeg-resampler(1) for the two modes of compensation.
- *
- * @param s[in] initialized Swr context
- * @param pts[in] timestamp for the next input sample, INT64_MIN if unknown
- * @see swr_set_compensation(), swr_drop_output(), and swr_inject_silence() are
- * function used internally for timestamp compensation.
- * @return the output timestamp for the next output sample
- */
-int64_t swr_next_pts(struct SwrContext *s, int64_t pts);
-
-/**
- * @}
- *
- * @name Low-level option setting functions
- * These functons provide a means to set low-level options that is not possible
- * with the AVOption API.
- * @{
- */
-
-/**
- * Activate resampling compensation ("soft" compensation). This function is
- * internally called when needed in swr_next_pts().
- *
- * @param[in,out] s allocated Swr context. If it is not initialized,
- * or SWR_FLAG_RESAMPLE is not set, swr_init() is
- * called with the flag set.
- * @param[in] sample_delta delta in PTS per sample
- * @param[in] compensation_distance number of samples to compensate for
- * @return >= 0 on success, AVERROR error codes if:
- * @li @c s is NULL,
- * @li @c compensation_distance is less than 0,
- * @li @c compensation_distance is 0 but sample_delta is not,
- * @li compensation unsupported by resampler, or
- * @li swr_init() fails when called.
- */
-int swr_set_compensation(struct SwrContext *s, int sample_delta, int compensation_distance);
-
-/**
- * Set a customized input channel mapping.
- *
- * @param[in,out] s allocated Swr context, not yet initialized
- * @param[in] channel_map customized input channel mapping (array of channel
- * indexes, -1 for a muted channel)
- * @return >= 0 on success, or AVERROR error code in case of failure.
- */
-int swr_set_channel_mapping(struct SwrContext *s, const int *channel_map);
-
-/**
- * Set a customized remix matrix.
- *
- * @param s allocated Swr context, not yet initialized
- * @param matrix remix coefficients; matrix[i + stride * o] is
- * the weight of input channel i in output channel o
- * @param stride offset between lines of the matrix
- * @return >= 0 on success, or AVERROR error code in case of failure.
- */
-int swr_set_matrix(struct SwrContext *s, const double *matrix, int stride);
-
-/**
- * @}
- *
- * @name Sample handling functions
- * @{
- */
-
-/**
- * Drops the specified number of output samples.
- *
- * This function, along with swr_inject_silence(), is called by swr_next_pts()
- * if needed for "hard" compensation.
- *
- * @param s allocated Swr context
- * @param count number of samples to be dropped
- *
- * @return >= 0 on success, or a negative AVERROR code on failure
- */
-int swr_drop_output(struct SwrContext *s, int count);
-
-/**
- * Injects the specified number of silence samples.
- *
- * This function, along with swr_drop_output(), is called by swr_next_pts()
- * if needed for "hard" compensation.
- *
- * @param s allocated Swr context
- * @param count number of samples to be dropped
- *
- * @return >= 0 on success, or a negative AVERROR code on failure
- */
-int swr_inject_silence(struct SwrContext *s, int count);
-
-/**
- * Gets the delay the next input sample will experience relative to the next output sample.
- *
- * Swresample can buffer data if more input has been provided than available
- * output space, also converting between sample rates needs a delay.
- * This function returns the sum of all such delays.
- * The exact delay is not necessarily an integer value in either input or
- * output sample rate. Especially when downsampling by a large value, the
- * output sample rate may be a poor choice to represent the delay, similarly
- * for upsampling and the input sample rate.
- *
- * @param s swr context
- * @param base timebase in which the returned delay will be:
- * @li if it's set to 1 the returned delay is in seconds
- * @li if it's set to 1000 the returned delay is in milliseconds
- * @li if it's set to the input sample rate then the returned
- * delay is in input samples
- * @li if it's set to the output sample rate then the returned
- * delay is in output samples
- * @li if it's the least common multiple of in_sample_rate and
- * out_sample_rate then an exact rounding-free delay will be
- * returned
- * @returns the delay in 1 / @c base units.
- */
-int64_t swr_get_delay(struct SwrContext *s, int64_t base);
-
-/**
- * @}
- *
- * @name Configuration accessors
- * @{
- */
-
-/**
- * Return the @ref LIBSWRESAMPLE_VERSION_INT constant.
- *
- * This is useful to check if the build-time libswresample has the same version
- * as the run-time one.
- *
- * @returns the unsigned int-typed version
- */
-unsigned swresample_version(void);
-
-/**
- * Return the swr build-time configuration.
- *
- * @returns the build-time @c ./configure flags
- */
-const char *swresample_configuration(void);
-
-/**
- * Return the swr license.
- *
- * @returns the license of libswresample, determined at build-time
- */
-const char *swresample_license(void);
-
-/**
- * @}
- *
- * @name AVFrame based API
- * @{
- */
-
-/**
- * Convert the samples in the input AVFrame and write them to the output AVFrame.
- *
- * Input and output AVFrames must have channel_layout, sample_rate and format set.
- *
- * If the output AVFrame does not have the data pointers allocated the nb_samples
- * field will be set using av_frame_get_buffer()
- * is called to allocate the frame.
- *
- * The output AVFrame can be NULL or have fewer allocated samples than required.
- * In this case, any remaining samples not written to the output will be added
- * to an internal FIFO buffer, to be returned at the next call to this function
- * or to swr_convert().
- *
- * If converting sample rate, there may be data remaining in the internal
- * resampling delay buffer. swr_get_delay() tells the number of
- * remaining samples. To get this data as output, call this function or
- * swr_convert() with NULL input.
- *
- * If the SwrContext configuration does not match the output and
- * input AVFrame settings the conversion does not take place and depending on
- * which AVFrame is not matching AVERROR_OUTPUT_CHANGED, AVERROR_INPUT_CHANGED
- * or the result of a bitwise-OR of them is returned.
- *
- * @see swr_delay()
- * @see swr_convert()
- * @see swr_get_delay()
- *
- * @param swr audio resample context
- * @param output output AVFrame
- * @param input input AVFrame
- * @return 0 on success, AVERROR on failure or nonmatching
- * configuration.
- */
-int swr_convert_frame(SwrContext *swr,
- AVFrame *output, const AVFrame *input);
-
-/**
- * Configure or reconfigure the SwrContext using the information
- * provided by the AVFrames.
- *
- * The original resampling context is reset even on failure.
- * The function calls swr_close() internally if the context is open.
- *
- * @see swr_close();
- *
- * @param swr audio resample context
- * @param output output AVFrame
- * @param input input AVFrame
- * @return 0 on success, AVERROR on failure.
- */
-int swr_config_frame(SwrContext *swr, const AVFrame *out, const AVFrame *in);
-
-/**
- * @}
- * @}
- */
-
-#endif /* SWRESAMPLE_SWRESAMPLE_H */
diff --git a/Externals/ffmpeg/dev/include/libswresample/version.h b/Externals/ffmpeg/dev/include/libswresample/version.h
deleted file mode 100644
index 61c76fa2f4..0000000000
--- a/Externals/ffmpeg/dev/include/libswresample/version.h
+++ /dev/null
@@ -1,45 +0,0 @@
-/*
- * Version macros.
- *
- * This file is part of libswresample
- *
- * libswresample is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * libswresample is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with libswresample; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#ifndef SWR_VERSION_H
-#define SWR_VERSION_H
-
-/**
- * @file
- * Libswresample version macros
- */
-
-#include "libavutil/avutil.h"
-
-#define LIBSWRESAMPLE_VERSION_MAJOR 1
-#define LIBSWRESAMPLE_VERSION_MINOR 1
-#define LIBSWRESAMPLE_VERSION_MICRO 100
-
-#define LIBSWRESAMPLE_VERSION_INT AV_VERSION_INT(LIBSWRESAMPLE_VERSION_MAJOR, \
- LIBSWRESAMPLE_VERSION_MINOR, \
- LIBSWRESAMPLE_VERSION_MICRO)
-#define LIBSWRESAMPLE_VERSION AV_VERSION(LIBSWRESAMPLE_VERSION_MAJOR, \
- LIBSWRESAMPLE_VERSION_MINOR, \
- LIBSWRESAMPLE_VERSION_MICRO)
-#define LIBSWRESAMPLE_BUILD LIBSWRESAMPLE_VERSION_INT
-
-#define LIBSWRESAMPLE_IDENT "SwR" AV_STRINGIFY(LIBSWRESAMPLE_VERSION)
-
-#endif /* SWR_VERSION_H */
diff --git a/Externals/ffmpeg/dev/lib/avcodec-56.def b/Externals/ffmpeg/dev/lib/avcodec-56.def
deleted file mode 100644
index 962bd0f5e0..0000000000
--- a/Externals/ffmpeg/dev/lib/avcodec-56.def
+++ /dev/null
@@ -1,219 +0,0 @@
-EXPORTS
- audio_resample
- audio_resample_close
- av_audio_convert
- av_audio_convert_alloc
- av_audio_convert_free
- av_audio_resample_init
- av_bitstream_filter_close
- av_bitstream_filter_filter
- av_bitstream_filter_init
- av_bitstream_filter_next
- av_codec_ffversion DATA
- av_codec_get_chroma_intra_matrix
- av_codec_get_codec_descriptor
- av_codec_get_lowres
- av_codec_get_max_lowres
- av_codec_get_pkt_timebase
- av_codec_get_seek_preroll
- av_codec_is_decoder
- av_codec_is_encoder
- av_codec_next
- av_codec_set_chroma_intra_matrix
- av_codec_set_codec_descriptor
- av_codec_set_lowres
- av_codec_set_pkt_timebase
- av_codec_set_seek_preroll
- av_copy_packet
- av_copy_packet_side_data
- av_dct_calc
- av_dct_end
- av_dct_init
- av_destruct_packet
- av_dup_packet
- av_dv_codec_profile
- av_dv_codec_profile2
- av_dv_frame_profile
- av_fast_padded_malloc
- av_fast_padded_mallocz
- av_fft_calc
- av_fft_end
- av_fft_init
- av_fft_permute
- av_free_packet
- av_get_audio_frame_duration
- av_get_bits_per_sample
- av_get_codec_tag_string
- av_get_exact_bits_per_sample
- av_get_pcm_codec
- av_get_profile_name
- av_grow_packet
- av_hwaccel_next
- av_imdct_calc
- av_imdct_half
- av_init_packet
- av_lockmgr_register
- av_log_ask_for_sample
- av_log_missing_feature
- av_mdct_calc
- av_mdct_end
- av_mdct_init
- av_new_packet
- av_packet_copy_props
- av_packet_free_side_data
- av_packet_from_data
- av_packet_get_side_data
- av_packet_merge_side_data
- av_packet_move_ref
- av_packet_new_side_data
- av_packet_pack_dictionary
- av_packet_ref
- av_packet_rescale_ts
- av_packet_shrink_side_data
- av_packet_split_side_data
- av_packet_unpack_dictionary
- av_packet_unref
- av_parser_change
- av_parser_close
- av_parser_init
- av_parser_next
- av_parser_parse2
- av_picture_copy
- av_picture_crop
- av_picture_pad
- av_rdft_calc
- av_rdft_end
- av_rdft_init
- av_register_bitstream_filter
- av_register_codec_parser
- av_register_hwaccel
- av_resample
- av_resample_close
- av_resample_compensate
- av_resample_init
- av_shrink_packet
- av_vorbis_parse_frame
- av_vorbis_parse_frame_flags
- av_vorbis_parse_free
- av_vorbis_parse_init
- av_vorbis_parse_reset
- av_xiphlacing
- available_bits
- avcodec_align_dimensions
- avcodec_align_dimensions2
- avcodec_alloc_context3
- avcodec_alloc_frame
- avcodec_chroma_pos_to_enum
- avcodec_close
- avcodec_configuration
- avcodec_copy_context
- avcodec_dct_alloc
- avcodec_dct_get_class
- avcodec_dct_init
- avcodec_decode_audio3
- avcodec_decode_audio4
- avcodec_decode_subtitle2
- avcodec_decode_video2
- avcodec_default_execute
- avcodec_default_execute2
- avcodec_default_get_buffer
- avcodec_default_get_buffer2
- avcodec_default_get_format
- avcodec_default_reget_buffer
- avcodec_default_release_buffer
- avcodec_descriptor_get
- avcodec_descriptor_get_by_name
- avcodec_descriptor_next
- avcodec_encode_audio
- avcodec_encode_audio2
- avcodec_encode_subtitle
- avcodec_encode_video
- avcodec_encode_video2
- avcodec_enum_to_chroma_pos
- avcodec_fill_audio_frame
- avcodec_find_best_pix_fmt2
- avcodec_find_best_pix_fmt_of_2
- avcodec_find_best_pix_fmt_of_list
- avcodec_find_decoder
- avcodec_find_decoder_by_name
- avcodec_find_encoder
- avcodec_find_encoder_by_name
- avcodec_flush_buffers
- avcodec_free_context
- avcodec_free_frame
- avcodec_get_chroma_sub_sample
- avcodec_get_class
- avcodec_get_context_defaults3
- avcodec_get_edge_width
- avcodec_get_frame_class
- avcodec_get_frame_defaults
- avcodec_get_name
- avcodec_get_pix_fmt_loss
- avcodec_get_subtitle_rect_class
- avcodec_get_type
- avcodec_is_open
- avcodec_license
- avcodec_open2
- avcodec_pix_fmt_to_codec_tag
- avcodec_register
- avcodec_register_all
- avcodec_set_dimensions
- avcodec_string
- avcodec_version
- aver_isf_history
- avpicture_alloc
- avpicture_deinterlace
- avpicture_fill
- avpicture_free
- avpicture_get_size
- avpicture_layout
- avpriv_aac_parse_header
- avpriv_ac3_channel_layout_tab DATA
- avpriv_ac3_parse_header
- avpriv_ac3_parse_header2
- avpriv_align_put_bits
- avpriv_bprint_to_extradata
- avpriv_color_frame
- avpriv_copy_bits
- avpriv_copy_pce_data
- avpriv_dca_convert_bitstream
- avpriv_dca_sample_rates DATA
- avpriv_dirac_parse_sequence_header
- avpriv_dnxhd_get_frame_size
- avpriv_do_elbg
- avpriv_dv_frame_profile2
- avpriv_exif_decode_ifd
- avpriv_find_pix_fmt
- avpriv_find_start_code
- avpriv_flac_is_extradata_valid
- avpriv_flac_parse_streaminfo
- avpriv_get_raw_pix_fmt_tags
- avpriv_h264_has_num_reorder_frames
- avpriv_init_elbg
- avpriv_lock_avformat
- avpriv_mjpeg_bits_ac_chrominance DATA
- avpriv_mjpeg_bits_ac_luminance DATA
- avpriv_mjpeg_bits_dc_chrominance DATA
- avpriv_mjpeg_bits_dc_luminance DATA
- avpriv_mjpeg_val_ac_chrominance DATA
- avpriv_mjpeg_val_ac_luminance DATA
- avpriv_mjpeg_val_dc DATA
- avpriv_mpa_bitrate_tab DATA
- avpriv_mpa_decode_header
- avpriv_mpa_decode_header2
- avpriv_mpa_freq_tab DATA
- avpriv_mpeg4audio_get_config
- avpriv_mpeg4audio_sample_rates DATA
- avpriv_mpegaudio_decode_header
- avpriv_pix_fmt_bps_avi DATA
- avpriv_pix_fmt_bps_mov DATA
- avpriv_put_string
- avpriv_split_xiph_headers
- avpriv_tak_parse_streaminfo
- avpriv_toupper4
- avpriv_unlock_avformat
- avpriv_vorbis_parse_extradata
- avpriv_vorbis_parse_frame
- avpriv_vorbis_parse_frame_flags
- avpriv_vorbis_parse_reset
- avsubtitle_free
diff --git a/Externals/ffmpeg/dev/lib/avdevice-56.def b/Externals/ffmpeg/dev/lib/avdevice-56.def
deleted file mode 100644
index f453187e60..0000000000
--- a/Externals/ffmpeg/dev/lib/avdevice-56.def
+++ /dev/null
@@ -1,19 +0,0 @@
-EXPORTS
- av_device_capabilities DATA
- av_device_ffversion DATA
- av_input_audio_device_next
- av_input_video_device_next
- av_output_audio_device_next
- av_output_video_device_next
- avdevice_app_to_dev_control_message
- avdevice_capabilities_create
- avdevice_capabilities_free
- avdevice_configuration
- avdevice_dev_to_app_control_message
- avdevice_free_list_devices
- avdevice_license
- avdevice_list_devices
- avdevice_list_input_sources
- avdevice_list_output_sinks
- avdevice_register_all
- avdevice_version
diff --git a/Externals/ffmpeg/dev/lib/avdevice.lib b/Externals/ffmpeg/dev/lib/avdevice.lib
deleted file mode 100644
index 600f7b636c..0000000000
Binary files a/Externals/ffmpeg/dev/lib/avdevice.lib and /dev/null differ
diff --git a/Externals/ffmpeg/dev/lib/avfilter-5.def b/Externals/ffmpeg/dev/lib/avfilter-5.def
deleted file mode 100644
index 7268f51bbb..0000000000
--- a/Externals/ffmpeg/dev/lib/avfilter-5.def
+++ /dev/null
@@ -1,81 +0,0 @@
-EXPORTS
- av_abuffersink_params_alloc
- av_buffersink_get_buffer_ref
- av_buffersink_get_frame
- av_buffersink_get_frame_flags
- av_buffersink_get_frame_rate
- av_buffersink_get_samples
- av_buffersink_params_alloc
- av_buffersink_poll_frame
- av_buffersink_read
- av_buffersink_read_samples
- av_buffersink_set_frame_size
- av_buffersrc_add_frame
- av_buffersrc_add_frame_flags
- av_buffersrc_add_ref
- av_buffersrc_buffer
- av_buffersrc_get_nb_failed_requests
- av_buffersrc_write_frame
- av_filter_ffversion DATA
- av_filter_next
- avfilter_add_matrix
- avfilter_all_channel_layouts DATA
- avfilter_config_links
- avfilter_configuration
- avfilter_copy_buf_props
- avfilter_copy_buffer_ref_props
- avfilter_copy_frame_props
- avfilter_free
- avfilter_get_audio_buffer_ref_from_arrays
- avfilter_get_audio_buffer_ref_from_arrays_channels
- avfilter_get_audio_buffer_ref_from_frame
- avfilter_get_buffer_ref_from_frame
- avfilter_get_by_name
- avfilter_get_class
- avfilter_get_matrix
- avfilter_get_video_buffer_ref_from_arrays
- avfilter_get_video_buffer_ref_from_frame
- avfilter_graph_add_filter
- avfilter_graph_alloc
- avfilter_graph_alloc_filter
- avfilter_graph_config
- avfilter_graph_create_filter
- avfilter_graph_dump
- avfilter_graph_free
- avfilter_graph_get_filter
- avfilter_graph_parse
- avfilter_graph_parse2
- avfilter_graph_parse_ptr
- avfilter_graph_queue_command
- avfilter_graph_request_oldest
- avfilter_graph_send_command
- avfilter_graph_set_auto_convert
- avfilter_init_dict
- avfilter_init_filter
- avfilter_init_str
- avfilter_inout_alloc
- avfilter_inout_free
- avfilter_insert_filter
- avfilter_license
- avfilter_link
- avfilter_link_free
- avfilter_link_get_channels
- avfilter_link_set_closed
- avfilter_make_format64_list
- avfilter_mul_matrix
- avfilter_next
- avfilter_open
- avfilter_pad_count
- avfilter_pad_get_name
- avfilter_pad_get_type
- avfilter_process_command
- avfilter_ref_buffer
- avfilter_ref_get_channels
- avfilter_register
- avfilter_register_all
- avfilter_sub_matrix
- avfilter_transform
- avfilter_uninit
- avfilter_unref_buffer
- avfilter_unref_bufferp
- avfilter_version
diff --git a/Externals/ffmpeg/dev/lib/avfilter.lib b/Externals/ffmpeg/dev/lib/avfilter.lib
deleted file mode 100644
index 46b6cd509d..0000000000
Binary files a/Externals/ffmpeg/dev/lib/avfilter.lib and /dev/null differ
diff --git a/Externals/ffmpeg/dev/lib/avformat-56.def b/Externals/ffmpeg/dev/lib/avformat-56.def
deleted file mode 100644
index dfce181ede..0000000000
--- a/Externals/ffmpeg/dev/lib/avformat-56.def
+++ /dev/null
@@ -1,161 +0,0 @@
-EXPORTS
- av_add_index_entry
- av_append_packet
- av_codec_get_id
- av_codec_get_tag
- av_codec_get_tag2
- av_convert_lang_to
- av_demuxer_open
- av_dump_format
- av_filename_number_test
- av_find_best_stream
- av_find_default_stream_index
- av_find_input_format
- av_find_program_from_stream
- av_fmt_ctx_get_duration_estimation_method
- av_format_ffversion DATA
- av_format_get_audio_codec
- av_format_get_control_message_cb
- av_format_get_metadata_header_padding
- av_format_get_opaque
- av_format_get_probe_score
- av_format_get_subtitle_codec
- av_format_get_video_codec
- av_format_inject_global_side_data
- av_format_set_audio_codec
- av_format_set_control_message_cb
- av_format_set_metadata_header_padding
- av_format_set_opaque
- av_format_set_subtitle_codec
- av_format_set_video_codec
- av_get_frame_filename
- av_get_output_timestamp
- av_get_packet
- av_guess_codec
- av_guess_format
- av_guess_frame_rate
- av_guess_sample_aspect_ratio
- av_hex_dump
- av_hex_dump_log
- av_iformat_next
- av_index_search_timestamp
- av_interleaved_write_frame
- av_interleaved_write_uncoded_frame
- av_match_ext
- av_new_program
- av_oformat_next
- av_pkt_dump2
- av_pkt_dump_log2
- av_probe_input_buffer
- av_probe_input_buffer2
- av_probe_input_format
- av_probe_input_format2
- av_probe_input_format3
- av_read_frame
- av_read_pause
- av_read_play
- av_register_all
- av_register_input_format
- av_register_output_format
- av_sdp_create
- av_seek_frame
- av_stream_get_end_pts
- av_stream_get_parser
- av_stream_get_r_frame_rate
- av_stream_get_recommended_encoder_configuration
- av_stream_get_side_data
- av_stream_set_r_frame_rate
- av_stream_set_recommended_encoder_configuration
- av_url_split
- av_write_frame
- av_write_trailer
- av_write_uncoded_frame
- av_write_uncoded_frame_query
- avformat_alloc_context
- avformat_alloc_output_context2
- avformat_close_input
- avformat_configuration
- avformat_find_stream_info
- avformat_free_context
- avformat_get_class
- avformat_get_mov_audio_tags
- avformat_get_mov_video_tags
- avformat_get_riff_audio_tags
- avformat_get_riff_video_tags
- avformat_license
- avformat_match_stream_specifier
- avformat_network_deinit
- avformat_network_init
- avformat_new_stream
- avformat_open_input
- avformat_query_codec
- avformat_queue_attached_pictures
- avformat_seek_file
- avformat_version
- avformat_write_header
- avio_alloc_context
- avio_check
- avio_close
- avio_close_dyn_buf
- avio_closep
- avio_enum_protocols
- avio_feof
- avio_find_protocol_name
- avio_flush
- avio_get_str
- avio_get_str16be
- avio_get_str16le
- avio_open
- avio_open2
- avio_open_dyn_buf
- avio_pause
- avio_printf
- avio_put_str
- avio_put_str16le
- avio_r8
- avio_rb16
- avio_rb24
- avio_rb32
- avio_rb64
- avio_read
- avio_read_to_bprint
- avio_rl16
- avio_rl24
- avio_rl32
- avio_rl64
- avio_seek
- avio_seek_time
- avio_size
- avio_skip
- avio_w8
- avio_wb16
- avio_wb24
- avio_wb32
- avio_wb64
- avio_wl16
- avio_wl24
- avio_wl32
- avio_wl64
- avio_write
- avpriv_dv_get_packet
- avpriv_dv_init_demux
- avpriv_dv_produce_packet
- avpriv_mpegts_parse_close
- avpriv_mpegts_parse_open
- avpriv_mpegts_parse_packet
- avpriv_new_chapter
- avpriv_set_pts_info
- ff_inet_aton
- ff_rtp_get_local_rtcp_port
- ff_rtp_get_local_rtp_port
- ff_rtsp_parse_line
- ff_socket_nonblock
- ffio_open_dyn_packet_buf
- ffio_set_buf_size
- ffurl_close
- ffurl_open
- ffurl_read_complete
- ffurl_seek
- ffurl_size
- ffurl_write
- url_feof
diff --git a/Externals/ffmpeg/dev/lib/avutil-54.def b/Externals/ffmpeg/dev/lib/avutil-54.def
deleted file mode 100644
index e02e465fe6..0000000000
--- a/Externals/ffmpeg/dev/lib/avutil-54.def
+++ /dev/null
@@ -1,441 +0,0 @@
-EXPORTS
- av_add_q
- av_add_stable
- av_adler32_update
- av_aes_alloc
- av_aes_crypt
- av_aes_init
- av_aes_size DATA
- av_asprintf
- av_audio_fifo_alloc
- av_audio_fifo_drain
- av_audio_fifo_free
- av_audio_fifo_read
- av_audio_fifo_realloc
- av_audio_fifo_reset
- av_audio_fifo_size
- av_audio_fifo_space
- av_audio_fifo_write
- av_base64_decode
- av_base64_encode
- av_basename
- av_blowfish_crypt
- av_blowfish_crypt_ecb
- av_blowfish_init
- av_bmg_get
- av_bprint_append_data
- av_bprint_channel_layout
- av_bprint_chars
- av_bprint_clear
- av_bprint_escape
- av_bprint_finalize
- av_bprint_get_buffer
- av_bprint_init
- av_bprint_init_for_buffer
- av_bprint_strftime
- av_bprintf
- av_buffer_alloc
- av_buffer_allocz
- av_buffer_create
- av_buffer_default_free
- av_buffer_get_opaque
- av_buffer_get_ref_count
- av_buffer_is_writable
- av_buffer_make_writable
- av_buffer_pool_get
- av_buffer_pool_init
- av_buffer_pool_uninit
- av_buffer_realloc
- av_buffer_ref
- av_buffer_unref
- av_calloc
- av_camellia_alloc
- av_camellia_crypt
- av_camellia_init
- av_camellia_size DATA
- av_cast5_alloc
- av_cast5_crypt
- av_cast5_crypt2
- av_cast5_init
- av_cast5_size DATA
- av_channel_layout_extract_channel
- av_chroma_location_name
- av_color_primaries_name
- av_color_range_name
- av_color_space_name
- av_color_transfer_name
- av_compare_mod
- av_compare_ts
- av_cpu_count
- av_crc
- av_crc_get_table
- av_crc_init
- av_ctz
- av_d2q
- av_d2str
- av_default_get_category
- av_default_item_name
- av_des_crypt
- av_des_init
- av_des_mac
- av_dict_copy
- av_dict_count
- av_dict_free
- av_dict_get
- av_dict_get_string
- av_dict_parse_string
- av_dict_set
- av_dict_set_int
- av_dirname
- av_display_matrix_flip
- av_display_rotation_get
- av_display_rotation_set
- av_div_q
- av_downmix_info_update_side_data
- av_dynarray2_add
- av_dynarray_add
- av_dynarray_add_nofree
- av_escape
- av_expr_eval
- av_expr_free
- av_expr_parse
- av_expr_parse_and_eval
- av_fast_malloc
- av_fast_realloc
- av_fifo_alloc
- av_fifo_alloc_array
- av_fifo_drain
- av_fifo_free
- av_fifo_freep
- av_fifo_generic_read
- av_fifo_generic_write
- av_fifo_grow
- av_fifo_realloc2
- av_fifo_reset
- av_fifo_size
- av_fifo_space
- av_file_map
- av_file_unmap
- av_find_best_pix_fmt_of_2
- av_find_info_tag
- av_find_nearest_q_idx
- av_fopen_utf8
- av_force_cpu_flags
- av_frame_alloc
- av_frame_clone
- av_frame_copy
- av_frame_copy_props
- av_frame_free
- av_frame_get_best_effort_timestamp
- av_frame_get_buffer
- av_frame_get_channel_layout
- av_frame_get_channels
- av_frame_get_color_range
- av_frame_get_colorspace
- av_frame_get_decode_error_flags
- av_frame_get_metadata
- av_frame_get_pkt_duration
- av_frame_get_pkt_pos
- av_frame_get_pkt_size
- av_frame_get_plane_buffer
- av_frame_get_qp_table
- av_frame_get_sample_rate
- av_frame_get_side_data
- av_frame_is_writable
- av_frame_make_writable
- av_frame_move_ref
- av_frame_new_side_data
- av_frame_ref
- av_frame_remove_side_data
- av_frame_set_best_effort_timestamp
- av_frame_set_channel_layout
- av_frame_set_channels
- av_frame_set_color_range
- av_frame_set_colorspace
- av_frame_set_decode_error_flags
- av_frame_set_metadata
- av_frame_set_pkt_duration
- av_frame_set_pkt_pos
- av_frame_set_pkt_size
- av_frame_set_qp_table
- av_frame_set_sample_rate
- av_frame_side_data_name
- av_frame_unref
- av_free
- av_freep
- av_gcd
- av_get_alt_sample_fmt
- av_get_bits_per_pixel
- av_get_bytes_per_sample
- av_get_channel_description
- av_get_channel_layout
- av_get_channel_layout_channel_index
- av_get_channel_layout_nb_channels
- av_get_channel_layout_string
- av_get_channel_name
- av_get_colorspace_name
- av_get_cpu_flags
- av_get_default_channel_layout
- av_get_double
- av_get_int
- av_get_known_color_name
- av_get_media_type_string
- av_get_packed_sample_fmt
- av_get_padded_bits_per_pixel
- av_get_picture_type_char
- av_get_pix_fmt
- av_get_pix_fmt_loss
- av_get_pix_fmt_name
- av_get_pix_fmt_string
- av_get_planar_sample_fmt
- av_get_q
- av_get_random_seed
- av_get_sample_fmt
- av_get_sample_fmt_name
- av_get_sample_fmt_string
- av_get_standard_channel_layout
- av_get_string
- av_get_time_base_q
- av_get_token
- av_gettime
- av_gettime_relative
- av_gettime_relative_is_monotonic
- av_hash_alloc
- av_hash_final
- av_hash_final_b64
- av_hash_final_bin
- av_hash_final_hex
- av_hash_freep
- av_hash_get_name
- av_hash_get_size
- av_hash_init
- av_hash_names
- av_hash_update
- av_hmac_alloc
- av_hmac_calc
- av_hmac_final
- av_hmac_free
- av_hmac_init
- av_hmac_update
- av_image_alloc
- av_image_check_sar
- av_image_check_size
- av_image_copy
- av_image_copy_plane
- av_image_copy_to_buffer
- av_image_fill_arrays
- av_image_fill_linesizes
- av_image_fill_max_pixsteps
- av_image_fill_pointers
- av_image_get_buffer_size
- av_image_get_linesize
- av_int_list_length_for_size
- av_isdigit
- av_isgraph
- av_isspace
- av_isxdigit
- av_lfg_init
- av_log
- av_log2
- av_log2_16bit
- av_log_default_callback
- av_log_format_line
- av_log_get_flags
- av_log_get_level
- av_log_set_callback
- av_log_set_flags
- av_log_set_level
- av_lzo1x_decode
- av_malloc
- av_mallocz
- av_match_list
- av_match_name
- av_max_alloc
- av_md5_alloc
- av_md5_final
- av_md5_init
- av_md5_size DATA
- av_md5_sum
- av_md5_update
- av_memcpy_backptr
- av_memdup
- av_mul_q
- av_murmur3_alloc
- av_murmur3_final
- av_murmur3_init
- av_murmur3_init_seeded
- av_murmur3_update
- av_nearer_q
- av_next_option
- av_opt_child_class_next
- av_opt_child_next
- av_opt_copy
- av_opt_eval_double
- av_opt_eval_flags
- av_opt_eval_float
- av_opt_eval_int
- av_opt_eval_int64
- av_opt_eval_q
- av_opt_find
- av_opt_find2
- av_opt_flag_is_set
- av_opt_free
- av_opt_freep_ranges
- av_opt_get
- av_opt_get_channel_layout
- av_opt_get_dict_val
- av_opt_get_double
- av_opt_get_image_size
- av_opt_get_int
- av_opt_get_key_value
- av_opt_get_pixel_fmt
- av_opt_get_q
- av_opt_get_sample_fmt
- av_opt_get_video_rate
- av_opt_is_set_to_default
- av_opt_is_set_to_default_by_name
- av_opt_next
- av_opt_ptr
- av_opt_query_ranges
- av_opt_query_ranges_default
- av_opt_serialize
- av_opt_set
- av_opt_set_bin
- av_opt_set_channel_layout
- av_opt_set_defaults
- av_opt_set_defaults2
- av_opt_set_dict
- av_opt_set_dict2
- av_opt_set_dict_val
- av_opt_set_double
- av_opt_set_from_string
- av_opt_set_image_size
- av_opt_set_int
- av_opt_set_pixel_fmt
- av_opt_set_q
- av_opt_set_sample_fmt
- av_opt_set_video_rate
- av_opt_show2
- av_parse_color
- av_parse_cpu_caps
- av_parse_cpu_flags
- av_parse_ratio
- av_parse_time
- av_parse_video_rate
- av_parse_video_size
- av_pix_fmt_count_planes
- av_pix_fmt_desc_get
- av_pix_fmt_desc_get_id
- av_pix_fmt_desc_next
- av_pix_fmt_descriptors DATA
- av_pix_fmt_get_chroma_sub_sample
- av_pix_fmt_swap_endianness
- av_pixelutils_get_sad_fn
- av_rc4_crypt
- av_rc4_init
- av_read_image_line
- av_realloc
- av_realloc_array
- av_realloc_f
- av_reallocp
- av_reallocp_array
- av_reduce
- av_rescale
- av_rescale_delta
- av_rescale_q
- av_rescale_q_rnd
- av_rescale_rnd
- av_reverse DATA
- av_ripemd_alloc
- av_ripemd_final
- av_ripemd_init
- av_ripemd_size DATA
- av_ripemd_update
- av_sample_fmt_is_planar
- av_samples_alloc
- av_samples_alloc_array_and_samples
- av_samples_copy
- av_samples_fill_arrays
- av_samples_get_buffer_size
- av_samples_set_silence
- av_set_cpu_flags_mask
- av_set_double
- av_set_int
- av_set_options_string
- av_set_q
- av_set_string3
- av_sha512_alloc
- av_sha512_final
- av_sha512_init
- av_sha512_size DATA
- av_sha512_update
- av_sha_alloc
- av_sha_final
- av_sha_init
- av_sha_size DATA
- av_sha_update
- av_small_strptime
- av_stereo3d_alloc
- av_stereo3d_create_side_data
- av_strcasecmp
- av_strdup
- av_strerror
- av_stristart
- av_stristr
- av_strlcat
- av_strlcatf
- av_strlcpy
- av_strncasecmp
- av_strndup
- av_strnstr
- av_strstart
- av_strtod
- av_strtok
- av_sub_q
- av_tempfile
- av_thread_message_queue_alloc
- av_thread_message_queue_free
- av_thread_message_queue_recv
- av_thread_message_queue_send
- av_thread_message_queue_set_err_recv
- av_thread_message_queue_set_err_send
- av_timecode_adjust_ntsc_framenum2
- av_timecode_check_frame_rate
- av_timecode_get_smpte_from_framenum
- av_timecode_init
- av_timecode_init_from_string
- av_timecode_make_mpeg_tc_string
- av_timecode_make_smpte_tc_string
- av_timecode_make_string
- av_timegm
- av_tree_destroy
- av_tree_enumerate
- av_tree_find
- av_tree_insert
- av_tree_node_alloc
- av_tree_node_size DATA
- av_usleep
- av_utf8_decode
- av_util_ffversion DATA
- av_vbprintf
- av_vlog
- av_write_image_line
- av_xtea_crypt
- av_xtea_init
- avpriv_alloc_fixed_dsp
- avpriv_cga_font DATA
- avpriv_emms_yasm DATA
- avpriv_float_dsp_alloc
- avpriv_float_dsp_init
- avpriv_frame_get_metadatap
- avpriv_init_lls
- avpriv_open
- avpriv_report_missing_feature
- avpriv_request_sample
- avpriv_scalarproduct_float_c
- avpriv_set_systematic_pal2
- avpriv_solve_lls
- avpriv_vga16_font DATA
- avutil_configuration
- avutil_license
- avutil_version
diff --git a/Externals/ffmpeg/dev/lib/libavcodec.dll.a b/Externals/ffmpeg/dev/lib/libavcodec.dll.a
deleted file mode 100644
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diff --git a/Externals/ffmpeg/dev/lib/libavdevice.dll.a b/Externals/ffmpeg/dev/lib/libavdevice.dll.a
deleted file mode 100644
index 5a8f4bd651..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libavfilter.dll.a b/Externals/ffmpeg/dev/lib/libavfilter.dll.a
deleted file mode 100644
index cf8577a906..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libavformat.dll.a b/Externals/ffmpeg/dev/lib/libavformat.dll.a
deleted file mode 100644
index 720c267654..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libavutil.dll.a b/Externals/ffmpeg/dev/lib/libavutil.dll.a
deleted file mode 100644
index 0220047180..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libpostproc.dll.a b/Externals/ffmpeg/dev/lib/libpostproc.dll.a
deleted file mode 100644
index c7b8ba266a..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libswresample.dll.a b/Externals/ffmpeg/dev/lib/libswresample.dll.a
deleted file mode 100644
index 999ec7f7ae..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/libswscale.dll.a b/Externals/ffmpeg/dev/lib/libswscale.dll.a
deleted file mode 100644
index 1dafa6ed2e..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/postproc-53.def b/Externals/ffmpeg/dev/lib/postproc-53.def
deleted file mode 100644
index 62c4c69d7f..0000000000
--- a/Externals/ffmpeg/dev/lib/postproc-53.def
+++ /dev/null
@@ -1,11 +0,0 @@
-EXPORTS
- postproc_configuration
- postproc_ffversion DATA
- postproc_license
- postproc_version
- pp_free_context
- pp_free_mode
- pp_get_context
- pp_get_mode_by_name_and_quality
- pp_help DATA
- pp_postprocess
diff --git a/Externals/ffmpeg/dev/lib/postproc.lib b/Externals/ffmpeg/dev/lib/postproc.lib
deleted file mode 100644
index 1425faa559..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/swresample-1.def b/Externals/ffmpeg/dev/lib/swresample-1.def
deleted file mode 100644
index a4aedce94a..0000000000
--- a/Externals/ffmpeg/dev/lib/swresample-1.def
+++ /dev/null
@@ -1,22 +0,0 @@
-EXPORTS
- swr_alloc
- swr_alloc_set_opts
- swr_close
- swr_config_frame
- swr_convert
- swr_convert_frame
- swr_drop_output
- swr_ffversion DATA
- swr_free
- swr_get_class
- swr_get_delay
- swr_init
- swr_inject_silence
- swr_is_initialized
- swr_next_pts
- swr_set_channel_mapping
- swr_set_compensation
- swr_set_matrix
- swresample_configuration
- swresample_license
- swresample_version
diff --git a/Externals/ffmpeg/dev/lib/swresample.lib b/Externals/ffmpeg/dev/lib/swresample.lib
deleted file mode 100644
index eedf4a8c75..0000000000
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diff --git a/Externals/ffmpeg/dev/lib/swscale-3.def b/Externals/ffmpeg/dev/lib/swscale-3.def
deleted file mode 100644
index d6330d95f2..0000000000
--- a/Externals/ffmpeg/dev/lib/swscale-3.def
+++ /dev/null
@@ -1,36 +0,0 @@
-EXPORTS
- sws_addVec
- sws_allocVec
- sws_alloc_context
- sws_cloneVec
- sws_context_class DATA
- sws_convVec
- sws_convertPalette8ToPacked24
- sws_convertPalette8ToPacked32
- sws_freeContext
- sws_freeFilter
- sws_freeVec
- sws_getCachedContext
- sws_getCoefficients
- sws_getColorspaceDetails
- sws_getConstVec
- sws_getContext
- sws_getDefaultFilter
- sws_getGaussianVec
- sws_getIdentityVec
- sws_get_class
- sws_init_context
- sws_isSupportedEndiannessConversion
- sws_isSupportedInput
- sws_isSupportedOutput
- sws_normalizeVec
- sws_printVec2
- sws_rgb2rgb_init
- sws_scale
- sws_scaleVec
- sws_setColorspaceDetails
- sws_shiftVec
- sws_subVec
- swscale_configuration
- swscale_license
- swscale_version
diff --git a/Externals/ffmpeg/shared/bin/avdevice-56.dll b/Externals/ffmpeg/shared/bin/avdevice-56.dll
deleted file mode 100644
index 147f99f79f..0000000000
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diff --git a/Externals/ffmpeg/shared/bin/ffmpeg.exe b/Externals/ffmpeg/shared/bin/ffmpeg.exe
deleted file mode 100644
index 9221b38029..0000000000
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deleted file mode 100644
index a7072b8fc0..0000000000
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diff --git a/Externals/ffmpeg/shared/bin/ffprobe.exe b/Externals/ffmpeg/shared/bin/ffprobe.exe
deleted file mode 100644
index b22ed9356a..0000000000
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diff --git a/Externals/ffmpeg/shared/bin/postproc-53.dll b/Externals/ffmpeg/shared/bin/postproc-53.dll
deleted file mode 100644
index cd536480cd..0000000000
Binary files a/Externals/ffmpeg/shared/bin/postproc-53.dll and /dev/null differ
diff --git a/Externals/ffmpeg/shared/doc/developer.html b/Externals/ffmpeg/shared/doc/developer.html
deleted file mode 100644
index ac67aae49a..0000000000
--- a/Externals/ffmpeg/shared/doc/developer.html
+++ /dev/null
@@ -1,777 +0,0 @@
-
-
-
-
-
- Developer Documentation
-
-
-
- Developer Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Developers Guide# TOC
-
-
-
1.1 Notes for external developers# TOC
-
-
This document is mostly useful for internal FFmpeg developers.
-External developers who need to use the API in their application should
-refer to the API doxygen documentation in the public headers, and
-check the examples in doc/examples and in the source code to
-see how the public API is employed.
-
-
You can use the FFmpeg libraries in your commercial program, but you
-are encouraged to publish any patch you make . In this case the
-best way to proceed is to send your patches to the ffmpeg-devel
-mailing list following the guidelines illustrated in the remainder of
-this document.
-
-
For more detailed legal information about the use of FFmpeg in
-external programs read the LICENSE file in the source tree and
-consult http://ffmpeg.org/legal.html .
-
-
-
1.2 Contributing# TOC
-
-
There are 3 ways by which code gets into ffmpeg.
-
- Submitting Patches to the main developer mailing list
- see Submitting patches for details.
- Directly committing changes to the main tree.
- Committing changes to a git clone, for example on github.com or
- gitorious.org. And asking us to merge these changes.
-
-
-
Whichever way, changes should be reviewed by the maintainer of the code
-before they are committed. And they should follow the Coding Rules .
-The developer making the commit and the author are responsible for their changes
-and should try to fix issues their commit causes.
-
-
-
1.3 Coding Rules# TOC
-
-
-
1.3.1 Code formatting conventions# TOC
-
-
There are the following guidelines regarding the indentation in files:
-
-
- Indent size is 4.
-
- The TAB character is forbidden outside of Makefiles as is any
-form of trailing whitespace. Commits containing either will be
-rejected by the git repository.
-
- You should try to limit your code lines to 80 characters; however, do so if
-and only if this improves readability.
-
-
The presentation is one inspired by ’indent -i4 -kr -nut’.
-
-
The main priority in FFmpeg is simplicity and small code size in order to
-minimize the bug count.
-
-
-
1.3.2 Comments# TOC
-
Use the JavaDoc/Doxygen format (see examples below) so that code documentation
-can be generated automatically. All nontrivial functions should have a comment
-above them explaining what the function does, even if it is just one sentence.
-All structures and their member variables should be documented, too.
-
-
Avoid Qt-style and similar Doxygen syntax with ! in it, i.e. replace
-//! with /// and similar. Also @ syntax should be employed
-for markup commands, i.e. use @param and not \param.
-
-
-
/**
- * @file
- * MPEG codec.
- * @author ...
- */
-
-/**
- * Summary sentence.
- * more text ...
- * ...
- */
-typedef struct Foobar {
- int var1; /**< var1 description */
- int var2; ///< var2 description
- /** var3 description */
- int var3;
-} Foobar;
-
-/**
- * Summary sentence.
- * more text ...
- * ...
- * @param my_parameter description of my_parameter
- * @return return value description
- */
-int myfunc(int my_parameter)
-...
-
-
-
-
1.3.3 C language features# TOC
-
-
FFmpeg is programmed in the ISO C90 language with a few additional
-features from ISO C99, namely:
-
-
- the ‘inline ’ keyword;
-
- ‘// ’ comments;
-
- designated struct initializers (‘struct s x = { .i = 17 }; ’)
-
- compound literals (‘x = (struct s) { 17, 23 }; ’)
-
-
-
These features are supported by all compilers we care about, so we will not
-accept patches to remove their use unless they absolutely do not impair
-clarity and performance.
-
-
All code must compile with recent versions of GCC and a number of other
-currently supported compilers. To ensure compatibility, please do not use
-additional C99 features or GCC extensions. Especially watch out for:
-
-
- mixing statements and declarations;
-
- ‘long long ’ (use ‘int64_t ’ instead);
-
- ‘__attribute__ ’ not protected by ‘#ifdef __GNUC__ ’ or similar;
-
- GCC statement expressions (‘(x = ({ int y = 4; y; }) ’).
-
-
-
-
1.3.4 Naming conventions# TOC
-
All names should be composed with underscores (_), not CamelCase. For example,
-‘avfilter_get_video_buffer ’ is an acceptable function name and
-‘AVFilterGetVideo ’ is not. The exception from this are type names, like
-for example structs and enums; they should always be in the CamelCase
-
-
There are the following conventions for naming variables and functions:
-
-
- For local variables no prefix is required.
-
- For file-scope variables and functions declared as static, no prefix
-is required.
-
- For variables and functions visible outside of file scope, but only used
-internally by a library, an ff_ prefix should be used,
-e.g. ‘ff_w64_demuxer ’.
-
- For variables and functions visible outside of file scope, used internally
-across multiple libraries, use avpriv_ as prefix, for example,
-‘avpriv_aac_parse_header ’.
-
- Each library has its own prefix for public symbols, in addition to the
-commonly used av_ (avformat_ for libavformat,
-avcodec_ for libavcodec, swr_ for libswresample, etc).
-Check the existing code and choose names accordingly.
-Note that some symbols without these prefixes are also exported for
-retro-compatibility reasons. These exceptions are declared in the
-lib<name>/lib<name>.v files.
-
-
-
Furthermore, name space reserved for the system should not be invaded.
-Identifiers ending in _t are reserved by
-POSIX .
-Also avoid names starting with __ or _ followed by an uppercase
-letter as they are reserved by the C standard. Names starting with _
-are reserved at the file level and may not be used for externally visible
-symbols. If in doubt, just avoid names starting with _ altogether.
-
-
-
1.3.5 Miscellaneous conventions# TOC
-
-
- fprintf and printf are forbidden in libavformat and libavcodec,
-please use av_log() instead.
-
- Casts should be used only when necessary. Unneeded parentheses
-should also be avoided if they don’t make the code easier to understand.
-
-
-
-
1.3.6 Editor configuration# TOC
-
In order to configure Vim to follow FFmpeg formatting conventions, paste
-the following snippet into your .vimrc :
-
-
" indentation rules for FFmpeg: 4 spaces, no tabs
-set expandtab
-set shiftwidth=4
-set softtabstop=4
-set cindent
-set cinoptions=(0
-" Allow tabs in Makefiles.
-autocmd FileType make,automake set noexpandtab shiftwidth=8 softtabstop=8
-" Trailing whitespace and tabs are forbidden, so highlight them.
-highlight ForbiddenWhitespace ctermbg=red guibg=red
-match ForbiddenWhitespace /\s\+$\|\t/
-" Do not highlight spaces at the end of line while typing on that line.
-autocmd InsertEnter * match ForbiddenWhitespace /\t\|\s\+\%#\@<!$/
-
-
-
For Emacs, add these roughly equivalent lines to your .emacs.d/init.el :
-
-
(c-add-style "ffmpeg"
- '("k&r"
- (c-basic-offset . 4)
- (indent-tabs-mode . nil)
- (show-trailing-whitespace . t)
- (c-offsets-alist
- (statement-cont . (c-lineup-assignments +)))
- )
- )
-(setq c-default-style "ffmpeg")
-
-
-
-
1.4 Development Policy# TOC
-
-
- Contributions should be licensed under the
-LGPL 2.1 ,
-including an "or any later version" clause, or, if you prefer
-a gift-style license, the
-ISC or
-MIT license.
-GPL 2 including
-an "or any later version" clause is also acceptable, but LGPL is
-preferred.
-If you add a new file, give it a proper license header. Do not copy and
-paste it from a random place, use an existing file as template.
-
- You must not commit code which breaks FFmpeg! (Meaning unfinished but
-enabled code which breaks compilation or compiles but does not work or
-breaks the regression tests)
-You can commit unfinished stuff (for testing etc), but it must be disabled
-(#ifdef etc) by default so it does not interfere with other developers’
-work.
-
- The commit message should have a short first line in the form of
-a ‘topic: short description ’ as a header, separated by a newline
-from the body consisting of an explanation of why the change is necessary.
-If the commit fixes a known bug on the bug tracker, the commit message
-should include its bug ID. Referring to the issue on the bug tracker does
-not exempt you from writing an excerpt of the bug in the commit message.
-
- You do not have to over-test things. If it works for you, and you think it
-should work for others, then commit. If your code has problems
-(portability, triggers compiler bugs, unusual environment etc) they will be
-reported and eventually fixed.
-
- Do not commit unrelated changes together, split them into self-contained
-pieces. Also do not forget that if part B depends on part A, but A does not
-depend on B, then A can and should be committed first and separate from B.
-Keeping changes well split into self-contained parts makes reviewing and
-understanding them on the commit log mailing list easier. This also helps
-in case of debugging later on.
-Also if you have doubts about splitting or not splitting, do not hesitate to
-ask/discuss it on the developer mailing list.
-
- Do not change behavior of the programs (renaming options etc) or public
-API or ABI without first discussing it on the ffmpeg-devel mailing list.
-Do not remove functionality from the code. Just improve!
-
-Note: Redundant code can be removed.
-
- Do not commit changes to the build system (Makefiles, configure script)
-which change behavior, defaults etc, without asking first. The same
-applies to compiler warning fixes, trivial looking fixes and to code
-maintained by other developers. We usually have a reason for doing things
-the way we do. Send your changes as patches to the ffmpeg-devel mailing
-list, and if the code maintainers say OK, you may commit. This does not
-apply to files you wrote and/or maintain.
-
- We refuse source indentation and other cosmetic changes if they are mixed
-with functional changes, such commits will be rejected and removed. Every
-developer has his own indentation style, you should not change it. Of course
-if you (re)write something, you can use your own style, even though we would
-prefer if the indentation throughout FFmpeg was consistent (Many projects
-force a given indentation style - we do not.). If you really need to make
-indentation changes (try to avoid this), separate them strictly from real
-changes.
-
-NOTE: If you had to put if(){ .. } over a large (> 5 lines) chunk of code,
-then either do NOT change the indentation of the inner part within (do not
-move it to the right)! or do so in a separate commit
-
- Always fill out the commit log message. Describe in a few lines what you
-changed and why. You can refer to mailing list postings if you fix a
-particular bug. Comments such as "fixed!" or "Changed it." are unacceptable.
-Recommended format:
-
-
-
area changed: Short 1 line description
-
-details describing what and why and giving references.
- Make sure the author of the commit is set correctly. (see git commit –author)
-If you apply a patch, send an
-answer to ffmpeg-devel (or wherever you got the patch from) saying that
-you applied the patch.
-
- When applying patches that have been discussed (at length) on the mailing
-list, reference the thread in the log message.
-
- Do NOT commit to code actively maintained by others without permission.
-Send a patch to ffmpeg-devel instead. If no one answers within a reasonable
-timeframe (12h for build failures and security fixes, 3 days small changes,
-1 week for big patches) then commit your patch if you think it is OK.
-Also note, the maintainer can simply ask for more time to review!
-
- Subscribe to the ffmpeg-cvslog mailing list. The diffs of all commits
-are sent there and reviewed by all the other developers. Bugs and possible
-improvements or general questions regarding commits are discussed there. We
-expect you to react if problems with your code are uncovered.
-
- Update the documentation if you change behavior or add features. If you are
-unsure how best to do this, send a patch to ffmpeg-devel, the documentation
-maintainer(s) will review and commit your stuff.
-
- Try to keep important discussions and requests (also) on the public
-developer mailing list, so that all developers can benefit from them.
-
- Never write to unallocated memory, never write over the end of arrays,
-always check values read from some untrusted source before using them
-as array index or other risky things.
-
- Remember to check if you need to bump versions for the specific libav*
-parts (libavutil, libavcodec, libavformat) you are changing. You need
-to change the version integer.
-Incrementing the first component means no backward compatibility to
-previous versions (e.g. removal of a function from the public API).
-Incrementing the second component means backward compatible change
-(e.g. addition of a function to the public API or extension of an
-existing data structure).
-Incrementing the third component means a noteworthy binary compatible
-change (e.g. encoder bug fix that matters for the decoder). The third
-component always starts at 100 to distinguish FFmpeg from Libav.
-
- Compiler warnings indicate potential bugs or code with bad style. If a type of
-warning always points to correct and clean code, that warning should
-be disabled, not the code changed.
-Thus the remaining warnings can either be bugs or correct code.
-If it is a bug, the bug has to be fixed. If it is not, the code should
-be changed to not generate a warning unless that causes a slowdown
-or obfuscates the code.
-
- Make sure that no parts of the codebase that you maintain are missing from the
-MAINTAINERS file. If something that you want to maintain is missing add it with
-your name after it.
-If at some point you no longer want to maintain some code, then please help
-finding a new maintainer and also don’t forget updating the MAINTAINERS file.
-
-
-
We think our rules are not too hard. If you have comments, contact us.
-
-
-
1.5 Submitting patches# TOC
-
-
First, read the Coding Rules above if you did not yet, in particular
-the rules regarding patch submission.
-
-
When you submit your patch, please use git format-patch or
-git send-email. We cannot read other diffs :-)
-
-
Also please do not submit a patch which contains several unrelated changes.
-Split it into separate, self-contained pieces. This does not mean splitting
-file by file. Instead, make the patch as small as possible while still
-keeping it as a logical unit that contains an individual change, even
-if it spans multiple files. This makes reviewing your patches much easier
-for us and greatly increases your chances of getting your patch applied.
-
-
Use the patcheck tool of FFmpeg to check your patch.
-The tool is located in the tools directory.
-
-
Run the Regression tests before submitting a patch in order to verify
-it does not cause unexpected problems.
-
-
It also helps quite a bit if you tell us what the patch does (for example
-’replaces lrint by lrintf’), and why (for example ’*BSD isn’t C99 compliant
-and has no lrint()’)
-
-
Also please if you send several patches, send each patch as a separate mail,
-do not attach several unrelated patches to the same mail.
-
-
Patches should be posted to the
-ffmpeg-devel
-mailing list. Use git send-email when possible since it will properly
-send patches without requiring extra care. If you cannot, then send patches
-as base64-encoded attachments, so your patch is not trashed during
-transmission.
-
-
Your patch will be reviewed on the mailing list. You will likely be asked
-to make some changes and are expected to send in an improved version that
-incorporates the requests from the review. This process may go through
-several iterations. Once your patch is deemed good enough, some developer
-will pick it up and commit it to the official FFmpeg tree.
-
-
Give us a few days to react. But if some time passes without reaction,
-send a reminder by email. Your patch should eventually be dealt with.
-
-
-
-
1.6 New codecs or formats checklist# TOC
-
-
- Did you use av_cold for codec initialization and close functions?
-
- Did you add a long_name under NULL_IF_CONFIG_SMALL to the AVCodec or
-AVInputFormat/AVOutputFormat struct?
-
- Did you bump the minor version number (and reset the micro version
-number) in libavcodec/version.h or libavformat/version.h ?
-
- Did you register it in allcodecs.c or allformats.c ?
-
- Did you add the AVCodecID to avcodec.h ?
-When adding new codec IDs, also add an entry to the codec descriptor
-list in libavcodec/codec_desc.c .
-
- If it has a FourCC, did you add it to libavformat/riff.c ,
-even if it is only a decoder?
-
- Did you add a rule to compile the appropriate files in the Makefile?
-Remember to do this even if you’re just adding a format to a file that is
-already being compiled by some other rule, like a raw demuxer.
-
- Did you add an entry to the table of supported formats or codecs in
-doc/general.texi ?
-
- Did you add an entry in the Changelog?
-
- If it depends on a parser or a library, did you add that dependency in
-configure?
-
- Did you git add the appropriate files before committing?
-
- Did you make sure it compiles standalone, i.e. with
-configure --disable-everything --enable-decoder=foo
-(or --enable-demuxer or whatever your component is)?
-
-
-
-
-
1.7 patch submission checklist# TOC
-
-
- Does make fate pass with the patch applied?
-
- Was the patch generated with git format-patch or send-email?
-
- Did you sign off your patch? (git commit -s)
-See http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob_plain;f=Documentation/SubmittingPatches for the meaning
-of sign off.
-
- Did you provide a clear git commit log message?
-
- Is the patch against latest FFmpeg git master branch?
-
- Are you subscribed to ffmpeg-devel?
-(the list is subscribers only due to spam)
-
- Have you checked that the changes are minimal, so that the same cannot be
-achieved with a smaller patch and/or simpler final code?
-
- If the change is to speed critical code, did you benchmark it?
-
- If you did any benchmarks, did you provide them in the mail?
-
- Have you checked that the patch does not introduce buffer overflows or
-other security issues?
-
- Did you test your decoder or demuxer against damaged data? If no, see
-tools/trasher, the noise bitstream filter, and
-zzuf . Your decoder or demuxer
-should not crash, end in a (near) infinite loop, or allocate ridiculous
-amounts of memory when fed damaged data.
-
- Does the patch not mix functional and cosmetic changes?
-
- Did you add tabs or trailing whitespace to the code? Both are forbidden.
-
- Is the patch attached to the email you send?
-
- Is the mime type of the patch correct? It should be text/x-diff or
-text/x-patch or at least text/plain and not application/octet-stream.
-
- If the patch fixes a bug, did you provide a verbose analysis of the bug?
-
- If the patch fixes a bug, did you provide enough information, including
-a sample, so the bug can be reproduced and the fix can be verified?
-Note please do not attach samples >100k to mails but rather provide a
-URL, you can upload to ftp://upload.ffmpeg.org
-
- Did you provide a verbose summary about what the patch does change?
-
- Did you provide a verbose explanation why it changes things like it does?
-
- Did you provide a verbose summary of the user visible advantages and
-disadvantages if the patch is applied?
-
- Did you provide an example so we can verify the new feature added by the
-patch easily?
-
- If you added a new file, did you insert a license header? It should be
-taken from FFmpeg, not randomly copied and pasted from somewhere else.
-
- You should maintain alphabetical order in alphabetically ordered lists as
-long as doing so does not break API/ABI compatibility.
-
- Lines with similar content should be aligned vertically when doing so
-improves readability.
-
- Consider to add a regression test for your code.
-
- If you added YASM code please check that things still work with –disable-yasm
-
- Make sure you check the return values of function and return appropriate
-error codes. Especially memory allocation functions like av_malloc()
-are notoriously left unchecked, which is a serious problem.
-
- Test your code with valgrind and or Address Sanitizer to ensure it’s free
-of leaks, out of array accesses, etc.
-
-
-
-
1.8 Patch review process# TOC
-
-
All patches posted to ffmpeg-devel will be reviewed, unless they contain a
-clear note that the patch is not for the git master branch.
-Reviews and comments will be posted as replies to the patch on the
-mailing list. The patch submitter then has to take care of every comment,
-that can be by resubmitting a changed patch or by discussion. Resubmitted
-patches will themselves be reviewed like any other patch. If at some point
-a patch passes review with no comments then it is approved, that can for
-simple and small patches happen immediately while large patches will generally
-have to be changed and reviewed many times before they are approved.
-After a patch is approved it will be committed to the repository.
-
-
We will review all submitted patches, but sometimes we are quite busy so
-especially for large patches this can take several weeks.
-
-
If you feel that the review process is too slow and you are willing to try to
-take over maintainership of the area of code you change then just clone
-git master and maintain the area of code there. We will merge each area from
-where its best maintained.
-
-
When resubmitting patches, please do not make any significant changes
-not related to the comments received during review. Such patches will
-be rejected. Instead, submit significant changes or new features as
-separate patches.
-
-
-
1.9 Regression tests# TOC
-
-
Before submitting a patch (or committing to the repository), you should at least
-test that you did not break anything.
-
-
Running ’make fate’ accomplishes this, please see fate.html for details.
-
-
[Of course, some patches may change the results of the regression tests. In
-this case, the reference results of the regression tests shall be modified
-accordingly].
-
-
-
1.9.1 Adding files to the fate-suite dataset# TOC
-
-
When there is no muxer or encoder available to generate test media for a
-specific test then the media has to be included in the fate-suite.
-First please make sure that the sample file is as small as possible to test the
-respective decoder or demuxer sufficiently. Large files increase network
-bandwidth and disk space requirements.
-Once you have a working fate test and fate sample, provide in the commit
-message or introductory message for the patch series that you post to
-the ffmpeg-devel mailing list, a direct link to download the sample media.
-
-
-
-
1.9.2 Visualizing Test Coverage# TOC
-
-
The FFmpeg build system allows visualizing the test coverage in an easy
-manner with the coverage tools gcov/lcov. This involves
-the following steps:
-
-
- Configure to compile with instrumentation enabled:
- configure --toolchain=gcov.
-
- Run your test case, either manually or via FATE. This can be either
- the full FATE regression suite, or any arbitrary invocation of any
- front-end tool provided by FFmpeg, in any combination.
-
- Run make lcov to generate coverage data in HTML format.
-
- View lcov/index.html in your preferred HTML viewer.
-
-
-
You can use the command make lcov-reset to reset the coverage
-measurements. You will need to rerun make lcov after running a
-new test.
-
-
-
1.9.3 Using Valgrind# TOC
-
-
The configure script provides a shortcut for using valgrind to spot bugs
-related to memory handling. Just add the option
---toolchain=valgrind-memcheck or --toolchain=valgrind-massif
-to your configure line, and reasonable defaults will be set for running
-FATE under the supervision of either the memcheck or the
-massif tool of the valgrind suite.
-
-
In case you need finer control over how valgrind is invoked, use the
---target-exec='valgrind <your_custom_valgrind_options> option in
-your configure line instead.
-
-
-
1.10 Release process# TOC
-
-
FFmpeg maintains a set of release branches , which are the
-recommended deliverable for system integrators and distributors (such as
-Linux distributions, etc.). At regular times, a release
-manager prepares, tests and publishes tarballs on the
-http://ffmpeg.org website.
-
-
There are two kinds of releases:
-
-
- Major releases always include the latest and greatest
-features and functionality.
-
- Point releases are cut from release branches,
-which are named release/X, with X being the release
-version number.
-
-
-
Note that we promise to our users that shared libraries from any FFmpeg
-release never break programs that have been compiled against
-previous versions of the same release series in any case!
-
-
However, from time to time, we do make API changes that require adaptations
-in applications. Such changes are only allowed in (new) major releases and
-require further steps such as bumping library version numbers and/or
-adjustments to the symbol versioning file. Please discuss such changes
-on the ffmpeg-devel mailing list in time to allow forward planning.
-
-
-
1.10.1 Criteria for Point Releases# TOC
-
-
Changes that match the following criteria are valid candidates for
-inclusion into a point release:
-
-
- Fixes a security issue, preferably identified by a CVE
-number issued by http://cve.mitre.org/ .
-
- Fixes a documented bug in https://trac.ffmpeg.org .
-
- Improves the included documentation.
-
- Retains both source code and binary compatibility with previous
-point releases of the same release branch.
-
-
-
The order for checking the rules is (1 OR 2 OR 3) AND 4.
-
-
-
-
1.10.2 Release Checklist# TOC
-
-
The release process involves the following steps:
-
-
- Ensure that the RELEASE file contains the version number for
-the upcoming release.
-
- Add the release at https://trac.ffmpeg.org/admin/ticket/versions .
-
- Announce the intent to do a release to the mailing list.
-
- Make sure all relevant security fixes have been backported. See
-https://ffmpeg.org/security.html .
-
- Ensure that the FATE regression suite still passes in the release
-branch on at least i386 and amd64
-(cf. Regression tests ).
-
- Prepare the release tarballs in bz2 and gz formats, and
-supplementing files that contain gpg signatures
-
- Publish the tarballs at http://ffmpeg.org/releases . Create and
-push an annotated tag in the form nX, with X
-containing the version number.
-
- Propose and send a patch to the ffmpeg-devel mailing list
-with a news entry for the website.
-
- Publish the news entry.
-
- Send announcement to the mailing list.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
-#include
-#include
-#include
-
-struct buffer_data {
- uint8_t *ptr;
- size_t size; ///< size left in the buffer
-};
-
-static int read_packet(void *opaque, uint8_t *buf, int buf_size)
-{
- struct buffer_data *bd = (struct buffer_data *)opaque;
- buf_size = FFMIN(buf_size, bd->size);
-
- printf("ptr:%p size:%zu\n", bd->ptr, bd->size);
-
- /* copy internal buffer data to buf */
- memcpy(buf, bd->ptr, buf_size);
- bd->ptr += buf_size;
- bd->size -= buf_size;
-
- return buf_size;
-}
-
-int main(int argc, char *argv[])
-{
- AVFormatContext *fmt_ctx = NULL;
- AVIOContext *avio_ctx = NULL;
- uint8_t *buffer = NULL, *avio_ctx_buffer = NULL;
- size_t buffer_size, avio_ctx_buffer_size = 4096;
- char *input_filename = NULL;
- int ret = 0;
- struct buffer_data bd = { 0 };
-
- if (argc != 2) {
- fprintf(stderr, "usage: %s input_file\n"
- "API example program to show how to read from a custom buffer "
- "accessed through AVIOContext.\n", argv[0]);
- return 1;
- }
- input_filename = argv[1];
-
- /* register codecs and formats and other lavf/lavc components*/
- av_register_all();
-
- /* slurp file content into buffer */
- ret = av_file_map(input_filename, &buffer, &buffer_size, 0, NULL);
- if (ret < 0)
- goto end;
-
- /* fill opaque structure used by the AVIOContext read callback */
- bd.ptr = buffer;
- bd.size = buffer_size;
-
- if (!(fmt_ctx = avformat_alloc_context())) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- avio_ctx_buffer = av_malloc(avio_ctx_buffer_size);
- if (!avio_ctx_buffer) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
- avio_ctx = avio_alloc_context(avio_ctx_buffer, avio_ctx_buffer_size,
- 0, &bd, &read_packet, NULL, NULL);
- if (!avio_ctx) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
- fmt_ctx->pb = avio_ctx;
-
- ret = avformat_open_input(&fmt_ctx, NULL, NULL, NULL);
- if (ret < 0) {
- fprintf(stderr, "Could not open input\n");
- goto end;
- }
-
- ret = avformat_find_stream_info(fmt_ctx, NULL);
- if (ret < 0) {
- fprintf(stderr, "Could not find stream information\n");
- goto end;
- }
-
- av_dump_format(fmt_ctx, 0, input_filename, 0);
-
-end:
- avformat_close_input(&fmt_ctx);
- /* note: the internal buffer could have changed, and be != avio_ctx_buffer */
- if (avio_ctx) {
- av_freep(&avio_ctx->buffer);
- av_freep(&avio_ctx);
- }
- av_file_unmap(buffer, buffer_size);
-
- if (ret < 0) {
- fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
- return 1;
- }
-
- return 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/decoding_encoding.c b/Externals/ffmpeg/shared/doc/examples/decoding_encoding.c
deleted file mode 100644
index 80da66431b..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/decoding_encoding.c
+++ /dev/null
@@ -1,665 +0,0 @@
-/*
- * Copyright (c) 2001 Fabrice Bellard
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * libavcodec API use example.
- *
- * @example decoding_encoding.c
- * Note that libavcodec only handles codecs (mpeg, mpeg4, etc...),
- * not file formats (avi, vob, mp4, mov, mkv, mxf, flv, mpegts, mpegps, etc...). See library 'libavformat' for the
- * format handling
- */
-
-#include
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-#define INBUF_SIZE 4096
-#define AUDIO_INBUF_SIZE 20480
-#define AUDIO_REFILL_THRESH 4096
-
-/* check that a given sample format is supported by the encoder */
-static int check_sample_fmt(AVCodec *codec, enum AVSampleFormat sample_fmt)
-{
- const enum AVSampleFormat *p = codec->sample_fmts;
-
- while (*p != AV_SAMPLE_FMT_NONE) {
- if (*p == sample_fmt)
- return 1;
- p++;
- }
- return 0;
-}
-
-/* just pick the highest supported samplerate */
-static int select_sample_rate(AVCodec *codec)
-{
- const int *p;
- int best_samplerate = 0;
-
- if (!codec->supported_samplerates)
- return 44100;
-
- p = codec->supported_samplerates;
- while (*p) {
- best_samplerate = FFMAX(*p, best_samplerate);
- p++;
- }
- return best_samplerate;
-}
-
-/* select layout with the highest channel count */
-static int select_channel_layout(AVCodec *codec)
-{
- const uint64_t *p;
- uint64_t best_ch_layout = 0;
- int best_nb_channels = 0;
-
- if (!codec->channel_layouts)
- return AV_CH_LAYOUT_STEREO;
-
- p = codec->channel_layouts;
- while (*p) {
- int nb_channels = av_get_channel_layout_nb_channels(*p);
-
- if (nb_channels > best_nb_channels) {
- best_ch_layout = *p;
- best_nb_channels = nb_channels;
- }
- p++;
- }
- return best_ch_layout;
-}
-
-/*
- * Audio encoding example
- */
-static void audio_encode_example(const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- AVFrame *frame;
- AVPacket pkt;
- int i, j, k, ret, got_output;
- int buffer_size;
- FILE *f;
- uint16_t *samples;
- float t, tincr;
-
- printf("Encode audio file %s\n", filename);
-
- /* find the MP2 encoder */
- codec = avcodec_find_encoder(AV_CODEC_ID_MP2);
- if (!codec) {
- fprintf(stderr, "Codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- if (!c) {
- fprintf(stderr, "Could not allocate audio codec context\n");
- exit(1);
- }
-
- /* put sample parameters */
- c->bit_rate = 64000;
-
- /* check that the encoder supports s16 pcm input */
- c->sample_fmt = AV_SAMPLE_FMT_S16;
- if (!check_sample_fmt(codec, c->sample_fmt)) {
- fprintf(stderr, "Encoder does not support sample format %s",
- av_get_sample_fmt_name(c->sample_fmt));
- exit(1);
- }
-
- /* select other audio parameters supported by the encoder */
- c->sample_rate = select_sample_rate(codec);
- c->channel_layout = select_channel_layout(codec);
- c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "Could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "wb");
- if (!f) {
- fprintf(stderr, "Could not open %s\n", filename);
- exit(1);
- }
-
- /* frame containing input raw audio */
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Could not allocate audio frame\n");
- exit(1);
- }
-
- frame->nb_samples = c->frame_size;
- frame->format = c->sample_fmt;
- frame->channel_layout = c->channel_layout;
-
- /* the codec gives us the frame size, in samples,
- * we calculate the size of the samples buffer in bytes */
- buffer_size = av_samples_get_buffer_size(NULL, c->channels, c->frame_size,
- c->sample_fmt, 0);
- if (buffer_size < 0) {
- fprintf(stderr, "Could not get sample buffer size\n");
- exit(1);
- }
- samples = av_malloc(buffer_size);
- if (!samples) {
- fprintf(stderr, "Could not allocate %d bytes for samples buffer\n",
- buffer_size);
- exit(1);
- }
- /* setup the data pointers in the AVFrame */
- ret = avcodec_fill_audio_frame(frame, c->channels, c->sample_fmt,
- (const uint8_t*)samples, buffer_size, 0);
- if (ret < 0) {
- fprintf(stderr, "Could not setup audio frame\n");
- exit(1);
- }
-
- /* encode a single tone sound */
- t = 0;
- tincr = 2 * M_PI * 440.0 / c->sample_rate;
- for (i = 0; i < 200; i++) {
- av_init_packet(&pkt);
- pkt.data = NULL; // packet data will be allocated by the encoder
- pkt.size = 0;
-
- for (j = 0; j < c->frame_size; j++) {
- samples[2*j] = (int)(sin(t) * 10000);
-
- for (k = 1; k < c->channels; k++)
- samples[2*j + k] = samples[2*j];
- t += tincr;
- }
- /* encode the samples */
- ret = avcodec_encode_audio2(c, &pkt, frame, &got_output);
- if (ret < 0) {
- fprintf(stderr, "Error encoding audio frame\n");
- exit(1);
- }
- if (got_output) {
- fwrite(pkt.data, 1, pkt.size, f);
- av_free_packet(&pkt);
- }
- }
-
- /* get the delayed frames */
- for (got_output = 1; got_output; i++) {
- ret = avcodec_encode_audio2(c, &pkt, NULL, &got_output);
- if (ret < 0) {
- fprintf(stderr, "Error encoding frame\n");
- exit(1);
- }
-
- if (got_output) {
- fwrite(pkt.data, 1, pkt.size, f);
- av_free_packet(&pkt);
- }
- }
- fclose(f);
-
- av_freep(&samples);
- av_frame_free(&frame);
- avcodec_close(c);
- av_free(c);
-}
-
-/*
- * Audio decoding.
- */
-static void audio_decode_example(const char *outfilename, const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int len;
- FILE *f, *outfile;
- uint8_t inbuf[AUDIO_INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
- AVPacket avpkt;
- AVFrame *decoded_frame = NULL;
-
- av_init_packet(&avpkt);
-
- printf("Decode audio file %s to %s\n", filename, outfilename);
-
- /* find the mpeg audio decoder */
- codec = avcodec_find_decoder(AV_CODEC_ID_MP2);
- if (!codec) {
- fprintf(stderr, "Codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- if (!c) {
- fprintf(stderr, "Could not allocate audio codec context\n");
- exit(1);
- }
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "Could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "rb");
- if (!f) {
- fprintf(stderr, "Could not open %s\n", filename);
- exit(1);
- }
- outfile = fopen(outfilename, "wb");
- if (!outfile) {
- av_free(c);
- exit(1);
- }
-
- /* decode until eof */
- avpkt.data = inbuf;
- avpkt.size = fread(inbuf, 1, AUDIO_INBUF_SIZE, f);
-
- while (avpkt.size > 0) {
- int i, ch;
- int got_frame = 0;
-
- if (!decoded_frame) {
- if (!(decoded_frame = av_frame_alloc())) {
- fprintf(stderr, "Could not allocate audio frame\n");
- exit(1);
- }
- }
-
- len = avcodec_decode_audio4(c, decoded_frame, &got_frame, &avpkt);
- if (len < 0) {
- fprintf(stderr, "Error while decoding\n");
- exit(1);
- }
- if (got_frame) {
- /* if a frame has been decoded, output it */
- int data_size = av_get_bytes_per_sample(c->sample_fmt);
- if (data_size < 0) {
- /* This should not occur, checking just for paranoia */
- fprintf(stderr, "Failed to calculate data size\n");
- exit(1);
- }
- for (i=0; inb_samples; i++)
- for (ch=0; chchannels; ch++)
- fwrite(decoded_frame->data[ch] + data_size*i, 1, data_size, outfile);
- }
- avpkt.size -= len;
- avpkt.data += len;
- avpkt.dts =
- avpkt.pts = AV_NOPTS_VALUE;
- if (avpkt.size < AUDIO_REFILL_THRESH) {
- /* Refill the input buffer, to avoid trying to decode
- * incomplete frames. Instead of this, one could also use
- * a parser, or use a proper container format through
- * libavformat. */
- memmove(inbuf, avpkt.data, avpkt.size);
- avpkt.data = inbuf;
- len = fread(avpkt.data + avpkt.size, 1,
- AUDIO_INBUF_SIZE - avpkt.size, f);
- if (len > 0)
- avpkt.size += len;
- }
- }
-
- fclose(outfile);
- fclose(f);
-
- avcodec_close(c);
- av_free(c);
- av_frame_free(&decoded_frame);
-}
-
-/*
- * Video encoding example
- */
-static void video_encode_example(const char *filename, int codec_id)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int i, ret, x, y, got_output;
- FILE *f;
- AVFrame *frame;
- AVPacket pkt;
- uint8_t endcode[] = { 0, 0, 1, 0xb7 };
-
- printf("Encode video file %s\n", filename);
-
- /* find the mpeg1 video encoder */
- codec = avcodec_find_encoder(codec_id);
- if (!codec) {
- fprintf(stderr, "Codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- if (!c) {
- fprintf(stderr, "Could not allocate video codec context\n");
- exit(1);
- }
-
- /* put sample parameters */
- c->bit_rate = 400000;
- /* resolution must be a multiple of two */
- c->width = 352;
- c->height = 288;
- /* frames per second */
- c->time_base = (AVRational){1,25};
- /* emit one intra frame every ten frames
- * check frame pict_type before passing frame
- * to encoder, if frame->pict_type is AV_PICTURE_TYPE_I
- * then gop_size is ignored and the output of encoder
- * will always be I frame irrespective to gop_size
- */
- c->gop_size = 10;
- c->max_b_frames = 1;
- c->pix_fmt = AV_PIX_FMT_YUV420P;
-
- if (codec_id == AV_CODEC_ID_H264)
- av_opt_set(c->priv_data, "preset", "slow", 0);
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "Could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "wb");
- if (!f) {
- fprintf(stderr, "Could not open %s\n", filename);
- exit(1);
- }
-
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Could not allocate video frame\n");
- exit(1);
- }
- frame->format = c->pix_fmt;
- frame->width = c->width;
- frame->height = c->height;
-
- /* the image can be allocated by any means and av_image_alloc() is
- * just the most convenient way if av_malloc() is to be used */
- ret = av_image_alloc(frame->data, frame->linesize, c->width, c->height,
- c->pix_fmt, 32);
- if (ret < 0) {
- fprintf(stderr, "Could not allocate raw picture buffer\n");
- exit(1);
- }
-
- /* encode 1 second of video */
- for (i = 0; i < 25; i++) {
- av_init_packet(&pkt);
- pkt.data = NULL; // packet data will be allocated by the encoder
- pkt.size = 0;
-
- fflush(stdout);
- /* prepare a dummy image */
- /* Y */
- for (y = 0; y < c->height; y++) {
- for (x = 0; x < c->width; x++) {
- frame->data[0][y * frame->linesize[0] + x] = x + y + i * 3;
- }
- }
-
- /* Cb and Cr */
- for (y = 0; y < c->height/2; y++) {
- for (x = 0; x < c->width/2; x++) {
- frame->data[1][y * frame->linesize[1] + x] = 128 + y + i * 2;
- frame->data[2][y * frame->linesize[2] + x] = 64 + x + i * 5;
- }
- }
-
- frame->pts = i;
-
- /* encode the image */
- ret = avcodec_encode_video2(c, &pkt, frame, &got_output);
- if (ret < 0) {
- fprintf(stderr, "Error encoding frame\n");
- exit(1);
- }
-
- if (got_output) {
- printf("Write frame %3d (size=%5d)\n", i, pkt.size);
- fwrite(pkt.data, 1, pkt.size, f);
- av_free_packet(&pkt);
- }
- }
-
- /* get the delayed frames */
- for (got_output = 1; got_output; i++) {
- fflush(stdout);
-
- ret = avcodec_encode_video2(c, &pkt, NULL, &got_output);
- if (ret < 0) {
- fprintf(stderr, "Error encoding frame\n");
- exit(1);
- }
-
- if (got_output) {
- printf("Write frame %3d (size=%5d)\n", i, pkt.size);
- fwrite(pkt.data, 1, pkt.size, f);
- av_free_packet(&pkt);
- }
- }
-
- /* add sequence end code to have a real mpeg file */
- fwrite(endcode, 1, sizeof(endcode), f);
- fclose(f);
-
- avcodec_close(c);
- av_free(c);
- av_freep(&frame->data[0]);
- av_frame_free(&frame);
- printf("\n");
-}
-
-/*
- * Video decoding example
- */
-
-static void pgm_save(unsigned char *buf, int wrap, int xsize, int ysize,
- char *filename)
-{
- FILE *f;
- int i;
-
- f = fopen(filename,"w");
- fprintf(f, "P5\n%d %d\n%d\n", xsize, ysize, 255);
- for (i = 0; i < ysize; i++)
- fwrite(buf + i * wrap, 1, xsize, f);
- fclose(f);
-}
-
-static int decode_write_frame(const char *outfilename, AVCodecContext *avctx,
- AVFrame *frame, int *frame_count, AVPacket *pkt, int last)
-{
- int len, got_frame;
- char buf[1024];
-
- len = avcodec_decode_video2(avctx, frame, &got_frame, pkt);
- if (len < 0) {
- fprintf(stderr, "Error while decoding frame %d\n", *frame_count);
- return len;
- }
- if (got_frame) {
- printf("Saving %sframe %3d\n", last ? "last " : "", *frame_count);
- fflush(stdout);
-
- /* the picture is allocated by the decoder, no need to free it */
- snprintf(buf, sizeof(buf), outfilename, *frame_count);
- pgm_save(frame->data[0], frame->linesize[0],
- avctx->width, avctx->height, buf);
- (*frame_count)++;
- }
- if (pkt->data) {
- pkt->size -= len;
- pkt->data += len;
- }
- return 0;
-}
-
-static void video_decode_example(const char *outfilename, const char *filename)
-{
- AVCodec *codec;
- AVCodecContext *c= NULL;
- int frame_count;
- FILE *f;
- AVFrame *frame;
- uint8_t inbuf[INBUF_SIZE + FF_INPUT_BUFFER_PADDING_SIZE];
- AVPacket avpkt;
-
- av_init_packet(&avpkt);
-
- /* set end of buffer to 0 (this ensures that no overreading happens for damaged mpeg streams) */
- memset(inbuf + INBUF_SIZE, 0, FF_INPUT_BUFFER_PADDING_SIZE);
-
- printf("Decode video file %s to %s\n", filename, outfilename);
-
- /* find the mpeg1 video decoder */
- codec = avcodec_find_decoder(AV_CODEC_ID_MPEG1VIDEO);
- if (!codec) {
- fprintf(stderr, "Codec not found\n");
- exit(1);
- }
-
- c = avcodec_alloc_context3(codec);
- if (!c) {
- fprintf(stderr, "Could not allocate video codec context\n");
- exit(1);
- }
-
- if(codec->capabilities&CODEC_CAP_TRUNCATED)
- c->flags|= CODEC_FLAG_TRUNCATED; /* we do not send complete frames */
-
- /* For some codecs, such as msmpeg4 and mpeg4, width and height
- MUST be initialized there because this information is not
- available in the bitstream. */
-
- /* open it */
- if (avcodec_open2(c, codec, NULL) < 0) {
- fprintf(stderr, "Could not open codec\n");
- exit(1);
- }
-
- f = fopen(filename, "rb");
- if (!f) {
- fprintf(stderr, "Could not open %s\n", filename);
- exit(1);
- }
-
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Could not allocate video frame\n");
- exit(1);
- }
-
- frame_count = 0;
- for (;;) {
- avpkt.size = fread(inbuf, 1, INBUF_SIZE, f);
- if (avpkt.size == 0)
- break;
-
- /* NOTE1: some codecs are stream based (mpegvideo, mpegaudio)
- and this is the only method to use them because you cannot
- know the compressed data size before analysing it.
-
- BUT some other codecs (msmpeg4, mpeg4) are inherently frame
- based, so you must call them with all the data for one
- frame exactly. You must also initialize 'width' and
- 'height' before initializing them. */
-
- /* NOTE2: some codecs allow the raw parameters (frame size,
- sample rate) to be changed at any frame. We handle this, so
- you should also take care of it */
-
- /* here, we use a stream based decoder (mpeg1video), so we
- feed decoder and see if it could decode a frame */
- avpkt.data = inbuf;
- while (avpkt.size > 0)
- if (decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 0) < 0)
- exit(1);
- }
-
- /* some codecs, such as MPEG, transmit the I and P frame with a
- latency of one frame. You must do the following to have a
- chance to get the last frame of the video */
- avpkt.data = NULL;
- avpkt.size = 0;
- decode_write_frame(outfilename, c, frame, &frame_count, &avpkt, 1);
-
- fclose(f);
-
- avcodec_close(c);
- av_free(c);
- av_frame_free(&frame);
- printf("\n");
-}
-
-int main(int argc, char **argv)
-{
- const char *output_type;
-
- /* register all the codecs */
- avcodec_register_all();
-
- if (argc < 2) {
- printf("usage: %s output_type\n"
- "API example program to decode/encode a media stream with libavcodec.\n"
- "This program generates a synthetic stream and encodes it to a file\n"
- "named test.h264, test.mp2 or test.mpg depending on output_type.\n"
- "The encoded stream is then decoded and written to a raw data output.\n"
- "output_type must be chosen between 'h264', 'mp2', 'mpg'.\n",
- argv[0]);
- return 1;
- }
- output_type = argv[1];
-
- if (!strcmp(output_type, "h264")) {
- video_encode_example("test.h264", AV_CODEC_ID_H264);
- } else if (!strcmp(output_type, "mp2")) {
- audio_encode_example("test.mp2");
- audio_decode_example("test.pcm", "test.mp2");
- } else if (!strcmp(output_type, "mpg")) {
- video_encode_example("test.mpg", AV_CODEC_ID_MPEG1VIDEO);
- video_decode_example("test%02d.pgm", "test.mpg");
- } else {
- fprintf(stderr, "Invalid output type '%s', choose between 'h264', 'mp2', or 'mpg'\n",
- output_type);
- return 1;
- }
-
- return 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/demuxing_decoding.c b/Externals/ffmpeg/shared/doc/examples/demuxing_decoding.c
deleted file mode 100644
index 2ce4018c79..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/demuxing_decoding.c
+++ /dev/null
@@ -1,386 +0,0 @@
-/*
- * Copyright (c) 2012 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * Demuxing and decoding example.
- *
- * Show how to use the libavformat and libavcodec API to demux and
- * decode audio and video data.
- * @example demuxing_decoding.c
- */
-
-#include
-#include
-#include
-#include
-
-static AVFormatContext *fmt_ctx = NULL;
-static AVCodecContext *video_dec_ctx = NULL, *audio_dec_ctx;
-static AVStream *video_stream = NULL, *audio_stream = NULL;
-static const char *src_filename = NULL;
-static const char *video_dst_filename = NULL;
-static const char *audio_dst_filename = NULL;
-static FILE *video_dst_file = NULL;
-static FILE *audio_dst_file = NULL;
-
-static uint8_t *video_dst_data[4] = {NULL};
-static int video_dst_linesize[4];
-static int video_dst_bufsize;
-
-static int video_stream_idx = -1, audio_stream_idx = -1;
-static AVFrame *frame = NULL;
-static AVPacket pkt;
-static int video_frame_count = 0;
-static int audio_frame_count = 0;
-
-/* The different ways of decoding and managing data memory. You are not
- * supposed to support all the modes in your application but pick the one most
- * appropriate to your needs. Look for the use of api_mode in this example to
- * see what are the differences of API usage between them */
-enum {
- API_MODE_OLD = 0, /* old method, deprecated */
- API_MODE_NEW_API_REF_COUNT = 1, /* new method, using the frame reference counting */
- API_MODE_NEW_API_NO_REF_COUNT = 2, /* new method, without reference counting */
-};
-
-static int api_mode = API_MODE_OLD;
-
-static int decode_packet(int *got_frame, int cached)
-{
- int ret = 0;
- int decoded = pkt.size;
-
- *got_frame = 0;
-
- if (pkt.stream_index == video_stream_idx) {
- /* decode video frame */
- ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret));
- return ret;
- }
-
- if (*got_frame) {
- printf("video_frame%s n:%d coded_n:%d pts:%s\n",
- cached ? "(cached)" : "",
- video_frame_count++, frame->coded_picture_number,
- av_ts2timestr(frame->pts, &video_dec_ctx->time_base));
-
- /* copy decoded frame to destination buffer:
- * this is required since rawvideo expects non aligned data */
- av_image_copy(video_dst_data, video_dst_linesize,
- (const uint8_t **)(frame->data), frame->linesize,
- video_dec_ctx->pix_fmt, video_dec_ctx->width, video_dec_ctx->height);
-
- /* write to rawvideo file */
- fwrite(video_dst_data[0], 1, video_dst_bufsize, video_dst_file);
- }
- } else if (pkt.stream_index == audio_stream_idx) {
- /* decode audio frame */
- ret = avcodec_decode_audio4(audio_dec_ctx, frame, got_frame, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error decoding audio frame (%s)\n", av_err2str(ret));
- return ret;
- }
- /* Some audio decoders decode only part of the packet, and have to be
- * called again with the remainder of the packet data.
- * Sample: fate-suite/lossless-audio/luckynight-partial.shn
- * Also, some decoders might over-read the packet. */
- decoded = FFMIN(ret, pkt.size);
-
- if (*got_frame) {
- size_t unpadded_linesize = frame->nb_samples * av_get_bytes_per_sample(frame->format);
- printf("audio_frame%s n:%d nb_samples:%d pts:%s\n",
- cached ? "(cached)" : "",
- audio_frame_count++, frame->nb_samples,
- av_ts2timestr(frame->pts, &audio_dec_ctx->time_base));
-
- /* Write the raw audio data samples of the first plane. This works
- * fine for packed formats (e.g. AV_SAMPLE_FMT_S16). However,
- * most audio decoders output planar audio, which uses a separate
- * plane of audio samples for each channel (e.g. AV_SAMPLE_FMT_S16P).
- * In other words, this code will write only the first audio channel
- * in these cases.
- * You should use libswresample or libavfilter to convert the frame
- * to packed data. */
- fwrite(frame->extended_data[0], 1, unpadded_linesize, audio_dst_file);
- }
- }
-
- /* If we use the new API with reference counting, we own the data and need
- * to de-reference it when we don't use it anymore */
- if (*got_frame && api_mode == API_MODE_NEW_API_REF_COUNT)
- av_frame_unref(frame);
-
- return decoded;
-}
-
-static int open_codec_context(int *stream_idx,
- AVFormatContext *fmt_ctx, enum AVMediaType type)
-{
- int ret;
- AVStream *st;
- AVCodecContext *dec_ctx = NULL;
- AVCodec *dec = NULL;
- AVDictionary *opts = NULL;
-
- ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
- if (ret < 0) {
- fprintf(stderr, "Could not find %s stream in input file '%s'\n",
- av_get_media_type_string(type), src_filename);
- return ret;
- } else {
- *stream_idx = ret;
- st = fmt_ctx->streams[*stream_idx];
-
- /* find decoder for the stream */
- dec_ctx = st->codec;
- dec = avcodec_find_decoder(dec_ctx->codec_id);
- if (!dec) {
- fprintf(stderr, "Failed to find %s codec\n",
- av_get_media_type_string(type));
- return AVERROR(EINVAL);
- }
-
- /* Init the decoders, with or without reference counting */
- if (api_mode == API_MODE_NEW_API_REF_COUNT)
- av_dict_set(&opts, "refcounted_frames", "1", 0);
- if ((ret = avcodec_open2(dec_ctx, dec, &opts)) < 0) {
- fprintf(stderr, "Failed to open %s codec\n",
- av_get_media_type_string(type));
- return ret;
- }
- }
-
- return 0;
-}
-
-static int get_format_from_sample_fmt(const char **fmt,
- enum AVSampleFormat sample_fmt)
-{
- int i;
- struct sample_fmt_entry {
- enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
- } sample_fmt_entries[] = {
- { AV_SAMPLE_FMT_U8, "u8", "u8" },
- { AV_SAMPLE_FMT_S16, "s16be", "s16le" },
- { AV_SAMPLE_FMT_S32, "s32be", "s32le" },
- { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
- { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
- };
- *fmt = NULL;
-
- for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
- struct sample_fmt_entry *entry = &sample_fmt_entries[i];
- if (sample_fmt == entry->sample_fmt) {
- *fmt = AV_NE(entry->fmt_be, entry->fmt_le);
- return 0;
- }
- }
-
- fprintf(stderr,
- "sample format %s is not supported as output format\n",
- av_get_sample_fmt_name(sample_fmt));
- return -1;
-}
-
-int main (int argc, char **argv)
-{
- int ret = 0, got_frame;
-
- if (argc != 4 && argc != 5) {
- fprintf(stderr, "usage: %s [-refcount=] "
- "input_file video_output_file audio_output_file\n"
- "API example program to show how to read frames from an input file.\n"
- "This program reads frames from a file, decodes them, and writes decoded\n"
- "video frames to a rawvideo file named video_output_file, and decoded\n"
- "audio frames to a rawaudio file named audio_output_file.\n\n"
- "If the -refcount option is specified, the program use the\n"
- "reference counting frame system which allows keeping a copy of\n"
- "the data for longer than one decode call. If unset, it's using\n"
- "the classic old method.\n"
- "\n", argv[0]);
- exit(1);
- }
- if (argc == 5) {
- const char *mode = argv[1] + strlen("-refcount=");
- if (!strcmp(mode, "old")) api_mode = API_MODE_OLD;
- else if (!strcmp(mode, "new_norefcount")) api_mode = API_MODE_NEW_API_NO_REF_COUNT;
- else if (!strcmp(mode, "new_refcount")) api_mode = API_MODE_NEW_API_REF_COUNT;
- else {
- fprintf(stderr, "unknow mode '%s'\n", mode);
- exit(1);
- }
- argv++;
- }
- src_filename = argv[1];
- video_dst_filename = argv[2];
- audio_dst_filename = argv[3];
-
- /* register all formats and codecs */
- av_register_all();
-
- /* open input file, and allocate format context */
- if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
- fprintf(stderr, "Could not open source file %s\n", src_filename);
- exit(1);
- }
-
- /* retrieve stream information */
- if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
- fprintf(stderr, "Could not find stream information\n");
- exit(1);
- }
-
- if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) {
- video_stream = fmt_ctx->streams[video_stream_idx];
- video_dec_ctx = video_stream->codec;
-
- video_dst_file = fopen(video_dst_filename, "wb");
- if (!video_dst_file) {
- fprintf(stderr, "Could not open destination file %s\n", video_dst_filename);
- ret = 1;
- goto end;
- }
-
- /* allocate image where the decoded image will be put */
- ret = av_image_alloc(video_dst_data, video_dst_linesize,
- video_dec_ctx->width, video_dec_ctx->height,
- video_dec_ctx->pix_fmt, 1);
- if (ret < 0) {
- fprintf(stderr, "Could not allocate raw video buffer\n");
- goto end;
- }
- video_dst_bufsize = ret;
- }
-
- if (open_codec_context(&audio_stream_idx, fmt_ctx, AVMEDIA_TYPE_AUDIO) >= 0) {
- audio_stream = fmt_ctx->streams[audio_stream_idx];
- audio_dec_ctx = audio_stream->codec;
- audio_dst_file = fopen(audio_dst_filename, "wb");
- if (!audio_dst_file) {
- fprintf(stderr, "Could not open destination file %s\n", audio_dst_filename);
- ret = 1;
- goto end;
- }
- }
-
- /* dump input information to stderr */
- av_dump_format(fmt_ctx, 0, src_filename, 0);
-
- if (!audio_stream && !video_stream) {
- fprintf(stderr, "Could not find audio or video stream in the input, aborting\n");
- ret = 1;
- goto end;
- }
-
- /* When using the new API, you need to use the libavutil/frame.h API, while
- * the classic frame management is available in libavcodec */
- if (api_mode == API_MODE_OLD)
- frame = avcodec_alloc_frame();
- else
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Could not allocate frame\n");
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- /* initialize packet, set data to NULL, let the demuxer fill it */
- av_init_packet(&pkt);
- pkt.data = NULL;
- pkt.size = 0;
-
- if (video_stream)
- printf("Demuxing video from file '%s' into '%s'\n", src_filename, video_dst_filename);
- if (audio_stream)
- printf("Demuxing audio from file '%s' into '%s'\n", src_filename, audio_dst_filename);
-
- /* read frames from the file */
- while (av_read_frame(fmt_ctx, &pkt) >= 0) {
- AVPacket orig_pkt = pkt;
- do {
- ret = decode_packet(&got_frame, 0);
- if (ret < 0)
- break;
- pkt.data += ret;
- pkt.size -= ret;
- } while (pkt.size > 0);
- av_free_packet(&orig_pkt);
- }
-
- /* flush cached frames */
- pkt.data = NULL;
- pkt.size = 0;
- do {
- decode_packet(&got_frame, 1);
- } while (got_frame);
-
- printf("Demuxing succeeded.\n");
-
- if (video_stream) {
- printf("Play the output video file with the command:\n"
- "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
- av_get_pix_fmt_name(video_dec_ctx->pix_fmt), video_dec_ctx->width, video_dec_ctx->height,
- video_dst_filename);
- }
-
- if (audio_stream) {
- enum AVSampleFormat sfmt = audio_dec_ctx->sample_fmt;
- int n_channels = audio_dec_ctx->channels;
- const char *fmt;
-
- if (av_sample_fmt_is_planar(sfmt)) {
- const char *packed = av_get_sample_fmt_name(sfmt);
- printf("Warning: the sample format the decoder produced is planar "
- "(%s). This example will output the first channel only.\n",
- packed ? packed : "?");
- sfmt = av_get_packed_sample_fmt(sfmt);
- n_channels = 1;
- }
-
- if ((ret = get_format_from_sample_fmt(&fmt, sfmt)) < 0)
- goto end;
-
- printf("Play the output audio file with the command:\n"
- "ffplay -f %s -ac %d -ar %d %s\n",
- fmt, n_channels, audio_dec_ctx->sample_rate,
- audio_dst_filename);
- }
-
-end:
- avcodec_close(video_dec_ctx);
- avcodec_close(audio_dec_ctx);
- avformat_close_input(&fmt_ctx);
- if (video_dst_file)
- fclose(video_dst_file);
- if (audio_dst_file)
- fclose(audio_dst_file);
- if (api_mode == API_MODE_OLD)
- avcodec_free_frame(&frame);
- else
- av_frame_free(&frame);
- av_free(video_dst_data[0]);
-
- return ret < 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/extract_mvs.c b/Externals/ffmpeg/shared/doc/examples/extract_mvs.c
deleted file mode 100644
index d6fd61335e..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/extract_mvs.c
+++ /dev/null
@@ -1,185 +0,0 @@
-/*
- * Copyright (c) 2012 Stefano Sabatini
- * Copyright (c) 2014 Clément Bœsch
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-#include
-#include
-
-static AVFormatContext *fmt_ctx = NULL;
-static AVCodecContext *video_dec_ctx = NULL;
-static AVStream *video_stream = NULL;
-static const char *src_filename = NULL;
-
-static int video_stream_idx = -1;
-static AVFrame *frame = NULL;
-static AVPacket pkt;
-static int video_frame_count = 0;
-
-static int decode_packet(int *got_frame, int cached)
-{
- int decoded = pkt.size;
-
- *got_frame = 0;
-
- if (pkt.stream_index == video_stream_idx) {
- int ret = avcodec_decode_video2(video_dec_ctx, frame, got_frame, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error decoding video frame (%s)\n", av_err2str(ret));
- return ret;
- }
-
- if (*got_frame) {
- int i;
- AVFrameSideData *sd;
-
- video_frame_count++;
- sd = av_frame_get_side_data(frame, AV_FRAME_DATA_MOTION_VECTORS);
- if (sd) {
- const AVMotionVector *mvs = (const AVMotionVector *)sd->data;
- for (i = 0; i < sd->size / sizeof(*mvs); i++) {
- const AVMotionVector *mv = &mvs[i];
- printf("%d,%2d,%2d,%2d,%4d,%4d,%4d,%4d,0x%"PRIx64"\n",
- video_frame_count, mv->source,
- mv->w, mv->h, mv->src_x, mv->src_y,
- mv->dst_x, mv->dst_y, mv->flags);
- }
- }
- }
- }
-
- return decoded;
-}
-
-static int open_codec_context(int *stream_idx,
- AVFormatContext *fmt_ctx, enum AVMediaType type)
-{
- int ret;
- AVStream *st;
- AVCodecContext *dec_ctx = NULL;
- AVCodec *dec = NULL;
- AVDictionary *opts = NULL;
-
- ret = av_find_best_stream(fmt_ctx, type, -1, -1, NULL, 0);
- if (ret < 0) {
- fprintf(stderr, "Could not find %s stream in input file '%s'\n",
- av_get_media_type_string(type), src_filename);
- return ret;
- } else {
- *stream_idx = ret;
- st = fmt_ctx->streams[*stream_idx];
-
- /* find decoder for the stream */
- dec_ctx = st->codec;
- dec = avcodec_find_decoder(dec_ctx->codec_id);
- if (!dec) {
- fprintf(stderr, "Failed to find %s codec\n",
- av_get_media_type_string(type));
- return AVERROR(EINVAL);
- }
-
- /* Init the video decoder */
- av_dict_set(&opts, "flags2", "+export_mvs", 0);
- if ((ret = avcodec_open2(dec_ctx, dec, &opts)) < 0) {
- fprintf(stderr, "Failed to open %s codec\n",
- av_get_media_type_string(type));
- return ret;
- }
- }
-
- return 0;
-}
-
-int main(int argc, char **argv)
-{
- int ret = 0, got_frame;
-
- if (argc != 2) {
- fprintf(stderr, "Usage: %s \n", argv[0]);
- exit(1);
- }
- src_filename = argv[1];
-
- av_register_all();
-
- if (avformat_open_input(&fmt_ctx, src_filename, NULL, NULL) < 0) {
- fprintf(stderr, "Could not open source file %s\n", src_filename);
- exit(1);
- }
-
- if (avformat_find_stream_info(fmt_ctx, NULL) < 0) {
- fprintf(stderr, "Could not find stream information\n");
- exit(1);
- }
-
- if (open_codec_context(&video_stream_idx, fmt_ctx, AVMEDIA_TYPE_VIDEO) >= 0) {
- video_stream = fmt_ctx->streams[video_stream_idx];
- video_dec_ctx = video_stream->codec;
- }
-
- av_dump_format(fmt_ctx, 0, src_filename, 0);
-
- if (!video_stream) {
- fprintf(stderr, "Could not find video stream in the input, aborting\n");
- ret = 1;
- goto end;
- }
-
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Could not allocate frame\n");
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- printf("framenum,source,blockw,blockh,srcx,srcy,dstx,dsty,flags\n");
-
- /* initialize packet, set data to NULL, let the demuxer fill it */
- av_init_packet(&pkt);
- pkt.data = NULL;
- pkt.size = 0;
-
- /* read frames from the file */
- while (av_read_frame(fmt_ctx, &pkt) >= 0) {
- AVPacket orig_pkt = pkt;
- do {
- ret = decode_packet(&got_frame, 0);
- if (ret < 0)
- break;
- pkt.data += ret;
- pkt.size -= ret;
- } while (pkt.size > 0);
- av_free_packet(&orig_pkt);
- }
-
- /* flush cached frames */
- pkt.data = NULL;
- pkt.size = 0;
- do {
- decode_packet(&got_frame, 1);
- } while (got_frame);
-
-end:
- avcodec_close(video_dec_ctx);
- avformat_close_input(&fmt_ctx);
- av_frame_free(&frame);
- return ret < 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/filter_audio.c b/Externals/ffmpeg/shared/doc/examples/filter_audio.c
deleted file mode 100644
index 01761dcee4..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/filter_audio.c
+++ /dev/null
@@ -1,365 +0,0 @@
-/*
- * copyright (c) 2013 Andrew Kelley
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * libavfilter API usage example.
- *
- * @example filter_audio.c
- * This example will generate a sine wave audio,
- * pass it through a simple filter chain, and then compute the MD5 checksum of
- * the output data.
- *
- * The filter chain it uses is:
- * (input) -> abuffer -> volume -> aformat -> abuffersink -> (output)
- *
- * abuffer: This provides the endpoint where you can feed the decoded samples.
- * volume: In this example we hardcode it to 0.90.
- * aformat: This converts the samples to the samplefreq, channel layout,
- * and sample format required by the audio device.
- * abuffersink: This provides the endpoint where you can read the samples after
- * they have passed through the filter chain.
- */
-
-#include
-#include
-#include
-#include
-
-#include "libavutil/channel_layout.h"
-#include "libavutil/md5.h"
-#include "libavutil/mem.h"
-#include "libavutil/opt.h"
-#include "libavutil/samplefmt.h"
-
-#include "libavfilter/avfilter.h"
-#include "libavfilter/buffersink.h"
-#include "libavfilter/buffersrc.h"
-
-#define INPUT_SAMPLERATE 48000
-#define INPUT_FORMAT AV_SAMPLE_FMT_FLTP
-#define INPUT_CHANNEL_LAYOUT AV_CH_LAYOUT_5POINT0
-
-#define VOLUME_VAL 0.90
-
-static int init_filter_graph(AVFilterGraph **graph, AVFilterContext **src,
- AVFilterContext **sink)
-{
- AVFilterGraph *filter_graph;
- AVFilterContext *abuffer_ctx;
- AVFilter *abuffer;
- AVFilterContext *volume_ctx;
- AVFilter *volume;
- AVFilterContext *aformat_ctx;
- AVFilter *aformat;
- AVFilterContext *abuffersink_ctx;
- AVFilter *abuffersink;
-
- AVDictionary *options_dict = NULL;
- uint8_t options_str[1024];
- uint8_t ch_layout[64];
-
- int err;
-
- /* Create a new filtergraph, which will contain all the filters. */
- filter_graph = avfilter_graph_alloc();
- if (!filter_graph) {
- fprintf(stderr, "Unable to create filter graph.\n");
- return AVERROR(ENOMEM);
- }
-
- /* Create the abuffer filter;
- * it will be used for feeding the data into the graph. */
- abuffer = avfilter_get_by_name("abuffer");
- if (!abuffer) {
- fprintf(stderr, "Could not find the abuffer filter.\n");
- return AVERROR_FILTER_NOT_FOUND;
- }
-
- abuffer_ctx = avfilter_graph_alloc_filter(filter_graph, abuffer, "src");
- if (!abuffer_ctx) {
- fprintf(stderr, "Could not allocate the abuffer instance.\n");
- return AVERROR(ENOMEM);
- }
-
- /* Set the filter options through the AVOptions API. */
- av_get_channel_layout_string(ch_layout, sizeof(ch_layout), 0, INPUT_CHANNEL_LAYOUT);
- av_opt_set (abuffer_ctx, "channel_layout", ch_layout, AV_OPT_SEARCH_CHILDREN);
- av_opt_set (abuffer_ctx, "sample_fmt", av_get_sample_fmt_name(INPUT_FORMAT), AV_OPT_SEARCH_CHILDREN);
- av_opt_set_q (abuffer_ctx, "time_base", (AVRational){ 1, INPUT_SAMPLERATE }, AV_OPT_SEARCH_CHILDREN);
- av_opt_set_int(abuffer_ctx, "sample_rate", INPUT_SAMPLERATE, AV_OPT_SEARCH_CHILDREN);
-
- /* Now initialize the filter; we pass NULL options, since we have already
- * set all the options above. */
- err = avfilter_init_str(abuffer_ctx, NULL);
- if (err < 0) {
- fprintf(stderr, "Could not initialize the abuffer filter.\n");
- return err;
- }
-
- /* Create volume filter. */
- volume = avfilter_get_by_name("volume");
- if (!volume) {
- fprintf(stderr, "Could not find the volume filter.\n");
- return AVERROR_FILTER_NOT_FOUND;
- }
-
- volume_ctx = avfilter_graph_alloc_filter(filter_graph, volume, "volume");
- if (!volume_ctx) {
- fprintf(stderr, "Could not allocate the volume instance.\n");
- return AVERROR(ENOMEM);
- }
-
- /* A different way of passing the options is as key/value pairs in a
- * dictionary. */
- av_dict_set(&options_dict, "volume", AV_STRINGIFY(VOLUME_VAL), 0);
- err = avfilter_init_dict(volume_ctx, &options_dict);
- av_dict_free(&options_dict);
- if (err < 0) {
- fprintf(stderr, "Could not initialize the volume filter.\n");
- return err;
- }
-
- /* Create the aformat filter;
- * it ensures that the output is of the format we want. */
- aformat = avfilter_get_by_name("aformat");
- if (!aformat) {
- fprintf(stderr, "Could not find the aformat filter.\n");
- return AVERROR_FILTER_NOT_FOUND;
- }
-
- aformat_ctx = avfilter_graph_alloc_filter(filter_graph, aformat, "aformat");
- if (!aformat_ctx) {
- fprintf(stderr, "Could not allocate the aformat instance.\n");
- return AVERROR(ENOMEM);
- }
-
- /* A third way of passing the options is in a string of the form
- * key1=value1:key2=value2.... */
- snprintf(options_str, sizeof(options_str),
- "sample_fmts=%s:sample_rates=%d:channel_layouts=0x%"PRIx64,
- av_get_sample_fmt_name(AV_SAMPLE_FMT_S16), 44100,
- (uint64_t)AV_CH_LAYOUT_STEREO);
- err = avfilter_init_str(aformat_ctx, options_str);
- if (err < 0) {
- av_log(NULL, AV_LOG_ERROR, "Could not initialize the aformat filter.\n");
- return err;
- }
-
- /* Finally create the abuffersink filter;
- * it will be used to get the filtered data out of the graph. */
- abuffersink = avfilter_get_by_name("abuffersink");
- if (!abuffersink) {
- fprintf(stderr, "Could not find the abuffersink filter.\n");
- return AVERROR_FILTER_NOT_FOUND;
- }
-
- abuffersink_ctx = avfilter_graph_alloc_filter(filter_graph, abuffersink, "sink");
- if (!abuffersink_ctx) {
- fprintf(stderr, "Could not allocate the abuffersink instance.\n");
- return AVERROR(ENOMEM);
- }
-
- /* This filter takes no options. */
- err = avfilter_init_str(abuffersink_ctx, NULL);
- if (err < 0) {
- fprintf(stderr, "Could not initialize the abuffersink instance.\n");
- return err;
- }
-
- /* Connect the filters;
- * in this simple case the filters just form a linear chain. */
- err = avfilter_link(abuffer_ctx, 0, volume_ctx, 0);
- if (err >= 0)
- err = avfilter_link(volume_ctx, 0, aformat_ctx, 0);
- if (err >= 0)
- err = avfilter_link(aformat_ctx, 0, abuffersink_ctx, 0);
- if (err < 0) {
- fprintf(stderr, "Error connecting filters\n");
- return err;
- }
-
- /* Configure the graph. */
- err = avfilter_graph_config(filter_graph, NULL);
- if (err < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error configuring the filter graph\n");
- return err;
- }
-
- *graph = filter_graph;
- *src = abuffer_ctx;
- *sink = abuffersink_ctx;
-
- return 0;
-}
-
-/* Do something useful with the filtered data: this simple
- * example just prints the MD5 checksum of each plane to stdout. */
-static int process_output(struct AVMD5 *md5, AVFrame *frame)
-{
- int planar = av_sample_fmt_is_planar(frame->format);
- int channels = av_get_channel_layout_nb_channels(frame->channel_layout);
- int planes = planar ? channels : 1;
- int bps = av_get_bytes_per_sample(frame->format);
- int plane_size = bps * frame->nb_samples * (planar ? 1 : channels);
- int i, j;
-
- for (i = 0; i < planes; i++) {
- uint8_t checksum[16];
-
- av_md5_init(md5);
- av_md5_sum(checksum, frame->extended_data[i], plane_size);
-
- fprintf(stdout, "plane %d: 0x", i);
- for (j = 0; j < sizeof(checksum); j++)
- fprintf(stdout, "%02X", checksum[j]);
- fprintf(stdout, "\n");
- }
- fprintf(stdout, "\n");
-
- return 0;
-}
-
-/* Construct a frame of audio data to be filtered;
- * this simple example just synthesizes a sine wave. */
-static int get_input(AVFrame *frame, int frame_num)
-{
- int err, i, j;
-
-#define FRAME_SIZE 1024
-
- /* Set up the frame properties and allocate the buffer for the data. */
- frame->sample_rate = INPUT_SAMPLERATE;
- frame->format = INPUT_FORMAT;
- frame->channel_layout = INPUT_CHANNEL_LAYOUT;
- frame->nb_samples = FRAME_SIZE;
- frame->pts = frame_num * FRAME_SIZE;
-
- err = av_frame_get_buffer(frame, 0);
- if (err < 0)
- return err;
-
- /* Fill the data for each channel. */
- for (i = 0; i < 5; i++) {
- float *data = (float*)frame->extended_data[i];
-
- for (j = 0; j < frame->nb_samples; j++)
- data[j] = sin(2 * M_PI * (frame_num + j) * (i + 1) / FRAME_SIZE);
- }
-
- return 0;
-}
-
-int main(int argc, char *argv[])
-{
- struct AVMD5 *md5;
- AVFilterGraph *graph;
- AVFilterContext *src, *sink;
- AVFrame *frame;
- uint8_t errstr[1024];
- float duration;
- int err, nb_frames, i;
-
- if (argc < 2) {
- fprintf(stderr, "Usage: %s \n", argv[0]);
- return 1;
- }
-
- duration = atof(argv[1]);
- nb_frames = duration * INPUT_SAMPLERATE / FRAME_SIZE;
- if (nb_frames <= 0) {
- fprintf(stderr, "Invalid duration: %s\n", argv[1]);
- return 1;
- }
-
- avfilter_register_all();
-
- /* Allocate the frame we will be using to store the data. */
- frame = av_frame_alloc();
- if (!frame) {
- fprintf(stderr, "Error allocating the frame\n");
- return 1;
- }
-
- md5 = av_md5_alloc();
- if (!md5) {
- fprintf(stderr, "Error allocating the MD5 context\n");
- return 1;
- }
-
- /* Set up the filtergraph. */
- err = init_filter_graph(&graph, &src, &sink);
- if (err < 0) {
- fprintf(stderr, "Unable to init filter graph:");
- goto fail;
- }
-
- /* the main filtering loop */
- for (i = 0; i < nb_frames; i++) {
- /* get an input frame to be filtered */
- err = get_input(frame, i);
- if (err < 0) {
- fprintf(stderr, "Error generating input frame:");
- goto fail;
- }
-
- /* Send the frame to the input of the filtergraph. */
- err = av_buffersrc_add_frame(src, frame);
- if (err < 0) {
- av_frame_unref(frame);
- fprintf(stderr, "Error submitting the frame to the filtergraph:");
- goto fail;
- }
-
- /* Get all the filtered output that is available. */
- while ((err = av_buffersink_get_frame(sink, frame)) >= 0) {
- /* now do something with our filtered frame */
- err = process_output(md5, frame);
- if (err < 0) {
- fprintf(stderr, "Error processing the filtered frame:");
- goto fail;
- }
- av_frame_unref(frame);
- }
-
- if (err == AVERROR(EAGAIN)) {
- /* Need to feed more frames in. */
- continue;
- } else if (err == AVERROR_EOF) {
- /* Nothing more to do, finish. */
- break;
- } else if (err < 0) {
- /* An error occurred. */
- fprintf(stderr, "Error filtering the data:");
- goto fail;
- }
- }
-
- avfilter_graph_free(&graph);
- av_frame_free(&frame);
- av_freep(&md5);
-
- return 0;
-
-fail:
- av_strerror(err, errstr, sizeof(errstr));
- fprintf(stderr, "%s\n", errstr);
- return 1;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/filtering_audio.c b/Externals/ffmpeg/shared/doc/examples/filtering_audio.c
deleted file mode 100644
index 46595fb3b8..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/filtering_audio.c
+++ /dev/null
@@ -1,280 +0,0 @@
-/*
- * Copyright (c) 2010 Nicolas George
- * Copyright (c) 2011 Stefano Sabatini
- * Copyright (c) 2012 Clément Bœsch
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * API example for audio decoding and filtering
- * @example filtering_audio.c
- */
-
-#include
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-static const char *filter_descr = "aresample=8000,aformat=sample_fmts=s16:channel_layouts=mono";
-static const char *player = "ffplay -f s16le -ar 8000 -ac 1 -";
-
-static AVFormatContext *fmt_ctx;
-static AVCodecContext *dec_ctx;
-AVFilterContext *buffersink_ctx;
-AVFilterContext *buffersrc_ctx;
-AVFilterGraph *filter_graph;
-static int audio_stream_index = -1;
-
-static int open_input_file(const char *filename)
-{
- int ret;
- AVCodec *dec;
-
- if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
- return ret;
- }
-
- if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
- return ret;
- }
-
- /* select the audio stream */
- ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_AUDIO, -1, -1, &dec, 0);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot find a audio stream in the input file\n");
- return ret;
- }
- audio_stream_index = ret;
- dec_ctx = fmt_ctx->streams[audio_stream_index]->codec;
- av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0);
-
- /* init the audio decoder */
- if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open audio decoder\n");
- return ret;
- }
-
- return 0;
-}
-
-static int init_filters(const char *filters_descr)
-{
- char args[512];
- int ret = 0;
- AVFilter *abuffersrc = avfilter_get_by_name("abuffer");
- AVFilter *abuffersink = avfilter_get_by_name("abuffersink");
- AVFilterInOut *outputs = avfilter_inout_alloc();
- AVFilterInOut *inputs = avfilter_inout_alloc();
- static const enum AVSampleFormat out_sample_fmts[] = { AV_SAMPLE_FMT_S16, -1 };
- static const int64_t out_channel_layouts[] = { AV_CH_LAYOUT_MONO, -1 };
- static const int out_sample_rates[] = { 8000, -1 };
- const AVFilterLink *outlink;
- AVRational time_base = fmt_ctx->streams[audio_stream_index]->time_base;
-
- filter_graph = avfilter_graph_alloc();
- if (!outputs || !inputs || !filter_graph) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- /* buffer audio source: the decoded frames from the decoder will be inserted here. */
- if (!dec_ctx->channel_layout)
- dec_ctx->channel_layout = av_get_default_channel_layout(dec_ctx->channels);
- snprintf(args, sizeof(args),
- "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
- time_base.num, time_base.den, dec_ctx->sample_rate,
- av_get_sample_fmt_name(dec_ctx->sample_fmt), dec_ctx->channel_layout);
- ret = avfilter_graph_create_filter(&buffersrc_ctx, abuffersrc, "in",
- args, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
- goto end;
- }
-
- /* buffer audio sink: to terminate the filter chain. */
- ret = avfilter_graph_create_filter(&buffersink_ctx, abuffersink, "out",
- NULL, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
- goto end;
- }
-
- ret = av_opt_set_int_list(buffersink_ctx, "sample_fmts", out_sample_fmts, -1,
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
- goto end;
- }
-
- ret = av_opt_set_int_list(buffersink_ctx, "channel_layouts", out_channel_layouts, -1,
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
- goto end;
- }
-
- ret = av_opt_set_int_list(buffersink_ctx, "sample_rates", out_sample_rates, -1,
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
- goto end;
- }
-
- /* Endpoints for the filter graph. */
- outputs->name = av_strdup("in");
- outputs->filter_ctx = buffersrc_ctx;
- outputs->pad_idx = 0;
- outputs->next = NULL;
-
- inputs->name = av_strdup("out");
- inputs->filter_ctx = buffersink_ctx;
- inputs->pad_idx = 0;
- inputs->next = NULL;
-
- if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
- &inputs, &outputs, NULL)) < 0)
- goto end;
-
- if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
- goto end;
-
- /* Print summary of the sink buffer
- * Note: args buffer is reused to store channel layout string */
- outlink = buffersink_ctx->inputs[0];
- av_get_channel_layout_string(args, sizeof(args), -1, outlink->channel_layout);
- av_log(NULL, AV_LOG_INFO, "Output: srate:%dHz fmt:%s chlayout:%s\n",
- (int)outlink->sample_rate,
- (char *)av_x_if_null(av_get_sample_fmt_name(outlink->format), "?"),
- args);
-
-end:
- avfilter_inout_free(&inputs);
- avfilter_inout_free(&outputs);
-
- return ret;
-}
-
-static void print_frame(const AVFrame *frame)
-{
- const int n = frame->nb_samples * av_get_channel_layout_nb_channels(av_frame_get_channel_layout(frame));
- const uint16_t *p = (uint16_t*)frame->data[0];
- const uint16_t *p_end = p + n;
-
- while (p < p_end) {
- fputc(*p & 0xff, stdout);
- fputc(*p>>8 & 0xff, stdout);
- p++;
- }
- fflush(stdout);
-}
-
-int main(int argc, char **argv)
-{
- int ret;
- AVPacket packet0, packet;
- AVFrame *frame = av_frame_alloc();
- AVFrame *filt_frame = av_frame_alloc();
- int got_frame;
-
- if (!frame || !filt_frame) {
- perror("Could not allocate frame");
- exit(1);
- }
- if (argc != 2) {
- fprintf(stderr, "Usage: %s file | %s\n", argv[0], player);
- exit(1);
- }
-
- av_register_all();
- avfilter_register_all();
-
- if ((ret = open_input_file(argv[1])) < 0)
- goto end;
- if ((ret = init_filters(filter_descr)) < 0)
- goto end;
-
- /* read all packets */
- packet0.data = NULL;
- packet.data = NULL;
- while (1) {
- if (!packet0.data) {
- if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
- break;
- packet0 = packet;
- }
-
- if (packet.stream_index == audio_stream_index) {
- got_frame = 0;
- ret = avcodec_decode_audio4(dec_ctx, frame, &got_frame, &packet);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error decoding audio\n");
- continue;
- }
- packet.size -= ret;
- packet.data += ret;
-
- if (got_frame) {
- /* push the audio data from decoded frame into the filtergraph */
- if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, 0) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error while feeding the audio filtergraph\n");
- break;
- }
-
- /* pull filtered audio from the filtergraph */
- while (1) {
- ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
- if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
- break;
- if (ret < 0)
- goto end;
- print_frame(filt_frame);
- av_frame_unref(filt_frame);
- }
- }
-
- if (packet.size <= 0)
- av_free_packet(&packet0);
- } else {
- /* discard non-wanted packets */
- av_free_packet(&packet0);
- }
- }
-end:
- avfilter_graph_free(&filter_graph);
- avcodec_close(dec_ctx);
- avformat_close_input(&fmt_ctx);
- av_frame_free(&frame);
- av_frame_free(&filt_frame);
-
- if (ret < 0 && ret != AVERROR_EOF) {
- fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
- exit(1);
- }
-
- exit(0);
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/filtering_video.c b/Externals/ffmpeg/shared/doc/examples/filtering_video.c
deleted file mode 100644
index 601c3d87f0..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/filtering_video.c
+++ /dev/null
@@ -1,262 +0,0 @@
-/*
- * Copyright (c) 2010 Nicolas George
- * Copyright (c) 2011 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * API example for decoding and filtering
- * @example filtering_video.c
- */
-
-#define _XOPEN_SOURCE 600 /* for usleep */
-#include
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-const char *filter_descr = "scale=78:24";
-
-static AVFormatContext *fmt_ctx;
-static AVCodecContext *dec_ctx;
-AVFilterContext *buffersink_ctx;
-AVFilterContext *buffersrc_ctx;
-AVFilterGraph *filter_graph;
-static int video_stream_index = -1;
-static int64_t last_pts = AV_NOPTS_VALUE;
-
-static int open_input_file(const char *filename)
-{
- int ret;
- AVCodec *dec;
-
- if ((ret = avformat_open_input(&fmt_ctx, filename, NULL, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
- return ret;
- }
-
- if ((ret = avformat_find_stream_info(fmt_ctx, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
- return ret;
- }
-
- /* select the video stream */
- ret = av_find_best_stream(fmt_ctx, AVMEDIA_TYPE_VIDEO, -1, -1, &dec, 0);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot find a video stream in the input file\n");
- return ret;
- }
- video_stream_index = ret;
- dec_ctx = fmt_ctx->streams[video_stream_index]->codec;
- av_opt_set_int(dec_ctx, "refcounted_frames", 1, 0);
-
- /* init the video decoder */
- if ((ret = avcodec_open2(dec_ctx, dec, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open video decoder\n");
- return ret;
- }
-
- return 0;
-}
-
-static int init_filters(const char *filters_descr)
-{
- char args[512];
- int ret = 0;
- AVFilter *buffersrc = avfilter_get_by_name("buffer");
- AVFilter *buffersink = avfilter_get_by_name("buffersink");
- AVFilterInOut *outputs = avfilter_inout_alloc();
- AVFilterInOut *inputs = avfilter_inout_alloc();
- AVRational time_base = fmt_ctx->streams[video_stream_index]->time_base;
- enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
-
- filter_graph = avfilter_graph_alloc();
- if (!outputs || !inputs || !filter_graph) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- /* buffer video source: the decoded frames from the decoder will be inserted here. */
- snprintf(args, sizeof(args),
- "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
- dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
- time_base.num, time_base.den,
- dec_ctx->sample_aspect_ratio.num, dec_ctx->sample_aspect_ratio.den);
-
- ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
- args, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
- goto end;
- }
-
- /* buffer video sink: to terminate the filter chain. */
- ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
- NULL, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
- goto end;
- }
-
- ret = av_opt_set_int_list(buffersink_ctx, "pix_fmts", pix_fmts,
- AV_PIX_FMT_NONE, AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
- goto end;
- }
-
- /* Endpoints for the filter graph. */
- outputs->name = av_strdup("in");
- outputs->filter_ctx = buffersrc_ctx;
- outputs->pad_idx = 0;
- outputs->next = NULL;
-
- inputs->name = av_strdup("out");
- inputs->filter_ctx = buffersink_ctx;
- inputs->pad_idx = 0;
- inputs->next = NULL;
-
- if ((ret = avfilter_graph_parse_ptr(filter_graph, filters_descr,
- &inputs, &outputs, NULL)) < 0)
- goto end;
-
- if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
- goto end;
-
-end:
- avfilter_inout_free(&inputs);
- avfilter_inout_free(&outputs);
-
- return ret;
-}
-
-static void display_frame(const AVFrame *frame, AVRational time_base)
-{
- int x, y;
- uint8_t *p0, *p;
- int64_t delay;
-
- if (frame->pts != AV_NOPTS_VALUE) {
- if (last_pts != AV_NOPTS_VALUE) {
- /* sleep roughly the right amount of time;
- * usleep is in microseconds, just like AV_TIME_BASE. */
- delay = av_rescale_q(frame->pts - last_pts,
- time_base, AV_TIME_BASE_Q);
- if (delay > 0 && delay < 1000000)
- usleep(delay);
- }
- last_pts = frame->pts;
- }
-
- /* Trivial ASCII grayscale display. */
- p0 = frame->data[0];
- puts("\033c");
- for (y = 0; y < frame->height; y++) {
- p = p0;
- for (x = 0; x < frame->width; x++)
- putchar(" .-+#"[*(p++) / 52]);
- putchar('\n');
- p0 += frame->linesize[0];
- }
- fflush(stdout);
-}
-
-int main(int argc, char **argv)
-{
- int ret;
- AVPacket packet;
- AVFrame *frame = av_frame_alloc();
- AVFrame *filt_frame = av_frame_alloc();
- int got_frame;
-
- if (!frame || !filt_frame) {
- perror("Could not allocate frame");
- exit(1);
- }
- if (argc != 2) {
- fprintf(stderr, "Usage: %s file\n", argv[0]);
- exit(1);
- }
-
- av_register_all();
- avfilter_register_all();
-
- if ((ret = open_input_file(argv[1])) < 0)
- goto end;
- if ((ret = init_filters(filter_descr)) < 0)
- goto end;
-
- /* read all packets */
- while (1) {
- if ((ret = av_read_frame(fmt_ctx, &packet)) < 0)
- break;
-
- if (packet.stream_index == video_stream_index) {
- got_frame = 0;
- ret = avcodec_decode_video2(dec_ctx, frame, &got_frame, &packet);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error decoding video\n");
- break;
- }
-
- if (got_frame) {
- frame->pts = av_frame_get_best_effort_timestamp(frame);
-
- /* push the decoded frame into the filtergraph */
- if (av_buffersrc_add_frame_flags(buffersrc_ctx, frame, AV_BUFFERSRC_FLAG_KEEP_REF) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
- break;
- }
-
- /* pull filtered frames from the filtergraph */
- while (1) {
- ret = av_buffersink_get_frame(buffersink_ctx, filt_frame);
- if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
- break;
- if (ret < 0)
- goto end;
- display_frame(filt_frame, buffersink_ctx->inputs[0]->time_base);
- av_frame_unref(filt_frame);
- }
- av_frame_unref(frame);
- }
- }
- av_free_packet(&packet);
- }
-end:
- avfilter_graph_free(&filter_graph);
- avcodec_close(dec_ctx);
- avformat_close_input(&fmt_ctx);
- av_frame_free(&frame);
- av_frame_free(&filt_frame);
-
- if (ret < 0 && ret != AVERROR_EOF) {
- fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
- exit(1);
- }
-
- exit(0);
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/metadata.c b/Externals/ffmpeg/shared/doc/examples/metadata.c
deleted file mode 100644
index f73c267369..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/metadata.c
+++ /dev/null
@@ -1,56 +0,0 @@
-/*
- * Copyright (c) 2011 Reinhard Tartler
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * Shows how the metadata API can be used in application programs.
- * @example metadata.c
- */
-
-#include
-
-#include
-#include
-
-int main (int argc, char **argv)
-{
- AVFormatContext *fmt_ctx = NULL;
- AVDictionaryEntry *tag = NULL;
- int ret;
-
- if (argc != 2) {
- printf("usage: %s \n"
- "example program to demonstrate the use of the libavformat metadata API.\n"
- "\n", argv[0]);
- return 1;
- }
-
- av_register_all();
- if ((ret = avformat_open_input(&fmt_ctx, argv[1], NULL, NULL)))
- return ret;
-
- while ((tag = av_dict_get(fmt_ctx->metadata, "", tag, AV_DICT_IGNORE_SUFFIX)))
- printf("%s=%s\n", tag->key, tag->value);
-
- avformat_close_input(&fmt_ctx);
- return 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/muxing.c b/Externals/ffmpeg/shared/doc/examples/muxing.c
deleted file mode 100644
index 8b0ea60bb3..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/muxing.c
+++ /dev/null
@@ -1,670 +0,0 @@
-/*
- * Copyright (c) 2003 Fabrice Bellard
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * libavformat API example.
- *
- * Output a media file in any supported libavformat format. The default
- * codecs are used.
- * @example muxing.c
- */
-
-#include
-#include
-#include
-#include
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-#define STREAM_DURATION 10.0
-#define STREAM_FRAME_RATE 25 /* 25 images/s */
-#define STREAM_PIX_FMT AV_PIX_FMT_YUV420P /* default pix_fmt */
-
-#define SCALE_FLAGS SWS_BICUBIC
-
-// a wrapper around a single output AVStream
-typedef struct OutputStream {
- AVStream *st;
-
- /* pts of the next frame that will be generated */
- int64_t next_pts;
- int samples_count;
-
- AVFrame *frame;
- AVFrame *tmp_frame;
-
- float t, tincr, tincr2;
-
- struct SwsContext *sws_ctx;
- struct SwrContext *swr_ctx;
-} OutputStream;
-
-static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt)
-{
- AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;
-
- printf("pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
- av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
- av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
- av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
- pkt->stream_index);
-}
-
-static int write_frame(AVFormatContext *fmt_ctx, const AVRational *time_base, AVStream *st, AVPacket *pkt)
-{
- /* rescale output packet timestamp values from codec to stream timebase */
- av_packet_rescale_ts(pkt, *time_base, st->time_base);
- pkt->stream_index = st->index;
-
- /* Write the compressed frame to the media file. */
- log_packet(fmt_ctx, pkt);
- return av_interleaved_write_frame(fmt_ctx, pkt);
-}
-
-/* Add an output stream. */
-static void add_stream(OutputStream *ost, AVFormatContext *oc,
- AVCodec **codec,
- enum AVCodecID codec_id)
-{
- AVCodecContext *c;
- int i;
-
- /* find the encoder */
- *codec = avcodec_find_encoder(codec_id);
- if (!(*codec)) {
- fprintf(stderr, "Could not find encoder for '%s'\n",
- avcodec_get_name(codec_id));
- exit(1);
- }
-
- ost->st = avformat_new_stream(oc, *codec);
- if (!ost->st) {
- fprintf(stderr, "Could not allocate stream\n");
- exit(1);
- }
- ost->st->id = oc->nb_streams-1;
- c = ost->st->codec;
-
- switch ((*codec)->type) {
- case AVMEDIA_TYPE_AUDIO:
- c->sample_fmt = (*codec)->sample_fmts ?
- (*codec)->sample_fmts[0] : AV_SAMPLE_FMT_FLTP;
- c->bit_rate = 64000;
- c->sample_rate = 44100;
- if ((*codec)->supported_samplerates) {
- c->sample_rate = (*codec)->supported_samplerates[0];
- for (i = 0; (*codec)->supported_samplerates[i]; i++) {
- if ((*codec)->supported_samplerates[i] == 44100)
- c->sample_rate = 44100;
- }
- }
- c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
- c->channel_layout = AV_CH_LAYOUT_STEREO;
- if ((*codec)->channel_layouts) {
- c->channel_layout = (*codec)->channel_layouts[0];
- for (i = 0; (*codec)->channel_layouts[i]; i++) {
- if ((*codec)->channel_layouts[i] == AV_CH_LAYOUT_STEREO)
- c->channel_layout = AV_CH_LAYOUT_STEREO;
- }
- }
- c->channels = av_get_channel_layout_nb_channels(c->channel_layout);
- ost->st->time_base = (AVRational){ 1, c->sample_rate };
- break;
-
- case AVMEDIA_TYPE_VIDEO:
- c->codec_id = codec_id;
-
- c->bit_rate = 400000;
- /* Resolution must be a multiple of two. */
- c->width = 352;
- c->height = 288;
- /* timebase: This is the fundamental unit of time (in seconds) in terms
- * of which frame timestamps are represented. For fixed-fps content,
- * timebase should be 1/framerate and timestamp increments should be
- * identical to 1. */
- ost->st->time_base = (AVRational){ 1, STREAM_FRAME_RATE };
- c->time_base = ost->st->time_base;
-
- c->gop_size = 12; /* emit one intra frame every twelve frames at most */
- c->pix_fmt = STREAM_PIX_FMT;
- if (c->codec_id == AV_CODEC_ID_MPEG2VIDEO) {
- /* just for testing, we also add B frames */
- c->max_b_frames = 2;
- }
- if (c->codec_id == AV_CODEC_ID_MPEG1VIDEO) {
- /* Needed to avoid using macroblocks in which some coeffs overflow.
- * This does not happen with normal video, it just happens here as
- * the motion of the chroma plane does not match the luma plane. */
- c->mb_decision = 2;
- }
- break;
-
- default:
- break;
- }
-
- /* Some formats want stream headers to be separate. */
- if (oc->oformat->flags & AVFMT_GLOBALHEADER)
- c->flags |= CODEC_FLAG_GLOBAL_HEADER;
-}
-
-/**************************************************************/
-/* audio output */
-
-static AVFrame *alloc_audio_frame(enum AVSampleFormat sample_fmt,
- uint64_t channel_layout,
- int sample_rate, int nb_samples)
-{
- AVFrame *frame = av_frame_alloc();
- int ret;
-
- if (!frame) {
- fprintf(stderr, "Error allocating an audio frame\n");
- exit(1);
- }
-
- frame->format = sample_fmt;
- frame->channel_layout = channel_layout;
- frame->sample_rate = sample_rate;
- frame->nb_samples = nb_samples;
-
- if (nb_samples) {
- ret = av_frame_get_buffer(frame, 0);
- if (ret < 0) {
- fprintf(stderr, "Error allocating an audio buffer\n");
- exit(1);
- }
- }
-
- return frame;
-}
-
-static void open_audio(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
-{
- AVCodecContext *c;
- int nb_samples;
- int ret;
- AVDictionary *opt = NULL;
-
- c = ost->st->codec;
-
- /* open it */
- av_dict_copy(&opt, opt_arg, 0);
- ret = avcodec_open2(c, codec, &opt);
- av_dict_free(&opt);
- if (ret < 0) {
- fprintf(stderr, "Could not open audio codec: %s\n", av_err2str(ret));
- exit(1);
- }
-
- /* init signal generator */
- ost->t = 0;
- ost->tincr = 2 * M_PI * 110.0 / c->sample_rate;
- /* increment frequency by 110 Hz per second */
- ost->tincr2 = 2 * M_PI * 110.0 / c->sample_rate / c->sample_rate;
-
- if (c->codec->capabilities & CODEC_CAP_VARIABLE_FRAME_SIZE)
- nb_samples = 10000;
- else
- nb_samples = c->frame_size;
-
- ost->frame = alloc_audio_frame(c->sample_fmt, c->channel_layout,
- c->sample_rate, nb_samples);
- ost->tmp_frame = alloc_audio_frame(AV_SAMPLE_FMT_S16, c->channel_layout,
- c->sample_rate, nb_samples);
-
- /* create resampler context */
- ost->swr_ctx = swr_alloc();
- if (!ost->swr_ctx) {
- fprintf(stderr, "Could not allocate resampler context\n");
- exit(1);
- }
-
- /* set options */
- av_opt_set_int (ost->swr_ctx, "in_channel_count", c->channels, 0);
- av_opt_set_int (ost->swr_ctx, "in_sample_rate", c->sample_rate, 0);
- av_opt_set_sample_fmt(ost->swr_ctx, "in_sample_fmt", AV_SAMPLE_FMT_S16, 0);
- av_opt_set_int (ost->swr_ctx, "out_channel_count", c->channels, 0);
- av_opt_set_int (ost->swr_ctx, "out_sample_rate", c->sample_rate, 0);
- av_opt_set_sample_fmt(ost->swr_ctx, "out_sample_fmt", c->sample_fmt, 0);
-
- /* initialize the resampling context */
- if ((ret = swr_init(ost->swr_ctx)) < 0) {
- fprintf(stderr, "Failed to initialize the resampling context\n");
- exit(1);
- }
-}
-
-/* Prepare a 16 bit dummy audio frame of 'frame_size' samples and
- * 'nb_channels' channels. */
-static AVFrame *get_audio_frame(OutputStream *ost)
-{
- AVFrame *frame = ost->tmp_frame;
- int j, i, v;
- int16_t *q = (int16_t*)frame->data[0];
-
- /* check if we want to generate more frames */
- if (av_compare_ts(ost->next_pts, ost->st->codec->time_base,
- STREAM_DURATION, (AVRational){ 1, 1 }) >= 0)
- return NULL;
-
- for (j = 0; j nb_samples; j++) {
- v = (int)(sin(ost->t) * 10000);
- for (i = 0; i < ost->st->codec->channels; i++)
- *q++ = v;
- ost->t += ost->tincr;
- ost->tincr += ost->tincr2;
- }
-
- frame->pts = ost->next_pts;
- ost->next_pts += frame->nb_samples;
-
- return frame;
-}
-
-/*
- * encode one audio frame and send it to the muxer
- * return 1 when encoding is finished, 0 otherwise
- */
-static int write_audio_frame(AVFormatContext *oc, OutputStream *ost)
-{
- AVCodecContext *c;
- AVPacket pkt = { 0 }; // data and size must be 0;
- AVFrame *frame;
- int ret;
- int got_packet;
- int dst_nb_samples;
-
- av_init_packet(&pkt);
- c = ost->st->codec;
-
- frame = get_audio_frame(ost);
-
- if (frame) {
- /* convert samples from native format to destination codec format, using the resampler */
- /* compute destination number of samples */
- dst_nb_samples = av_rescale_rnd(swr_get_delay(ost->swr_ctx, c->sample_rate) + frame->nb_samples,
- c->sample_rate, c->sample_rate, AV_ROUND_UP);
- av_assert0(dst_nb_samples == frame->nb_samples);
-
- /* when we pass a frame to the encoder, it may keep a reference to it
- * internally;
- * make sure we do not overwrite it here
- */
- ret = av_frame_make_writable(ost->frame);
- if (ret < 0)
- exit(1);
-
- /* convert to destination format */
- ret = swr_convert(ost->swr_ctx,
- ost->frame->data, dst_nb_samples,
- (const uint8_t **)frame->data, frame->nb_samples);
- if (ret < 0) {
- fprintf(stderr, "Error while converting\n");
- exit(1);
- }
- frame = ost->frame;
-
- frame->pts = av_rescale_q(ost->samples_count, (AVRational){1, c->sample_rate}, c->time_base);
- ost->samples_count += dst_nb_samples;
- }
-
- ret = avcodec_encode_audio2(c, &pkt, frame, &got_packet);
- if (ret < 0) {
- fprintf(stderr, "Error encoding audio frame: %s\n", av_err2str(ret));
- exit(1);
- }
-
- if (got_packet) {
- ret = write_frame(oc, &c->time_base, ost->st, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error while writing audio frame: %s\n",
- av_err2str(ret));
- exit(1);
- }
- }
-
- return (frame || got_packet) ? 0 : 1;
-}
-
-/**************************************************************/
-/* video output */
-
-static AVFrame *alloc_picture(enum AVPixelFormat pix_fmt, int width, int height)
-{
- AVFrame *picture;
- int ret;
-
- picture = av_frame_alloc();
- if (!picture)
- return NULL;
-
- picture->format = pix_fmt;
- picture->width = width;
- picture->height = height;
-
- /* allocate the buffers for the frame data */
- ret = av_frame_get_buffer(picture, 32);
- if (ret < 0) {
- fprintf(stderr, "Could not allocate frame data.\n");
- exit(1);
- }
-
- return picture;
-}
-
-static void open_video(AVFormatContext *oc, AVCodec *codec, OutputStream *ost, AVDictionary *opt_arg)
-{
- int ret;
- AVCodecContext *c = ost->st->codec;
- AVDictionary *opt = NULL;
-
- av_dict_copy(&opt, opt_arg, 0);
-
- /* open the codec */
- ret = avcodec_open2(c, codec, &opt);
- av_dict_free(&opt);
- if (ret < 0) {
- fprintf(stderr, "Could not open video codec: %s\n", av_err2str(ret));
- exit(1);
- }
-
- /* allocate and init a re-usable frame */
- ost->frame = alloc_picture(c->pix_fmt, c->width, c->height);
- if (!ost->frame) {
- fprintf(stderr, "Could not allocate video frame\n");
- exit(1);
- }
-
- /* If the output format is not YUV420P, then a temporary YUV420P
- * picture is needed too. It is then converted to the required
- * output format. */
- ost->tmp_frame = NULL;
- if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
- ost->tmp_frame = alloc_picture(AV_PIX_FMT_YUV420P, c->width, c->height);
- if (!ost->tmp_frame) {
- fprintf(stderr, "Could not allocate temporary picture\n");
- exit(1);
- }
- }
-}
-
-/* Prepare a dummy image. */
-static void fill_yuv_image(AVFrame *pict, int frame_index,
- int width, int height)
-{
- int x, y, i, ret;
-
- /* when we pass a frame to the encoder, it may keep a reference to it
- * internally;
- * make sure we do not overwrite it here
- */
- ret = av_frame_make_writable(pict);
- if (ret < 0)
- exit(1);
-
- i = frame_index;
-
- /* Y */
- for (y = 0; y < height; y++)
- for (x = 0; x < width; x++)
- pict->data[0][y * pict->linesize[0] + x] = x + y + i * 3;
-
- /* Cb and Cr */
- for (y = 0; y < height / 2; y++) {
- for (x = 0; x < width / 2; x++) {
- pict->data[1][y * pict->linesize[1] + x] = 128 + y + i * 2;
- pict->data[2][y * pict->linesize[2] + x] = 64 + x + i * 5;
- }
- }
-}
-
-static AVFrame *get_video_frame(OutputStream *ost)
-{
- AVCodecContext *c = ost->st->codec;
-
- /* check if we want to generate more frames */
- if (av_compare_ts(ost->next_pts, ost->st->codec->time_base,
- STREAM_DURATION, (AVRational){ 1, 1 }) >= 0)
- return NULL;
-
- if (c->pix_fmt != AV_PIX_FMT_YUV420P) {
- /* as we only generate a YUV420P picture, we must convert it
- * to the codec pixel format if needed */
- if (!ost->sws_ctx) {
- ost->sws_ctx = sws_getContext(c->width, c->height,
- AV_PIX_FMT_YUV420P,
- c->width, c->height,
- c->pix_fmt,
- SCALE_FLAGS, NULL, NULL, NULL);
- if (!ost->sws_ctx) {
- fprintf(stderr,
- "Could not initialize the conversion context\n");
- exit(1);
- }
- }
- fill_yuv_image(ost->tmp_frame, ost->next_pts, c->width, c->height);
- sws_scale(ost->sws_ctx,
- (const uint8_t * const *)ost->tmp_frame->data, ost->tmp_frame->linesize,
- 0, c->height, ost->frame->data, ost->frame->linesize);
- } else {
- fill_yuv_image(ost->frame, ost->next_pts, c->width, c->height);
- }
-
- ost->frame->pts = ost->next_pts++;
-
- return ost->frame;
-}
-
-/*
- * encode one video frame and send it to the muxer
- * return 1 when encoding is finished, 0 otherwise
- */
-static int write_video_frame(AVFormatContext *oc, OutputStream *ost)
-{
- int ret;
- AVCodecContext *c;
- AVFrame *frame;
- int got_packet = 0;
-
- c = ost->st->codec;
-
- frame = get_video_frame(ost);
-
- if (oc->oformat->flags & AVFMT_RAWPICTURE) {
- /* a hack to avoid data copy with some raw video muxers */
- AVPacket pkt;
- av_init_packet(&pkt);
-
- if (!frame)
- return 1;
-
- pkt.flags |= AV_PKT_FLAG_KEY;
- pkt.stream_index = ost->st->index;
- pkt.data = (uint8_t *)frame;
- pkt.size = sizeof(AVPicture);
-
- pkt.pts = pkt.dts = frame->pts;
- av_packet_rescale_ts(&pkt, c->time_base, ost->st->time_base);
-
- ret = av_interleaved_write_frame(oc, &pkt);
- } else {
- AVPacket pkt = { 0 };
- av_init_packet(&pkt);
-
- /* encode the image */
- ret = avcodec_encode_video2(c, &pkt, frame, &got_packet);
- if (ret < 0) {
- fprintf(stderr, "Error encoding video frame: %s\n", av_err2str(ret));
- exit(1);
- }
-
- if (got_packet) {
- ret = write_frame(oc, &c->time_base, ost->st, &pkt);
- } else {
- ret = 0;
- }
- }
-
- if (ret < 0) {
- fprintf(stderr, "Error while writing video frame: %s\n", av_err2str(ret));
- exit(1);
- }
-
- return (frame || got_packet) ? 0 : 1;
-}
-
-static void close_stream(AVFormatContext *oc, OutputStream *ost)
-{
- avcodec_close(ost->st->codec);
- av_frame_free(&ost->frame);
- av_frame_free(&ost->tmp_frame);
- sws_freeContext(ost->sws_ctx);
- swr_free(&ost->swr_ctx);
-}
-
-/**************************************************************/
-/* media file output */
-
-int main(int argc, char **argv)
-{
- OutputStream video_st = { 0 }, audio_st = { 0 };
- const char *filename;
- AVOutputFormat *fmt;
- AVFormatContext *oc;
- AVCodec *audio_codec, *video_codec;
- int ret;
- int have_video = 0, have_audio = 0;
- int encode_video = 0, encode_audio = 0;
- AVDictionary *opt = NULL;
-
- /* Initialize libavcodec, and register all codecs and formats. */
- av_register_all();
-
- if (argc < 2) {
- printf("usage: %s output_file\n"
- "API example program to output a media file with libavformat.\n"
- "This program generates a synthetic audio and video stream, encodes and\n"
- "muxes them into a file named output_file.\n"
- "The output format is automatically guessed according to the file extension.\n"
- "Raw images can also be output by using '%%d' in the filename.\n"
- "\n", argv[0]);
- return 1;
- }
-
- filename = argv[1];
- if (argc > 3 && !strcmp(argv[2], "-flags")) {
- av_dict_set(&opt, argv[2]+1, argv[3], 0);
- }
-
- /* allocate the output media context */
- avformat_alloc_output_context2(&oc, NULL, NULL, filename);
- if (!oc) {
- printf("Could not deduce output format from file extension: using MPEG.\n");
- avformat_alloc_output_context2(&oc, NULL, "mpeg", filename);
- }
- if (!oc)
- return 1;
-
- fmt = oc->oformat;
-
- /* Add the audio and video streams using the default format codecs
- * and initialize the codecs. */
- if (fmt->video_codec != AV_CODEC_ID_NONE) {
- add_stream(&video_st, oc, &video_codec, fmt->video_codec);
- have_video = 1;
- encode_video = 1;
- }
- if (fmt->audio_codec != AV_CODEC_ID_NONE) {
- add_stream(&audio_st, oc, &audio_codec, fmt->audio_codec);
- have_audio = 1;
- encode_audio = 1;
- }
-
- /* Now that all the parameters are set, we can open the audio and
- * video codecs and allocate the necessary encode buffers. */
- if (have_video)
- open_video(oc, video_codec, &video_st, opt);
-
- if (have_audio)
- open_audio(oc, audio_codec, &audio_st, opt);
-
- av_dump_format(oc, 0, filename, 1);
-
- /* open the output file, if needed */
- if (!(fmt->flags & AVFMT_NOFILE)) {
- ret = avio_open(&oc->pb, filename, AVIO_FLAG_WRITE);
- if (ret < 0) {
- fprintf(stderr, "Could not open '%s': %s\n", filename,
- av_err2str(ret));
- return 1;
- }
- }
-
- /* Write the stream header, if any. */
- ret = avformat_write_header(oc, &opt);
- if (ret < 0) {
- fprintf(stderr, "Error occurred when opening output file: %s\n",
- av_err2str(ret));
- return 1;
- }
-
- while (encode_video || encode_audio) {
- /* select the stream to encode */
- if (encode_video &&
- (!encode_audio || av_compare_ts(video_st.next_pts, video_st.st->codec->time_base,
- audio_st.next_pts, audio_st.st->codec->time_base) <= 0)) {
- encode_video = !write_video_frame(oc, &video_st);
- } else {
- encode_audio = !write_audio_frame(oc, &audio_st);
- }
- }
-
- /* Write the trailer, if any. The trailer must be written before you
- * close the CodecContexts open when you wrote the header; otherwise
- * av_write_trailer() may try to use memory that was freed on
- * av_codec_close(). */
- av_write_trailer(oc);
-
- /* Close each codec. */
- if (have_video)
- close_stream(oc, &video_st);
- if (have_audio)
- close_stream(oc, &audio_st);
-
- if (!(fmt->flags & AVFMT_NOFILE))
- /* Close the output file. */
- avio_closep(&oc->pb);
-
- /* free the stream */
- avformat_free_context(oc);
-
- return 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/remuxing.c b/Externals/ffmpeg/shared/doc/examples/remuxing.c
deleted file mode 100644
index e9758a8dcb..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/remuxing.c
+++ /dev/null
@@ -1,165 +0,0 @@
-/*
- * Copyright (c) 2013 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * libavformat/libavcodec demuxing and muxing API example.
- *
- * Remux streams from one container format to another.
- * @example remuxing.c
- */
-
-#include
-#include
-
-static void log_packet(const AVFormatContext *fmt_ctx, const AVPacket *pkt, const char *tag)
-{
- AVRational *time_base = &fmt_ctx->streams[pkt->stream_index]->time_base;
-
- printf("%s: pts:%s pts_time:%s dts:%s dts_time:%s duration:%s duration_time:%s stream_index:%d\n",
- tag,
- av_ts2str(pkt->pts), av_ts2timestr(pkt->pts, time_base),
- av_ts2str(pkt->dts), av_ts2timestr(pkt->dts, time_base),
- av_ts2str(pkt->duration), av_ts2timestr(pkt->duration, time_base),
- pkt->stream_index);
-}
-
-int main(int argc, char **argv)
-{
- AVOutputFormat *ofmt = NULL;
- AVFormatContext *ifmt_ctx = NULL, *ofmt_ctx = NULL;
- AVPacket pkt;
- const char *in_filename, *out_filename;
- int ret, i;
-
- if (argc < 3) {
- printf("usage: %s input output\n"
- "API example program to remux a media file with libavformat and libavcodec.\n"
- "The output format is guessed according to the file extension.\n"
- "\n", argv[0]);
- return 1;
- }
-
- in_filename = argv[1];
- out_filename = argv[2];
-
- av_register_all();
-
- if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, 0)) < 0) {
- fprintf(stderr, "Could not open input file '%s'", in_filename);
- goto end;
- }
-
- if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0) {
- fprintf(stderr, "Failed to retrieve input stream information");
- goto end;
- }
-
- av_dump_format(ifmt_ctx, 0, in_filename, 0);
-
- avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
- if (!ofmt_ctx) {
- fprintf(stderr, "Could not create output context\n");
- ret = AVERROR_UNKNOWN;
- goto end;
- }
-
- ofmt = ofmt_ctx->oformat;
-
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- AVStream *in_stream = ifmt_ctx->streams[i];
- AVStream *out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
- if (!out_stream) {
- fprintf(stderr, "Failed allocating output stream\n");
- ret = AVERROR_UNKNOWN;
- goto end;
- }
-
- ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
- if (ret < 0) {
- fprintf(stderr, "Failed to copy context from input to output stream codec context\n");
- goto end;
- }
- out_stream->codec->codec_tag = 0;
- if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
- out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
- }
- av_dump_format(ofmt_ctx, 0, out_filename, 1);
-
- if (!(ofmt->flags & AVFMT_NOFILE)) {
- ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
- if (ret < 0) {
- fprintf(stderr, "Could not open output file '%s'", out_filename);
- goto end;
- }
- }
-
- ret = avformat_write_header(ofmt_ctx, NULL);
- if (ret < 0) {
- fprintf(stderr, "Error occurred when opening output file\n");
- goto end;
- }
-
- while (1) {
- AVStream *in_stream, *out_stream;
-
- ret = av_read_frame(ifmt_ctx, &pkt);
- if (ret < 0)
- break;
-
- in_stream = ifmt_ctx->streams[pkt.stream_index];
- out_stream = ofmt_ctx->streams[pkt.stream_index];
-
- log_packet(ifmt_ctx, &pkt, "in");
-
- /* copy packet */
- pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
- pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, AV_ROUND_NEAR_INF|AV_ROUND_PASS_MINMAX);
- pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
- pkt.pos = -1;
- log_packet(ofmt_ctx, &pkt, "out");
-
- ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
- if (ret < 0) {
- fprintf(stderr, "Error muxing packet\n");
- break;
- }
- av_free_packet(&pkt);
- }
-
- av_write_trailer(ofmt_ctx);
-end:
-
- avformat_close_input(&ifmt_ctx);
-
- /* close output */
- if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
- avio_closep(&ofmt_ctx->pb);
- avformat_free_context(ofmt_ctx);
-
- if (ret < 0 && ret != AVERROR_EOF) {
- fprintf(stderr, "Error occurred: %s\n", av_err2str(ret));
- return 1;
- }
-
- return 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/resampling_audio.c b/Externals/ffmpeg/shared/doc/examples/resampling_audio.c
deleted file mode 100644
index f35e7e1779..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/resampling_audio.c
+++ /dev/null
@@ -1,214 +0,0 @@
-/*
- * Copyright (c) 2012 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @example resampling_audio.c
- * libswresample API use example.
- */
-
-#include
-#include
-#include
-#include
-
-static int get_format_from_sample_fmt(const char **fmt,
- enum AVSampleFormat sample_fmt)
-{
- int i;
- struct sample_fmt_entry {
- enum AVSampleFormat sample_fmt; const char *fmt_be, *fmt_le;
- } sample_fmt_entries[] = {
- { AV_SAMPLE_FMT_U8, "u8", "u8" },
- { AV_SAMPLE_FMT_S16, "s16be", "s16le" },
- { AV_SAMPLE_FMT_S32, "s32be", "s32le" },
- { AV_SAMPLE_FMT_FLT, "f32be", "f32le" },
- { AV_SAMPLE_FMT_DBL, "f64be", "f64le" },
- };
- *fmt = NULL;
-
- for (i = 0; i < FF_ARRAY_ELEMS(sample_fmt_entries); i++) {
- struct sample_fmt_entry *entry = &sample_fmt_entries[i];
- if (sample_fmt == entry->sample_fmt) {
- *fmt = AV_NE(entry->fmt_be, entry->fmt_le);
- return 0;
- }
- }
-
- fprintf(stderr,
- "Sample format %s not supported as output format\n",
- av_get_sample_fmt_name(sample_fmt));
- return AVERROR(EINVAL);
-}
-
-/**
- * Fill dst buffer with nb_samples, generated starting from t.
- */
-static void fill_samples(double *dst, int nb_samples, int nb_channels, int sample_rate, double *t)
-{
- int i, j;
- double tincr = 1.0 / sample_rate, *dstp = dst;
- const double c = 2 * M_PI * 440.0;
-
- /* generate sin tone with 440Hz frequency and duplicated channels */
- for (i = 0; i < nb_samples; i++) {
- *dstp = sin(c * *t);
- for (j = 1; j < nb_channels; j++)
- dstp[j] = dstp[0];
- dstp += nb_channels;
- *t += tincr;
- }
-}
-
-int main(int argc, char **argv)
-{
- int64_t src_ch_layout = AV_CH_LAYOUT_STEREO, dst_ch_layout = AV_CH_LAYOUT_SURROUND;
- int src_rate = 48000, dst_rate = 44100;
- uint8_t **src_data = NULL, **dst_data = NULL;
- int src_nb_channels = 0, dst_nb_channels = 0;
- int src_linesize, dst_linesize;
- int src_nb_samples = 1024, dst_nb_samples, max_dst_nb_samples;
- enum AVSampleFormat src_sample_fmt = AV_SAMPLE_FMT_DBL, dst_sample_fmt = AV_SAMPLE_FMT_S16;
- const char *dst_filename = NULL;
- FILE *dst_file;
- int dst_bufsize;
- const char *fmt;
- struct SwrContext *swr_ctx;
- double t;
- int ret;
-
- if (argc != 2) {
- fprintf(stderr, "Usage: %s output_file\n"
- "API example program to show how to resample an audio stream with libswresample.\n"
- "This program generates a series of audio frames, resamples them to a specified "
- "output format and rate and saves them to an output file named output_file.\n",
- argv[0]);
- exit(1);
- }
- dst_filename = argv[1];
-
- dst_file = fopen(dst_filename, "wb");
- if (!dst_file) {
- fprintf(stderr, "Could not open destination file %s\n", dst_filename);
- exit(1);
- }
-
- /* create resampler context */
- swr_ctx = swr_alloc();
- if (!swr_ctx) {
- fprintf(stderr, "Could not allocate resampler context\n");
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- /* set options */
- av_opt_set_int(swr_ctx, "in_channel_layout", src_ch_layout, 0);
- av_opt_set_int(swr_ctx, "in_sample_rate", src_rate, 0);
- av_opt_set_sample_fmt(swr_ctx, "in_sample_fmt", src_sample_fmt, 0);
-
- av_opt_set_int(swr_ctx, "out_channel_layout", dst_ch_layout, 0);
- av_opt_set_int(swr_ctx, "out_sample_rate", dst_rate, 0);
- av_opt_set_sample_fmt(swr_ctx, "out_sample_fmt", dst_sample_fmt, 0);
-
- /* initialize the resampling context */
- if ((ret = swr_init(swr_ctx)) < 0) {
- fprintf(stderr, "Failed to initialize the resampling context\n");
- goto end;
- }
-
- /* allocate source and destination samples buffers */
-
- src_nb_channels = av_get_channel_layout_nb_channels(src_ch_layout);
- ret = av_samples_alloc_array_and_samples(&src_data, &src_linesize, src_nb_channels,
- src_nb_samples, src_sample_fmt, 0);
- if (ret < 0) {
- fprintf(stderr, "Could not allocate source samples\n");
- goto end;
- }
-
- /* compute the number of converted samples: buffering is avoided
- * ensuring that the output buffer will contain at least all the
- * converted input samples */
- max_dst_nb_samples = dst_nb_samples =
- av_rescale_rnd(src_nb_samples, dst_rate, src_rate, AV_ROUND_UP);
-
- /* buffer is going to be directly written to a rawaudio file, no alignment */
- dst_nb_channels = av_get_channel_layout_nb_channels(dst_ch_layout);
- ret = av_samples_alloc_array_and_samples(&dst_data, &dst_linesize, dst_nb_channels,
- dst_nb_samples, dst_sample_fmt, 0);
- if (ret < 0) {
- fprintf(stderr, "Could not allocate destination samples\n");
- goto end;
- }
-
- t = 0;
- do {
- /* generate synthetic audio */
- fill_samples((double *)src_data[0], src_nb_samples, src_nb_channels, src_rate, &t);
-
- /* compute destination number of samples */
- dst_nb_samples = av_rescale_rnd(swr_get_delay(swr_ctx, src_rate) +
- src_nb_samples, dst_rate, src_rate, AV_ROUND_UP);
- if (dst_nb_samples > max_dst_nb_samples) {
- av_freep(&dst_data[0]);
- ret = av_samples_alloc(dst_data, &dst_linesize, dst_nb_channels,
- dst_nb_samples, dst_sample_fmt, 1);
- if (ret < 0)
- break;
- max_dst_nb_samples = dst_nb_samples;
- }
-
- /* convert to destination format */
- ret = swr_convert(swr_ctx, dst_data, dst_nb_samples, (const uint8_t **)src_data, src_nb_samples);
- if (ret < 0) {
- fprintf(stderr, "Error while converting\n");
- goto end;
- }
- dst_bufsize = av_samples_get_buffer_size(&dst_linesize, dst_nb_channels,
- ret, dst_sample_fmt, 1);
- if (dst_bufsize < 0) {
- fprintf(stderr, "Could not get sample buffer size\n");
- goto end;
- }
- printf("t:%f in:%d out:%d\n", t, src_nb_samples, ret);
- fwrite(dst_data[0], 1, dst_bufsize, dst_file);
- } while (t < 10);
-
- if ((ret = get_format_from_sample_fmt(&fmt, dst_sample_fmt)) < 0)
- goto end;
- fprintf(stderr, "Resampling succeeded. Play the output file with the command:\n"
- "ffplay -f %s -channel_layout %"PRId64" -channels %d -ar %d %s\n",
- fmt, dst_ch_layout, dst_nb_channels, dst_rate, dst_filename);
-
-end:
- fclose(dst_file);
-
- if (src_data)
- av_freep(&src_data[0]);
- av_freep(&src_data);
-
- if (dst_data)
- av_freep(&dst_data[0]);
- av_freep(&dst_data);
-
- swr_free(&swr_ctx);
- return ret < 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/scaling_video.c b/Externals/ffmpeg/shared/doc/examples/scaling_video.c
deleted file mode 100644
index 587f3abe4f..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/scaling_video.c
+++ /dev/null
@@ -1,140 +0,0 @@
-/*
- * Copyright (c) 2012 Stefano Sabatini
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * libswscale API use example.
- * @example scaling_video.c
- */
-
-#include
-#include
-#include
-
-static void fill_yuv_image(uint8_t *data[4], int linesize[4],
- int width, int height, int frame_index)
-{
- int x, y;
-
- /* Y */
- for (y = 0; y < height; y++)
- for (x = 0; x < width; x++)
- data[0][y * linesize[0] + x] = x + y + frame_index * 3;
-
- /* Cb and Cr */
- for (y = 0; y < height / 2; y++) {
- for (x = 0; x < width / 2; x++) {
- data[1][y * linesize[1] + x] = 128 + y + frame_index * 2;
- data[2][y * linesize[2] + x] = 64 + x + frame_index * 5;
- }
- }
-}
-
-int main(int argc, char **argv)
-{
- uint8_t *src_data[4], *dst_data[4];
- int src_linesize[4], dst_linesize[4];
- int src_w = 320, src_h = 240, dst_w, dst_h;
- enum AVPixelFormat src_pix_fmt = AV_PIX_FMT_YUV420P, dst_pix_fmt = AV_PIX_FMT_RGB24;
- const char *dst_size = NULL;
- const char *dst_filename = NULL;
- FILE *dst_file;
- int dst_bufsize;
- struct SwsContext *sws_ctx;
- int i, ret;
-
- if (argc != 3) {
- fprintf(stderr, "Usage: %s output_file output_size\n"
- "API example program to show how to scale an image with libswscale.\n"
- "This program generates a series of pictures, rescales them to the given "
- "output_size and saves them to an output file named output_file\n."
- "\n", argv[0]);
- exit(1);
- }
- dst_filename = argv[1];
- dst_size = argv[2];
-
- if (av_parse_video_size(&dst_w, &dst_h, dst_size) < 0) {
- fprintf(stderr,
- "Invalid size '%s', must be in the form WxH or a valid size abbreviation\n",
- dst_size);
- exit(1);
- }
-
- dst_file = fopen(dst_filename, "wb");
- if (!dst_file) {
- fprintf(stderr, "Could not open destination file %s\n", dst_filename);
- exit(1);
- }
-
- /* create scaling context */
- sws_ctx = sws_getContext(src_w, src_h, src_pix_fmt,
- dst_w, dst_h, dst_pix_fmt,
- SWS_BILINEAR, NULL, NULL, NULL);
- if (!sws_ctx) {
- fprintf(stderr,
- "Impossible to create scale context for the conversion "
- "fmt:%s s:%dx%d -> fmt:%s s:%dx%d\n",
- av_get_pix_fmt_name(src_pix_fmt), src_w, src_h,
- av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h);
- ret = AVERROR(EINVAL);
- goto end;
- }
-
- /* allocate source and destination image buffers */
- if ((ret = av_image_alloc(src_data, src_linesize,
- src_w, src_h, src_pix_fmt, 16)) < 0) {
- fprintf(stderr, "Could not allocate source image\n");
- goto end;
- }
-
- /* buffer is going to be written to rawvideo file, no alignment */
- if ((ret = av_image_alloc(dst_data, dst_linesize,
- dst_w, dst_h, dst_pix_fmt, 1)) < 0) {
- fprintf(stderr, "Could not allocate destination image\n");
- goto end;
- }
- dst_bufsize = ret;
-
- for (i = 0; i < 100; i++) {
- /* generate synthetic video */
- fill_yuv_image(src_data, src_linesize, src_w, src_h, i);
-
- /* convert to destination format */
- sws_scale(sws_ctx, (const uint8_t * const*)src_data,
- src_linesize, 0, src_h, dst_data, dst_linesize);
-
- /* write scaled image to file */
- fwrite(dst_data[0], 1, dst_bufsize, dst_file);
- }
-
- fprintf(stderr, "Scaling succeeded. Play the output file with the command:\n"
- "ffplay -f rawvideo -pix_fmt %s -video_size %dx%d %s\n",
- av_get_pix_fmt_name(dst_pix_fmt), dst_w, dst_h, dst_filename);
-
-end:
- fclose(dst_file);
- av_freep(&src_data[0]);
- av_freep(&dst_data[0]);
- sws_freeContext(sws_ctx);
- return ret < 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/transcode_aac.c b/Externals/ffmpeg/shared/doc/examples/transcode_aac.c
deleted file mode 100644
index 6998aac72b..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/transcode_aac.c
+++ /dev/null
@@ -1,755 +0,0 @@
-/*
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-/**
- * @file
- * simple audio converter
- *
- * @example transcode_aac.c
- * Convert an input audio file to AAC in an MP4 container using FFmpeg.
- * @author Andreas Unterweger (dustsigns@gmail.com)
- */
-
-#include
-
-#include "libavformat/avformat.h"
-#include "libavformat/avio.h"
-
-#include "libavcodec/avcodec.h"
-
-#include "libavutil/audio_fifo.h"
-#include "libavutil/avassert.h"
-#include "libavutil/avstring.h"
-#include "libavutil/frame.h"
-#include "libavutil/opt.h"
-
-#include "libswresample/swresample.h"
-
-/** The output bit rate in kbit/s */
-#define OUTPUT_BIT_RATE 48000
-/** The number of output channels */
-#define OUTPUT_CHANNELS 2
-/** The audio sample output format */
-#define OUTPUT_SAMPLE_FORMAT AV_SAMPLE_FMT_S16
-
-/**
- * Convert an error code into a text message.
- * @param error Error code to be converted
- * @return Corresponding error text (not thread-safe)
- */
-static const char *get_error_text(const int error)
-{
- static char error_buffer[255];
- av_strerror(error, error_buffer, sizeof(error_buffer));
- return error_buffer;
-}
-
-/** Open an input file and the required decoder. */
-static int open_input_file(const char *filename,
- AVFormatContext **input_format_context,
- AVCodecContext **input_codec_context)
-{
- AVCodec *input_codec;
- int error;
-
- /** Open the input file to read from it. */
- if ((error = avformat_open_input(input_format_context, filename, NULL,
- NULL)) < 0) {
- fprintf(stderr, "Could not open input file '%s' (error '%s')\n",
- filename, get_error_text(error));
- *input_format_context = NULL;
- return error;
- }
-
- /** Get information on the input file (number of streams etc.). */
- if ((error = avformat_find_stream_info(*input_format_context, NULL)) < 0) {
- fprintf(stderr, "Could not open find stream info (error '%s')\n",
- get_error_text(error));
- avformat_close_input(input_format_context);
- return error;
- }
-
- /** Make sure that there is only one stream in the input file. */
- if ((*input_format_context)->nb_streams != 1) {
- fprintf(stderr, "Expected one audio input stream, but found %d\n",
- (*input_format_context)->nb_streams);
- avformat_close_input(input_format_context);
- return AVERROR_EXIT;
- }
-
- /** Find a decoder for the audio stream. */
- if (!(input_codec = avcodec_find_decoder((*input_format_context)->streams[0]->codec->codec_id))) {
- fprintf(stderr, "Could not find input codec\n");
- avformat_close_input(input_format_context);
- return AVERROR_EXIT;
- }
-
- /** Open the decoder for the audio stream to use it later. */
- if ((error = avcodec_open2((*input_format_context)->streams[0]->codec,
- input_codec, NULL)) < 0) {
- fprintf(stderr, "Could not open input codec (error '%s')\n",
- get_error_text(error));
- avformat_close_input(input_format_context);
- return error;
- }
-
- /** Save the decoder context for easier access later. */
- *input_codec_context = (*input_format_context)->streams[0]->codec;
-
- return 0;
-}
-
-/**
- * Open an output file and the required encoder.
- * Also set some basic encoder parameters.
- * Some of these parameters are based on the input file's parameters.
- */
-static int open_output_file(const char *filename,
- AVCodecContext *input_codec_context,
- AVFormatContext **output_format_context,
- AVCodecContext **output_codec_context)
-{
- AVIOContext *output_io_context = NULL;
- AVStream *stream = NULL;
- AVCodec *output_codec = NULL;
- int error;
-
- /** Open the output file to write to it. */
- if ((error = avio_open(&output_io_context, filename,
- AVIO_FLAG_WRITE)) < 0) {
- fprintf(stderr, "Could not open output file '%s' (error '%s')\n",
- filename, get_error_text(error));
- return error;
- }
-
- /** Create a new format context for the output container format. */
- if (!(*output_format_context = avformat_alloc_context())) {
- fprintf(stderr, "Could not allocate output format context\n");
- return AVERROR(ENOMEM);
- }
-
- /** Associate the output file (pointer) with the container format context. */
- (*output_format_context)->pb = output_io_context;
-
- /** Guess the desired container format based on the file extension. */
- if (!((*output_format_context)->oformat = av_guess_format(NULL, filename,
- NULL))) {
- fprintf(stderr, "Could not find output file format\n");
- goto cleanup;
- }
-
- av_strlcpy((*output_format_context)->filename, filename,
- sizeof((*output_format_context)->filename));
-
- /** Find the encoder to be used by its name. */
- if (!(output_codec = avcodec_find_encoder(AV_CODEC_ID_AAC))) {
- fprintf(stderr, "Could not find an AAC encoder.\n");
- goto cleanup;
- }
-
- /** Create a new audio stream in the output file container. */
- if (!(stream = avformat_new_stream(*output_format_context, output_codec))) {
- fprintf(stderr, "Could not create new stream\n");
- error = AVERROR(ENOMEM);
- goto cleanup;
- }
-
- /** Save the encoder context for easiert access later. */
- *output_codec_context = stream->codec;
-
- /**
- * Set the basic encoder parameters.
- * The input file's sample rate is used to avoid a sample rate conversion.
- */
- (*output_codec_context)->channels = OUTPUT_CHANNELS;
- (*output_codec_context)->channel_layout = av_get_default_channel_layout(OUTPUT_CHANNELS);
- (*output_codec_context)->sample_rate = input_codec_context->sample_rate;
- (*output_codec_context)->sample_fmt = AV_SAMPLE_FMT_S16;
- (*output_codec_context)->bit_rate = OUTPUT_BIT_RATE;
-
- /**
- * Some container formats (like MP4) require global headers to be present
- * Mark the encoder so that it behaves accordingly.
- */
- if ((*output_format_context)->oformat->flags & AVFMT_GLOBALHEADER)
- (*output_codec_context)->flags |= CODEC_FLAG_GLOBAL_HEADER;
-
- /** Open the encoder for the audio stream to use it later. */
- if ((error = avcodec_open2(*output_codec_context, output_codec, NULL)) < 0) {
- fprintf(stderr, "Could not open output codec (error '%s')\n",
- get_error_text(error));
- goto cleanup;
- }
-
- return 0;
-
-cleanup:
- avio_closep(&(*output_format_context)->pb);
- avformat_free_context(*output_format_context);
- *output_format_context = NULL;
- return error < 0 ? error : AVERROR_EXIT;
-}
-
-/** Initialize one data packet for reading or writing. */
-static void init_packet(AVPacket *packet)
-{
- av_init_packet(packet);
- /** Set the packet data and size so that it is recognized as being empty. */
- packet->data = NULL;
- packet->size = 0;
-}
-
-/** Initialize one audio frame for reading from the input file */
-static int init_input_frame(AVFrame **frame)
-{
- if (!(*frame = av_frame_alloc())) {
- fprintf(stderr, "Could not allocate input frame\n");
- return AVERROR(ENOMEM);
- }
- return 0;
-}
-
-/**
- * Initialize the audio resampler based on the input and output codec settings.
- * If the input and output sample formats differ, a conversion is required
- * libswresample takes care of this, but requires initialization.
- */
-static int init_resampler(AVCodecContext *input_codec_context,
- AVCodecContext *output_codec_context,
- SwrContext **resample_context)
-{
- int error;
-
- /**
- * Create a resampler context for the conversion.
- * Set the conversion parameters.
- * Default channel layouts based on the number of channels
- * are assumed for simplicity (they are sometimes not detected
- * properly by the demuxer and/or decoder).
- */
- *resample_context = swr_alloc_set_opts(NULL,
- av_get_default_channel_layout(output_codec_context->channels),
- output_codec_context->sample_fmt,
- output_codec_context->sample_rate,
- av_get_default_channel_layout(input_codec_context->channels),
- input_codec_context->sample_fmt,
- input_codec_context->sample_rate,
- 0, NULL);
- if (!*resample_context) {
- fprintf(stderr, "Could not allocate resample context\n");
- return AVERROR(ENOMEM);
- }
- /**
- * Perform a sanity check so that the number of converted samples is
- * not greater than the number of samples to be converted.
- * If the sample rates differ, this case has to be handled differently
- */
- av_assert0(output_codec_context->sample_rate == input_codec_context->sample_rate);
-
- /** Open the resampler with the specified parameters. */
- if ((error = swr_init(*resample_context)) < 0) {
- fprintf(stderr, "Could not open resample context\n");
- swr_free(resample_context);
- return error;
- }
- return 0;
-}
-
-/** Initialize a FIFO buffer for the audio samples to be encoded. */
-static int init_fifo(AVAudioFifo **fifo)
-{
- /** Create the FIFO buffer based on the specified output sample format. */
- if (!(*fifo = av_audio_fifo_alloc(OUTPUT_SAMPLE_FORMAT, OUTPUT_CHANNELS, 1))) {
- fprintf(stderr, "Could not allocate FIFO\n");
- return AVERROR(ENOMEM);
- }
- return 0;
-}
-
-/** Write the header of the output file container. */
-static int write_output_file_header(AVFormatContext *output_format_context)
-{
- int error;
- if ((error = avformat_write_header(output_format_context, NULL)) < 0) {
- fprintf(stderr, "Could not write output file header (error '%s')\n",
- get_error_text(error));
- return error;
- }
- return 0;
-}
-
-/** Decode one audio frame from the input file. */
-static int decode_audio_frame(AVFrame *frame,
- AVFormatContext *input_format_context,
- AVCodecContext *input_codec_context,
- int *data_present, int *finished)
-{
- /** Packet used for temporary storage. */
- AVPacket input_packet;
- int error;
- init_packet(&input_packet);
-
- /** Read one audio frame from the input file into a temporary packet. */
- if ((error = av_read_frame(input_format_context, &input_packet)) < 0) {
- /** If we are at the end of the file, flush the decoder below. */
- if (error == AVERROR_EOF)
- *finished = 1;
- else {
- fprintf(stderr, "Could not read frame (error '%s')\n",
- get_error_text(error));
- return error;
- }
- }
-
- /**
- * Decode the audio frame stored in the temporary packet.
- * The input audio stream decoder is used to do this.
- * If we are at the end of the file, pass an empty packet to the decoder
- * to flush it.
- */
- if ((error = avcodec_decode_audio4(input_codec_context, frame,
- data_present, &input_packet)) < 0) {
- fprintf(stderr, "Could not decode frame (error '%s')\n",
- get_error_text(error));
- av_free_packet(&input_packet);
- return error;
- }
-
- /**
- * If the decoder has not been flushed completely, we are not finished,
- * so that this function has to be called again.
- */
- if (*finished && *data_present)
- *finished = 0;
- av_free_packet(&input_packet);
- return 0;
-}
-
-/**
- * Initialize a temporary storage for the specified number of audio samples.
- * The conversion requires temporary storage due to the different format.
- * The number of audio samples to be allocated is specified in frame_size.
- */
-static int init_converted_samples(uint8_t ***converted_input_samples,
- AVCodecContext *output_codec_context,
- int frame_size)
-{
- int error;
-
- /**
- * Allocate as many pointers as there are audio channels.
- * Each pointer will later point to the audio samples of the corresponding
- * channels (although it may be NULL for interleaved formats).
- */
- if (!(*converted_input_samples = calloc(output_codec_context->channels,
- sizeof(**converted_input_samples)))) {
- fprintf(stderr, "Could not allocate converted input sample pointers\n");
- return AVERROR(ENOMEM);
- }
-
- /**
- * Allocate memory for the samples of all channels in one consecutive
- * block for convenience.
- */
- if ((error = av_samples_alloc(*converted_input_samples, NULL,
- output_codec_context->channels,
- frame_size,
- output_codec_context->sample_fmt, 0)) < 0) {
- fprintf(stderr,
- "Could not allocate converted input samples (error '%s')\n",
- get_error_text(error));
- av_freep(&(*converted_input_samples)[0]);
- free(*converted_input_samples);
- return error;
- }
- return 0;
-}
-
-/**
- * Convert the input audio samples into the output sample format.
- * The conversion happens on a per-frame basis, the size of which is specified
- * by frame_size.
- */
-static int convert_samples(const uint8_t **input_data,
- uint8_t **converted_data, const int frame_size,
- SwrContext *resample_context)
-{
- int error;
-
- /** Convert the samples using the resampler. */
- if ((error = swr_convert(resample_context,
- converted_data, frame_size,
- input_data , frame_size)) < 0) {
- fprintf(stderr, "Could not convert input samples (error '%s')\n",
- get_error_text(error));
- return error;
- }
-
- return 0;
-}
-
-/** Add converted input audio samples to the FIFO buffer for later processing. */
-static int add_samples_to_fifo(AVAudioFifo *fifo,
- uint8_t **converted_input_samples,
- const int frame_size)
-{
- int error;
-
- /**
- * Make the FIFO as large as it needs to be to hold both,
- * the old and the new samples.
- */
- if ((error = av_audio_fifo_realloc(fifo, av_audio_fifo_size(fifo) + frame_size)) < 0) {
- fprintf(stderr, "Could not reallocate FIFO\n");
- return error;
- }
-
- /** Store the new samples in the FIFO buffer. */
- if (av_audio_fifo_write(fifo, (void **)converted_input_samples,
- frame_size) < frame_size) {
- fprintf(stderr, "Could not write data to FIFO\n");
- return AVERROR_EXIT;
- }
- return 0;
-}
-
-/**
- * Read one audio frame from the input file, decodes, converts and stores
- * it in the FIFO buffer.
- */
-static int read_decode_convert_and_store(AVAudioFifo *fifo,
- AVFormatContext *input_format_context,
- AVCodecContext *input_codec_context,
- AVCodecContext *output_codec_context,
- SwrContext *resampler_context,
- int *finished)
-{
- /** Temporary storage of the input samples of the frame read from the file. */
- AVFrame *input_frame = NULL;
- /** Temporary storage for the converted input samples. */
- uint8_t **converted_input_samples = NULL;
- int data_present;
- int ret = AVERROR_EXIT;
-
- /** Initialize temporary storage for one input frame. */
- if (init_input_frame(&input_frame))
- goto cleanup;
- /** Decode one frame worth of audio samples. */
- if (decode_audio_frame(input_frame, input_format_context,
- input_codec_context, &data_present, finished))
- goto cleanup;
- /**
- * If we are at the end of the file and there are no more samples
- * in the decoder which are delayed, we are actually finished.
- * This must not be treated as an error.
- */
- if (*finished && !data_present) {
- ret = 0;
- goto cleanup;
- }
- /** If there is decoded data, convert and store it */
- if (data_present) {
- /** Initialize the temporary storage for the converted input samples. */
- if (init_converted_samples(&converted_input_samples, output_codec_context,
- input_frame->nb_samples))
- goto cleanup;
-
- /**
- * Convert the input samples to the desired output sample format.
- * This requires a temporary storage provided by converted_input_samples.
- */
- if (convert_samples((const uint8_t**)input_frame->extended_data, converted_input_samples,
- input_frame->nb_samples, resampler_context))
- goto cleanup;
-
- /** Add the converted input samples to the FIFO buffer for later processing. */
- if (add_samples_to_fifo(fifo, converted_input_samples,
- input_frame->nb_samples))
- goto cleanup;
- ret = 0;
- }
- ret = 0;
-
-cleanup:
- if (converted_input_samples) {
- av_freep(&converted_input_samples[0]);
- free(converted_input_samples);
- }
- av_frame_free(&input_frame);
-
- return ret;
-}
-
-/**
- * Initialize one input frame for writing to the output file.
- * The frame will be exactly frame_size samples large.
- */
-static int init_output_frame(AVFrame **frame,
- AVCodecContext *output_codec_context,
- int frame_size)
-{
- int error;
-
- /** Create a new frame to store the audio samples. */
- if (!(*frame = av_frame_alloc())) {
- fprintf(stderr, "Could not allocate output frame\n");
- return AVERROR_EXIT;
- }
-
- /**
- * Set the frame's parameters, especially its size and format.
- * av_frame_get_buffer needs this to allocate memory for the
- * audio samples of the frame.
- * Default channel layouts based on the number of channels
- * are assumed for simplicity.
- */
- (*frame)->nb_samples = frame_size;
- (*frame)->channel_layout = output_codec_context->channel_layout;
- (*frame)->format = output_codec_context->sample_fmt;
- (*frame)->sample_rate = output_codec_context->sample_rate;
-
- /**
- * Allocate the samples of the created frame. This call will make
- * sure that the audio frame can hold as many samples as specified.
- */
- if ((error = av_frame_get_buffer(*frame, 0)) < 0) {
- fprintf(stderr, "Could allocate output frame samples (error '%s')\n",
- get_error_text(error));
- av_frame_free(frame);
- return error;
- }
-
- return 0;
-}
-
-/** Encode one frame worth of audio to the output file. */
-static int encode_audio_frame(AVFrame *frame,
- AVFormatContext *output_format_context,
- AVCodecContext *output_codec_context,
- int *data_present)
-{
- /** Packet used for temporary storage. */
- AVPacket output_packet;
- int error;
- init_packet(&output_packet);
-
- /**
- * Encode the audio frame and store it in the temporary packet.
- * The output audio stream encoder is used to do this.
- */
- if ((error = avcodec_encode_audio2(output_codec_context, &output_packet,
- frame, data_present)) < 0) {
- fprintf(stderr, "Could not encode frame (error '%s')\n",
- get_error_text(error));
- av_free_packet(&output_packet);
- return error;
- }
-
- /** Write one audio frame from the temporary packet to the output file. */
- if (*data_present) {
- if ((error = av_write_frame(output_format_context, &output_packet)) < 0) {
- fprintf(stderr, "Could not write frame (error '%s')\n",
- get_error_text(error));
- av_free_packet(&output_packet);
- return error;
- }
-
- av_free_packet(&output_packet);
- }
-
- return 0;
-}
-
-/**
- * Load one audio frame from the FIFO buffer, encode and write it to the
- * output file.
- */
-static int load_encode_and_write(AVAudioFifo *fifo,
- AVFormatContext *output_format_context,
- AVCodecContext *output_codec_context)
-{
- /** Temporary storage of the output samples of the frame written to the file. */
- AVFrame *output_frame;
- /**
- * Use the maximum number of possible samples per frame.
- * If there is less than the maximum possible frame size in the FIFO
- * buffer use this number. Otherwise, use the maximum possible frame size
- */
- const int frame_size = FFMIN(av_audio_fifo_size(fifo),
- output_codec_context->frame_size);
- int data_written;
-
- /** Initialize temporary storage for one output frame. */
- if (init_output_frame(&output_frame, output_codec_context, frame_size))
- return AVERROR_EXIT;
-
- /**
- * Read as many samples from the FIFO buffer as required to fill the frame.
- * The samples are stored in the frame temporarily.
- */
- if (av_audio_fifo_read(fifo, (void **)output_frame->data, frame_size) < frame_size) {
- fprintf(stderr, "Could not read data from FIFO\n");
- av_frame_free(&output_frame);
- return AVERROR_EXIT;
- }
-
- /** Encode one frame worth of audio samples. */
- if (encode_audio_frame(output_frame, output_format_context,
- output_codec_context, &data_written)) {
- av_frame_free(&output_frame);
- return AVERROR_EXIT;
- }
- av_frame_free(&output_frame);
- return 0;
-}
-
-/** Write the trailer of the output file container. */
-static int write_output_file_trailer(AVFormatContext *output_format_context)
-{
- int error;
- if ((error = av_write_trailer(output_format_context)) < 0) {
- fprintf(stderr, "Could not write output file trailer (error '%s')\n",
- get_error_text(error));
- return error;
- }
- return 0;
-}
-
-/** Convert an audio file to an AAC file in an MP4 container. */
-int main(int argc, char **argv)
-{
- AVFormatContext *input_format_context = NULL, *output_format_context = NULL;
- AVCodecContext *input_codec_context = NULL, *output_codec_context = NULL;
- SwrContext *resample_context = NULL;
- AVAudioFifo *fifo = NULL;
- int ret = AVERROR_EXIT;
-
- if (argc < 3) {
- fprintf(stderr, "Usage: %s \n", argv[0]);
- exit(1);
- }
-
- /** Register all codecs and formats so that they can be used. */
- av_register_all();
- /** Open the input file for reading. */
- if (open_input_file(argv[1], &input_format_context,
- &input_codec_context))
- goto cleanup;
- /** Open the output file for writing. */
- if (open_output_file(argv[2], input_codec_context,
- &output_format_context, &output_codec_context))
- goto cleanup;
- /** Initialize the resampler to be able to convert audio sample formats. */
- if (init_resampler(input_codec_context, output_codec_context,
- &resample_context))
- goto cleanup;
- /** Initialize the FIFO buffer to store audio samples to be encoded. */
- if (init_fifo(&fifo))
- goto cleanup;
- /** Write the header of the output file container. */
- if (write_output_file_header(output_format_context))
- goto cleanup;
-
- /**
- * Loop as long as we have input samples to read or output samples
- * to write; abort as soon as we have neither.
- */
- while (1) {
- /** Use the encoder's desired frame size for processing. */
- const int output_frame_size = output_codec_context->frame_size;
- int finished = 0;
-
- /**
- * Make sure that there is one frame worth of samples in the FIFO
- * buffer so that the encoder can do its work.
- * Since the decoder's and the encoder's frame size may differ, we
- * need to FIFO buffer to store as many frames worth of input samples
- * that they make up at least one frame worth of output samples.
- */
- while (av_audio_fifo_size(fifo) < output_frame_size) {
- /**
- * Decode one frame worth of audio samples, convert it to the
- * output sample format and put it into the FIFO buffer.
- */
- if (read_decode_convert_and_store(fifo, input_format_context,
- input_codec_context,
- output_codec_context,
- resample_context, &finished))
- goto cleanup;
-
- /**
- * If we are at the end of the input file, we continue
- * encoding the remaining audio samples to the output file.
- */
- if (finished)
- break;
- }
-
- /**
- * If we have enough samples for the encoder, we encode them.
- * At the end of the file, we pass the remaining samples to
- * the encoder.
- */
- while (av_audio_fifo_size(fifo) >= output_frame_size ||
- (finished && av_audio_fifo_size(fifo) > 0))
- /**
- * Take one frame worth of audio samples from the FIFO buffer,
- * encode it and write it to the output file.
- */
- if (load_encode_and_write(fifo, output_format_context,
- output_codec_context))
- goto cleanup;
-
- /**
- * If we are at the end of the input file and have encoded
- * all remaining samples, we can exit this loop and finish.
- */
- if (finished) {
- int data_written;
- /** Flush the encoder as it may have delayed frames. */
- do {
- if (encode_audio_frame(NULL, output_format_context,
- output_codec_context, &data_written))
- goto cleanup;
- } while (data_written);
- break;
- }
- }
-
- /** Write the trailer of the output file container. */
- if (write_output_file_trailer(output_format_context))
- goto cleanup;
- ret = 0;
-
-cleanup:
- if (fifo)
- av_audio_fifo_free(fifo);
- swr_free(&resample_context);
- if (output_codec_context)
- avcodec_close(output_codec_context);
- if (output_format_context) {
- avio_closep(&output_format_context->pb);
- avformat_free_context(output_format_context);
- }
- if (input_codec_context)
- avcodec_close(input_codec_context);
- if (input_format_context)
- avformat_close_input(&input_format_context);
-
- return ret;
-}
diff --git a/Externals/ffmpeg/shared/doc/examples/transcoding.c b/Externals/ffmpeg/shared/doc/examples/transcoding.c
deleted file mode 100644
index 2a8220eefa..0000000000
--- a/Externals/ffmpeg/shared/doc/examples/transcoding.c
+++ /dev/null
@@ -1,583 +0,0 @@
-/*
- * Copyright (c) 2010 Nicolas George
- * Copyright (c) 2011 Stefano Sabatini
- * Copyright (c) 2014 Andrey Utkin
- *
- * Permission is hereby granted, free of charge, to any person obtaining a copy
- * of this software and associated documentation files (the "Software"), to deal
- * in the Software without restriction, including without limitation the rights
- * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
- * copies of the Software, and to permit persons to whom the Software is
- * furnished to do so, subject to the following conditions:
- *
- * The above copyright notice and this permission notice shall be included in
- * all copies or substantial portions of the Software.
- *
- * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
- * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
- * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
- * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
- * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
- * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
- * THE SOFTWARE.
- */
-
-/**
- * @file
- * API example for demuxing, decoding, filtering, encoding and muxing
- * @example transcoding.c
- */
-
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-#include
-
-static AVFormatContext *ifmt_ctx;
-static AVFormatContext *ofmt_ctx;
-typedef struct FilteringContext {
- AVFilterContext *buffersink_ctx;
- AVFilterContext *buffersrc_ctx;
- AVFilterGraph *filter_graph;
-} FilteringContext;
-static FilteringContext *filter_ctx;
-
-static int open_input_file(const char *filename)
-{
- int ret;
- unsigned int i;
-
- ifmt_ctx = NULL;
- if ((ret = avformat_open_input(&ifmt_ctx, filename, NULL, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open input file\n");
- return ret;
- }
-
- if ((ret = avformat_find_stream_info(ifmt_ctx, NULL)) < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot find stream information\n");
- return ret;
- }
-
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- AVStream *stream;
- AVCodecContext *codec_ctx;
- stream = ifmt_ctx->streams[i];
- codec_ctx = stream->codec;
- /* Reencode video & audio and remux subtitles etc. */
- if (codec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
- || codec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
- /* Open decoder */
- ret = avcodec_open2(codec_ctx,
- avcodec_find_decoder(codec_ctx->codec_id), NULL);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Failed to open decoder for stream #%u\n", i);
- return ret;
- }
- }
- }
-
- av_dump_format(ifmt_ctx, 0, filename, 0);
- return 0;
-}
-
-static int open_output_file(const char *filename)
-{
- AVStream *out_stream;
- AVStream *in_stream;
- AVCodecContext *dec_ctx, *enc_ctx;
- AVCodec *encoder;
- int ret;
- unsigned int i;
-
- ofmt_ctx = NULL;
- avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, filename);
- if (!ofmt_ctx) {
- av_log(NULL, AV_LOG_ERROR, "Could not create output context\n");
- return AVERROR_UNKNOWN;
- }
-
-
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- out_stream = avformat_new_stream(ofmt_ctx, NULL);
- if (!out_stream) {
- av_log(NULL, AV_LOG_ERROR, "Failed allocating output stream\n");
- return AVERROR_UNKNOWN;
- }
-
- in_stream = ifmt_ctx->streams[i];
- dec_ctx = in_stream->codec;
- enc_ctx = out_stream->codec;
-
- if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO
- || dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
- /* in this example, we choose transcoding to same codec */
- encoder = avcodec_find_encoder(dec_ctx->codec_id);
- if (!encoder) {
- av_log(NULL, AV_LOG_FATAL, "Neccessary encoder not found\n");
- return AVERROR_INVALIDDATA;
- }
-
- /* In this example, we transcode to same properties (picture size,
- * sample rate etc.). These properties can be changed for output
- * streams easily using filters */
- if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
- enc_ctx->height = dec_ctx->height;
- enc_ctx->width = dec_ctx->width;
- enc_ctx->sample_aspect_ratio = dec_ctx->sample_aspect_ratio;
- /* take first format from list of supported formats */
- enc_ctx->pix_fmt = encoder->pix_fmts[0];
- /* video time_base can be set to whatever is handy and supported by encoder */
- enc_ctx->time_base = dec_ctx->time_base;
- } else {
- enc_ctx->sample_rate = dec_ctx->sample_rate;
- enc_ctx->channel_layout = dec_ctx->channel_layout;
- enc_ctx->channels = av_get_channel_layout_nb_channels(enc_ctx->channel_layout);
- /* take first format from list of supported formats */
- enc_ctx->sample_fmt = encoder->sample_fmts[0];
- enc_ctx->time_base = (AVRational){1, enc_ctx->sample_rate};
- }
-
- /* Third parameter can be used to pass settings to encoder */
- ret = avcodec_open2(enc_ctx, encoder, NULL);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot open video encoder for stream #%u\n", i);
- return ret;
- }
- } else if (dec_ctx->codec_type == AVMEDIA_TYPE_UNKNOWN) {
- av_log(NULL, AV_LOG_FATAL, "Elementary stream #%d is of unknown type, cannot proceed\n", i);
- return AVERROR_INVALIDDATA;
- } else {
- /* if this stream must be remuxed */
- ret = avcodec_copy_context(ofmt_ctx->streams[i]->codec,
- ifmt_ctx->streams[i]->codec);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Copying stream context failed\n");
- return ret;
- }
- }
-
- if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
- enc_ctx->flags |= CODEC_FLAG_GLOBAL_HEADER;
-
- }
- av_dump_format(ofmt_ctx, 0, filename, 1);
-
- if (!(ofmt_ctx->oformat->flags & AVFMT_NOFILE)) {
- ret = avio_open(&ofmt_ctx->pb, filename, AVIO_FLAG_WRITE);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Could not open output file '%s'", filename);
- return ret;
- }
- }
-
- /* init muxer, write output file header */
- ret = avformat_write_header(ofmt_ctx, NULL);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error occurred when opening output file\n");
- return ret;
- }
-
- return 0;
-}
-
-static int init_filter(FilteringContext* fctx, AVCodecContext *dec_ctx,
- AVCodecContext *enc_ctx, const char *filter_spec)
-{
- char args[512];
- int ret = 0;
- AVFilter *buffersrc = NULL;
- AVFilter *buffersink = NULL;
- AVFilterContext *buffersrc_ctx = NULL;
- AVFilterContext *buffersink_ctx = NULL;
- AVFilterInOut *outputs = avfilter_inout_alloc();
- AVFilterInOut *inputs = avfilter_inout_alloc();
- AVFilterGraph *filter_graph = avfilter_graph_alloc();
-
- if (!outputs || !inputs || !filter_graph) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- if (dec_ctx->codec_type == AVMEDIA_TYPE_VIDEO) {
- buffersrc = avfilter_get_by_name("buffer");
- buffersink = avfilter_get_by_name("buffersink");
- if (!buffersrc || !buffersink) {
- av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
- ret = AVERROR_UNKNOWN;
- goto end;
- }
-
- snprintf(args, sizeof(args),
- "video_size=%dx%d:pix_fmt=%d:time_base=%d/%d:pixel_aspect=%d/%d",
- dec_ctx->width, dec_ctx->height, dec_ctx->pix_fmt,
- dec_ctx->time_base.num, dec_ctx->time_base.den,
- dec_ctx->sample_aspect_ratio.num,
- dec_ctx->sample_aspect_ratio.den);
-
- ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
- args, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create buffer source\n");
- goto end;
- }
-
- ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
- NULL, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create buffer sink\n");
- goto end;
- }
-
- ret = av_opt_set_bin(buffersink_ctx, "pix_fmts",
- (uint8_t*)&enc_ctx->pix_fmt, sizeof(enc_ctx->pix_fmt),
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output pixel format\n");
- goto end;
- }
- } else if (dec_ctx->codec_type == AVMEDIA_TYPE_AUDIO) {
- buffersrc = avfilter_get_by_name("abuffer");
- buffersink = avfilter_get_by_name("abuffersink");
- if (!buffersrc || !buffersink) {
- av_log(NULL, AV_LOG_ERROR, "filtering source or sink element not found\n");
- ret = AVERROR_UNKNOWN;
- goto end;
- }
-
- if (!dec_ctx->channel_layout)
- dec_ctx->channel_layout =
- av_get_default_channel_layout(dec_ctx->channels);
- snprintf(args, sizeof(args),
- "time_base=%d/%d:sample_rate=%d:sample_fmt=%s:channel_layout=0x%"PRIx64,
- dec_ctx->time_base.num, dec_ctx->time_base.den, dec_ctx->sample_rate,
- av_get_sample_fmt_name(dec_ctx->sample_fmt),
- dec_ctx->channel_layout);
- ret = avfilter_graph_create_filter(&buffersrc_ctx, buffersrc, "in",
- args, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer source\n");
- goto end;
- }
-
- ret = avfilter_graph_create_filter(&buffersink_ctx, buffersink, "out",
- NULL, NULL, filter_graph);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot create audio buffer sink\n");
- goto end;
- }
-
- ret = av_opt_set_bin(buffersink_ctx, "sample_fmts",
- (uint8_t*)&enc_ctx->sample_fmt, sizeof(enc_ctx->sample_fmt),
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output sample format\n");
- goto end;
- }
-
- ret = av_opt_set_bin(buffersink_ctx, "channel_layouts",
- (uint8_t*)&enc_ctx->channel_layout,
- sizeof(enc_ctx->channel_layout), AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output channel layout\n");
- goto end;
- }
-
- ret = av_opt_set_bin(buffersink_ctx, "sample_rates",
- (uint8_t*)&enc_ctx->sample_rate, sizeof(enc_ctx->sample_rate),
- AV_OPT_SEARCH_CHILDREN);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Cannot set output sample rate\n");
- goto end;
- }
- } else {
- ret = AVERROR_UNKNOWN;
- goto end;
- }
-
- /* Endpoints for the filter graph. */
- outputs->name = av_strdup("in");
- outputs->filter_ctx = buffersrc_ctx;
- outputs->pad_idx = 0;
- outputs->next = NULL;
-
- inputs->name = av_strdup("out");
- inputs->filter_ctx = buffersink_ctx;
- inputs->pad_idx = 0;
- inputs->next = NULL;
-
- if (!outputs->name || !inputs->name) {
- ret = AVERROR(ENOMEM);
- goto end;
- }
-
- if ((ret = avfilter_graph_parse_ptr(filter_graph, filter_spec,
- &inputs, &outputs, NULL)) < 0)
- goto end;
-
- if ((ret = avfilter_graph_config(filter_graph, NULL)) < 0)
- goto end;
-
- /* Fill FilteringContext */
- fctx->buffersrc_ctx = buffersrc_ctx;
- fctx->buffersink_ctx = buffersink_ctx;
- fctx->filter_graph = filter_graph;
-
-end:
- avfilter_inout_free(&inputs);
- avfilter_inout_free(&outputs);
-
- return ret;
-}
-
-static int init_filters(void)
-{
- const char *filter_spec;
- unsigned int i;
- int ret;
- filter_ctx = av_malloc_array(ifmt_ctx->nb_streams, sizeof(*filter_ctx));
- if (!filter_ctx)
- return AVERROR(ENOMEM);
-
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- filter_ctx[i].buffersrc_ctx = NULL;
- filter_ctx[i].buffersink_ctx = NULL;
- filter_ctx[i].filter_graph = NULL;
- if (!(ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_AUDIO
- || ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO))
- continue;
-
-
- if (ifmt_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
- filter_spec = "null"; /* passthrough (dummy) filter for video */
- else
- filter_spec = "anull"; /* passthrough (dummy) filter for audio */
- ret = init_filter(&filter_ctx[i], ifmt_ctx->streams[i]->codec,
- ofmt_ctx->streams[i]->codec, filter_spec);
- if (ret)
- return ret;
- }
- return 0;
-}
-
-static int encode_write_frame(AVFrame *filt_frame, unsigned int stream_index, int *got_frame) {
- int ret;
- int got_frame_local;
- AVPacket enc_pkt;
- int (*enc_func)(AVCodecContext *, AVPacket *, const AVFrame *, int *) =
- (ifmt_ctx->streams[stream_index]->codec->codec_type ==
- AVMEDIA_TYPE_VIDEO) ? avcodec_encode_video2 : avcodec_encode_audio2;
-
- if (!got_frame)
- got_frame = &got_frame_local;
-
- av_log(NULL, AV_LOG_INFO, "Encoding frame\n");
- /* encode filtered frame */
- enc_pkt.data = NULL;
- enc_pkt.size = 0;
- av_init_packet(&enc_pkt);
- ret = enc_func(ofmt_ctx->streams[stream_index]->codec, &enc_pkt,
- filt_frame, got_frame);
- av_frame_free(&filt_frame);
- if (ret < 0)
- return ret;
- if (!(*got_frame))
- return 0;
-
- /* prepare packet for muxing */
- enc_pkt.stream_index = stream_index;
- av_packet_rescale_ts(&enc_pkt,
- ofmt_ctx->streams[stream_index]->codec->time_base,
- ofmt_ctx->streams[stream_index]->time_base);
-
- av_log(NULL, AV_LOG_DEBUG, "Muxing frame\n");
- /* mux encoded frame */
- ret = av_interleaved_write_frame(ofmt_ctx, &enc_pkt);
- return ret;
-}
-
-static int filter_encode_write_frame(AVFrame *frame, unsigned int stream_index)
-{
- int ret;
- AVFrame *filt_frame;
-
- av_log(NULL, AV_LOG_INFO, "Pushing decoded frame to filters\n");
- /* push the decoded frame into the filtergraph */
- ret = av_buffersrc_add_frame_flags(filter_ctx[stream_index].buffersrc_ctx,
- frame, 0);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Error while feeding the filtergraph\n");
- return ret;
- }
-
- /* pull filtered frames from the filtergraph */
- while (1) {
- filt_frame = av_frame_alloc();
- if (!filt_frame) {
- ret = AVERROR(ENOMEM);
- break;
- }
- av_log(NULL, AV_LOG_INFO, "Pulling filtered frame from filters\n");
- ret = av_buffersink_get_frame(filter_ctx[stream_index].buffersink_ctx,
- filt_frame);
- if (ret < 0) {
- /* if no more frames for output - returns AVERROR(EAGAIN)
- * if flushed and no more frames for output - returns AVERROR_EOF
- * rewrite retcode to 0 to show it as normal procedure completion
- */
- if (ret == AVERROR(EAGAIN) || ret == AVERROR_EOF)
- ret = 0;
- av_frame_free(&filt_frame);
- break;
- }
-
- filt_frame->pict_type = AV_PICTURE_TYPE_NONE;
- ret = encode_write_frame(filt_frame, stream_index, NULL);
- if (ret < 0)
- break;
- }
-
- return ret;
-}
-
-static int flush_encoder(unsigned int stream_index)
-{
- int ret;
- int got_frame;
-
- if (!(ofmt_ctx->streams[stream_index]->codec->codec->capabilities &
- CODEC_CAP_DELAY))
- return 0;
-
- while (1) {
- av_log(NULL, AV_LOG_INFO, "Flushing stream #%u encoder\n", stream_index);
- ret = encode_write_frame(NULL, stream_index, &got_frame);
- if (ret < 0)
- break;
- if (!got_frame)
- return 0;
- }
- return ret;
-}
-
-int main(int argc, char **argv)
-{
- int ret;
- AVPacket packet = { .data = NULL, .size = 0 };
- AVFrame *frame = NULL;
- enum AVMediaType type;
- unsigned int stream_index;
- unsigned int i;
- int got_frame;
- int (*dec_func)(AVCodecContext *, AVFrame *, int *, const AVPacket *);
-
- if (argc != 3) {
- av_log(NULL, AV_LOG_ERROR, "Usage: %s \n", argv[0]);
- return 1;
- }
-
- av_register_all();
- avfilter_register_all();
-
- if ((ret = open_input_file(argv[1])) < 0)
- goto end;
- if ((ret = open_output_file(argv[2])) < 0)
- goto end;
- if ((ret = init_filters()) < 0)
- goto end;
-
- /* read all packets */
- while (1) {
- if ((ret = av_read_frame(ifmt_ctx, &packet)) < 0)
- break;
- stream_index = packet.stream_index;
- type = ifmt_ctx->streams[packet.stream_index]->codec->codec_type;
- av_log(NULL, AV_LOG_DEBUG, "Demuxer gave frame of stream_index %u\n",
- stream_index);
-
- if (filter_ctx[stream_index].filter_graph) {
- av_log(NULL, AV_LOG_DEBUG, "Going to reencode&filter the frame\n");
- frame = av_frame_alloc();
- if (!frame) {
- ret = AVERROR(ENOMEM);
- break;
- }
- av_packet_rescale_ts(&packet,
- ifmt_ctx->streams[stream_index]->time_base,
- ifmt_ctx->streams[stream_index]->codec->time_base);
- dec_func = (type == AVMEDIA_TYPE_VIDEO) ? avcodec_decode_video2 :
- avcodec_decode_audio4;
- ret = dec_func(ifmt_ctx->streams[stream_index]->codec, frame,
- &got_frame, &packet);
- if (ret < 0) {
- av_frame_free(&frame);
- av_log(NULL, AV_LOG_ERROR, "Decoding failed\n");
- break;
- }
-
- if (got_frame) {
- frame->pts = av_frame_get_best_effort_timestamp(frame);
- ret = filter_encode_write_frame(frame, stream_index);
- av_frame_free(&frame);
- if (ret < 0)
- goto end;
- } else {
- av_frame_free(&frame);
- }
- } else {
- /* remux this frame without reencoding */
- av_packet_rescale_ts(&packet,
- ifmt_ctx->streams[stream_index]->time_base,
- ofmt_ctx->streams[stream_index]->time_base);
-
- ret = av_interleaved_write_frame(ofmt_ctx, &packet);
- if (ret < 0)
- goto end;
- }
- av_free_packet(&packet);
- }
-
- /* flush filters and encoders */
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- /* flush filter */
- if (!filter_ctx[i].filter_graph)
- continue;
- ret = filter_encode_write_frame(NULL, i);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Flushing filter failed\n");
- goto end;
- }
-
- /* flush encoder */
- ret = flush_encoder(i);
- if (ret < 0) {
- av_log(NULL, AV_LOG_ERROR, "Flushing encoder failed\n");
- goto end;
- }
- }
-
- av_write_trailer(ofmt_ctx);
-end:
- av_free_packet(&packet);
- av_frame_free(&frame);
- for (i = 0; i < ifmt_ctx->nb_streams; i++) {
- avcodec_close(ifmt_ctx->streams[i]->codec);
- if (ofmt_ctx && ofmt_ctx->nb_streams > i && ofmt_ctx->streams[i] && ofmt_ctx->streams[i]->codec)
- avcodec_close(ofmt_ctx->streams[i]->codec);
- if (filter_ctx && filter_ctx[i].filter_graph)
- avfilter_graph_free(&filter_ctx[i].filter_graph);
- }
- av_free(filter_ctx);
- avformat_close_input(&ifmt_ctx);
- if (ofmt_ctx && !(ofmt_ctx->oformat->flags & AVFMT_NOFILE))
- avio_closep(&ofmt_ctx->pb);
- avformat_free_context(ofmt_ctx);
-
- if (ret < 0)
- av_log(NULL, AV_LOG_ERROR, "Error occurred: %s\n", av_err2str(ret));
-
- return ret ? 1 : 0;
-}
diff --git a/Externals/ffmpeg/shared/doc/faq.html b/Externals/ffmpeg/shared/doc/faq.html
deleted file mode 100644
index be6ea62995..0000000000
--- a/Externals/ffmpeg/shared/doc/faq.html
+++ /dev/null
@@ -1,719 +0,0 @@
-
-
-
-
-
- FFmpeg FAQ
-
-
-
- FFmpeg FAQ
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 General Questions# TOC
-
-
-
1.1 Why doesn’t FFmpeg support feature [xyz]?# TOC
-
-
Because no one has taken on that task yet. FFmpeg development is
-driven by the tasks that are important to the individual developers.
-If there is a feature that is important to you, the best way to get
-it implemented is to undertake the task yourself or sponsor a developer.
-
-
-
1.2 FFmpeg does not support codec XXX. Can you include a Windows DLL loader to support it?# TOC
-
-
No. Windows DLLs are not portable, bloated and often slow.
-Moreover FFmpeg strives to support all codecs natively.
-A DLL loader is not conducive to that goal.
-
-
-
1.3 I cannot read this file although this format seems to be supported by ffmpeg.# TOC
-
-
Even if ffmpeg can read the container format, it may not support all its
-codecs. Please consult the supported codec list in the ffmpeg
-documentation.
-
-
-
1.4 Which codecs are supported by Windows?# TOC
-
-
Windows does not support standard formats like MPEG very well, unless you
-install some additional codecs.
-
-
The following list of video codecs should work on most Windows systems:
-
-msmpeg4v2 .avi/.asf
-
msmpeg4 .asf only
-
wmv1 .asf only
-
wmv2 .asf only
-
mpeg4 Only if you have some MPEG-4 codec like ffdshow or Xvid installed.
-
mpeg1video .mpg only
-
-
Note, ASF files often have .wmv or .wma extensions in Windows. It should also
-be mentioned that Microsoft claims a patent on the ASF format, and may sue
-or threaten users who create ASF files with non-Microsoft software. It is
-strongly advised to avoid ASF where possible.
-
-
The following list of audio codecs should work on most Windows systems:
-
-adpcm_ima_wav adpcm_ms pcm_s16le always
-
libmp3lame If some MP3 codec like LAME is installed.
-
-
-
-
-
2 Compilation# TOC
-
-
-
2.1 error: can't find a register in class 'GENERAL_REGS' while reloading 'asm'# TOC
-
-
This is a bug in gcc. Do not report it to us. Instead, please report it to
-the gcc developers. Note that we will not add workarounds for gcc bugs.
-
-
Also note that (some of) the gcc developers believe this is not a bug or
-not a bug they should fix:
-http://gcc.gnu.org/bugzilla/show_bug.cgi?id=11203 .
-Then again, some of them do not know the difference between an undecidable
-problem and an NP-hard problem...
-
-
-
2.2 I have installed this library with my distro’s package manager. Why does configure not see it?# TOC
-
-
Distributions usually split libraries in several packages. The main package
-contains the files necessary to run programs using the library. The
-development package contains the files necessary to build programs using the
-library. Sometimes, docs and/or data are in a separate package too.
-
-
To build FFmpeg, you need to install the development package. It is usually
-called libfoo-dev or libfoo-devel . You can remove it after the
-build is finished, but be sure to keep the main package.
-
-
-
2.3 How do I make pkg-config find my libraries?# TOC
-
-
Somewhere along with your libraries, there is a .pc file (or several)
-in a pkgconfig directory. You need to set environment variables to
-point pkg-config to these files.
-
-
If you need to add directories to pkg-config’s search list
-(typical use case: library installed separately), add it to
-$PKG_CONFIG_PATH:
-
-
-
export PKG_CONFIG_PATH=/opt/x264/lib/pkgconfig:/opt/opus/lib/pkgconfig
-
-
-
If you need to replace pkg-config’s search list
-(typical use case: cross-compiling), set it in
-$PKG_CONFIG_LIBDIR:
-
-
-
export PKG_CONFIG_LIBDIR=/home/me/cross/usr/lib/pkgconfig:/home/me/cross/usr/local/lib/pkgconfig
-
-
-
If you need to know the library’s internal dependencies (typical use: static
-linking), add the --static option to pkg-config:
-
-
-
./configure --pkg-config-flags=--static
-
-
-
-
2.4 How do I use pkg-config when cross-compiling?# TOC
-
-
The best way is to install pkg-config in your cross-compilation
-environment. It will automatically use the cross-compilation libraries.
-
-
You can also use pkg-config from the host environment by
-specifying explicitly --pkg-config=pkg-config to configure.
-In that case, you must point pkg-config to the correct directories
-using the PKG_CONFIG_LIBDIR, as explained in the previous entry.
-
-
As an intermediate solution, you can place in your cross-compilation
-environment a script that calls the host pkg-config with
-PKG_CONFIG_LIBDIR set. That script can look like that:
-
-
-
#!/bin/sh
-PKG_CONFIG_LIBDIR=/path/to/cross/lib/pkgconfig
-export PKG_CONFIG_LIBDIR
-exec /usr/bin/pkg-config "$@"
-
-
-
-
-
-
-
3.1 ffmpeg does not work; what is wrong?# TOC
-
-
Try a make distclean in the ffmpeg source directory before the build.
-If this does not help see
-(http://ffmpeg.org/bugreports.html ).
-
-
-
3.2 How do I encode single pictures into movies?# TOC
-
-
First, rename your pictures to follow a numerical sequence.
-For example, img1.jpg, img2.jpg, img3.jpg,...
-Then you may run:
-
-
-
ffmpeg -f image2 -i img%d.jpg /tmp/a.mpg
-
-
-
Notice that ‘%d ’ is replaced by the image number.
-
-
img%03d.jpg means the sequence img001.jpg , img002.jpg , etc.
-
-
Use the -start_number option to declare a starting number for
-the sequence. This is useful if your sequence does not start with
-img001.jpg but is still in a numerical order. The following
-example will start with img100.jpg :
-
-
-
ffmpeg -f image2 -start_number 100 -i img%d.jpg /tmp/a.mpg
-
-
-
If you have large number of pictures to rename, you can use the
-following command to ease the burden. The command, using the bourne
-shell syntax, symbolically links all files in the current directory
-that match *jpg to the /tmp directory in the sequence of
-img001.jpg , img002.jpg and so on.
-
-
-
x=1; for i in *jpg; do counter=$(printf %03d $x); ln -s "$i" /tmp/img"$counter".jpg; x=$(($x+1)); done
-
-
-
If you want to sequence them by oldest modified first, substitute
-$(ls -r -t *jpg) in place of *jpg.
-
-
Then run:
-
-
-
ffmpeg -f image2 -i /tmp/img%03d.jpg /tmp/a.mpg
-
-
-
The same logic is used for any image format that ffmpeg reads.
-
-
You can also use cat to pipe images to ffmpeg:
-
-
-
cat *.jpg | ffmpeg -f image2pipe -c:v mjpeg -i - output.mpg
-
-
-
-
3.3 How do I encode movie to single pictures?# TOC
-
-
Use:
-
-
-
ffmpeg -i movie.mpg movie%d.jpg
-
-
-
The movie.mpg used as input will be converted to
-movie1.jpg , movie2.jpg , etc...
-
-
Instead of relying on file format self-recognition, you may also use
-
--c:v ppm -c:v png -c:v mjpeg
-
to force the encoding.
-
-
Applying that to the previous example:
-
-
ffmpeg -i movie.mpg -f image2 -c:v mjpeg menu%d.jpg
-
-
-
Beware that there is no "jpeg" codec. Use "mjpeg" instead.
-
-
-
3.4 Why do I see a slight quality degradation with multithreaded MPEG* encoding?# TOC
-
-
For multithreaded MPEG* encoding, the encoded slices must be independent,
-otherwise thread n would practically have to wait for n-1 to finish, so it’s
-quite logical that there is a small reduction of quality. This is not a bug.
-
-
-
3.5 How can I read from the standard input or write to the standard output?# TOC
-
-
Use - as file name.
-
-
-
3.6 -f jpeg doesn’t work.# TOC
-
-
Try ’-f image2 test%d.jpg’.
-
-
-
3.7 Why can I not change the frame rate?# TOC
-
-
Some codecs, like MPEG-1/2, only allow a small number of fixed frame rates.
-Choose a different codec with the -c:v command line option.
-
-
-
3.8 How do I encode Xvid or DivX video with ffmpeg?# TOC
-
-
Both Xvid and DivX (version 4+) are implementations of the ISO MPEG-4
-standard (note that there are many other coding formats that use this
-same standard). Thus, use ’-c:v mpeg4’ to encode in these formats. The
-default fourcc stored in an MPEG-4-coded file will be ’FMP4’. If you want
-a different fourcc, use the ’-vtag’ option. E.g., ’-vtag xvid’ will
-force the fourcc ’xvid’ to be stored as the video fourcc rather than the
-default.
-
-
-
3.9 Which are good parameters for encoding high quality MPEG-4?# TOC
-
-
’-mbd rd -flags +mv4+aic -trellis 2 -cmp 2 -subcmp 2 -g 300 -pass 1/2’,
-things to try: ’-bf 2’, ’-flags qprd’, ’-flags mv0’, ’-flags skiprd’.
-
-
-
3.10 Which are good parameters for encoding high quality MPEG-1/MPEG-2?# TOC
-
-
’-mbd rd -trellis 2 -cmp 2 -subcmp 2 -g 100 -pass 1/2’
-but beware the ’-g 100’ might cause problems with some decoders.
-Things to try: ’-bf 2’, ’-flags qprd’, ’-flags mv0’, ’-flags skiprd.
-
-
-
3.11 Interlaced video looks very bad when encoded with ffmpeg, what is wrong?# TOC
-
-
You should use ’-flags +ilme+ildct’ and maybe ’-flags +alt’ for interlaced
-material, and try ’-top 0/1’ if the result looks really messed-up.
-
-
-
3.12 How can I read DirectShow files?# TOC
-
-
If you have built FFmpeg with ./configure --enable-avisynth
-(only possible on MinGW/Cygwin platforms),
-then you may use any file that DirectShow can read as input.
-
-
Just create an "input.avs" text file with this single line ...
-
-
DirectShowSource("C:\path to your file\yourfile.asf")
-
-
... and then feed that text file to ffmpeg:
-
-
-
For ANY other help on AviSynth, please visit the
-AviSynth homepage .
-
-
-
3.13 How can I join video files?# TOC
-
-
To "join" video files is quite ambiguous. The following list explains the
-different kinds of "joining" and points out how those are addressed in
-FFmpeg. To join video files may mean:
-
-
- To put them one after the other: this is called to concatenate them
-(in short: concat) and is addressed
-in this very faq .
-
- To put them together in the same file, to let the user choose between the
-different versions (example: different audio languages): this is called to
-multiplex them together (in short: mux), and is done by simply
-invoking ffmpeg with several -i options.
-
- For audio, to put all channels together in a single stream (example: two
-mono streams into one stereo stream): this is sometimes called to
-merge them, and can be done using the
-amerge For audio, to play one on top of the other: this is called to mix
-them, and can be done by first merging them into a single stream and then
-using the pan For video, to display both together, side by side or one on top of a part of
-the other; it can be done using the
-overlay
-
-
-
3.14 How can I concatenate video files?# TOC
-
-
There are several solutions, depending on the exact circumstances.
-
-
-
3.14.1 Concatenating using the concat filter # TOC
-
-
FFmpeg has a concat
-
-
3.14.2 Concatenating using the concat demuxer # TOC
-
-
FFmpeg has a concat
-
-
3.14.3 Concatenating using the concat protocol (file level)# TOC
-
-
FFmpeg has a concat
-
A few multimedia containers (MPEG-1, MPEG-2 PS, DV) allow to concatenate
-video by merely concatenating the files containing them.
-
-
Hence you may concatenate your multimedia files by first transcoding them to
-these privileged formats, then using the humble cat command (or the
-equally humble copy under Windows), and finally transcoding back to your
-format of choice.
-
-
-
ffmpeg -i input1.avi -qscale:v 1 intermediate1.mpg
-ffmpeg -i input2.avi -qscale:v 1 intermediate2.mpg
-cat intermediate1.mpg intermediate2.mpg > intermediate_all.mpg
-ffmpeg -i intermediate_all.mpg -qscale:v 2 output.avi
-
-
-
Additionally, you can use the concat protocol instead of cat or
-copy which will avoid creation of a potentially huge intermediate file.
-
-
-
ffmpeg -i input1.avi -qscale:v 1 intermediate1.mpg
-ffmpeg -i input2.avi -qscale:v 1 intermediate2.mpg
-ffmpeg -i concat:"intermediate1.mpg|intermediate2.mpg" -c copy intermediate_all.mpg
-ffmpeg -i intermediate_all.mpg -qscale:v 2 output.avi
-
-
-
Note that you may need to escape the character "|" which is special for many
-shells.
-
-
Another option is usage of named pipes, should your platform support it:
-
-
-
mkfifo intermediate1.mpg
-mkfifo intermediate2.mpg
-ffmpeg -i input1.avi -qscale:v 1 -y intermediate1.mpg < /dev/null &
-ffmpeg -i input2.avi -qscale:v 1 -y intermediate2.mpg < /dev/null &
-cat intermediate1.mpg intermediate2.mpg |\
-ffmpeg -f mpeg -i - -c:v mpeg4 -acodec libmp3lame output.avi
-
-
-
-
3.14.4 Concatenating using raw audio and video# TOC
-
-
Similarly, the yuv4mpegpipe format, and the raw video, raw audio codecs also
-allow concatenation, and the transcoding step is almost lossless.
-When using multiple yuv4mpegpipe(s), the first line needs to be discarded
-from all but the first stream. This can be accomplished by piping through
-tail as seen below. Note that when piping through tail you
-must use command grouping, { ;}, to background properly.
-
-
For example, let’s say we want to concatenate two FLV files into an
-output.flv file:
-
-
-
mkfifo temp1.a
-mkfifo temp1.v
-mkfifo temp2.a
-mkfifo temp2.v
-mkfifo all.a
-mkfifo all.v
-ffmpeg -i input1.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp1.a < /dev/null &
-ffmpeg -i input2.flv -vn -f u16le -acodec pcm_s16le -ac 2 -ar 44100 - > temp2.a < /dev/null &
-ffmpeg -i input1.flv -an -f yuv4mpegpipe - > temp1.v < /dev/null &
-{ ffmpeg -i input2.flv -an -f yuv4mpegpipe - < /dev/null | tail -n +2 > temp2.v ; } &
-cat temp1.a temp2.a > all.a &
-cat temp1.v temp2.v > all.v &
-ffmpeg -f u16le -acodec pcm_s16le -ac 2 -ar 44100 -i all.a \
- -f yuv4mpegpipe -i all.v \
- -y output.flv
-rm temp[12].[av] all.[av]
-
-
-
-
3.15 Using -f lavfi , audio becomes mono for no apparent reason.# TOC
-
-
Use -dumpgraph - to find out exactly where the channel layout is
-lost.
-
-
Most likely, it is through auto-inserted aresample. Try to understand
-why the converting filter was needed at that place.
-
-
Just before the output is a likely place, as -f lavfi currently
-only support packed S16.
-
-
Then insert the correct aformat explicitly in the filtergraph,
-specifying the exact format.
-
-
-
aformat=sample_fmts=s16:channel_layouts=stereo
-
-
-
-
3.16 Why does FFmpeg not see the subtitles in my VOB file?# TOC
-
-
VOB and a few other formats do not have a global header that describes
-everything present in the file. Instead, applications are supposed to scan
-the file to see what it contains. Since VOB files are frequently large, only
-the beginning is scanned. If the subtitles happen only later in the file,
-they will not be initially detected.
-
-
Some applications, including the ffmpeg command-line tool, can only
-work with streams that were detected during the initial scan; streams that
-are detected later are ignored.
-
-
The size of the initial scan is controlled by two options: probesize
-(default ~5 Mo) and analyzeduration (default 5,000,000 µs = 5 s). For
-the subtitle stream to be detected, both values must be large enough.
-
-
-
3.17 Why was the ffmpeg -sameq option removed? What to use instead?# TOC
-
-
The -sameq option meant "same quantizer", and made sense only in a
-very limited set of cases. Unfortunately, a lot of people mistook it for
-"same quality" and used it in places where it did not make sense: it had
-roughly the expected visible effect, but achieved it in a very inefficient
-way.
-
-
Each encoder has its own set of options to set the quality-vs-size balance,
-use the options for the encoder you are using to set the quality level to a
-point acceptable for your tastes. The most common options to do that are
--qscale and -qmax , but you should peruse the documentation
-of the encoder you chose.
-
-
-
4 Development# TOC
-
-
-
4.1 Are there examples illustrating how to use the FFmpeg libraries, particularly libavcodec and libavformat?# TOC
-
-
Yes. Check the doc/examples directory in the source
-repository, also available online at:
-https://github.com/FFmpeg/FFmpeg/tree/master/doc/examples .
-
-
Examples are also installed by default, usually in
-$PREFIX/share/ffmpeg/examples.
-
-
Also you may read the Developers Guide of the FFmpeg documentation. Alternatively,
-examine the source code for one of the many open source projects that
-already incorporate FFmpeg at (projects.html ).
-
-
-
4.2 Can you support my C compiler XXX?# TOC
-
-
It depends. If your compiler is C99-compliant, then patches to support
-it are likely to be welcome if they do not pollute the source code
-with #ifdefs related to the compiler.
-
-
-
4.3 Is Microsoft Visual C++ supported?# TOC
-
-
Yes. Please see the Microsoft Visual C++
-section in the FFmpeg documentation.
-
-
-
4.4 Can you add automake, libtool or autoconf support?# TOC
-
-
No. These tools are too bloated and they complicate the build.
-
-
-
4.5 Why not rewrite FFmpeg in object-oriented C++?# TOC
-
-
FFmpeg is already organized in a highly modular manner and does not need to
-be rewritten in a formal object language. Further, many of the developers
-favor straight C; it works for them. For more arguments on this matter,
-read "Programming Religion" .
-
-
-
4.6 Why are the ffmpeg programs devoid of debugging symbols?# TOC
-
-
The build process creates ffmpeg_g, ffplay_g, etc. which
-contain full debug information. Those binaries are stripped to create
-ffmpeg, ffplay, etc. If you need the debug information, use
-the *_g versions.
-
-
-
4.7 I do not like the LGPL, can I contribute code under the GPL instead?# TOC
-
-
Yes, as long as the code is optional and can easily and cleanly be placed
-under #if CONFIG_GPL without breaking anything. So, for example, a new codec
-or filter would be OK under GPL while a bug fix to LGPL code would not.
-
-
-
4.8 I’m using FFmpeg from within my C application but the linker complains about missing symbols from the libraries themselves.# TOC
-
-
FFmpeg builds static libraries by default. In static libraries, dependencies
-are not handled. That has two consequences. First, you must specify the
-libraries in dependency order: -lavdevice must come before
--lavformat, -lavutil must come after everything else, etc.
-Second, external libraries that are used in FFmpeg have to be specified too.
-
-
An easy way to get the full list of required libraries in dependency order
-is to use pkg-config.
-
-
-
c99 -o program program.c $(pkg-config --cflags --libs libavformat libavcodec)
-
-
-
See doc/example/Makefile and doc/example/pc-uninstalled for
-more details.
-
-
-
4.9 I’m using FFmpeg from within my C++ application but the linker complains about missing symbols which seem to be available.# TOC
-
-
FFmpeg is a pure C project, so to use the libraries within your C++ application
-you need to explicitly state that you are using a C library. You can do this by
-encompassing your FFmpeg includes using extern "C".
-
-
See http://www.parashift.com/c++-faq-lite/mixing-c-and-cpp.html#faq-32.3
-
-
-
4.10 I’m using libavutil from within my C++ application but the compiler complains about ’UINT64_C’ was not declared in this scope# TOC
-
-
FFmpeg is a pure C project using C99 math features, in order to enable C++
-to use them you have to append -D__STDC_CONSTANT_MACROS to your CXXFLAGS
-
-
-
4.11 I have a file in memory / a API different from *open/*read/ libc how do I use it with libavformat?# TOC
-
-
You have to create a custom AVIOContext using avio_alloc_context,
-see libavformat/aviobuf.c in FFmpeg and libmpdemux/demux_lavf.c in MPlayer or MPlayer2 sources.
-
-
-
4.12 Where is the documentation about ffv1, msmpeg4, asv1, 4xm?# TOC
-
-
see http://www.ffmpeg.org/~michael/
-
-
-
4.13 How do I feed H.263-RTP (and other codecs in RTP) to libavcodec?# TOC
-
-
Even if peculiar since it is network oriented, RTP is a container like any
-other. You have to demux RTP before feeding the payload to libavcodec.
-In this specific case please look at RFC 4629 to see how it should be done.
-
-
-
4.14 AVStream.r_frame_rate is wrong, it is much larger than the frame rate.# TOC
-
-
r_frame_rate is NOT the average frame rate, it is the smallest frame rate
-that can accurately represent all timestamps. So no, it is not
-wrong if it is larger than the average!
-For example, if you have mixed 25 and 30 fps content, then r_frame_rate
-will be 150 (it is the least common multiple).
-If you are looking for the average frame rate, see AVStream.avg_frame_rate.
-
-
-
4.15 Why is make fate not running all tests?# TOC
-
-
Make sure you have the fate-suite samples and the SAMPLES Make variable
-or FATE_SAMPLES environment variable or the --samples
-configure option is set to the right path.
-
-
-
4.16 Why is make fate not finding the samples?# TOC
-
-
Do you happen to have a ~ character in the samples path to indicate a
-home directory? The value is used in ways where the shell cannot expand it,
-causing FATE to not find files. Just replace ~ by the full path.
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Automated Testing Environment
-
-
-
- FFmpeg Automated Testing Environment
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Introduction# TOC
-
-
FATE is an extended regression suite on the client-side and a means
-for results aggregation and presentation on the server-side.
-
-
The first part of this document explains how you can use FATE from
-your FFmpeg source directory to test your ffmpeg binary. The second
-part describes how you can run FATE to submit the results to FFmpeg’s
-FATE server.
-
-
In any way you can have a look at the publicly viewable FATE results
-by visiting this website:
-
-
http://fate.ffmpeg.org/
-
-
This is especially recommended for all people contributing source
-code to FFmpeg, as it can be seen if some test on some platform broke
-with their recent contribution. This usually happens on the platforms
-the developers could not test on.
-
-
The second part of this document describes how you can run FATE to
-submit your results to FFmpeg’s FATE server. If you want to submit your
-results be sure to check that your combination of CPU, OS and compiler
-is not already listed on the above mentioned website.
-
-
In the third part you can find a comprehensive listing of FATE makefile
-targets and variables.
-
-
-
-
2 Using FATE from your FFmpeg source directory# TOC
-
-
If you want to run FATE on your machine you need to have the samples
-in place. You can get the samples via the build target fate-rsync.
-Use this command from the top-level source directory:
-
-
-
make fate-rsync SAMPLES=fate-suite/
-make fate SAMPLES=fate-suite/
-
-
-
The above commands set the samples location by passing a makefile
-variable via command line. It is also possible to set the samples
-location at source configuration time by invoking configure with
-‘–samples=<path to the samples directory>’. Afterwards you can
-invoke the makefile targets without setting the SAMPLES makefile
-variable. This is illustrated by the following commands:
-
-
-
./configure --samples=fate-suite/
-make fate-rsync
-make fate
-
-
-
Yet another way to tell FATE about the location of the sample
-directory is by making sure the environment variable FATE_SAMPLES
-contains the path to your samples directory. This can be achieved
-by e.g. putting that variable in your shell profile or by setting
-it in your interactive session.
-
-
-
FATE_SAMPLES=fate-suite/ make fate
-
-
-
-
Do not put a ’~’ character in the samples path to indicate a home
-directory. Because of shell nuances, this will cause FATE to fail.
-
-
To use a custom wrapper to run the test, pass --target-exec to
-configure or set the TARGET_EXEC Make variable.
-
-
-
-
3 Submitting the results to the FFmpeg result aggregation server# TOC
-
-
To submit your results to the server you should run fate through the
-shell script tests/fate.sh from the FFmpeg sources. This script needs
-to be invoked with a configuration file as its first argument.
-
-
-
tests/fate.sh /path/to/fate_config
-
-
-
A configuration file template with comments describing the individual
-configuration variables can be found at doc/fate_config.sh.template .
-
-
The mentioned configuration template is also available here:
-
slot= # some unique identifier
-repo=git://source.ffmpeg.org/ffmpeg.git # the source repository
-samples= # path to samples directory
-workdir= # directory in which to do all the work
-#fate_recv="ssh -T fate@fate.ffmpeg.org" # command to submit report
-comment= # optional description
-build_only= # set to "yes" for a compile-only instance that skips tests
-
-# the following are optional and map to configure options
-arch=
-cpu=
-cross_prefix=
-as=
-cc=
-ld=
-target_os=
-sysroot=
-target_exec=
-target_path=
-target_samples=
-extra_cflags=
-extra_ldflags=
-extra_libs=
-extra_conf= # extra configure options not covered above
-
-#make= # name of GNU make if not 'make'
-makeopts= # extra options passed to 'make'
-#tar= # command to create a tar archive from its arguments on stdout,
- # defaults to 'tar c'
-
-
Create a configuration that suits your needs, based on the configuration
-template. The ‘slot’ configuration variable can be any string that is not
-yet used, but it is suggested that you name it adhering to the following
-pattern <arch>-<os>-<compiler>-<compiler version>. The configuration file
-itself will be sourced in a shell script, therefore all shell features may
-be used. This enables you to setup the environment as you need it for your
-build.
-
-
For your first test runs the ‘fate_recv’ variable should be empty or
-commented out. This will run everything as normal except that it will omit
-the submission of the results to the server. The following files should be
-present in $workdir as specified in the configuration file:
-
-
- configure.log
- compile.log
- test.log
- report
- version
-
-
-
When you have everything working properly you can create an SSH key pair
-and send the public key to the FATE server administrator who can be contacted
-at the email address fate-admin@ffmpeg.org .
-
-
Configure your SSH client to use public key authentication with that key
-when connecting to the FATE server. Also do not forget to check the identity
-of the server and to accept its host key. This can usually be achieved by
-running your SSH client manually and killing it after you accepted the key.
-The FATE server’s fingerprint is:
-
-
-RSA d3:f1:83:97:a4:75:2b:a6:fb:d6:e8:aa:81:93:97:51
-
ECDSA 76:9f:68:32:04:1e:d5:d4:ec:47:3f:dc:fc:18:17:86
-
-
-
If you have problems connecting to the FATE server, it may help to try out
-the ssh command with one or more -v options. You should
-get detailed output concerning your SSH configuration and the authentication
-process.
-
-
The only thing left is to automate the execution of the fate.sh script and
-the synchronisation of the samples directory.
-
-
-
-
4 FATE makefile targets and variables# TOC
-
-
-
4.1 Makefile targets# TOC
-
-
-fate-rsync Download/synchronize sample files to the configured samples directory.
-
-fate-list Will list all fate/regression test targets.
-
-fate Run the FATE test suite (requires the fate-suite dataset).
-
-
-
-
4.2 Makefile variables# TOC
-
-
-V Verbosity level, can be set to 0, 1 or 2.
-
- 0: show just the test arguments
- 1: show just the command used in the test
- 2: show everything
-
-
-SAMPLES Specify or override the path to the FATE samples at make time, it has a
-meaning only while running the regression tests.
-
-THREADS Specify how many threads to use while running regression tests, it is
-quite useful to detect thread-related regressions.
-
-THREAD_TYPE Specify which threading strategy test, either slice or frame ,
-by default slice+frame
-
-CPUFLAGS Specify CPU flags.
-
-TARGET_EXEC Specify or override the wrapper used to run the tests.
-The TARGET_EXEC option provides a way to run FATE wrapped in
-valgrind, qemu-user or wine or on remote targets
-through ssh.
-
-GEN Set to 1 to generate the missing or mismatched references.
-
-
-
-
4.3 Examples# TOC
-
-
-
make V=1 SAMPLES=/var/fate/samples THREADS=2 CPUFLAGS=mmx fate
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffmpeg Documentation
-
-
-
- ffmpeg Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffmpeg [global_options ] {[input_file_options ] -i input_file } ... {[output_file_options ] output_file } ...
-
-
-
2 Description# TOC
-
-
ffmpeg is a very fast video and audio converter that can also grab from
-a live audio/video source. It can also convert between arbitrary sample
-rates and resize video on the fly with a high quality polyphase filter.
-
-
ffmpeg reads from an arbitrary number of input "files" (which can be regular
-files, pipes, network streams, grabbing devices, etc.), specified by the
--i option, and writes to an arbitrary number of output "files", which are
-specified by a plain output filename. Anything found on the command line which
-cannot be interpreted as an option is considered to be an output filename.
-
-
Each input or output file can, in principle, contain any number of streams of
-different types (video/audio/subtitle/attachment/data). The allowed number and/or
-types of streams may be limited by the container format. Selecting which
-streams from which inputs will go into which output is either done automatically
-or with the -map option (see the Stream selection chapter).
-
-
To refer to input files in options, you must use their indices (0-based). E.g.
-the first input file is 0, the second is 1, etc. Similarly, streams
-within a file are referred to by their indices. E.g. 2:3 refers to the
-fourth stream in the third input file. Also see the Stream specifiers chapter.
-
-
As a general rule, options are applied to the next specified
-file. Therefore, order is important, and you can have the same
-option on the command line multiple times. Each occurrence is
-then applied to the next input or output file.
-Exceptions from this rule are the global options (e.g. verbosity level),
-which should be specified first.
-
-
Do not mix input and output files – first specify all input files, then all
-output files. Also do not mix options which belong to different files. All
-options apply ONLY to the next input or output file and are reset between files.
-
-
- To set the video bitrate of the output file to 64 kbit/s:
-
-
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
- To force the frame rate of the output file to 24 fps:
-
-
ffmpeg -i input.avi -r 24 output.avi
- To force the frame rate of the input file (valid for raw formats only)
-to 1 fps and the frame rate of the output file to 24 fps:
-
-
ffmpeg -r 1 -i input.m2v -r 24 output.avi
-
-
-
The format option may be needed for raw input files.
-
-
-
-
3 Detailed description# TOC
-
-
The transcoding process in ffmpeg for each output can be described by
-the following diagram:
-
-
-
_______ ______________
-| | | |
-| input | demuxer | encoded data | decoder
-| file | ---------> | packets | -----+
-|_______| |______________| |
- v
- _________
- | |
- | decoded |
- | frames |
- |_________|
- ________ ______________ |
-| | | | |
-| output | <-------- | encoded data | <----+
-| file | muxer | packets | encoder
-|________| |______________|
-
-
-
-
-
ffmpeg calls the libavformat library (containing demuxers) to read
-input files and get packets containing encoded data from them. When there are
-multiple input files, ffmpeg tries to keep them synchronized by
-tracking lowest timestamp on any active input stream.
-
-
Encoded packets are then passed to the decoder (unless streamcopy is selected
-for the stream, see further for a description). The decoder produces
-uncompressed frames (raw video/PCM audio/...) which can be processed further by
-filtering (see next section). After filtering, the frames are passed to the
-encoder, which encodes them and outputs encoded packets. Finally those are
-passed to the muxer, which writes the encoded packets to the output file.
-
-
-
3.1 Filtering# TOC
-
Before encoding, ffmpeg can process raw audio and video frames using
-filters from the libavfilter library. Several chained filters form a filter
-graph. ffmpeg distinguishes between two types of filtergraphs:
-simple and complex.
-
-
-
3.1.1 Simple filtergraphs# TOC
-
Simple filtergraphs are those that have exactly one input and output, both of
-the same type. In the above diagram they can be represented by simply inserting
-an additional step between decoding and encoding:
-
-
-
_________ ______________
-| | | |
-| decoded | | encoded data |
-| frames |\ _ | packets |
-|_________| \ /||______________|
- \ __________ /
- simple _\|| | / encoder
- filtergraph | filtered |/
- | frames |
- |__________|
-
-
-
-
Simple filtergraphs are configured with the per-stream -filter option
-(with -vf and -af aliases for video and audio respectively).
-A simple filtergraph for video can look for example like this:
-
-
-
_______ _____________ _______ ________
-| | | | | | | |
-| input | ---> | deinterlace | ---> | scale | ---> | output |
-|_______| |_____________| |_______| |________|
-
-
-
-
Note that some filters change frame properties but not frame contents. E.g. the
-fps filter in the example above changes number of frames, but does not
-touch the frame contents. Another example is the setpts filter, which
-only sets timestamps and otherwise passes the frames unchanged.
-
-
-
3.1.2 Complex filtergraphs# TOC
-
Complex filtergraphs are those which cannot be described as simply a linear
-processing chain applied to one stream. This is the case, for example, when the graph has
-more than one input and/or output, or when output stream type is different from
-input. They can be represented with the following diagram:
-
-
-
_________
-| |
-| input 0 |\ __________
-|_________| \ | |
- \ _________ /| output 0 |
- \ | | / |__________|
- _________ \| complex | /
-| | | |/
-| input 1 |---->| filter |\
-|_________| | | \ __________
- /| graph | \ | |
- / | | \| output 1 |
- _________ / |_________| |__________|
-| | /
-| input 2 |/
-|_________|
-
-
-
-
Complex filtergraphs are configured with the -filter_complex option.
-Note that this option is global, since a complex filtergraph, by its nature,
-cannot be unambiguously associated with a single stream or file.
-
-
The -lavfi option is equivalent to -filter_complex .
-
-
A trivial example of a complex filtergraph is the overlay filter, which
-has two video inputs and one video output, containing one video overlaid on top
-of the other. Its audio counterpart is the amix filter.
-
-
-
3.2 Stream copy# TOC
-
Stream copy is a mode selected by supplying the copy parameter to the
--codec option. It makes ffmpeg omit the decoding and encoding
-step for the specified stream, so it does only demuxing and muxing. It is useful
-for changing the container format or modifying container-level metadata. The
-diagram above will, in this case, simplify to this:
-
-
-
_______ ______________ ________
-| | | | | |
-| input | demuxer | encoded data | muxer | output |
-| file | ---------> | packets | -------> | file |
-|_______| |______________| |________|
-
-
-
-
Since there is no decoding or encoding, it is very fast and there is no quality
-loss. However, it might not work in some cases because of many factors. Applying
-filters is obviously also impossible, since filters work on uncompressed data.
-
-
-
-
4 Stream selection# TOC
-
-
By default, ffmpeg includes only one stream of each type (video, audio, subtitle)
-present in the input files and adds them to each output file. It picks the
-"best" of each based upon the following criteria: for video, it is the stream
-with the highest resolution, for audio, it is the stream with the most channels, for
-subtitles, it is the first subtitle stream. In the case where several streams of
-the same type rate equally, the stream with the lowest index is chosen.
-
-
You can disable some of those defaults by using the -vn/-an/-sn options. For
-full manual control, use the -map option, which disables the defaults just
-described.
-
-
-
-
5 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
5.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
5.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
5.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
5.4 Main options# TOC
-
-
--f fmt (input/output ) Force input or output file format. The format is normally auto detected for input
-files and guessed from the file extension for output files, so this option is not
-needed in most cases.
-
--i filename (input ) input file name
-
--y (global ) Overwrite output files without asking.
-
--n (global ) Do not overwrite output files, and exit immediately if a specified
-output file already exists.
-
--c[:stream_specifier ] codec (input/output,per-stream ) -codec[:stream_specifier ] codec (input/output,per-stream ) Select an encoder (when used before an output file) or a decoder (when used
-before an input file) for one or more streams. codec is the name of a
-decoder/encoder or a special value copy (output only) to indicate that
-the stream is not to be re-encoded.
-
-For example
-
-
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
- encodes all video streams with libx264 and copies all audio streams.
-
-For each stream, the last matching c option is applied, so
-
-
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
- will copy all the streams except the second video, which will be encoded with
-libx264, and the 138th audio, which will be encoded with libvorbis.
-
--t duration (input/output ) When used as an input option (before -i), limit the duration of
-data read from the input file.
-
-When used as an output option (before an output filename), stop writing the
-output after its duration reaches duration .
-
-duration may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--to position (output ) Stop writing the output at position .
-position may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--fs limit_size (output ) Set the file size limit, expressed in bytes.
-
--ss position (input/output ) When used as an input option (before -i), seeks in this input file to
-position . Note the in most formats it is not possible to seek exactly, so
-ffmpeg will seek to the closest seek point before position .
-When transcoding and -accurate_seek is enabled (the default), this
-extra segment between the seek point and position will be decoded and
-discarded. When doing stream copy or when -noaccurate_seek is used, it
-will be preserved.
-
-When used as an output option (before an output filename), decodes but discards
-input until the timestamps reach position .
-
-position may be either in seconds or in hh:mm:ss[.xxx] form.
-
--itsoffset offset (input ) Set the input time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added to the timestamps of the input files. Specifying
-a positive offset means that the corresponding streams are delayed by
-the time duration specified in offset .
-
--timestamp date (output ) Set the recording timestamp in the container.
-
-date must be a time duration specification,
-see (ffmpeg-utils)the Date section in the ffmpeg-utils(1) manual .
-
--metadata[:metadata_specifier] key =value (output,per-metadata ) Set a metadata key/value pair.
-
-An optional metadata_specifier may be given to set metadata
-on streams or chapters. See -map_metadata documentation for
-details.
-
-This option overrides metadata set with -map_metadata. It is
-also possible to delete metadata by using an empty value.
-
-For example, for setting the title in the output file:
-
-
ffmpeg -i in.avi -metadata title="my title" out.flv
- To set the language of the first audio stream:
-
-
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
- -target type (output ) Specify target file type (vcd, svcd, dvd, dv,
-dv50). type may be prefixed with pal-, ntsc- or
-film- to use the corresponding standard. All the format options
-(bitrate, codecs, buffer sizes) are then set automatically. You can just type:
-
-
-
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
- Nevertheless you can specify additional options as long as you know
-they do not conflict with the standard, as in:
-
-
-
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
- -dframes number (output ) Set the number of data frames to output. This is an alias for -frames:d.
-
--frames[:stream_specifier ] framecount (output,per-stream ) Stop writing to the stream after framecount frames.
-
--q[:stream_specifier ] q (output,per-stream ) -qscale[:stream_specifier ] q (output,per-stream ) Use fixed quality scale (VBR). The meaning of q /qscale is
-codec-dependent.
-If qscale is used without a stream_specifier then it applies only
-to the video stream, this is to maintain compatibility with previous behavior
-and as specifying the same codec specific value to 2 different codecs that is
-audio and video generally is not what is intended when no stream_specifier is
-used.
-
--filter[:stream_specifier ] filtergraph (output,per-stream ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single input and a single output of the
-same type of the stream. In the filtergraph, the input is associated
-to the label in, and the output to the label out. See
-the ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-See the -filter_complex option if you
-want to create filtergraphs with multiple inputs and/or outputs.
-
--filter_script[:stream_specifier ] filename (output,per-stream ) This option is similar to -filter , the only difference is that its
-argument is the name of the file from which a filtergraph description is to be
-read.
-
--pre[:stream_specifier ] preset_name (output,per-stream ) Specify the preset for matching stream(s).
-
--stats (global ) Print encoding progress/statistics. It is on by default, to explicitly
-disable it you need to specify -nostats.
-
--progress url (global ) Send program-friendly progress information to url .
-
-Progress information is written approximately every second and at the end of
-the encoding process. It is made of "key =value " lines. key
-consists of only alphanumeric characters. The last key of a sequence of
-progress information is always "progress".
-
--stdin Enable interaction on standard input. On by default unless standard input is
-used as an input. To explicitly disable interaction you need to specify
--nostdin.
-
-Disabling interaction on standard input is useful, for example, if
-ffmpeg is in the background process group. Roughly the same result can
-be achieved with ffmpeg ... < /dev/null but it requires a
-shell.
-
--debug_ts (global ) Print timestamp information. It is off by default. This option is
-mostly useful for testing and debugging purposes, and the output
-format may change from one version to another, so it should not be
-employed by portable scripts.
-
-See also the option -fdebug ts.
-
--attach filename (output ) Add an attachment to the output file. This is supported by a few formats
-like Matroska for e.g. fonts used in rendering subtitles. Attachments
-are implemented as a specific type of stream, so this option will add
-a new stream to the file. It is then possible to use per-stream options
-on this stream in the usual way. Attachment streams created with this
-option will be created after all the other streams (i.e. those created
-with -map or automatic mappings).
-
-Note that for Matroska you also have to set the mimetype metadata tag:
-
-
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
- (assuming that the attachment stream will be third in the output file).
-
--dump_attachment[:stream_specifier ] filename (input,per-stream ) Extract the matching attachment stream into a file named filename . If
-filename is empty, then the value of the filename metadata tag
-will be used.
-
-E.g. to extract the first attachment to a file named ’out.ttf’:
-
-
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
- To extract all attachments to files determined by the filename tag:
-
-
ffmpeg -dump_attachment:t "" -i INPUT
- Technical note – attachments are implemented as codec extradata, so this
-option can actually be used to extract extradata from any stream, not just
-attachments.
-
-
-
-
-
5.5 Video Options# TOC
-
-
--vframes number (output ) Set the number of video frames to output. This is an alias for -frames:v.
-
-r[:stream_specifier ] fps (input/output,per-stream ) Set frame rate (Hz value, fraction or abbreviation).
-
-As an input option, ignore any timestamps stored in the file and instead
-generate timestamps assuming constant frame rate fps .
-This is not the same as the -framerate option used for some input formats
-like image2 or v4l2 (it used to be the same in older versions of FFmpeg).
-If in doubt use -framerate instead of the input option -r .
-
-As an output option, duplicate or drop input frames to achieve constant output
-frame rate fps .
-
--s[:stream_specifier ] size (input/output,per-stream ) Set frame size.
-
-As an input option, this is a shortcut for the video_size private
-option, recognized by some demuxers for which the frame size is either not
-stored in the file or is configurable – e.g. raw video or video grabbers.
-
-As an output option, this inserts the scale video filter to the
-end of the corresponding filtergraph. Please use the scale filter
-directly to insert it at the beginning or some other place.
-
-The format is ‘wxh ’ (default - same as source).
-
--aspect[:stream_specifier ] aspect (output,per-stream ) Set the video display aspect ratio specified by aspect .
-
-aspect can be a floating point number string, or a string of the
-form num :den , where num and den are the
-numerator and denominator of the aspect ratio. For example "4:3",
-"16:9", "1.3333", and "1.7777" are valid argument values.
-
-If used together with -vcodec copy , it will affect the aspect ratio
-stored at container level, but not the aspect ratio stored in encoded
-frames, if it exists.
-
--vn (output ) Disable video recording.
-
--vcodec codec (output ) Set the video codec. This is an alias for -codec:v.
-
--pass[:stream_specifier ] n (output,per-stream ) Select the pass number (1 or 2). It is used to do two-pass
-video encoding. The statistics of the video are recorded in the first
-pass into a log file (see also the option -passlogfile),
-and in the second pass that log file is used to generate the video
-at the exact requested bitrate.
-On pass 1, you may just deactivate audio and set output to null,
-examples for Windows and Unix:
-
-
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
-ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
- -passlogfile[:stream_specifier ] prefix (output,per-stream ) Set two-pass log file name prefix to prefix , the default file name
-prefix is “ffmpeg2pass”. The complete file name will be
-PREFIX-N.log , where N is a number specific to the output
-stream
-
--vf filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:v, see the -filter option .
-
-
-
-
5.6 Advanced Video options# TOC
-
-
--pix_fmt[:stream_specifier ] format (input/output,per-stream ) Set pixel format. Use -pix_fmts to show all the supported
-pixel formats.
-If the selected pixel format can not be selected, ffmpeg will print a
-warning and select the best pixel format supported by the encoder.
-If pix_fmt is prefixed by a +, ffmpeg will exit with an error
-if the requested pixel format can not be selected, and automatic conversions
-inside filtergraphs are disabled.
-If pix_fmt is a single +, ffmpeg selects the same pixel format
-as the input (or graph output) and automatic conversions are disabled.
-
--sws_flags flags (input/output ) Set SwScaler flags.
-
-vdt n Discard threshold.
-
--rc_override[:stream_specifier ] override (output,per-stream ) Rate control override for specific intervals, formatted as "int,int,int"
-list separated with slashes. Two first values are the beginning and
-end frame numbers, last one is quantizer to use if positive, or quality
-factor if negative.
-
--ilme Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
-Use this option if your input file is interlaced and you want
-to keep the interlaced format for minimum losses.
-The alternative is to deinterlace the input stream with
--deinterlace , but deinterlacing introduces losses.
-
-psnr Calculate PSNR of compressed frames.
-
-vstats Dump video coding statistics to vstats_HHMMSS.log .
-
-vstats_file file Dump video coding statistics to file .
-
-top[:stream_specifier ] n (output,per-stream ) top=1/bottom=0/auto=-1 field first
-
-dc precision Intra_dc_precision.
-
-vtag fourcc/tag (output ) Force video tag/fourcc. This is an alias for -tag:v.
-
-qphist (global ) Show QP histogram
-
-vbsf bitstream_filter Deprecated see -bsf
-
--force_key_frames[:stream_specifier ] time [,time ...] (output,per-stream ) -force_key_frames[:stream_specifier ] expr:expr (output,per-stream ) Force key frames at the specified timestamps, more precisely at the first
-frames after each specified time.
-
-If the argument is prefixed with expr:, the string expr
-is interpreted like an expression and is evaluated for each frame. A
-key frame is forced in case the evaluation is non-zero.
-
-If one of the times is "chapters[delta ]", it is expanded into
-the time of the beginning of all chapters in the file, shifted by
-delta , expressed as a time in seconds.
-This option can be useful to ensure that a seek point is present at a
-chapter mark or any other designated place in the output file.
-
-For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
-before the beginning of every chapter:
-
-
-force_key_frames 0:05:00,chapters-0.1
- The expression in expr can contain the following constants:
-
-n the number of current processed frame, starting from 0
-
n_forced the number of forced frames
-
prev_forced_n the number of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
prev_forced_t the time of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
t the time of the current processed frame
-
-
-For example to force a key frame every 5 seconds, you can specify:
-
-
-force_key_frames expr:gte(t,n_forced*5)
- To force a key frame 5 seconds after the time of the last forced one,
-starting from second 13:
-
-
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
- Note that forcing too many keyframes is very harmful for the lookahead
-algorithms of certain encoders: using fixed-GOP options or similar
-would be more efficient.
-
--copyinkf[:stream_specifier ] (output,per-stream ) When doing stream copy, copy also non-key frames found at the
-beginning.
-
--hwaccel[:stream_specifier ] hwaccel (input,per-stream ) Use hardware acceleration to decode the matching stream(s). The allowed values
-of hwaccel are:
-
-none Do not use any hardware acceleration (the default).
-
-auto Automatically select the hardware acceleration method.
-
-vda Use Apple VDA hardware acceleration.
-
-vdpau Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
-
-dxva2 Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
-
-
-This option has no effect if the selected hwaccel is not available or not
-supported by the chosen decoder.
-
-Note that most acceleration methods are intended for playback and will not be
-faster than software decoding on modern CPUs. Additionally, ffmpeg
-will usually need to copy the decoded frames from the GPU memory into the system
-memory, resulting in further performance loss. This option is thus mainly
-useful for testing.
-
--hwaccel_device[:stream_specifier ] hwaccel_device (input,per-stream ) Select a device to use for hardware acceleration.
-
-This option only makes sense when the -hwaccel option is also
-specified. Its exact meaning depends on the specific hardware acceleration
-method chosen.
-
-
-vdpau For VDPAU, this option specifies the X11 display/screen to use. If this option
-is not specified, the value of the DISPLAY environment variable is used
-
-dxva2 For DXVA2, this option should contain the number of the display adapter to use.
-If this option is not specified, the default adapter is used.
-
-
-
-
-
5.7 Audio Options# TOC
-
-
--aframes number (output ) Set the number of audio frames to output. This is an alias for -frames:a.
-
-ar[:stream_specifier ] freq (input/output,per-stream ) Set the audio sampling frequency. For output streams it is set by
-default to the frequency of the corresponding input stream. For input
-streams this option only makes sense for audio grabbing devices and raw
-demuxers and is mapped to the corresponding demuxer options.
-
-aq q (output ) Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
-
-ac[:stream_specifier ] channels (input/output,per-stream ) Set the number of audio channels. For output streams it is set by
-default to the number of input audio channels. For input streams
-this option only makes sense for audio grabbing devices and raw demuxers
-and is mapped to the corresponding demuxer options.
-
-an (output ) Disable audio recording.
-
-acodec codec (input/output ) Set the audio codec. This is an alias for -codec:a.
-
-sample_fmt[:stream_specifier ] sample_fmt (output,per-stream ) Set the audio sample format. Use -sample_fmts to get a list
-of supported sample formats.
-
--af filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:a, see the -filter option .
-
-
-
-
5.8 Advanced Audio options# TOC
-
-
--atag fourcc/tag (output ) Force audio tag/fourcc. This is an alias for -tag:a.
-
-absf bitstream_filter Deprecated, see -bsf
-
-guess_layout_max channels (input,per-stream ) If some input channel layout is not known, try to guess only if it
-corresponds to at most the specified number of channels. For example, 2
-tells to ffmpeg to recognize 1 channel as mono and 2 channels as
-stereo but not 6 channels as 5.1. The default is to always try to guess. Use
-0 to disable all guessing.
-
-
-
-
5.9 Subtitle options# TOC
-
-
--scodec codec (input/output ) Set the subtitle codec. This is an alias for -codec:s.
-
-sn (output ) Disable subtitle recording.
-
-sbsf bitstream_filter Deprecated, see -bsf
-
-
-
-
5.10 Advanced Subtitle options# TOC
-
-
--fix_sub_duration Fix subtitles durations. For each subtitle, wait for the next packet in the
-same stream and adjust the duration of the first to avoid overlap. This is
-necessary with some subtitles codecs, especially DVB subtitles, because the
-duration in the original packet is only a rough estimate and the end is
-actually marked by an empty subtitle frame. Failing to use this option when
-necessary can result in exaggerated durations or muxing failures due to
-non-monotonic timestamps.
-
-Note that this option will delay the output of all data until the next
-subtitle packet is decoded: it may increase memory consumption and latency a
-lot.
-
--canvas_size size Set the size of the canvas used to render subtitles.
-
-
-
-
-
5.11 Advanced options# TOC
-
-
--map [-]input_file_id [:stream_specifier ][,sync_file_id [:stream_specifier ]] | [linklabel] (output )
-Designate one or more input streams as a source for the output file. Each input
-stream is identified by the input file index input_file_id and
-the input stream index input_stream_id within the input
-file. Both indices start at 0. If specified,
-sync_file_id :stream_specifier sets which input stream
-is used as a presentation sync reference.
-
-The first -map option on the command line specifies the
-source for output stream 0, the second -map option specifies
-the source for output stream 1, etc.
-
-A - character before the stream identifier creates a "negative" mapping.
-It disables matching streams from already created mappings.
-
-An alternative [linklabel] form will map outputs from complex filter
-graphs (see the -filter_complex option) to the output file.
-linklabel must correspond to a defined output link label in the graph.
-
-For example, to map ALL streams from the first input file to output
-
-
ffmpeg -i INPUT -map 0 output
- For example, if you have two audio streams in the first input file,
-these streams are identified by "0:0" and "0:1". You can use
--map to select which streams to place in an output file. For
-example:
-
-
ffmpeg -i INPUT -map 0:1 out.wav
- will map the input stream in INPUT identified by "0:1" to
-the (single) output stream in out.wav .
-
-For example, to select the stream with index 2 from input file
-a.mov (specified by the identifier "0:2"), and stream with
-index 6 from input b.mov (specified by the identifier "1:6"),
-and copy them to the output file out.mov :
-
-
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
- To select all video and the third audio stream from an input file:
-
-
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
- To map all the streams except the second audio, use negative mappings
-
-
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
- To pick the English audio stream:
-
-
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
- Note that using this option disables the default mappings for this output file.
-
-
--map_channel [input_file_id .stream_specifier .channel_id |-1][:output_file_id .stream_specifier ] Map an audio channel from a given input to an output. If
-output_file_id .stream_specifier is not set, the audio channel will
-be mapped on all the audio streams.
-
-Using "-1" instead of
-input_file_id .stream_specifier .channel_id will map a muted
-channel.
-
-For example, assuming INPUT is a stereo audio file, you can switch the
-two audio channels with the following command:
-
-
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
- If you want to mute the first channel and keep the second:
-
-
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
- The order of the "-map_channel" option specifies the order of the channels in
-the output stream. The output channel layout is guessed from the number of
-channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
-in combination of "-map_channel" makes the channel gain levels to be updated if
-input and output channel layouts don’t match (for instance two "-map_channel"
-options and "-ac 6").
-
-You can also extract each channel of an input to specific outputs; the following
-command extracts two channels of the INPUT audio stream (file 0, stream 0)
-to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:
-
-
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
- The following example splits the channels of a stereo input into two separate
-streams, which are put into the same output file:
-
-
ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
- Note that currently each output stream can only contain channels from a single
-input stream; you can’t for example use "-map_channel" to pick multiple input
-audio channels contained in different streams (from the same or different files)
-and merge them into a single output stream. It is therefore not currently
-possible, for example, to turn two separate mono streams into a single stereo
-stream. However splitting a stereo stream into two single channel mono streams
-is possible.
-
-If you need this feature, a possible workaround is to use the amerge
-filter. For example, if you need to merge a media (here input.mkv ) with 2
-mono audio streams into one single stereo channel audio stream (and keep the
-video stream), you can use the following command:
-
-
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
- -map_metadata[:metadata_spec_out ] infile [:metadata_spec_in ] (output,per-metadata ) Set metadata information of the next output file from infile . Note that
-those are file indices (zero-based), not filenames.
-Optional metadata_spec_in/out parameters specify, which metadata to copy.
-A metadata specifier can have the following forms:
-
-g global metadata, i.e. metadata that applies to the whole file
-
-s [:stream_spec ]per-stream metadata. stream_spec is a stream specifier as described
-in the Stream specifiers chapter. In an input metadata specifier, the first
-matching stream is copied from. In an output metadata specifier, all matching
-streams are copied to.
-
-c :chapter_index per-chapter metadata. chapter_index is the zero-based chapter index.
-
-p :program_index per-program metadata. program_index is the zero-based program index.
-
-If metadata specifier is omitted, it defaults to global.
-
-By default, global metadata is copied from the first input file,
-per-stream and per-chapter metadata is copied along with streams/chapters. These
-default mappings are disabled by creating any mapping of the relevant type. A negative
-file index can be used to create a dummy mapping that just disables automatic copying.
-
-For example to copy metadata from the first stream of the input file to global metadata
-of the output file:
-
-
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
- To do the reverse, i.e. copy global metadata to all audio streams:
-
-
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
- Note that simple 0 would work as well in this example, since global
-metadata is assumed by default.
-
--map_chapters input_file_index (output ) Copy chapters from input file with index input_file_index to the next
-output file. If no chapter mapping is specified, then chapters are copied from
-the first input file with at least one chapter. Use a negative file index to
-disable any chapter copying.
-
--benchmark (global ) Show benchmarking information at the end of an encode.
-Shows CPU time used and maximum memory consumption.
-Maximum memory consumption is not supported on all systems,
-it will usually display as 0 if not supported.
-
-benchmark_all (global ) Show benchmarking information during the encode.
-Shows CPU time used in various steps (audio/video encode/decode).
-
-timelimit duration (global ) Exit after ffmpeg has been running for duration seconds.
-
-dump (global ) Dump each input packet to stderr.
-
-hex (global ) When dumping packets, also dump the payload.
-
-re (input ) Read input at native frame rate. Mainly used to simulate a grab device.
-or live input stream (e.g. when reading from a file). Should not be used
-with actual grab devices or live input streams (where it can cause packet
-loss).
-By default ffmpeg attempts to read the input(s) as fast as possible.
-This option will slow down the reading of the input(s) to the native frame rate
-of the input(s). It is useful for real-time output (e.g. live streaming).
-
-loop_input Loop over the input stream. Currently it works only for image
-streams. This option is used for automatic FFserver testing.
-This option is deprecated, use -loop 1.
-
-loop_output number_of_times Repeatedly loop output for formats that support looping such as animated GIF
-(0 will loop the output infinitely).
-This option is deprecated, use -loop.
-
-vsync parameter Video sync method.
-For compatibility reasons old values can be specified as numbers.
-Newly added values will have to be specified as strings always.
-
-
-0, passthrough Each frame is passed with its timestamp from the demuxer to the muxer.
-
1, cfr Frames will be duplicated and dropped to achieve exactly the requested
-constant frame rate.
-
2, vfr Frames are passed through with their timestamp or dropped so as to
-prevent 2 frames from having the same timestamp.
-
drop As passthrough but destroys all timestamps, making the muxer generate
-fresh timestamps based on frame-rate.
-
-1, auto Chooses between 1 and 2 depending on muxer capabilities. This is the
-default method.
-
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-With -map you can select from which stream the timestamps should be
-taken. You can leave either video or audio unchanged and sync the
-remaining stream(s) to the unchanged one.
-
--async samples_per_second Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
-the parameter is the maximum samples per second by which the audio is changed.
--async 1 is a special case where only the start of the audio stream is corrected
-without any later correction.
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-This option has been deprecated. Use the aresample audio filter instead.
-
--copyts Do not process input timestamps, but keep their values without trying
-to sanitize them. In particular, do not remove the initial start time
-offset value.
-
-Note that, depending on the vsync option or on specific muxer
-processing (e.g. in case the format option avoid_negative_ts
-is enabled) the output timestamps may mismatch with the input
-timestamps even when this option is selected.
-
--start_at_zero When used with copyts , shift input timestamps so they start at zero.
-
-This means that using e.g. -ss 50 will make output timestamps start at
-50 seconds, regardless of what timestamp the input file started at.
-
--copytb mode Specify how to set the encoder timebase when stream copying. mode is an
-integer numeric value, and can assume one of the following values:
-
-
-1 Use the demuxer timebase.
-
-The time base is copied to the output encoder from the corresponding input
-demuxer. This is sometimes required to avoid non monotonically increasing
-timestamps when copying video streams with variable frame rate.
-
-0 Use the decoder timebase.
-
-The time base is copied to the output encoder from the corresponding input
-decoder.
-
--1 Try to make the choice automatically, in order to generate a sane output.
-
-
-Default value is -1.
-
--shortest (output ) Finish encoding when the shortest input stream ends.
-
-dts_delta_threshold Timestamp discontinuity delta threshold.
-
-muxdelay seconds (input ) Set the maximum demux-decode delay.
-
-muxpreload seconds (input ) Set the initial demux-decode delay.
-
-streamid output-stream-index :new-value (output ) Assign a new stream-id value to an output stream. This option should be
-specified prior to the output filename to which it applies.
-For the situation where multiple output files exist, a streamid
-may be reassigned to a different value.
-
-For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
-an output mpegts file:
-
-
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
- -bsf[:stream_specifier ] bitstream_filters (output,per-stream ) Set bitstream filters for matching streams. bitstream_filters is
-a comma-separated list of bitstream filters. Use the -bsfs option
-to get the list of bitstream filters.
-
-
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
-
-
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
- -tag[:stream_specifier ] codec_tag (input/output,per-stream ) Force a tag/fourcc for matching streams.
-
--timecode hh :mm :ss SEPff Specify Timecode for writing. SEP is ’:’ for non drop timecode and ’;’
-(or ’.’) for drop.
-
-
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
- -filter_complex filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. For simple graphs – those with one input and one output of the same
-type – see the -filter options. filtergraph is a description of
-the filtergraph, as described in the “Filtergraph syntax” section of the
-ffmpeg-filters manual.
-
-Input link labels must refer to input streams using the
-[file_index:stream_specifier] syntax (i.e. the same as -map
-uses). If stream_specifier matches multiple streams, the first one will be
-used. An unlabeled input will be connected to the first unused input stream of
-the matching type.
-
-Output link labels are referred to with -map . Unlabeled outputs are
-added to the first output file.
-
-Note that with this option it is possible to use only lavfi sources without
-normal input files.
-
-For example, to overlay an image over video
-
-
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
-'[out]' out.mkv
- Here [0:v] refers to the first video stream in the first input file,
-which is linked to the first (main) input of the overlay filter. Similarly the
-first video stream in the second input is linked to the second (overlay) input
-of overlay.
-
-Assuming there is only one video stream in each input file, we can omit input
-labels, so the above is equivalent to
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
-'[out]' out.mkv
- Furthermore we can omit the output label and the single output from the filter
-graph will be added to the output file automatically, so we can simply write
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
- To generate 5 seconds of pure red video using lavfi color source:
-
-
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
- -lavfi filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. Equivalent to -filter_complex .
-
--filter_complex_script filename (global ) This option is similar to -filter_complex , the only difference is that
-its argument is the name of the file from which a complex filtergraph
-description is to be read.
-
--accurate_seek (input ) This option enables or disables accurate seeking in input files with the
--ss option. It is enabled by default, so seeking is accurate when
-transcoding. Use -noaccurate_seek to disable it, which may be useful
-e.g. when copying some streams and transcoding the others.
-
--override_ffserver (global ) Overrides the input specifications from ffserver. Using this
-option you can map any input stream to ffserver and control
-many aspects of the encoding from ffmpeg. Without this
-option ffmpeg will transmit to ffserver what is
-requested by ffserver.
-
-The option is intended for cases where features are needed that cannot be
-specified to ffserver but can be to ffmpeg.
-
--sdp_file file (global ) Print sdp information to file .
-This allows dumping sdp information when at least one output isn’t an
-rtp stream.
-
--discard (input ) Allows discarding specific streams or frames of streams at the demuxer.
-Not all demuxers support this.
-
-
-none Discard no frame.
-
-default Default, which discards no frames.
-
-noref Discard all non-reference frames.
-
-bidir Discard all bidirectional frames.
-
-nokey Discard all frames excepts keyframes.
-
-all Discard all frames.
-
-
-
-
-
As a special exception, you can use a bitmap subtitle stream as input: it
-will be converted into a video with the same size as the largest video in
-the file, or 720x576 if no video is present. Note that this is an
-experimental and temporary solution. It will be removed once libavfilter has
-proper support for subtitles.
-
-
For example, to hardcode subtitles on top of a DVB-T recording stored in
-MPEG-TS format, delaying the subtitles by 1 second:
-
-
ffmpeg -i input.ts -filter_complex \
- '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
- -sn -map '#0x2dc' output.mkv
-
-
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
-audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
-
-
-
5.12 Preset files# TOC
-
A preset file contains a sequence of option =value pairs,
-one for each line, specifying a sequence of options which would be
-awkward to specify on the command line. Lines starting with the hash
-(’#’) character are ignored and are used to provide comments. Check
-the presets directory in the FFmpeg source tree for examples.
-
-
There are two types of preset files: ffpreset and avpreset files.
-
-
-
5.12.1 ffpreset files# TOC
-
ffpreset files are specified with the vpre, apre,
-spre, and fpre options. The fpre option takes the
-filename of the preset instead of a preset name as input and can be
-used for any kind of codec. For the vpre, apre, and
-spre options, the options specified in a preset file are
-applied to the currently selected codec of the same type as the preset
-option.
-
-
The argument passed to the vpre, apre, and spre
-preset options identifies the preset file to use according to the
-following rules:
-
-
First ffmpeg searches for a file named arg .ffpreset in the
-directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg , and in
-the datadir defined at configuration time (usually PREFIX/share/ffmpeg )
-or in a ffpresets folder along the executable on win32,
-in that order. For example, if the argument is libvpx-1080p, it will
-search for the file libvpx-1080p.ffpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-codec_name -arg .ffpreset in the above-mentioned
-directories, where codec_name is the name of the codec to which
-the preset file options will be applied. For example, if you select
-the video codec with -vcodec libvpx and use -vpre 1080p,
-then it will search for the file libvpx-1080p.ffpreset .
-
-
-
5.12.2 avpreset files# TOC
-
avpreset files are specified with the pre option. They work similar to
-ffpreset files, but they only allow encoder- specific options. Therefore, an
-option =value pair specifying an encoder cannot be used.
-
-
When the pre option is specified, ffmpeg will look for files with the
-suffix .avpreset in the directories $AVCONV_DATADIR (if set), and
-$HOME/.avconv , and in the datadir defined at configuration time (usually
-PREFIX/share/ffmpeg ), in that order.
-
-
First ffmpeg searches for a file named codec_name -arg .avpreset in
-the above-mentioned directories, where codec_name is the name of the codec
-to which the preset file options will be applied. For example, if you select the
-video codec with -vcodec libvpx and use -pre 1080p, then it will
-search for the file libvpx-1080p.avpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-arg .avpreset in the same directories.
-
-
-
-
-
-
- For streaming at very low bitrates, use a low frame rate
-and a small GOP size. This is especially true for RealVideo where
-the Linux player does not seem to be very fast, so it can miss
-frames. An example is:
-
-
-
ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
- The parameter ’q’ which is displayed while encoding is the current
-quantizer. The value 1 indicates that a very good quality could
-be achieved. The value 31 indicates the worst quality. If q=31 appears
-too often, it means that the encoder cannot compress enough to meet
-your bitrate. You must either increase the bitrate, decrease the
-frame rate or decrease the frame size.
-
- If your computer is not fast enough, you can speed up the
-compression at the expense of the compression ratio. You can use
-’-me zero’ to speed up motion estimation, and ’-g 0’ to disable
-motion estimation completely (you have only I-frames, which means it
-is about as good as JPEG compression).
-
- To have very low audio bitrates, reduce the sampling frequency
-(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
-
- To have a constant quality (but a variable bitrate), use the option
-’-qscale n’ when ’n’ is between 1 (excellent quality) and 31 (worst
-quality).
-
-
-
-
-
7 Examples# TOC
-
-
-
7.1 Video and Audio grabbing# TOC
-
-
If you specify the input format and device then ffmpeg can grab video
-and audio directly.
-
-
-
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
-
-
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Note that you must activate the right video source and channel before
-launching ffmpeg with any TV viewer such as
-xawtv by Gerd Knorr. You also
-have to set the audio recording levels correctly with a
-standard mixer.
-
-
-
7.2 X11 grabbing# TOC
-
-
Grab the X11 display with ffmpeg via
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as
-the DISPLAY environment variable.
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
-variable. 10 is the x-offset and 20 the y-offset for the grabbing.
-
-
-
7.3 Video and Audio file format conversion# TOC
-
-
Any supported file format and protocol can serve as input to ffmpeg:
-
-
Examples:
-
- You can use YUV files as input:
-
-
-
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
- It will use the files:
-
-
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
-/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
- The Y files use twice the resolution of the U and V files. They are
-raw files, without header. They can be generated by all decent video
-decoders. You must specify the size of the image with the -s option
-if ffmpeg cannot guess it.
-
- You can input from a raw YUV420P file:
-
-
-
ffmpeg -i /tmp/test.yuv /tmp/out.avi
- test.yuv is a file containing raw YUV planar data. Each frame is composed
-of the Y plane followed by the U and V planes at half vertical and
-horizontal resolution.
-
- You can output to a raw YUV420P file:
-
-
-
ffmpeg -i mydivx.avi hugefile.yuv
- You can set several input files and output files:
-
-
-
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
- Converts the audio file a.wav and the raw YUV video file a.yuv
-to MPEG file a.mpg.
-
- You can also do audio and video conversions at the same time:
-
-
-
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
- Converts a.wav to MPEG audio at 22050 Hz sample rate.
-
- You can encode to several formats at the same time and define a
-mapping from input stream to output streams:
-
-
-
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
- Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map
-file:index’ specifies which input stream is used for each output
-stream, in the order of the definition of output streams.
-
- You can transcode decrypted VOBs:
-
-
-
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
- This is a typical DVD ripping example; the input is a VOB file, the
-output an AVI file with MPEG-4 video and MP3 audio. Note that in this
-command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
-GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
-input video. Furthermore, the audio stream is MP3-encoded so you need
-to enable LAME support by passing --enable-libmp3lame to configure.
-The mapping is particularly useful for DVD transcoding
-to get the desired audio language.
-
-NOTE: To see the supported input formats, use ffmpeg -formats.
-
- You can extract images from a video, or create a video from many images:
-
-For extracting images from a video:
-
-
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
- This will extract one video frame per second from the video and will
-output them in files named foo-001.jpeg , foo-002.jpeg ,
-etc. Images will be rescaled to fit the new WxH values.
-
-If you want to extract just a limited number of frames, you can use the
-above command in combination with the -vframes or -t option, or in
-combination with -ss to start extracting from a certain point in time.
-
-For creating a video from many images:
-
-
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
- The syntax foo-%03d.jpeg specifies to use a decimal number
-composed of three digits padded with zeroes to express the sequence
-number. It is the same syntax supported by the C printf function, but
-only formats accepting a normal integer are suitable.
-
-When importing an image sequence, -i also supports expanding
-shell-like wildcard patterns (globbing) internally, by selecting the
-image2-specific -pattern_type glob option.
-
-For example, for creating a video from filenames matching the glob pattern
-foo-*.jpeg:
-
-
ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
- You can put many streams of the same type in the output:
-
-
-
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
- The resulting output file test12.nut will contain the first four streams
-from the input files in reverse order.
-
- To force CBR video output:
-
-
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
- The four options lmin, lmax, mblmin and mblmax use ’lambda’ units,
-but you may use the QP2LAMBDA constant to easily convert from ’q’ units:
-
-
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
-
-
-
-
8 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
8.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
8.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
8.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
8.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
8.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
8.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
8.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
8.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
8.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
8.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
9 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
10 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
11 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
12 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
13 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
13.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
13.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
14 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
14.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
14.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
14.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
14.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
14.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
14.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
14.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
14.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
14.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
14.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
15 Subtitles Decoders# TOC
-
-
-
15.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
15.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
15.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
15.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
16 Encoders# TOC
-
-
Encoders are configured elements in FFmpeg which allow the encoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native encoders
-are enabled by default. Encoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available encoders using the configure option --list-encoders.
-
-
You can disable all the encoders with the configure option
---disable-encoders and selectively enable / disable single encoders
-with the options --enable-encoder=ENCODER /
---disable-encoder=ENCODER .
-
-
The option -encoders of the ff* tools will display the list of
-enabled encoders.
-
-
-
-
17 Audio Encoders# TOC
-
-
A description of some of the currently available audio encoders
-follows.
-
-
-
17.1 aac# TOC
-
-
Advanced Audio Coding (AAC) encoder.
-
-
This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
-low complexity (AAC-LC) profile is supported. To use this encoder, you must set
-strict option to ‘experimental ’ or lower.
-
-
As this encoder is experimental, unexpected behavior may exist from time to
-time. For a more stable AAC encoder, see libvo-aacenc . However, be warned
-that it has a worse quality reported by some users.
-
-
See also libfdk_aac and libfaac .
-
-
-
17.1.1 Options# TOC
-
-
-b Set bit rate in bits/s. Setting this automatically activates constant bit rate
-(CBR) mode.
-
-q Set quality for variable bit rate (VBR) mode. This option is valid only using
-the ffmpeg command-line tool. For library interface users, use
-global_quality .
-
-stereo_mode Set stereo encoding mode. Possible values:
-
-
-‘auto ’
-Automatically selected by the encoder.
-
-‘ms_off ’
-Disable middle/side encoding. This is the default.
-
-‘ms_force ’
-Force middle/side encoding.
-
-
-aac_coder Set AAC encoder coding method. Possible values:
-
-
-‘faac ’
-FAAC-inspired method.
-
-This method is a simplified reimplementation of the method used in FAAC, which
-sets thresholds proportional to the band energies, and then decreases all the
-thresholds with quantizer steps to find the appropriate quantization with
-distortion below threshold band by band.
-
-The quality of this method is comparable to the two loop searching method
-described below, but somewhat a little better and slower.
-
-‘anmr ’
-Average noise to mask ratio (ANMR) trellis-based solution.
-
-This has a theoretic best quality out of all the coding methods, but at the
-cost of the slowest speed.
-
-‘twoloop ’
-Two loop searching (TLS) method.
-
-This method first sets quantizers depending on band thresholds and then tries
-to find an optimal combination by adding or subtracting a specific value from
-all quantizers and adjusting some individual quantizer a little.
-
-This method produces similar quality with the FAAC method and is the default.
-
-‘fast ’
-Constant quantizer method.
-
-This method sets a constant quantizer for all bands. This is the fastest of all
-the methods, yet produces the worst quality.
-
-
-
-
-
-
-
17.2 ac3 and ac3_fixed# TOC
-
-
AC-3 audio encoders.
-
-
These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
The ac3 encoder uses floating-point math, while the ac3_fixed
-encoder only uses fixed-point integer math. This does not mean that one is
-always faster, just that one or the other may be better suited to a
-particular system. The floating-point encoder will generally produce better
-quality audio for a given bitrate. The ac3_fixed encoder is not the
-default codec for any of the output formats, so it must be specified explicitly
-using the option -acodec ac3_fixed in order to use it.
-
-
-
17.2.1 AC-3 Metadata# TOC
-
-
The AC-3 metadata options are used to set parameters that describe the audio,
-but in most cases do not affect the audio encoding itself. Some of the options
-do directly affect or influence the decoding and playback of the resulting
-bitstream, while others are just for informational purposes. A few of the
-options will add bits to the output stream that could otherwise be used for
-audio data, and will thus affect the quality of the output. Those will be
-indicated accordingly with a note in the option list below.
-
-
These parameters are described in detail in several publicly-available
-documents.
-
-
-
-
17.2.1.1 Metadata Control Options# TOC
-
-
--per_frame_metadata boolean Allow Per-Frame Metadata. Specifies if the encoder should check for changing
-metadata for each frame.
-
-0 The metadata values set at initialization will be used for every frame in the
-stream. (default)
-
1 Metadata values can be changed before encoding each frame.
-
-
-
-
-
-
17.2.1.2 Downmix Levels# TOC
-
-
--center_mixlev level Center Mix Level. The amount of gain the decoder should apply to the center
-channel when downmixing to stereo. This field will only be written to the
-bitstream if a center channel is present. The value is specified as a scale
-factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6dB gain
-
-
--surround_mixlev level Surround Mix Level. The amount of gain the decoder should apply to the surround
-channel(s) when downmixing to stereo. This field will only be written to the
-bitstream if one or more surround channels are present. The value is specified
-as a scale factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.500 Apply -6dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
17.2.1.3 Audio Production Information# TOC
-
Audio Production Information is optional information describing the mixing
-environment. Either none or both of the fields are written to the bitstream.
-
-
--mixing_level number Mixing Level. Specifies peak sound pressure level (SPL) in the production
-environment when the mix was mastered. Valid values are 80 to 111, or -1 for
-unknown or not indicated. The default value is -1, but that value cannot be
-used if the Audio Production Information is written to the bitstream. Therefore,
-if the room_type option is not the default value, the mixing_level
-option must not be -1.
-
--room_type type Room Type. Describes the equalization used during the final mixing session at
-the studio or on the dubbing stage. A large room is a dubbing stage with the
-industry standard X-curve equalization; a small room has flat equalization.
-This field will not be written to the bitstream if both the mixing_level
-option and the room_type option have the default values.
-
-0 notindicated Not Indicated (default)
-
1 large Large Room
-
2 small Small Room
-
-
-
-
-
-
17.2.1.4 Other Metadata Options# TOC
-
-
--copyright boolean Copyright Indicator. Specifies whether a copyright exists for this audio.
-
-0 off No Copyright Exists (default)
-
1 on Copyright Exists
-
-
--dialnorm value Dialogue Normalization. Indicates how far the average dialogue level of the
-program is below digital 100% full scale (0 dBFS). This parameter determines a
-level shift during audio reproduction that sets the average volume of the
-dialogue to a preset level. The goal is to match volume level between program
-sources. A value of -31dB will result in no volume level change, relative to
-the source volume, during audio reproduction. Valid values are whole numbers in
-the range -31 to -1, with -31 being the default.
-
--dsur_mode mode Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
-(Pro Logic). This field will only be written to the bitstream if the audio
-stream is stereo. Using this option does NOT mean the encoder will actually
-apply Dolby Surround processing.
-
-0 notindicated Not Indicated (default)
-
1 off Not Dolby Surround Encoded
-
2 on Dolby Surround Encoded
-
-
--original boolean Original Bit Stream Indicator. Specifies whether this audio is from the
-original source and not a copy.
-
-0 off Not Original Source
-
1 on Original Source (default)
-
-
-
-
-
-
17.2.2 Extended Bitstream Information# TOC
-
The extended bitstream options are part of the Alternate Bit Stream Syntax as
-specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
-If any one parameter in a group is specified, all values in that group will be
-written to the bitstream. Default values are used for those that are written
-but have not been specified. If the mixing levels are written, the decoder
-will use these values instead of the ones specified in the center_mixlev
-and surround_mixlev options if it supports the Alternate Bit Stream
-Syntax.
-
-
-
17.2.2.1 Extended Bitstream Information - Part 1# TOC
-
-
--dmix_mode mode Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
-(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
-
-0 notindicated Not Indicated (default)
-
1 ltrt Lt/Rt Downmix Preferred
-
2 loro Lo/Ro Downmix Preferred
-
-
--ltrt_cmixlev level Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lt/Rt mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--ltrt_surmixlev level Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lt/Rt mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
--loro_cmixlev level Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lo/Ro mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--loro_surmixlev level Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lo/Ro mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
17.2.2.2 Extended Bitstream Information - Part 2# TOC
-
-
--dsurex_mode mode Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
-(7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually
-apply Dolby Surround EX processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Surround EX Off
-
2 off Dolby Surround EX On
-
-
--dheadphone_mode mode Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
-encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
-option does NOT mean the encoder will actually apply Dolby Headphone
-processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Headphone Off
-
2 off Dolby Headphone On
-
-
--ad_conv_type type A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
-conversion.
-
-0 standard Standard A/D Converter (default)
-
1 hdcd HDCD A/D Converter
-
-
-
-
-
-
17.2.3 Other AC-3 Encoding Options# TOC
-
-
--stereo_rematrixing boolean Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
-is an optional AC-3 feature that increases quality by selectively encoding
-the left/right channels as mid/side. This option is enabled by default, and it
-is highly recommended that it be left as enabled except for testing purposes.
-
-
-
-
-
17.2.4 Floating-Point-Only AC-3 Encoding Options# TOC
-
-
These options are only valid for the floating-point encoder and do not exist
-for the fixed-point encoder due to the corresponding features not being
-implemented in fixed-point.
-
-
--channel_coupling boolean Enables/Disables use of channel coupling, which is an optional AC-3 feature
-that increases quality by combining high frequency information from multiple
-channels into a single channel. The per-channel high frequency information is
-sent with less accuracy in both the frequency and time domains. This allows
-more bits to be used for lower frequencies while preserving enough information
-to reconstruct the high frequencies. This option is enabled by default for the
-floating-point encoder and should generally be left as enabled except for
-testing purposes or to increase encoding speed.
-
--1 auto Selected by Encoder (default)
-
0 off Disable Channel Coupling
-
1 on Enable Channel Coupling
-
-
--cpl_start_band number Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
-value higher than the bandwidth is used, it will be reduced to 1 less than the
-coupling end band. If auto is used, the start band will be determined by
-the encoder based on the bit rate, sample rate, and channel layout. This option
-has no effect if channel coupling is disabled.
-
--1 auto Selected by Encoder (default)
-
-
-
-
-
-
17.3 libfaac# TOC
-
-
libfaac AAC (Advanced Audio Coding) encoder wrapper.
-
-
Requires the presence of the libfaac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfaac --enable-nonfree.
-
-
This encoder is considered to be of higher quality with respect to the
-the native experimental FFmpeg AAC encoder .
-
-
For more information see the libfaac project at
-http://www.audiocoding.com/faac.html/ .
-
-
-
17.3.1 Options# TOC
-
-
The following shared FFmpeg codec options are recognized.
-
-
The following options are supported by the libfaac wrapper. The
-faac-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bit rate in bits/s for ABR (Average Bit Rate) mode. If the bit rate
-is not explicitly specified, it is automatically set to a suitable
-value depending on the selected profile. faac bitrate is
-expressed in kilobits/s.
-
-Note that libfaac does not support CBR (Constant Bit Rate) but only
-ABR (Average Bit Rate).
-
-If VBR mode is enabled this option is ignored.
-
-ar (-R ) Set audio sampling rate (in Hz).
-
-ac (-c ) Set the number of audio channels.
-
-cutoff (-C ) Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_main ’
-Main AAC (Main)
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_ssr ’
-Scalable Sample Rate (SSR)
-
-‘aac_ltp ’
-Long Term Prediction (LTP)
-
-
-If not specified it is set to ‘aac_low ’.
-
-flags +qscale Set constant quality VBR (Variable Bit Rate) mode.
-
-global_quality Set quality in VBR mode as an integer number of lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-and used to set the quality value used by libfaac. A reasonable range
-for the option value in QP units is [10-500], the higher the value the
-higher the quality.
-
-q (-q ) Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value sets the quality value used by libfaac. A reasonable range
-for the option value is [10-500], the higher the value the higher the
-quality.
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
17.3.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to ABR 128 kbps AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfaac -b:a 128k -output.m4a
- Use ffmpeg to convert an audio file to VBR AAC, using the
-LTP AAC profile:
-
-
ffmpeg -i input.wav -c:a libfaac -profile:a aac_ltp -q:a 100 output.m4a
-
-
-
-
17.4 libfdk_aac# TOC
-
-
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
-
-
The libfdk-aac library is based on the Fraunhofer FDK AAC code from
-the Android project.
-
-
Requires the presence of the libfdk-aac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfdk-aac. The library is also incompatible with GPL,
-so if you allow the use of GPL, you should configure with
---enable-gpl --enable-nonfree --enable-libfdk-aac.
-
-
This encoder is considered to be of higher quality with respect to
-both the native experimental FFmpeg AAC encoder and
-libfaac .
-
-
VBR encoding, enabled through the vbr or flags
-+qscale options, is experimental and only works with some
-combinations of parameters.
-
-
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
-higher.
-
-
For more information see the fdk-aac project at
-http://sourceforge.net/p/opencore-amr/fdk-aac/ .
-
-
-
17.4.1 Options# TOC
-
-
The following options are mapped on the shared FFmpeg codec options.
-
-
-b Set bit rate in bits/s. If the bitrate is not explicitly specified, it
-is automatically set to a suitable value depending on the selected
-profile.
-
-In case VBR mode is enabled the option is ignored.
-
-ar Set audio sampling rate (in Hz).
-
-channels Set the number of audio channels.
-
-flags +qscale Enable fixed quality, VBR (Variable Bit Rate) mode.
-Note that VBR is implicitly enabled when the vbr value is
-positive.
-
-cutoff Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_he ’
-High Efficiency AAC (HE-AAC)
-
-‘aac_he_v2 ’
-High Efficiency AAC version 2 (HE-AACv2)
-
-‘aac_ld ’
-Low Delay AAC (LD)
-
-‘aac_eld ’
-Enhanced Low Delay AAC (ELD)
-
-
-If not specified it is set to ‘aac_low ’.
-
-
-
The following are private options of the libfdk_aac encoder.
-
-
-afterburner Enable afterburner feature if set to 1, disabled if set to 0. This
-improves the quality but also the required processing power.
-
-Default value is 1.
-
-eld_sbr Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
-if set to 0.
-
-Default value is 0.
-
-signaling Set SBR/PS signaling style.
-
-It can assume one of the following values:
-
-‘default ’
-choose signaling implicitly (explicit hierarchical by default,
-implicit if global header is disabled)
-
-‘implicit ’
-implicit backwards compatible signaling
-
-‘explicit_sbr ’
-explicit SBR, implicit PS signaling
-
-‘explicit_hierarchical ’
-explicit hierarchical signaling
-
-
-Default value is ‘default ’.
-
-latm Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
-
-Default value is 0.
-
-header_period Set StreamMuxConfig and PCE repetition period (in frames) for sending
-in-band configuration buffers within LATM/LOAS transport layer.
-
-Must be a 16-bits non-negative integer.
-
-Default value is 0.
-
-vbr Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
-good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
-(Constant Bit Rate) is enabled.
-
-Currently only the ‘aac_low ’ profile supports VBR encoding.
-
-VBR modes 1-5 correspond to roughly the following average bit rates:
-
-
-‘1 ’
-32 kbps/channel
-
‘2 ’
-40 kbps/channel
-
‘3 ’
-48-56 kbps/channel
-
‘4 ’
-64 kbps/channel
-
‘5 ’
-about 80-96 kbps/channel
-
-
-Default value is 0.
-
-
-
-
17.4.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to VBR AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
- Use ffmpeg to convert an audio file to CBR 64k kbps AAC, using the
-High-Efficiency AAC profile:
-
-
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
-
-
-
-
17.5 libmp3lame# TOC
-
-
LAME (Lame Ain’t an MP3 Encoder) MP3 encoder wrapper.
-
-
Requires the presence of the libmp3lame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libmp3lame.
-
-
See libshine for a fixed-point MP3 encoder, although with a
-lower quality.
-
-
-
17.5.1 Options# TOC
-
-
The following options are supported by the libmp3lame wrapper. The
-lame-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR or ABR. LAME bitrate is
-expressed in kilobits/s.
-
-q (-V ) Set constant quality setting for VBR. This option is valid only
-using the ffmpeg command-line tool. For library interface
-users, use global_quality .
-
-compression_level (-q ) Set algorithm quality. Valid arguments are integers in the 0-9 range,
-with 0 meaning highest quality but slowest, and 9 meaning fastest
-while producing the worst quality.
-
-reservoir Enable use of bit reservoir when set to 1. Default value is 1. LAME
-has this enabled by default, but can be overridden by use
---nores option.
-
-joint_stereo (-m j ) Enable the encoder to use (on a frame by frame basis) either L/R
-stereo or mid/side stereo. Default value is 1.
-
-abr (--abr ) Enable the encoder to use ABR when set to 1. The lame
---abr sets the target bitrate, while this options only
-tells FFmpeg to use ABR still relies on b to set bitrate.
-
-
-
-
-
17.6 libopencore-amrnb# TOC
-
-
OpenCORE Adaptive Multi-Rate Narrowband encoder.
-
-
Requires the presence of the libopencore-amrnb headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopencore-amrnb --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
-but you can override it by setting strict to ‘unofficial ’ or
-lower.
-
-
-
17.6.1 Options# TOC
-
-
-b Set bitrate in bits per second. Only the following bitrates are supported,
-otherwise libavcodec will round to the nearest valid bitrate.
-
-
-4750 5150 5900 6700 7400 7950 10200 12200
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
17.7 libshine# TOC
-
-
Shine Fixed-Point MP3 encoder wrapper.
-
-
Shine is a fixed-point MP3 encoder. It has a far better performance on
-platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
-However, as it is more targeted on performance than quality, it is not on par
-with LAME and other production-grade encoders quality-wise. Also, according to
-the project’s homepage, this encoder may not be free of bugs as the code was
-written a long time ago and the project was dead for at least 5 years.
-
-
This encoder only supports stereo and mono input. This is also CBR-only.
-
-
The original project (last updated in early 2007) is at
-http://sourceforge.net/projects/libshine-fxp/ . We only support the
-updated fork by the Savonet/Liquidsoap project at https://github.com/savonet/shine .
-
-
Requires the presence of the libshine headers and library during
-configuration. You need to explicitly configure the build with
---enable-libshine.
-
-
See also libmp3lame .
-
-
-
17.7.1 Options# TOC
-
-
The following options are supported by the libshine wrapper. The
-shineenc-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. shineenc -b option
-is expressed in kilobits/s.
-
-
-
-
-
17.8 libtwolame# TOC
-
-
TwoLAME MP2 encoder wrapper.
-
-
Requires the presence of the libtwolame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtwolame.
-
-
-
17.8.1 Options# TOC
-
-
The following options are supported by the libtwolame wrapper. The
-twolame-equivalent options follow the FFmpeg ones and are in
-parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. twolame b
-option is expressed in kilobits/s. Default value is 128k.
-
-q (-V ) Set quality for experimental VBR support. Maximum value range is
-from -50 to 50, useful range is from -10 to 10. The higher the
-value, the better the quality. This option is valid only using the
-ffmpeg command-line tool. For library interface users,
-use global_quality .
-
-mode (--mode ) Set the mode of the resulting audio. Possible values:
-
-
-‘auto ’
-Choose mode automatically based on the input. This is the default.
-
‘stereo ’
-Stereo
-
‘joint_stereo ’
-Joint stereo
-
‘dual_channel ’
-Dual channel
-
‘mono ’
-Mono
-
-
-psymodel (--psyc-mode ) Set psychoacoustic model to use in encoding. The argument must be
-an integer between -1 and 4, inclusive. The higher the value, the
-better the quality. The default value is 3.
-
-energy_levels (--energy ) Enable energy levels extensions when set to 1. The default value is
-0 (disabled).
-
-error_protection (--protect ) Enable CRC error protection when set to 1. The default value is 0
-(disabled).
-
-copyright (--copyright ) Set MPEG audio copyright flag when set to 1. The default value is 0
-(disabled).
-
-original (--original ) Set MPEG audio original flag when set to 1. The default value is 0
-(disabled).
-
-
-
-
-
17.9 libvo-aacenc# TOC
-
-
VisualOn AAC encoder.
-
-
Requires the presence of the libvo-aacenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-aacenc --enable-version3.
-
-
This encoder is considered to be worse than the
-native experimental FFmpeg AAC encoder , according to
-multiple sources.
-
-
-
17.9.1 Options# TOC
-
-
The VisualOn AAC encoder only support encoding AAC-LC and up to 2
-channels. It is also CBR-only.
-
-
-b Set bit rate in bits/s.
-
-
-
-
-
17.10 libvo-amrwbenc# TOC
-
-
VisualOn Adaptive Multi-Rate Wideband encoder.
-
-
Requires the presence of the libvo-amrwbenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-amrwbenc --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 16000Hz sample
-rate, but you can override it by setting strict to
-‘unofficial ’ or lower.
-
-
-
17.10.1 Options# TOC
-
-
-b Set bitrate in bits/s. Only the following bitrates are supported, otherwise
-libavcodec will round to the nearest valid bitrate.
-
-
-‘6600 ’
-‘8850 ’
-‘12650 ’
-‘14250 ’
-‘15850 ’
-‘18250 ’
-‘19850 ’
-‘23050 ’
-‘23850 ’
-
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
17.11 libopus# TOC
-
-
libopus Opus Interactive Audio Codec encoder wrapper.
-
-
Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
-
17.11.1 Option Mapping# TOC
-
-
Most libopus options are modelled after the opusenc utility from
-opus-tools. The following is an option mapping chart describing options
-supported by the libopus wrapper, and their opusenc-equivalent
-in parentheses.
-
-
-b (bitrate ) Set the bit rate in bits/s. FFmpeg’s b option is
-expressed in bits/s, while opusenc’s bitrate in
-kilobits/s.
-
-vbr (vbr , hard-cbr , and cvbr ) Set VBR mode. The FFmpeg vbr option has the following
-valid arguments, with the their opusenc equivalent options
-in parentheses:
-
-
-‘off (hard-cbr ) ’
-Use constant bit rate encoding.
-
-‘on (vbr ) ’
-Use variable bit rate encoding (the default).
-
-‘constrained (cvbr ) ’
-Use constrained variable bit rate encoding.
-
-
-compression_level (comp ) Set encoding algorithm complexity. Valid options are integers in
-the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
-gives the highest quality but slowest encoding. The default is 10.
-
-frame_duration (framesize ) Set maximum frame size, or duration of a frame in milliseconds. The
-argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
-frame sizes achieve lower latency but less quality at a given bitrate.
-Sizes greater than 20ms are only interesting at fairly low bitrates.
-The default is 20ms.
-
-packet_loss (expect-loss ) Set expected packet loss percentage. The default is 0.
-
-application (N.A.) Set intended application type. Valid options are listed below:
-
-
-‘voip ’
-Favor improved speech intelligibility.
-
‘audio ’
-Favor faithfulness to the input (the default).
-
‘lowdelay ’
-Restrict to only the lowest delay modes.
-
-
-cutoff (N.A.) Set cutoff bandwidth in Hz. The argument must be exactly one of the
-following: 4000, 6000, 8000, 12000, or 20000, corresponding to
-narrowband, mediumband, wideband, super wideband, and fullband
-respectively. The default is 0 (cutoff disabled).
-
-
-
-
-
17.12 libvorbis# TOC
-
-
libvorbis encoder wrapper.
-
-
Requires the presence of the libvorbisenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvorbis.
-
-
-
17.12.1 Options# TOC
-
-
The following options are supported by the libvorbis wrapper. The
-oggenc-equivalent of the options are listed in parentheses.
-
-
To get a more accurate and extensive documentation of the libvorbis
-options, consult the libvorbisenc’s and oggenc’s documentations.
-See http://xiph.org/vorbis/ ,
-http://wiki.xiph.org/Vorbis-tools , and oggenc(1).
-
-
-b (-b ) Set bitrate expressed in bits/s for ABR. oggenc -b is
-expressed in kilobits/s.
-
-q (-q ) Set constant quality setting for VBR. The value should be a float
-number in the range of -1.0 to 10.0. The higher the value, the better
-the quality. The default value is ‘3.0 ’.
-
-This option is valid only using the ffmpeg command-line tool.
-For library interface users, use global_quality .
-
-cutoff (--advanced-encode-option lowpass_frequency=N ) Set cutoff bandwidth in Hz, a value of 0 disables cutoff. oggenc’s
-related option is expressed in kHz. The default value is ‘0 ’ (cutoff
-disabled).
-
-minrate (-m ) Set minimum bitrate expressed in bits/s. oggenc -m is
-expressed in kilobits/s.
-
-maxrate (-M ) Set maximum bitrate expressed in bits/s. oggenc -M is
-expressed in kilobits/s. This only has effect on ABR mode.
-
-iblock (--advanced-encode-option impulse_noisetune=N ) Set noise floor bias for impulse blocks. The value is a float number from
--15.0 to 0.0. A negative bias instructs the encoder to pay special attention
-to the crispness of transients in the encoded audio. The tradeoff for better
-transient response is a higher bitrate.
-
-
-
-
-
17.13 libwavpack# TOC
-
-
A wrapper providing WavPack encoding through libwavpack.
-
-
Only lossless mode using 32-bit integer samples is supported currently.
-
-
Requires the presence of the libwavpack headers and library during
-configuration. You need to explicitly configure the build with
---enable-libwavpack.
-
-
Note that a libavcodec-native encoder for the WavPack codec exists so users can
-encode audios with this codec without using this encoder. See wavpackenc .
-
-
-
17.13.1 Options# TOC
-
-
wavpack command line utility’s corresponding options are listed in
-parentheses, if any.
-
-
-frame_size (--blocksize ) Default is 32768.
-
-compression_level Set speed vs. compression tradeoff. Acceptable arguments are listed below:
-
-
-‘0 (-f ) ’
-Fast mode.
-
-‘1 ’
-Normal (default) settings.
-
-‘2 (-h ) ’
-High quality.
-
-‘3 (-hh ) ’
-Very high quality.
-
-‘4-8 (-hh -x EXTRAPROC ) ’
-Same as ‘3 ’, but with extra processing enabled.
-
-‘4 ’ is the same as -x2 and ‘8 ’ is the same as -x6 .
-
-
-
-
-
-
17.14 wavpack# TOC
-
-
WavPack lossless audio encoder.
-
-
This is a libavcodec-native WavPack encoder. There is also an encoder based on
-libwavpack, but there is virtually no reason to use that encoder.
-
-
See also libwavpack .
-
-
-
17.14.1 Options# TOC
-
-
The equivalent options for wavpack command line utility are listed in
-parentheses.
-
-
-
17.14.1.1 Shared options# TOC
-
-
The following shared options are effective for this encoder. Only special notes
-about this particular encoder will be documented here. For the general meaning
-of the options, see the Codec Options chapter .
-
-
-frame_size (--blocksize ) For this encoder, the range for this option is between 128 and 131072. Default
-is automatically decided based on sample rate and number of channel.
-
-For the complete formula of calculating default, see
-libavcodec/wavpackenc.c .
-
-compression_level (-f , -h , -hh , and -x ) This option’s syntax is consistent with libwavpack ’s.
-
-
-
-
17.14.1.2 Private options# TOC
-
-
-joint_stereo (-j ) Set whether to enable joint stereo. Valid values are:
-
-
-‘on (1 ) ’
-Force mid/side audio encoding.
-
‘off (0 ) ’
-Force left/right audio encoding.
-
‘auto ’
-Let the encoder decide automatically.
-
-
-optimize_mono Set whether to enable optimization for mono. This option is only effective for
-non-mono streams. Available values:
-
-
-‘on ’
-enabled
-
‘off ’
-disabled
-
-
-
-
-
-
-
18 Video Encoders# TOC
-
-
A description of some of the currently available video encoders
-follows.
-
-
-
18.1 libtheora# TOC
-
-
libtheora Theora encoder wrapper.
-
-
Requires the presence of the libtheora headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtheora.
-
-
For more information about the libtheora project see
-http://www.theora.org/ .
-
-
-
18.1.1 Options# TOC
-
-
The following global options are mapped to internal libtheora options
-which affect the quality and the bitrate of the encoded stream.
-
-
-b Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
-case VBR (Variable Bit Rate) mode is enabled this option is ignored.
-
-flags Used to enable constant quality mode (VBR) encoding through the
-qscale flag, and to enable the pass1 and pass2
-modes.
-
-g Set the GOP size.
-
-global_quality Set the global quality as an integer in lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
-value in the native libtheora range [0-63]. A higher value corresponds
-to a higher quality.
-
-q Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value is clipped in the [0-10] range, and then multiplied by 6.3
-to get a value in the native libtheora range [0-63].
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
18.1.2 Examples# TOC
-
-
- Set maximum constant quality (VBR) encoding with ffmpeg:
-
-
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
- Use ffmpeg to convert a CBR 1000 kbps Theora video stream:
-
-
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
-
-
-
-
18.2 libvpx# TOC
-
-
VP8/VP9 format supported through libvpx.
-
-
Requires the presence of the libvpx headers and library during configuration.
-You need to explicitly configure the build with --enable-libvpx.
-
-
-
18.2.1 Options# TOC
-
-
Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
-
-
-threads g_threads
-
-profile g_profile
-
-vb rc_target_bitrate
-
-g kf_max_dist
-
-keyint_min kf_min_dist
-
-qmin rc_min_quantizer
-
-qmax rc_max_quantizer
-
-bufsize, vb rc_buf_sz
-(bufsize * 1000 / vb)
-
-rc_buf_optimal_sz
-(bufsize * 1000 / vb * 5 / 6)
-
-rc_init_occupancy, vb rc_buf_initial_sz
-(rc_init_occupancy * 1000 / vb)
-
-rc_buffer_aggressivity rc_undershoot_pct
-
-skip_threshold rc_dropframe_thresh
-
-qcomp rc_2pass_vbr_bias_pct
-
-maxrate, vb rc_2pass_vbr_maxsection_pct
-(maxrate * 100 / vb)
-
-minrate, vb rc_2pass_vbr_minsection_pct
-(minrate * 100 / vb)
-
-minrate, maxrate, vb VPX_CBR
-(minrate == maxrate == vb)
-
-crf VPX_CQ, VP8E_SET_CQ_LEVEL
-
-quality
-best VPX_DL_BEST_QUALITY
-
good VPX_DL_GOOD_QUALITY
-
realtime VPX_DL_REALTIME
-
-
-speed VP8E_SET_CPUUSED
-
-nr VP8E_SET_NOISE_SENSITIVITY
-
-mb_threshold VP8E_SET_STATIC_THRESHOLD
-
-slices VP8E_SET_TOKEN_PARTITIONS
-
-max-intra-rate VP8E_SET_MAX_INTRA_BITRATE_PCT
-
-force_key_frames VPX_EFLAG_FORCE_KF
-
-Alternate reference frame related
-vp8flags altref VP8E_SET_ENABLEAUTOALTREF
-
arnr_max_frames VP8E_SET_ARNR_MAXFRAMES
-
arnr_type VP8E_SET_ARNR_TYPE
-
arnr_strength VP8E_SET_ARNR_STRENGTH
-
rc_lookahead g_lag_in_frames
-
-
-vp8flags error_resilient g_error_resilient
-
-aq_mode VP9E_SET_AQ_MODE
-
-
-
-
For more information about libvpx see:
-http://www.webmproject.org/
-
-
-
-
18.3 libwebp# TOC
-
-
libwebp WebP Image encoder wrapper
-
-
libwebp is Google’s official encoder for WebP images. It can encode in either
-lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
-frame. Lossless images are a separate codec developed by Google.
-
-
-
18.3.1 Pixel Format# TOC
-
-
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
-to limitations of the format and libwebp. Alpha is supported for either mode.
-Because of API limitations, if RGB is passed in when encoding lossy or YUV is
-passed in for encoding lossless, the pixel format will automatically be
-converted using functions from libwebp. This is not ideal and is done only for
-convenience.
-
-
-
18.3.2 Options# TOC
-
-
--lossless boolean Enables/Disables use of lossless mode. Default is 0.
-
--compression_level integer For lossy, this is a quality/speed tradeoff. Higher values give better quality
-for a given size at the cost of increased encoding time. For lossless, this is
-a size/speed tradeoff. Higher values give smaller size at the cost of increased
-encoding time. More specifically, it controls the number of extra algorithms
-and compression tools used, and varies the combination of these tools. This
-maps to the method option in libwebp. The valid range is 0 to 6.
-Default is 4.
-
--qscale float For lossy encoding, this controls image quality, 0 to 100. For lossless
-encoding, this controls the effort and time spent at compressing more. The
-default value is 75. Note that for usage via libavcodec, this option is called
-global_quality and must be multiplied by FF_QP2LAMBDA .
-
--preset type Configuration preset. This does some automatic settings based on the general
-type of the image.
-
-none Do not use a preset.
-
default Use the encoder default.
-
picture Digital picture, like portrait, inner shot
-
photo Outdoor photograph, with natural lighting
-
drawing Hand or line drawing, with high-contrast details
-
icon Small-sized colorful images
-
text Text-like
-
-
-
-
-
-
18.4 libx264, libx264rgb# TOC
-
-
x264 H.264/MPEG-4 AVC encoder wrapper.
-
-
This encoder requires the presence of the libx264 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx264.
-
-
libx264 supports an impressive number of features, including 8x8 and
-4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
-entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
-for detail retention (adaptive quantization, psy-RD, psy-trellis).
-
-
Many libx264 encoder options are mapped to FFmpeg global codec
-options, while unique encoder options are provided through private
-options. Additionally the x264opts and x264-params
-private options allows one to pass a list of key=value tuples as accepted
-by the libx264 x264_param_parse function.
-
-
The x264 project website is at
-http://www.videolan.org/developers/x264.html .
-
-
The libx264rgb encoder is the same as libx264, except it accepts packed RGB
-pixel formats as input instead of YUV.
-
-
-
18.4.1 Supported Pixel Formats# TOC
-
-
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
-x264’s configure time. FFmpeg only supports one bit depth in one particular
-build. In other words, it is not possible to build one FFmpeg with multiple
-versions of x264 with different bit depths.
-
-
-
18.4.2 Options# TOC
-
-
The following options are supported by the libx264 wrapper. The
-x264-equivalent options or values are listed in parentheses
-for easy migration.
-
-
To reduce the duplication of documentation, only the private options
-and some others requiring special attention are documented here. For
-the documentation of the undocumented generic options, see
-the Codec Options chapter .
-
-
To get a more accurate and extensive documentation of the libx264
-options, invoke the command x264 --full-help or consult
-the libx264 documentation.
-
-
-b (bitrate ) Set bitrate in bits/s. Note that FFmpeg’s b option is
-expressed in bits/s, while x264’s bitrate is in
-kilobits/s.
-
-bf (bframes ) g (keyint ) qmin (qpmin ) Minimum quantizer scale.
-
-qmax (qpmax ) Maximum quantizer scale.
-
-qdiff (qpstep ) Maximum difference between quantizer scales.
-
-qblur (qblur ) Quantizer curve blur
-
-qcomp (qcomp ) Quantizer curve compression factor
-
-refs (ref ) Number of reference frames each P-frame can use. The range is from 0-16 .
-
-sc_threshold (scenecut ) Sets the threshold for the scene change detection.
-
-trellis (trellis ) Performs Trellis quantization to increase efficiency. Enabled by default.
-
-nr (nr ) me_range (merange ) Maximum range of the motion search in pixels.
-
-me_method (me ) Set motion estimation method. Possible values in the decreasing order
-of speed:
-
-
-‘dia (dia ) ’
-‘epzs (dia ) ’
-Diamond search with radius 1 (fastest). ‘epzs ’ is an alias for
-‘dia ’.
-
‘hex (hex ) ’
-Hexagonal search with radius 2.
-
‘umh (umh ) ’
-Uneven multi-hexagon search.
-
‘esa (esa ) ’
-Exhaustive search.
-
‘tesa (tesa ) ’
-Hadamard exhaustive search (slowest).
-
-
-subq (subme ) Sub-pixel motion estimation method.
-
-b_strategy (b-adapt ) Adaptive B-frame placement decision algorithm. Use only on first-pass.
-
-keyint_min (min-keyint ) Minimum GOP size.
-
-coder Set entropy encoder. Possible values:
-
-
-‘ac ’
-Enable CABAC.
-
-‘vlc ’
-Enable CAVLC and disable CABAC. It generates the same effect as
-x264’s --no-cabac option.
-
-
-cmp Set full pixel motion estimation comparation algorithm. Possible values:
-
-
-‘chroma ’
-Enable chroma in motion estimation.
-
-‘sad ’
-Ignore chroma in motion estimation. It generates the same effect as
-x264’s --no-chroma-me option.
-
-
-threads (threads ) Number of encoding threads.
-
-thread_type Set multithreading technique. Possible values:
-
-
-‘slice ’
-Slice-based multithreading. It generates the same effect as
-x264’s --sliced-threads option.
-
‘frame ’
-Frame-based multithreading.
-
-
-flags Set encoding flags. It can be used to disable closed GOP and enable
-open GOP by setting it to -cgop. The result is similar to
-the behavior of x264’s --open-gop option.
-
-rc_init_occupancy (vbv-init ) preset (preset ) Set the encoding preset.
-
-tune (tune ) Set tuning of the encoding params.
-
-profile (profile ) Set profile restrictions.
-
-fastfirstpass Enable fast settings when encoding first pass, when set to 1. When set
-to 0, it has the same effect of x264’s
---slow-firstpass option.
-
-crf (crf ) Set the quality for constant quality mode.
-
-crf_max (crf-max ) In CRF mode, prevents VBV from lowering quality beyond this point.
-
-qp (qp ) Set constant quantization rate control method parameter.
-
-aq-mode (aq-mode ) Set AQ method. Possible values:
-
-
-‘none (0 ) ’
-Disabled.
-
-‘variance (1 ) ’
-Variance AQ (complexity mask).
-
-‘autovariance (2 ) ’
-Auto-variance AQ (experimental).
-
-
-aq-strength (aq-strength ) Set AQ strength, reduce blocking and blurring in flat and textured areas.
-
-psy Use psychovisual optimizations when set to 1. When set to 0, it has the
-same effect as x264’s --no-psy option.
-
-psy-rd (psy-rd ) Set strength of psychovisual optimization, in
-psy-rd :psy-trellis format.
-
-rc-lookahead (rc-lookahead ) Set number of frames to look ahead for frametype and ratecontrol.
-
-weightb Enable weighted prediction for B-frames when set to 1. When set to 0,
-it has the same effect as x264’s --no-weightb option.
-
-weightp (weightp ) Set weighted prediction method for P-frames. Possible values:
-
-
-‘none (0 ) ’
-Disabled
-
‘simple (1 ) ’
-Enable only weighted refs
-
‘smart (2 ) ’
-Enable both weighted refs and duplicates
-
-
-ssim (ssim ) Enable calculation and printing SSIM stats after the encoding.
-
-intra-refresh (intra-refresh ) Enable the use of Periodic Intra Refresh instead of IDR frames when set
-to 1.
-
-avcintra-class (class ) Configure the encoder to generate AVC-Intra.
-Valid values are 50,100 and 200
-
-bluray-compat (bluray-compat ) Configure the encoder to be compatible with the bluray standard.
-It is a shorthand for setting "bluray-compat=1 force-cfr=1".
-
-b-bias (b-bias ) Set the influence on how often B-frames are used.
-
-b-pyramid (b-pyramid ) Set method for keeping of some B-frames as references. Possible values:
-
-
-‘none (none ) ’
-Disabled.
-
‘strict (strict ) ’
-Strictly hierarchical pyramid.
-
‘normal (normal ) ’
-Non-strict (not Blu-ray compatible).
-
-
-mixed-refs Enable the use of one reference per partition, as opposed to one
-reference per macroblock when set to 1. When set to 0, it has the
-same effect as x264’s --no-mixed-refs option.
-
-8x8dct Enable adaptive spatial transform (high profile 8x8 transform)
-when set to 1. When set to 0, it has the same effect as
-x264’s --no-8x8dct option.
-
-fast-pskip Enable early SKIP detection on P-frames when set to 1. When set
-to 0, it has the same effect as x264’s
---no-fast-pskip option.
-
-aud (aud ) Enable use of access unit delimiters when set to 1.
-
-mbtree Enable use macroblock tree ratecontrol when set to 1. When set
-to 0, it has the same effect as x264’s
---no-mbtree option.
-
-deblock (deblock ) Set loop filter parameters, in alpha :beta form.
-
-cplxblur (cplxblur ) Set fluctuations reduction in QP (before curve compression).
-
-partitions (partitions ) Set partitions to consider as a comma-separated list of. Possible
-values in the list:
-
-
-‘p8x8 ’
-8x8 P-frame partition.
-
‘p4x4 ’
-4x4 P-frame partition.
-
‘b8x8 ’
-4x4 B-frame partition.
-
‘i8x8 ’
-8x8 I-frame partition.
-
‘i4x4 ’
-4x4 I-frame partition.
-(Enabling ‘p4x4 ’ requires ‘p8x8 ’ to be enabled. Enabling
-‘i8x8 ’ requires adaptive spatial transform (8x8dct
-option) to be enabled.)
-
‘none (none ) ’
-Do not consider any partitions.
-
‘all (all ) ’
-Consider every partition.
-
-
-direct-pred (direct ) Set direct MV prediction mode. Possible values:
-
-
-‘none (none ) ’
-Disable MV prediction.
-
‘spatial (spatial ) ’
-Enable spatial predicting.
-
‘temporal (temporal ) ’
-Enable temporal predicting.
-
‘auto (auto ) ’
-Automatically decided.
-
-
-slice-max-size (slice-max-size ) Set the limit of the size of each slice in bytes. If not specified
-but RTP payload size (ps ) is specified, that is used.
-
-stats (stats ) Set the file name for multi-pass stats.
-
-nal-hrd (nal-hrd ) Set signal HRD information (requires vbv-bufsize to be set).
-Possible values:
-
-
-‘none (none ) ’
-Disable HRD information signaling.
-
‘vbr (vbr ) ’
-Variable bit rate.
-
‘cbr (cbr ) ’
-Constant bit rate (not allowed in MP4 container).
-
-
-x264opts (N.A.) Set any x264 option, see x264 --fullhelp for a list.
-
-Argument is a list of key =value couples separated by
-":". In filter and psy-rd options that use ":" as a separator
-themselves, use "," instead. They accept it as well since long ago but this
-is kept undocumented for some reason.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
- x264-params (N.A.) Override the x264 configuration using a :-separated list of key=value
-parameters.
-
-This option is functionally the same as the x264opts , but is
-duplicated for compatibility with the Libav fork.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
-cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
-no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
-
-
-
Encoding ffpresets for common usages are provided so they can be used with the
-general presets system (e.g. passing the pre option).
-
-
-
18.5 libx265# TOC
-
-
x265 H.265/HEVC encoder wrapper.
-
-
This encoder requires the presence of the libx265 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx265 .
-
-
-
18.5.1 Options# TOC
-
-
-preset Set the x265 preset.
-
-tune Set the x265 tune parameter.
-
-x265-params Set x265 options using a list of key =value couples separated
-by ":". See x265 --help for a list of options.
-
-For example to specify libx265 encoding options with -x265-params :
-
-
-
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
-
-
-
-
18.6 libxvid# TOC
-
-
Xvid MPEG-4 Part 2 encoder wrapper.
-
-
This encoder requires the presence of the libxvidcore headers and library
-during configuration. You need to explicitly configure the build with
---enable-libxvid --enable-gpl.
-
-
The native mpeg4 encoder supports the MPEG-4 Part 2 format, so
-users can encode to this format without this library.
-
-
-
18.6.1 Options# TOC
-
-
The following options are supported by the libxvid wrapper. Some of
-the following options are listed but are not documented, and
-correspond to shared codec options. See the Codec
-Options chapter for their documentation. The other shared options
-which are not listed have no effect for the libxvid encoder.
-
-
-b g qmin qmax mpeg_quant threads bf b_qfactor b_qoffset flags Set specific encoding flags. Possible values:
-
-
-‘mv4 ’
-Use four motion vector by macroblock.
-
-‘aic ’
-Enable high quality AC prediction.
-
-‘gray ’
-Only encode grayscale.
-
-‘gmc ’
-Enable the use of global motion compensation (GMC).
-
-‘qpel ’
-Enable quarter-pixel motion compensation.
-
-‘cgop ’
-Enable closed GOP.
-
-‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
-
-
-trellis me_method Set motion estimation method. Possible values in decreasing order of
-speed and increasing order of quality:
-
-
-‘zero ’
-Use no motion estimation (default).
-
-‘phods ’
-‘x1 ’
-‘log ’
-Enable advanced diamond zonal search for 16x16 blocks and half-pixel
-refinement for 16x16 blocks. ‘x1 ’ and ‘log ’ are aliases for
-‘phods ’.
-
-‘epzs ’
-Enable all of the things described above, plus advanced diamond zonal
-search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
-estimation on chroma planes.
-
-‘full ’
-Enable all of the things described above, plus extended 16x16 and 8x8
-blocks search.
-
-
-mbd Set macroblock decision algorithm. Possible values in the increasing
-order of quality:
-
-
-‘simple ’
-Use macroblock comparing function algorithm (default).
-
-‘bits ’
-Enable rate distortion-based half pixel and quarter pixel refinement for
-16x16 blocks.
-
-‘rd ’
-Enable all of the things described above, plus rate distortion-based
-half pixel and quarter pixel refinement for 8x8 blocks, and rate
-distortion-based search using square pattern.
-
-
-lumi_aq Enable lumi masking adaptive quantization when set to 1. Default is 0
-(disabled).
-
-variance_aq Enable variance adaptive quantization when set to 1. Default is 0
-(disabled).
-
-When combined with lumi_aq , the resulting quality will not
-be better than any of the two specified individually. In other
-words, the resulting quality will be the worse one of the two
-effects.
-
-ssim Set structural similarity (SSIM) displaying method. Possible values:
-
-
-‘off ’
-Disable displaying of SSIM information.
-
-‘avg ’
-Output average SSIM at the end of encoding to stdout. The format of
-showing the average SSIM is:
-
-
-
-For users who are not familiar with C, %f means a float number, or
-a decimal (e.g. 0.939232).
-
-‘frame ’
-Output both per-frame SSIM data during encoding and average SSIM at
-the end of encoding to stdout. The format of per-frame information
-is:
-
-
-
SSIM: avg: %1.3f min: %1.3f max: %1.3f
- For users who are not familiar with C, %1.3f means a float number
-rounded to 3 digits after the dot (e.g. 0.932).
-
-
-
-ssim_acc Set SSIM accuracy. Valid options are integers within the range of
-0-4, while 0 gives the most accurate result and 4 computes the
-fastest.
-
-
-
-
-
18.7 mpeg2# TOC
-
-
MPEG-2 video encoder.
-
-
-
18.7.1 Options# TOC
-
-
-seq_disp_ext integer Specifies if the encoder should write a sequence_display_extension to the
-output.
-
--1 auto Decide automatically to write it or not (this is the default) by checking if
-the data to be written is different from the default or unspecified values.
-
0 never Never write it.
-
1 always Always write it.
-
-
-
-
-
18.8 png# TOC
-
-
PNG image encoder.
-
-
-
18.8.1 Private options# TOC
-
-
-dpi integer Set physical density of pixels, in dots per inch, unset by default
-
dpm integer Set physical density of pixels, in dots per meter, unset by default
-
-
-
-
18.9 ProRes# TOC
-
-
Apple ProRes encoder.
-
-
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
-The used encoder can be chosen with the -vcodec option.
-
-
-
18.9.1 Private Options for prores-ks# TOC
-
-
-profile integer Select the ProRes profile to encode
-
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-‘4444 ’
-
-
-quant_mat integer Select quantization matrix.
-
-‘auto ’
-‘default ’
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-
-If set to auto , the matrix matching the profile will be picked.
-If not set, the matrix providing the highest quality, default , will be
-picked.
-
-bits_per_mb integer How many bits to allot for coding one macroblock. Different profiles use
-between 200 and 2400 bits per macroblock, the maximum is 8000.
-
-mbs_per_slice integer Number of macroblocks in each slice (1-8); the default value (8)
-should be good in almost all situations.
-
-vendor string Override the 4-byte vendor ID.
-A custom vendor ID like apl0 would claim the stream was produced by
-the Apple encoder.
-
-alpha_bits integer Specify number of bits for alpha component.
-Possible values are 0 , 8 and 16 .
-Use 0 to disable alpha plane coding.
-
-
-
-
-
18.9.2 Speed considerations# TOC
-
-
In the default mode of operation the encoder has to honor frame constraints
-(i.e. not produce frames with size bigger than requested) while still making
-output picture as good as possible.
-A frame containing a lot of small details is harder to compress and the encoder
-would spend more time searching for appropriate quantizers for each slice.
-
-
Setting a higher bits_per_mb limit will improve the speed.
-
-
For the fastest encoding speed set the qscale parameter (4 is the
-recommended value) and do not set a size constraint.
-
-
-
-
19 Subtitles Encoders# TOC
-
-
-
19.1 dvdsub# TOC
-
-
This codec encodes the bitmap subtitle format that is used in DVDs.
-Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
-and they can also be used in Matroska files.
-
-
-
19.1.1 Options# TOC
-
-
-even_rows_fix When set to 1, enable a work-around that makes the number of pixel rows
-even in all subtitles. This fixes a problem with some players that
-cut off the bottom row if the number is odd. The work-around just adds
-a fully transparent row if needed. The overhead is low, typically
-one byte per subtitle on average.
-
-By default, this work-around is disabled.
-
-
-
-
20 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
20.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
20.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
20.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
20.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
20.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
20.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
20.7 mjpega_dump_header# TOC
-
-
-
20.8 movsub# TOC
-
-
-
20.9 mp3_header_decompress# TOC
-
-
-
20.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
20.11 remove_extra# TOC
-
-
-
21 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
21.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
22 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
22.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
22.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
22.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
22.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
22.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
22.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
22.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
22.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
22.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
22.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
22.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
22.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
22.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
22.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
22.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
22.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
23 Muxers# TOC
-
-
Muxers are configured elements in FFmpeg which allow writing
-multimedia streams to a particular type of file.
-
-
When you configure your FFmpeg build, all the supported muxers
-are enabled by default. You can list all available muxers using the
-configure option --list-muxers.
-
-
You can disable all the muxers with the configure option
---disable-muxers and selectively enable / disable single muxers
-with the options --enable-muxer=MUXER /
---disable-muxer=MUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled muxers.
-
-
A description of some of the currently available muxers follows.
-
-
-
23.1 aiff# TOC
-
-
Audio Interchange File Format muxer.
-
-
-
23.1.1 Options# TOC
-
-
It accepts the following options:
-
-
-write_id3v2 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
-
-id3v2_version Select ID3v2 version to write. Currently only version 3 and 4 (aka.
-ID3v2.3 and ID3v2.4) are supported. The default is version 4.
-
-
-
-
-
23.2 crc# TOC
-
-
CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a single line of the form:
-CRC=0xCRC , where CRC is a hexadecimal number 0-padded to
-8 digits containing the CRC for all the decoded input frames.
-
-
See also the framecrc muxer.
-
-
-
23.2.1 Examples# TOC
-
-
For example to compute the CRC of the input, and store it in the file
-out.crc :
-
-
ffmpeg -i INPUT -f crc out.crc
-
-
-
You can print the CRC to stdout with the command:
-
-
ffmpeg -i INPUT -f crc -
-
-
-
You can select the output format of each frame with ffmpeg by
-specifying the audio and video codec and format. For example to
-compute the CRC of the input audio converted to PCM unsigned 8-bit
-and the input video converted to MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
-
-
-
-
23.3 framecrc# TOC
-
-
Per-packet CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , 0xCRC
-
-
-
CRC is a hexadecimal number 0-padded to 8 digits containing the
-CRC of the packet.
-
-
-
23.3.1 Examples# TOC
-
-
For example to compute the CRC of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.crc :
-
-
ffmpeg -i INPUT -f framecrc out.crc
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framecrc -
-
-
-
With ffmpeg, you can select the output format to which the
-audio and video frames are encoded before computing the CRC for each
-packet by specifying the audio and video codec. For example, to
-compute the CRC of each decoded input audio frame converted to PCM
-unsigned 8-bit and of each decoded input video frame converted to
-MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
-
-
-
See also the crc muxer.
-
-
-
23.4 framemd5# TOC
-
-
Per-packet MD5 testing format.
-
-
This muxer computes and prints the MD5 hash for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , MD5
-
-
-
MD5 is a hexadecimal number representing the computed MD5 hash
-for the packet.
-
-
-
23.4.1 Examples# TOC
-
-
For example to compute the MD5 of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.md5 :
-
-
ffmpeg -i INPUT -f framemd5 out.md5
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framemd5 -
-
-
-
See also the md5 muxer.
-
-
-
23.5 gif# TOC
-
-
Animated GIF muxer.
-
-
It accepts the following options:
-
-
-loop Set the number of times to loop the output. Use -1 for no loop, 0
-for looping indefinitely (default).
-
-final_delay Force the delay (expressed in centiseconds) after the last frame. Each frame
-ends with a delay until the next frame. The default is -1, which is a
-special value to tell the muxer to re-use the previous delay. In case of a
-loop, you might want to customize this value to mark a pause for instance.
-
-
-
For example, to encode a gif looping 10 times, with a 5 seconds delay between
-the loops:
-
-
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
-
-
-
Note 1: if you wish to extract the frames in separate GIF files, you need to
-force the image2 muxer:
-
-
ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
-
-
-
Note 2: the GIF format has a very small time base: the delay between two frames
-can not be smaller than one centi second.
-
-
-
23.6 hls# TOC
-
-
Apple HTTP Live Streaming muxer that segments MPEG-TS according to
-the HTTP Live Streaming (HLS) specification.
-
-
It creates a playlist file, and one or more segment files. The output filename
-specifies the playlist filename.
-
-
By default, the muxer creates a file for each segment produced. These files
-have the same name as the playlist, followed by a sequential number and a
-.ts extension.
-
-
For example, to convert an input file with ffmpeg:
-
-
ffmpeg -i in.nut out.m3u8
-
-
This example will produce the playlist, out.m3u8 , and segment files:
-out0.ts , out1.ts , out2.ts , etc.
-
-
See also the segment muxer, which provides a more generic and
-flexible implementation of a segmenter, and can be used to perform HLS
-segmentation.
-
-
-
23.6.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-hls_time seconds Set the segment length in seconds. Default value is 2.
-
-hls_list_size size Set the maximum number of playlist entries. If set to 0 the list file
-will contain all the segments. Default value is 5.
-
-hls_ts_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing : special characters must be
-escaped.
-
-hls_wrap wrap Set the number after which the segment filename number (the number
-specified in each segment file) wraps. If set to 0 the number will be
-never wrapped. Default value is 0.
-
-This option is useful to avoid to fill the disk with many segment
-files, and limits the maximum number of segment files written to disk
-to wrap .
-
-start_number number Start the playlist sequence number from number . Default value is
-0.
-
-hls_allow_cache allowcache Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
-
-hls_base_url baseurl Append baseurl to every entry in the playlist.
-Useful to generate playlists with absolute paths.
-
-Note that the playlist sequence number must be unique for each segment
-and it is not to be confused with the segment filename sequence number
-which can be cyclic, for example if the wrap option is
-specified.
-
-hls_segment_filename filename Set the segment filename. Unless hls_flags single_file is set filename
-is used as a string format with the segment number:
-
-
ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
- This example will produce the playlist, out.m3u8 , and segment files:
-file000.ts , file001.ts , file002.ts , etc.
-
-hls_flags single_file If this flag is set, the muxer will store all segments in a single MPEG-TS
-file, and will use byte ranges in the playlist. HLS playlists generated with
-this way will have the version number 4.
-For example:
-
-
ffmpeg -i in.nut -hls_flags single_file out.m3u8
- Will produce the playlist, out.m3u8 , and a single segment file,
-out.ts .
-
-hls_flags delete_segments Segment files removed from the playlist are deleted after a period of time
-equal to the duration of the segment plus the duration of the playlist.
-
-
-
-
23.7 ico# TOC
-
-
ICO file muxer.
-
-
Microsoft’s icon file format (ICO) has some strict limitations that should be noted:
-
-
- Size cannot exceed 256 pixels in any dimension
-
- Only BMP and PNG images can be stored
-
- If a BMP image is used, it must be one of the following pixel formats:
-
-
BMP Bit Depth FFmpeg Pixel Format
-1bit pal8
-4bit pal8
-8bit pal8
-16bit rgb555le
-24bit bgr24
-32bit bgra
- If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
-
- If a PNG image is used, it must use the rgba pixel format
-
-
-
-
23.8 image2# TOC
-
-
Image file muxer.
-
-
The image file muxer writes video frames to image files.
-
-
The output filenames are specified by a pattern, which can be used to
-produce sequentially numbered series of files.
-The pattern may contain the string "%d" or "%0N d", this string
-specifies the position of the characters representing a numbering in
-the filenames. If the form "%0N d" is used, the string
-representing the number in each filename is 0-padded to N
-digits. The literal character ’%’ can be specified in the pattern with
-the string "%%".
-
-
If the pattern contains "%d" or "%0N d", the first filename of
-the file list specified will contain the number 1, all the following
-numbers will be sequential.
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the image files to write.
-
-
For example the pattern "img-%03d.bmp" will specify a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.
-The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
-form img%-1.jpg , img%-2.jpg , ..., img%-10.jpg ,
-etc.
-
-
-
23.8.1 Examples# TOC
-
-
The following example shows how to use ffmpeg for creating a
-sequence of files img-001.jpeg , img-002.jpeg , ...,
-taking one image every second from the input video:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
-
-
-
Note that with ffmpeg, if the format is not specified with the
--f option and the output filename specifies an image file
-format, the image2 muxer is automatically selected, so the previous
-command can be written as:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
-
-
-
Note also that the pattern must not necessarily contain "%d" or
-"%0N d", for example to create a single image file
-img.jpeg from the input video you can employ the command:
-
-
ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
-
-
-
The strftime option allows you to expand the filename with
-date and time information. Check the documentation of
-the strftime() function for the syntax.
-
-
For example to generate image files from the strftime()
-"%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command
-can be used:
-
-
ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
-
-
-
-
23.8.2 Options# TOC
-
-
-start_number Start the sequence from the specified number. Default value is 1. Must
-be a non-negative number.
-
-update If set to 1, the filename will always be interpreted as just a
-filename, not a pattern, and the corresponding file will be continuously
-overwritten with new images. Default value is 0.
-
-strftime If set to 1, expand the filename with date and time information from
-strftime(). Default value is 0.
-
-
-
The image muxer supports the .Y.U.V image file format. This format is
-special in that that each image frame consists of three files, for
-each of the YUV420P components. To read or write this image file format,
-specify the name of the ’.Y’ file. The muxer will automatically open the
-’.U’ and ’.V’ files as required.
-
-
-
23.9 matroska# TOC
-
-
Matroska container muxer.
-
-
This muxer implements the matroska and webm container specs.
-
-
-
23.9.1 Metadata# TOC
-
-
The recognized metadata settings in this muxer are:
-
-
-title Set title name provided to a single track.
-
-language Specify the language of the track in the Matroska languages form.
-
-The language can be either the 3 letters bibliographic ISO-639-2 (ISO
-639-2/B) form (like "fre" for French), or a language code mixed with a
-country code for specialities in languages (like "fre-ca" for Canadian
-French).
-
-stereo_mode Set stereo 3D video layout of two views in a single video track.
-
-The following values are recognized:
-
-‘mono ’
-video is not stereo
-
‘left_right ’
-Both views are arranged side by side, Left-eye view is on the left
-
‘bottom_top ’
-Both views are arranged in top-bottom orientation, Left-eye view is at bottom
-
‘top_bottom ’
-Both views are arranged in top-bottom orientation, Left-eye view is on top
-
‘checkerboard_rl ’
-Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
-
‘checkerboard_lr ’
-Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
-
‘row_interleaved_rl ’
-Each view is constituted by a row based interleaving, Right-eye view is first row
-
‘row_interleaved_lr ’
-Each view is constituted by a row based interleaving, Left-eye view is first row
-
‘col_interleaved_rl ’
-Both views are arranged in a column based interleaving manner, Right-eye view is first column
-
‘col_interleaved_lr ’
-Both views are arranged in a column based interleaving manner, Left-eye view is first column
-
‘anaglyph_cyan_red ’
-All frames are in anaglyph format viewable through red-cyan filters
-
‘right_left ’
-Both views are arranged side by side, Right-eye view is on the left
-
‘anaglyph_green_magenta ’
-All frames are in anaglyph format viewable through green-magenta filters
-
‘block_lr ’
-Both eyes laced in one Block, Left-eye view is first
-
‘block_rl ’
-Both eyes laced in one Block, Right-eye view is first
-
-
-
-
For example a 3D WebM clip can be created using the following command line:
-
-
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
-
-
-
-
23.9.2 Options# TOC
-
-
This muxer supports the following options:
-
-
-reserve_index_space By default, this muxer writes the index for seeking (called cues in Matroska
-terms) at the end of the file, because it cannot know in advance how much space
-to leave for the index at the beginning of the file. However for some use cases
-– e.g. streaming where seeking is possible but slow – it is useful to put the
-index at the beginning of the file.
-
-If this option is set to a non-zero value, the muxer will reserve a given amount
-of space in the file header and then try to write the cues there when the muxing
-finishes. If the available space does not suffice, muxing will fail. A safe size
-for most use cases should be about 50kB per hour of video.
-
-Note that cues are only written if the output is seekable and this option will
-have no effect if it is not.
-
-
-
-
23.10 md5# TOC
-
-
MD5 testing format.
-
-
This muxer computes and prints the MD5 hash of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a single line of the form:
-MD5=MD5 , where MD5 is a hexadecimal number representing
-the computed MD5 hash.
-
-
For example to compute the MD5 hash of the input converted to raw
-audio and video, and store it in the file out.md5 :
-
-
ffmpeg -i INPUT -f md5 out.md5
-
-
-
You can print the MD5 to stdout with the command:
-
-
ffmpeg -i INPUT -f md5 -
-
-
-
See also the framemd5 muxer.
-
-
-
23.11 mov, mp4, ismv# TOC
-
-
MOV/MP4/ISMV (Smooth Streaming) muxer.
-
-
The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
-file has all the metadata about all packets stored in one location
-(written at the end of the file, it can be moved to the start for
-better playback by adding faststart to the movflags , or
-using the qt-faststart tool). A fragmented
-file consists of a number of fragments, where packets and metadata
-about these packets are stored together. Writing a fragmented
-file has the advantage that the file is decodable even if the
-writing is interrupted (while a normal MOV/MP4 is undecodable if
-it is not properly finished), and it requires less memory when writing
-very long files (since writing normal MOV/MP4 files stores info about
-every single packet in memory until the file is closed). The downside
-is that it is less compatible with other applications.
-
-
-
23.11.1 Options# TOC
-
-
Fragmentation is enabled by setting one of the AVOptions that define
-how to cut the file into fragments:
-
-
--moov_size bytes Reserves space for the moov atom at the beginning of the file instead of placing the
-moov atom at the end. If the space reserved is insufficient, muxing will fail.
-
-movflags frag_keyframe Start a new fragment at each video keyframe.
-
-frag_duration duration Create fragments that are duration microseconds long.
-
-frag_size size Create fragments that contain up to size bytes of payload data.
-
-movflags frag_custom Allow the caller to manually choose when to cut fragments, by
-calling av_write_frame(ctx, NULL) to write a fragment with
-the packets written so far. (This is only useful with other
-applications integrating libavformat, not from ffmpeg.)
-
-min_frag_duration duration Don’t create fragments that are shorter than duration microseconds long.
-
-
-
If more than one condition is specified, fragments are cut when
-one of the specified conditions is fulfilled. The exception to this is
--min_frag_duration, which has to be fulfilled for any of the other
-conditions to apply.
-
-
Additionally, the way the output file is written can be adjusted
-through a few other options:
-
-
--movflags empty_moov Write an initial moov atom directly at the start of the file, without
-describing any samples in it. Generally, an mdat/moov pair is written
-at the start of the file, as a normal MOV/MP4 file, containing only
-a short portion of the file. With this option set, there is no initial
-mdat atom, and the moov atom only describes the tracks but has
-a zero duration.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags separate_moof Write a separate moof (movie fragment) atom for each track. Normally,
-packets for all tracks are written in a moof atom (which is slightly
-more efficient), but with this option set, the muxer writes one moof/mdat
-pair for each track, making it easier to separate tracks.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags faststart Run a second pass moving the index (moov atom) to the beginning of the file.
-This operation can take a while, and will not work in various situations such
-as fragmented output, thus it is not enabled by default.
-
-movflags rtphint Add RTP hinting tracks to the output file.
-
-movflags disable_chpl Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
-and a QuickTime chapter track are written to the file. With this option
-set, only the QuickTime chapter track will be written. Nero chapters can
-cause failures when the file is reprocessed with certain tagging programs, like
-mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
-
-movflags omit_tfhd_offset Do not write any absolute base_data_offset in tfhd atoms. This avoids
-tying fragments to absolute byte positions in the file/streams.
-
-movflags default_base_moof Similarly to the omit_tfhd_offset, this flag avoids writing the
-absolute base_data_offset field in tfhd atoms, but does so by using
-the new default-base-is-moof flag instead. This flag is new from
-14496-12:2012. This may make the fragments easier to parse in certain
-circumstances (avoiding basing track fragment location calculations
-on the implicit end of the previous track fragment).
-
-
-
-
23.11.2 Example# TOC
-
-
Smooth Streaming content can be pushed in real time to a publishing
-point on IIS with this muxer. Example:
-
-
ffmpeg -re <normal input/transcoding options> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
-
-
-
-
23.12 mp3# TOC
-
-
The MP3 muxer writes a raw MP3 stream with the following optional features:
-
- An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
-2.4 are supported, the id3v2_version private option controls which one is
-used (3 or 4). Setting id3v2_version to 0 disables the ID3v2 header
-completely.
-
-The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
-The pictures are supplied to the muxer in form of a video stream with a single
-packet. There can be any number of those streams, each will correspond to a
-single APIC frame. The stream metadata tags title and comment map
-to APIC description and picture type respectively. See
-http://id3.org/id3v2.4.0-frames for allowed picture types.
-
-Note that the APIC frames must be written at the beginning, so the muxer will
-buffer the audio frames until it gets all the pictures. It is therefore advised
-to provide the pictures as soon as possible to avoid excessive buffering.
-
- A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
-default, but will be written only if the output is seekable. The
-write_xing private option can be used to disable it. The frame contains
-various information that may be useful to the decoder, like the audio duration
-or encoder delay.
-
- A legacy ID3v1 tag at the end of the file (disabled by default). It may be
-enabled with the write_id3v1 private option, but as its capabilities are
-very limited, its usage is not recommended.
-
-
-
Examples:
-
-
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
-
-
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
-
-
-
To attach a picture to an mp3 file select both the audio and the picture stream
-with map:
-
-
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
--metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
-
-
-
Write a "clean" MP3 without any extra features:
-
-
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
-
-
-
-
23.13 mpegts# TOC
-
-
MPEG transport stream muxer.
-
-
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
-
-
The recognized metadata settings in mpegts muxer are service_provider
-and service_name. If they are not set the default for
-service_provider is "FFmpeg" and the default for
-service_name is "Service01".
-
-
-
23.13.1 Options# TOC
-
-
The muxer options are:
-
-
--mpegts_original_network_id number Set the original_network_id (default 0x0001). This is unique identifier
-of a network in DVB. Its main use is in the unique identification of a
-service through the path Original_Network_ID, Transport_Stream_ID.
-
-mpegts_transport_stream_id number Set the transport_stream_id (default 0x0001). This identifies a
-transponder in DVB.
-
-mpegts_service_id number Set the service_id (default 0x0001) also known as program in DVB.
-
-mpegts_pmt_start_pid number Set the first PID for PMT (default 0x1000, max 0x1f00).
-
-mpegts_start_pid number Set the first PID for data packets (default 0x0100, max 0x0f00).
-
-mpegts_m2ts_mode number Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
-
-muxrate number Set a constant muxrate (default VBR).
-
-pcr_period numer Override the default PCR retransmission time (default 20ms), ignored
-if variable muxrate is selected.
-
-pes_payload_size number Set minimum PES packet payload in bytes.
-
-mpegts_flags flags Set flags (see below).
-
-mpegts_copyts number Preserve original timestamps, if value is set to 1. Default value is -1, which
-results in shifting timestamps so that they start from 0.
-
-tables_version number Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
-This option allows updating stream structure so that standard consumer may
-detect the change. To do so, reopen output AVFormatContext (in case of API
-usage) or restart ffmpeg instance, cyclically changing tables_version value:
-
-
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
-ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-
-
-
Option mpegts_flags may take a set of such flags:
-
-
-resend_headers Reemit PAT/PMT before writing the next packet.
-
latm Use LATM packetization for AAC.
-
-
-
-
23.13.2 Example# TOC
-
-
-
ffmpeg -i file.mpg -c copy \
- -mpegts_original_network_id 0x1122 \
- -mpegts_transport_stream_id 0x3344 \
- -mpegts_service_id 0x5566 \
- -mpegts_pmt_start_pid 0x1500 \
- -mpegts_start_pid 0x150 \
- -metadata service_provider="Some provider" \
- -metadata service_name="Some Channel" \
- -y out.ts
-
-
-
-
23.14 null# TOC
-
-
Null muxer.
-
-
This muxer does not generate any output file, it is mainly useful for
-testing or benchmarking purposes.
-
-
For example to benchmark decoding with ffmpeg you can use the
-command:
-
-
ffmpeg -benchmark -i INPUT -f null out.null
-
-
-
Note that the above command does not read or write the out.null
-file, but specifying the output file is required by the ffmpeg
-syntax.
-
-
Alternatively you can write the command as:
-
-
ffmpeg -benchmark -i INPUT -f null -
-
-
-
-
23.15 nut# TOC
-
-
--syncpoints flags Change the syncpoint usage in nut:
-
-default use the normal low-overhead seeking aids.none do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;Use of this option is not recommended, as the resulting files are very damage
- sensitive and seeking is not possible. Also in general the overhead from
- syncpoints is negligible. Note, -write_index 0 can be used to disable
- all growing data tables, allowing to mux endless streams with limited memory
- and without these disadvantages.
-
timestamped extend the syncpoint with a wallclock field.
-The none and timestamped flags are experimental.
-
-write_index bool Write index at the end, the default is to write an index.
-
-
-
-
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
-
-
-
-
23.16 ogg# TOC
-
-
Ogg container muxer.
-
-
--page_duration duration Preferred page duration, in microseconds. The muxer will attempt to create
-pages that are approximately duration microseconds long. This allows the
-user to compromise between seek granularity and container overhead. The default
-is 1 second. A value of 0 will fill all segments, making pages as large as
-possible. A value of 1 will effectively use 1 packet-per-page in most
-situations, giving a small seek granularity at the cost of additional container
-overhead.
-
-
-
-
23.17 segment, stream_segment, ssegment# TOC
-
-
Basic stream segmenter.
-
-
This muxer outputs streams to a number of separate files of nearly
-fixed duration. Output filename pattern can be set in a fashion similar to
-image2 .
-
-
stream_segment is a variant of the muxer used to write to
-streaming output formats, i.e. which do not require global headers,
-and is recommended for outputting e.g. to MPEG transport stream segments.
-ssegment is a shorter alias for stream_segment.
-
-
Every segment starts with a keyframe of the selected reference stream,
-which is set through the reference_stream option.
-
-
Note that if you want accurate splitting for a video file, you need to
-make the input key frames correspond to the exact splitting times
-expected by the segmenter, or the segment muxer will start the new
-segment with the key frame found next after the specified start
-time.
-
-
The segment muxer works best with a single constant frame rate video.
-
-
Optionally it can generate a list of the created segments, by setting
-the option segment_list . The list type is specified by the
-segment_list_type option. The entry filenames in the segment
-list are set by default to the basename of the corresponding segment
-files.
-
-
See also the hls muxer, which provides a more specific
-implementation for HLS segmentation.
-
-
-
23.17.1 Options# TOC
-
-
The segment muxer supports the following options:
-
-
-reference_stream specifier Set the reference stream, as specified by the string specifier .
-If specifier is set to auto, the reference is chosen
-automatically. Otherwise it must be a stream specifier (see the “Stream
-specifiers” chapter in the ffmpeg manual) which specifies the
-reference stream. The default value is auto.
-
-segment_format format Override the inner container format, by default it is guessed by the filename
-extension.
-
-segment_format_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing the : special character must be
-escaped.
-
-segment_list name Generate also a listfile named name . If not specified no
-listfile is generated.
-
-segment_list_flags flags Set flags affecting the segment list generation.
-
-It currently supports the following flags:
-
-‘cache ’
-Allow caching (only affects M3U8 list files).
-
-‘live ’
-Allow live-friendly file generation.
-
-
-segment_list_type type Select the listing format.
-
-flat use a simple flat list of entries.hls use a m3u8-like structure.
-
-segment_list_size size Update the list file so that it contains at most size
-segments. If 0 the list file will contain all the segments. Default
-value is 0.
-
-segment_list_entry_prefix prefix Prepend prefix to each entry. Useful to generate absolute paths.
-By default no prefix is applied.
-
-The following values are recognized:
-
-‘flat ’
-Generate a flat list for the created segments, one segment per line.
-
-‘csv, ext ’
-Generate a list for the created segments, one segment per line,
-each line matching the format (comma-separated values):
-
-
segment_filename ,segment_start_time ,segment_end_time
-segment_filename is the name of the output file generated by the
-muxer according to the provided pattern. CSV escaping (according to
-RFC4180) is applied if required.
-
-segment_start_time and segment_end_time specify
-the segment start and end time expressed in seconds.
-
-A list file with the suffix ".csv" or ".ext" will
-auto-select this format.
-
-‘ext ’ is deprecated in favor or ‘csv ’.
-
-‘ffconcat ’
-Generate an ffconcat file for the created segments. The resulting file
-can be read using the FFmpeg concat demuxer.
-
-A list file with the suffix ".ffcat" or ".ffconcat" will
-auto-select this format.
-
-‘m3u8 ’
-Generate an extended M3U8 file, version 3, compliant with
-http://tools.ietf.org/id/draft-pantos-http-live-streaming .
-
-A list file with the suffix ".m3u8" will auto-select this format.
-
-
-If not specified the type is guessed from the list file name suffix.
-
-segment_time time Set segment duration to time , the value must be a duration
-specification. Default value is "2". See also the
-segment_times option.
-
-Note that splitting may not be accurate, unless you force the
-reference stream key-frames at the given time. See the introductory
-notice and the examples below.
-
-segment_atclocktime 1|0 If set to "1" split at regular clock time intervals starting from 00:00
-o’clock. The time value specified in segment_time is
-used for setting the length of the splitting interval.
-
-For example with segment_time set to "900" this makes it possible
-to create files at 12:00 o’clock, 12:15, 12:30, etc.
-
-Default value is "0".
-
-segment_time_delta delta Specify the accuracy time when selecting the start time for a
-segment, expressed as a duration specification. Default value is "0".
-
-When delta is specified a key-frame will start a new segment if its
-PTS satisfies the relation:
-
-
PTS >= start_time - time_delta
- This option is useful when splitting video content, which is always
-split at GOP boundaries, in case a key frame is found just before the
-specified split time.
-
-In particular may be used in combination with the ffmpeg option
-force_key_frames . The key frame times specified by
-force_key_frames may not be set accurately because of rounding
-issues, with the consequence that a key frame time may result set just
-before the specified time. For constant frame rate videos a value of
-1/(2*frame_rate ) should address the worst case mismatch between
-the specified time and the time set by force_key_frames .
-
-segment_times times Specify a list of split points. times contains a list of comma
-separated duration specifications, in increasing order. See also
-the segment_time option.
-
-segment_frames frames Specify a list of split video frame numbers. frames contains a
-list of comma separated integer numbers, in increasing order.
-
-This option specifies to start a new segment whenever a reference
-stream key frame is found and the sequential number (starting from 0)
-of the frame is greater or equal to the next value in the list.
-
-segment_wrap limit Wrap around segment index once it reaches limit .
-
-segment_start_number number Set the sequence number of the first segment. Defaults to 0.
-
-reset_timestamps 1|0 Reset timestamps at the begin of each segment, so that each segment
-will start with near-zero timestamps. It is meant to ease the playback
-of the generated segments. May not work with some combinations of
-muxers/codecs. It is set to 0 by default.
-
-initial_offset offset Specify timestamp offset to apply to the output packet timestamps. The
-argument must be a time duration specification, and defaults to 0.
-
-
-
-
23.17.2 Examples# TOC
-
-
-
-
-
23.18 smoothstreaming# TOC
-
-
Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
-
-
-window_size Specify the number of fragments kept in the manifest. Default 0 (keep all).
-
-extra_window_size Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
-
-lookahead_count Specify the number of lookahead fragments. Default 2.
-
-min_frag_duration Specify the minimum fragment duration (in microseconds). Default 5000000.
-
-remove_at_exit Specify whether to remove all fragments when finished. Default 0 (do not remove).
-
-
-
-
-
23.19 tee# TOC
-
-
The tee muxer can be used to write the same data to several files or any
-other kind of muxer. It can be used, for example, to both stream a video to
-the network and save it to disk at the same time.
-
-
It is different from specifying several outputs to the ffmpeg
-command-line tool because the audio and video data will be encoded only once
-with the tee muxer; encoding can be a very expensive process. It is not
-useful when using the libavformat API directly because it is then possible
-to feed the same packets to several muxers directly.
-
-
The slave outputs are specified in the file name given to the muxer,
-separated by ’|’. If any of the slave name contains the ’|’ separator,
-leading or trailing spaces or any special character, it must be
-escaped (see (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual ).
-
-
Muxer options can be specified for each slave by prepending them as a list of
-key =value pairs separated by ’:’, between square brackets. If
-the options values contain a special character or the ’:’ separator, they
-must be escaped; note that this is a second level escaping.
-
-
The following special options are also recognized:
-
-f Specify the format name. Useful if it cannot be guessed from the
-output name suffix.
-
-bsfs[/spec ] Specify a list of bitstream filters to apply to the specified
-output.
-
-It is possible to specify to which streams a given bitstream filter
-applies, by appending a stream specifier to the option separated by
-/. spec must be a stream specifier (see Format stream specifiers ). If the stream specifier is not specified, the
-bitstream filters will be applied to all streams in the output.
-
-Several bitstream filters can be specified, separated by ",".
-
-select Select the streams that should be mapped to the slave output,
-specified by a stream specifier. If not specified, this defaults to
-all the input streams.
-
-
-
-
23.19.1 Examples# TOC
-
-
- Encode something and both archive it in a WebM file and stream it
-as MPEG-TS over UDP (the streams need to be explicitly mapped):
-
-
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
- "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Use ffmpeg to encode the input, and send the output
-to three different destinations. The dump_extra bitstream
-filter is used to add extradata information to all the output video
-keyframes packets, as requested by the MPEG-TS format. The select
-option is applied to out.aac in order to make it contain only
-audio packets.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
- As below, but select only stream a:1 for the audio output. Note
-that a second level escaping must be performed, as ":" is a special
-character used to separate options.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
-
-
-
Note: some codecs may need different options depending on the output format;
-the auto-detection of this can not work with the tee muxer. The main example
-is the global_header flag.
-
-
-
23.20 webm_dash_manifest# TOC
-
-
WebM DASH Manifest muxer.
-
-
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML.
-
-
-
23.20.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-adaptation_sets This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
-unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
-audio and video streams. Any number of adaptation sets can be added using this option.
-
-
-
-
23.20.2 Example# TOC
-
-
ffmpeg -f webm_dash_manifest -i video1.webm \
- -f webm_dash_manifest -i video2.webm \
- -f webm_dash_manifest -i audio1.webm \
- -f webm_dash_manifest -i audio2.webm \
- -map 0 -map 1 -map 2 -map 3 \
- -c copy \
- -f webm_dash_manifest \
- -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
- manifest.xml
-
-
-
-
24 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
25 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
25.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
25.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
25.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
25.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
25.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
25.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
25.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
25.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
25.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
25.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
25.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
25.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
25.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
25.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
25.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
25.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
25.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
25.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
25.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
25.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
25.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
25.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
25.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
25.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
25.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
25.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
25.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
25.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
25.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
25.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
25.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
25.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
25.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
25.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
25.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
25.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
25.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
25.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
25.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
26 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
27 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
27.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
27.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
27.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
27.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
27.3 bktr# TOC
-
-
BSD video input device.
-
-
-
27.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
27.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
27.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
27.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
27.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
27.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
27.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
27.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
27.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
27.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
27.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
27.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
27.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
27.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
27.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
27.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
27.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
27.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
27.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
27.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
27.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
27.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
27.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
27.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
27.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
27.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
27.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
27.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
27.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
27.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
27.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
27.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
27.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
28 Output Devices# TOC
-
-
Output devices are configured elements in FFmpeg that can write
-multimedia data to an output device attached to your system.
-
-
When you configure your FFmpeg build, all the supported output devices
-are enabled by default. You can list all available ones using the
-configure option "–list-outdevs".
-
-
You can disable all the output devices using the configure option
-"–disable-outdevs", and selectively enable an output device using the
-option "–enable-outdev=OUTDEV ", or you can disable a particular
-input device using the option "–disable-outdev=OUTDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-enabled output devices.
-
-
A description of the currently available output devices follows.
-
-
-
28.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) output device.
-
-
-
28.1.1 Examples# TOC
-
-
- Play a file on default ALSA device:
-
-
ffmpeg -i INPUT -f alsa default
- Play a file on soundcard 1, audio device 7:
-
-
ffmpeg -i INPUT -f alsa hw:1,7
-
-
-
-
28.2 caca# TOC
-
-
CACA output device.
-
-
This output device allows one to show a video stream in CACA window.
-Only one CACA window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need to configure FFmpeg with
---enable-libcaca.
-libcaca is a graphics library that outputs text instead of pixels.
-
-
For more information about libcaca, check:
-http://caca.zoy.org/wiki/libcaca
-
-
-
28.2.1 Options# TOC
-
-
-window_title Set the CACA window title, if not specified default to the filename
-specified for the output device.
-
-window_size Set the CACA window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video.
-
-driver Set display driver.
-
-algorithm Set dithering algorithm. Dithering is necessary
-because the picture being rendered has usually far more colours than
-the available palette.
-The accepted values are listed with -list_dither algorithms.
-
-antialias Set antialias method. Antialiasing smoothens the rendered
-image and avoids the commonly seen staircase effect.
-The accepted values are listed with -list_dither antialiases.
-
-charset Set which characters are going to be used when rendering text.
-The accepted values are listed with -list_dither charsets.
-
-color Set color to be used when rendering text.
-The accepted values are listed with -list_dither colors.
-
-list_drivers If set to true , print a list of available drivers and exit.
-
-list_dither List available dither options related to the argument.
-The argument must be one of algorithms, antialiases,
-charsets, colors.
-
-
-
-
28.2.2 Examples# TOC
-
-
- The following command shows the ffmpeg output is an
-CACA window, forcing its size to 80x25:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
- Show the list of available drivers and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
- Show the list of available dither colors and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
-
-
-
-
28.3 decklink# TOC
-
-
The decklink output device provides playback capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this output device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz.
-
-
-
28.3.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-preroll Amount of time to preroll video in seconds.
-Defaults to 0.5 .
-
-
-
-
-
28.3.2 Examples# TOC
-
-
- List output devices:
-
-
ffmpeg -i test.avi -f decklink -list_devices 1 dummy
- List supported formats:
-
-
ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
- Play video clip:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
- Play video clip with non-standard framerate or video size:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
-
-
-
-
28.4 fbdev# TOC
-
-
Linux framebuffer output device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
-
28.4.1 Options# TOC
-
-xoffset yoffset Set x/y coordinate of top left corner. Default is 0.
-
-
-
-
28.4.2 Examples# TOC
-
Play a file on framebuffer device /dev/fb0 .
-Required pixel format depends on current framebuffer settings.
-
-
ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
28.5 opengl# TOC
-
OpenGL output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-opengl.
-
-
This output device allows one to render to OpenGL context.
-Context may be provided by application or default SDL window is created.
-
-
When device renders to external context, application must implement handlers for following messages:
-AV_DEV_TO_APP_CREATE_WINDOW_BUFFER - create OpenGL context on current thread.
-AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER - make OpenGL context current.
-AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER - swap buffers.
-AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER - destroy OpenGL context.
-Application is also required to inform a device about current resolution by sending AV_APP_TO_DEV_WINDOW_SIZE message.
-
-
-
28.5.1 Options# TOC
-
-background Set background color. Black is a default.
-
no_window Disables default SDL window when set to non-zero value.
-Application must provide OpenGL context and both window_size_cb and window_swap_buffers_cb callbacks when set.
-
window_title Set the SDL window title, if not specified default to the filename specified for the output device.
-Ignored when no_window is set.
-
window_size Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.
-If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.
-Mostly usable when no_window is not set.
-
-
-
-
-
28.5.2 Examples# TOC
-
Play a file on SDL window using OpenGL rendering:
-
-
ffmpeg -i INPUT -f opengl "window title"
-
-
-
-
28.6 oss# TOC
-
-
OSS (Open Sound System) output device.
-
-
-
28.7 pulse# TOC
-
-
PulseAudio output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org
-
-
-
28.7.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is set to the specified output name.
-
-device Specify the device to use. Default device is used when not provided.
-List of output devices can be obtained with command pactl list sinks.
-
-buffer_size buffer_duration Control the size and duration of the PulseAudio buffer. A small buffer
-gives more control, but requires more frequent updates.
-
-buffer_size specifies size in bytes while
-buffer_duration specifies duration in milliseconds.
-
-When both options are provided then the highest value is used
-(duration is recalculated to bytes using stream parameters). If they
-are set to 0 (which is default), the device will use the default
-PulseAudio duration value. By default PulseAudio set buffer duration
-to around 2 seconds.
-
-prebuf Specify pre-buffering size in bytes. The server does not start with
-playback before at least prebuf bytes are available in the
-buffer. By default this option is initialized to the same value as
-buffer_size or buffer_duration (whichever is bigger).
-
-minreq Specify minimum request size in bytes. The server does not request less
-than minreq bytes from the client, instead waits until the buffer
-is free enough to request more bytes at once. It is recommended to not set
-this option, which will initialize this to a value that is deemed sensible
-by the server.
-
-
-
-
-
28.7.2 Examples# TOC
-
Play a file on default device on default server:
-
-
ffmpeg -i INPUT -f pulse "stream name"
-
-
-
-
28.8 sdl# TOC
-
-
SDL (Simple DirectMedia Layer) output device.
-
-
This output device allows one to show a video stream in an SDL
-window. Only one SDL window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need libsdl installed on your system
-when configuring your build.
-
-
For more information about SDL, check:
-http://www.libsdl.org/
-
-
-
28.8.1 Options# TOC
-
-
-window_title Set the SDL window title, if not specified default to the filename
-specified for the output device.
-
-icon_title Set the name of the iconified SDL window, if not specified it is set
-to the same value of window_title .
-
-window_size Set the SDL window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video,
-downscaled according to the aspect ratio.
-
-window_fullscreen Set fullscreen mode when non-zero value is provided.
-Default value is zero.
-
-
-
-
28.8.2 Interactive commands# TOC
-
-
The window created by the device can be controlled through the
-following interactive commands.
-
-
-q, ESC Quit the device immediately.
-
-
-
-
28.8.3 Examples# TOC
-
-
The following command shows the ffmpeg output is an
-SDL window, forcing its size to the qcif format:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
-
-
-
-
28.9 sndio# TOC
-
-
sndio audio output device.
-
-
-
28.10 xv# TOC
-
-
XV (XVideo) output device.
-
-
This output device allows one to show a video stream in a X Window System
-window.
-
-
-
28.10.1 Options# TOC
-
-
-display_name Specify the hardware display name, which determines the display and
-communications domain to be used.
-
-The display name or DISPLAY environment variable can be a string in
-the format hostname [:number [.screen_number ]].
-
-hostname specifies the name of the host machine on which the
-display is physically attached. number specifies the number of
-the display server on that host machine. screen_number specifies
-the screen to be used on that server.
-
-If unspecified, it defaults to the value of the DISPLAY environment
-variable.
-
-For example, dual-headed:0.1 would specify screen 1 of display
-0 on the machine named “dual-headed”.
-
-Check the X11 specification for more detailed information about the
-display name format.
-
-window_id When set to non-zero value then device doesn’t create new window,
-but uses existing one with provided window_id . By default
-this options is set to zero and device creates its own window.
-
-window_size Set the created window size, can be a string of the form
-width xheight or a video size abbreviation. If not
-specified it defaults to the size of the input video.
-Ignored when window_id is set.
-
-window_x window_y Set the X and Y window offsets for the created window. They are both
-set to 0 by default. The values may be ignored by the window manager.
-Ignored when window_id is set.
-
-window_title Set the window title, if not specified default to the filename
-specified for the output device. Ignored when window_id is set.
-
-
-
For more information about XVideo see http://www.x.org/ .
-
-
-
28.10.2 Examples# TOC
-
-
- Decode, display and encode video input with ffmpeg at the
-same time:
-
-
ffmpeg -i INPUT OUTPUT -f xv display
- Decode and display the input video to multiple X11 windows:
-
-
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
-
-
-
-
29 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
30 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
31 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
32 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
33 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
33.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
33.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
34 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
35 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
35.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
35.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
35.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
35.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
35.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
35.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
35.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
35.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
35.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
35.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
35.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
35.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
35.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
35.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
35.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
35.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
35.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
35.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
35.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
35.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
35.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
35.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
35.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
35.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
35.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
35.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
35.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
35.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
35.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
35.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
35.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
35.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
35.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
35.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
35.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
35.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
35.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
35.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
35.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
35.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
35.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
35.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
35.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
35.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
35.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
35.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
35.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
35.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
35.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
35.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
35.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
35.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
35.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
35.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
35.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
35.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
35.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
35.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
35.42.2 Examples# TOC
-
-
-
-
-
35.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
35.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
36 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
36.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
36.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
36.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
36.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
36.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
36.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
36.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
36.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
36.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
36.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
37 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
37.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
37.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
38 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
38.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
38.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
38.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
38.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
38.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
38.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
38.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
38.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
38.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
38.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
38.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
38.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
38.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
38.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
38.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
38.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
38.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
38.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
38.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
38.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
38.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
38.15.1 Examples# TOC
-
-
-
-
-
38.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
38.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
38.17.1 Examples# TOC
-
-
-
-
-
38.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
38.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
38.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
38.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
38.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
38.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
38.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
38.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
38.23.1 Examples# TOC
-
-
-
-
-
38.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
38.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
38.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
38.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
38.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
38.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
38.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
38.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
38.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
38.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
38.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
38.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
38.29.1 Examples# TOC
-
-
-
-
-
38.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
38.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
38.31.1 p/c/n/u/b meaning# TOC
-
-
-
38.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
38.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
38.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
38.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
38.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
38.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
38.34.1 Examples# TOC
-
-
-
-
-
38.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
38.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
38.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
38.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
38.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
38.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
38.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
38.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
38.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
38.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
38.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
38.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
38.42.1 Workflow examples# TOC
-
-
-
38.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
38.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
38.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
38.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
38.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
38.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
38.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
38.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
38.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
38.48.1 Examples# TOC
-
-
-
-
-
38.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
38.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
38.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
38.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
38.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
38.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
38.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
38.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
38.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
38.55.1 Examples# TOC
-
-
-
-
-
38.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
38.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
38.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
38.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
38.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
38.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
38.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
38.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
38.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
38.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
38.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
38.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
38.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
38.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
38.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
38.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
38.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
38.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.65.2 Examples# TOC
-
-
-
-
-
38.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
38.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.67.1 Examples# TOC
-
-
-
-
-
38.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
38.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
38.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
38.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
38.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
38.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
38.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
38.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
38.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
38.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
38.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
38.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
38.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
38.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
38.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
38.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
38.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.79.2 Examples# TOC
-
-
-
-
-
38.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
38.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
38.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
38.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
38.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
38.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
38.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
38.85.1 Examples# TOC
-
-
-
-
-
38.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
38.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
38.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
38.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
38.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
38.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
38.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
38.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
38.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
38.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
38.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
38.94.1 Examples# TOC
-
-
-
-
-
38.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
38.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
38.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
38.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
38.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
38.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
38.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
38.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
38.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
38.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
38.101.2 Examples# TOC
-
-
-
-
-
38.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
38.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
38.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
38.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
38.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
38.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
38.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
38.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
38.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
39 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
39.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
39.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
39.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
39.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
39.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
39.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
39.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
39.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
39.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
39.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
40 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
40.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
40.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
41 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
41.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
41.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
41.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
41.2.1 Examples# TOC
-
-
-
-
-
41.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
41.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
41.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
41.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
41.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
41.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
41.6.1 Examples# TOC
-
-
-
-
-
41.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
41.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
41.7.2 Examples# TOC
-
-
-
-
-
41.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
41.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
41.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
41.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
41.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
41.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
41.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
41.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
41.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
41.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
41.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
41.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
41.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
41.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
42 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
42.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
42.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
42.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
43 See Also# TOC
-
-
ffmpeg
-ffplay , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
44 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Bitstream Filters Documentation
-
-
-
- FFmpeg Bitstream Filters Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the bitstream filters provided by the
-libavcodec library.
-
-
A bitstream filter operates on the encoded stream data, and performs
-bitstream level modifications without performing decoding.
-
-
-
-
2 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
2.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
2.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
2.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
2.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
2.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
2.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
2.7 mjpega_dump_header# TOC
-
-
-
2.8 movsub# TOC
-
-
-
2.9 mp3_header_decompress# TOC
-
-
-
2.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
2.11 remove_extra# TOC
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavcodec
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Codecs Documentation
-
-
-
- FFmpeg Codecs Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the codecs (decoders and encoders) provided by
-the libavcodec library.
-
-
-
-
2 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
3 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
4 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
4.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
4.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
5 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
5.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
5.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
5.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
5.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
5.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
5.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
5.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
5.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
5.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
6 Subtitles Decoders# TOC
-
-
-
6.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
6.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
6.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
6.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
7 Encoders# TOC
-
-
Encoders are configured elements in FFmpeg which allow the encoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native encoders
-are enabled by default. Encoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available encoders using the configure option --list-encoders.
-
-
You can disable all the encoders with the configure option
---disable-encoders and selectively enable / disable single encoders
-with the options --enable-encoder=ENCODER /
---disable-encoder=ENCODER .
-
-
The option -encoders of the ff* tools will display the list of
-enabled encoders.
-
-
-
-
8 Audio Encoders# TOC
-
-
A description of some of the currently available audio encoders
-follows.
-
-
-
-
-
Advanced Audio Coding (AAC) encoder.
-
-
This encoder is an experimental FFmpeg-native AAC encoder. Currently only the
-low complexity (AAC-LC) profile is supported. To use this encoder, you must set
-strict option to ‘experimental ’ or lower.
-
-
As this encoder is experimental, unexpected behavior may exist from time to
-time. For a more stable AAC encoder, see libvo-aacenc . However, be warned
-that it has a worse quality reported by some users.
-
-
See also libfdk_aac and libfaac .
-
-
-
8.1.1 Options# TOC
-
-
-b Set bit rate in bits/s. Setting this automatically activates constant bit rate
-(CBR) mode.
-
-q Set quality for variable bit rate (VBR) mode. This option is valid only using
-the ffmpeg command-line tool. For library interface users, use
-global_quality .
-
-stereo_mode Set stereo encoding mode. Possible values:
-
-
-‘auto ’
-Automatically selected by the encoder.
-
-‘ms_off ’
-Disable middle/side encoding. This is the default.
-
-‘ms_force ’
-Force middle/side encoding.
-
-
-aac_coder Set AAC encoder coding method. Possible values:
-
-
-‘faac ’
-FAAC-inspired method.
-
-This method is a simplified reimplementation of the method used in FAAC, which
-sets thresholds proportional to the band energies, and then decreases all the
-thresholds with quantizer steps to find the appropriate quantization with
-distortion below threshold band by band.
-
-The quality of this method is comparable to the two loop searching method
-described below, but somewhat a little better and slower.
-
-‘anmr ’
-Average noise to mask ratio (ANMR) trellis-based solution.
-
-This has a theoretic best quality out of all the coding methods, but at the
-cost of the slowest speed.
-
-‘twoloop ’
-Two loop searching (TLS) method.
-
-This method first sets quantizers depending on band thresholds and then tries
-to find an optimal combination by adding or subtracting a specific value from
-all quantizers and adjusting some individual quantizer a little.
-
-This method produces similar quality with the FAAC method and is the default.
-
-‘fast ’
-Constant quantizer method.
-
-This method sets a constant quantizer for all bands. This is the fastest of all
-the methods, yet produces the worst quality.
-
-
-
-
-
-
-
8.2 ac3 and ac3_fixed# TOC
-
-
AC-3 audio encoders.
-
-
These encoders implement part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
The ac3 encoder uses floating-point math, while the ac3_fixed
-encoder only uses fixed-point integer math. This does not mean that one is
-always faster, just that one or the other may be better suited to a
-particular system. The floating-point encoder will generally produce better
-quality audio for a given bitrate. The ac3_fixed encoder is not the
-default codec for any of the output formats, so it must be specified explicitly
-using the option -acodec ac3_fixed in order to use it.
-
-
-
8.2.1 AC-3 Metadata# TOC
-
-
The AC-3 metadata options are used to set parameters that describe the audio,
-but in most cases do not affect the audio encoding itself. Some of the options
-do directly affect or influence the decoding and playback of the resulting
-bitstream, while others are just for informational purposes. A few of the
-options will add bits to the output stream that could otherwise be used for
-audio data, and will thus affect the quality of the output. Those will be
-indicated accordingly with a note in the option list below.
-
-
These parameters are described in detail in several publicly-available
-documents.
-
-
-
-
8.2.1.1 Metadata Control Options# TOC
-
-
--per_frame_metadata boolean Allow Per-Frame Metadata. Specifies if the encoder should check for changing
-metadata for each frame.
-
-0 The metadata values set at initialization will be used for every frame in the
-stream. (default)
-
1 Metadata values can be changed before encoding each frame.
-
-
-
-
-
-
8.2.1.2 Downmix Levels# TOC
-
-
--center_mixlev level Center Mix Level. The amount of gain the decoder should apply to the center
-channel when downmixing to stereo. This field will only be written to the
-bitstream if a center channel is present. The value is specified as a scale
-factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6dB gain
-
-
--surround_mixlev level Surround Mix Level. The amount of gain the decoder should apply to the surround
-channel(s) when downmixing to stereo. This field will only be written to the
-bitstream if one or more surround channels are present. The value is specified
-as a scale factor. There are 3 valid values:
-
-0.707 Apply -3dB gain
-
0.500 Apply -6dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
8.2.1.3 Audio Production Information# TOC
-
Audio Production Information is optional information describing the mixing
-environment. Either none or both of the fields are written to the bitstream.
-
-
--mixing_level number Mixing Level. Specifies peak sound pressure level (SPL) in the production
-environment when the mix was mastered. Valid values are 80 to 111, or -1 for
-unknown or not indicated. The default value is -1, but that value cannot be
-used if the Audio Production Information is written to the bitstream. Therefore,
-if the room_type option is not the default value, the mixing_level
-option must not be -1.
-
--room_type type Room Type. Describes the equalization used during the final mixing session at
-the studio or on the dubbing stage. A large room is a dubbing stage with the
-industry standard X-curve equalization; a small room has flat equalization.
-This field will not be written to the bitstream if both the mixing_level
-option and the room_type option have the default values.
-
-0 notindicated Not Indicated (default)
-
1 large Large Room
-
2 small Small Room
-
-
-
-
-
-
8.2.1.4 Other Metadata Options# TOC
-
-
--copyright boolean Copyright Indicator. Specifies whether a copyright exists for this audio.
-
-0 off No Copyright Exists (default)
-
1 on Copyright Exists
-
-
--dialnorm value Dialogue Normalization. Indicates how far the average dialogue level of the
-program is below digital 100% full scale (0 dBFS). This parameter determines a
-level shift during audio reproduction that sets the average volume of the
-dialogue to a preset level. The goal is to match volume level between program
-sources. A value of -31dB will result in no volume level change, relative to
-the source volume, during audio reproduction. Valid values are whole numbers in
-the range -31 to -1, with -31 being the default.
-
--dsur_mode mode Dolby Surround Mode. Specifies whether the stereo signal uses Dolby Surround
-(Pro Logic). This field will only be written to the bitstream if the audio
-stream is stereo. Using this option does NOT mean the encoder will actually
-apply Dolby Surround processing.
-
-0 notindicated Not Indicated (default)
-
1 off Not Dolby Surround Encoded
-
2 on Dolby Surround Encoded
-
-
--original boolean Original Bit Stream Indicator. Specifies whether this audio is from the
-original source and not a copy.
-
-0 off Not Original Source
-
1 on Original Source (default)
-
-
-
-
-
-
8.2.2 Extended Bitstream Information# TOC
-
The extended bitstream options are part of the Alternate Bit Stream Syntax as
-specified in Annex D of the A/52:2010 standard. It is grouped into 2 parts.
-If any one parameter in a group is specified, all values in that group will be
-written to the bitstream. Default values are used for those that are written
-but have not been specified. If the mixing levels are written, the decoder
-will use these values instead of the ones specified in the center_mixlev
-and surround_mixlev options if it supports the Alternate Bit Stream
-Syntax.
-
-
-
8.2.2.1 Extended Bitstream Information - Part 1# TOC
-
-
--dmix_mode mode Preferred Stereo Downmix Mode. Allows the user to select either Lt/Rt
-(Dolby Surround) or Lo/Ro (normal stereo) as the preferred stereo downmix mode.
-
-0 notindicated Not Indicated (default)
-
1 ltrt Lt/Rt Downmix Preferred
-
2 loro Lo/Ro Downmix Preferred
-
-
--ltrt_cmixlev level Lt/Rt Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lt/Rt mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--ltrt_surmixlev level Lt/Rt Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lt/Rt mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
--loro_cmixlev level Lo/Ro Center Mix Level. The amount of gain the decoder should apply to the
-center channel when downmixing to stereo in Lo/Ro mode.
-
-1.414 Apply +3dB gain
-
1.189 Apply +1.5dB gain
-
1.000 Apply 0dB gain
-
0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain (default)
-
0.500 Apply -6.0dB gain
-
0.000 Silence Center Channel
-
-
--loro_surmixlev level Lo/Ro Surround Mix Level. The amount of gain the decoder should apply to the
-surround channel(s) when downmixing to stereo in Lo/Ro mode.
-
-0.841 Apply -1.5dB gain
-
0.707 Apply -3.0dB gain
-
0.595 Apply -4.5dB gain
-
0.500 Apply -6.0dB gain (default)
-
0.000 Silence Surround Channel(s)
-
-
-
-
-
-
8.2.2.2 Extended Bitstream Information - Part 2# TOC
-
-
--dsurex_mode mode Dolby Surround EX Mode. Indicates whether the stream uses Dolby Surround EX
-(7.1 matrixed to 5.1). Using this option does NOT mean the encoder will actually
-apply Dolby Surround EX processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Surround EX Off
-
2 off Dolby Surround EX On
-
-
--dheadphone_mode mode Dolby Headphone Mode. Indicates whether the stream uses Dolby Headphone
-encoding (multi-channel matrixed to 2.0 for use with headphones). Using this
-option does NOT mean the encoder will actually apply Dolby Headphone
-processing.
-
-0 notindicated Not Indicated (default)
-
1 on Dolby Headphone Off
-
2 off Dolby Headphone On
-
-
--ad_conv_type type A/D Converter Type. Indicates whether the audio has passed through HDCD A/D
-conversion.
-
-0 standard Standard A/D Converter (default)
-
1 hdcd HDCD A/D Converter
-
-
-
-
-
-
8.2.3 Other AC-3 Encoding Options# TOC
-
-
--stereo_rematrixing boolean Stereo Rematrixing. Enables/Disables use of rematrixing for stereo input. This
-is an optional AC-3 feature that increases quality by selectively encoding
-the left/right channels as mid/side. This option is enabled by default, and it
-is highly recommended that it be left as enabled except for testing purposes.
-
-
-
-
-
8.2.4 Floating-Point-Only AC-3 Encoding Options# TOC
-
-
These options are only valid for the floating-point encoder and do not exist
-for the fixed-point encoder due to the corresponding features not being
-implemented in fixed-point.
-
-
--channel_coupling boolean Enables/Disables use of channel coupling, which is an optional AC-3 feature
-that increases quality by combining high frequency information from multiple
-channels into a single channel. The per-channel high frequency information is
-sent with less accuracy in both the frequency and time domains. This allows
-more bits to be used for lower frequencies while preserving enough information
-to reconstruct the high frequencies. This option is enabled by default for the
-floating-point encoder and should generally be left as enabled except for
-testing purposes or to increase encoding speed.
-
--1 auto Selected by Encoder (default)
-
0 off Disable Channel Coupling
-
1 on Enable Channel Coupling
-
-
--cpl_start_band number Coupling Start Band. Sets the channel coupling start band, from 1 to 15. If a
-value higher than the bandwidth is used, it will be reduced to 1 less than the
-coupling end band. If auto is used, the start band will be determined by
-the encoder based on the bit rate, sample rate, and channel layout. This option
-has no effect if channel coupling is disabled.
-
--1 auto Selected by Encoder (default)
-
-
-
-
-
-
8.3 libfaac# TOC
-
-
libfaac AAC (Advanced Audio Coding) encoder wrapper.
-
-
Requires the presence of the libfaac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfaac --enable-nonfree.
-
-
This encoder is considered to be of higher quality with respect to the
-the native experimental FFmpeg AAC encoder .
-
-
For more information see the libfaac project at
-http://www.audiocoding.com/faac.html/ .
-
-
-
8.3.1 Options# TOC
-
-
The following shared FFmpeg codec options are recognized.
-
-
The following options are supported by the libfaac wrapper. The
-faac-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bit rate in bits/s for ABR (Average Bit Rate) mode. If the bit rate
-is not explicitly specified, it is automatically set to a suitable
-value depending on the selected profile. faac bitrate is
-expressed in kilobits/s.
-
-Note that libfaac does not support CBR (Constant Bit Rate) but only
-ABR (Average Bit Rate).
-
-If VBR mode is enabled this option is ignored.
-
-ar (-R ) Set audio sampling rate (in Hz).
-
-ac (-c ) Set the number of audio channels.
-
-cutoff (-C ) Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_main ’
-Main AAC (Main)
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_ssr ’
-Scalable Sample Rate (SSR)
-
-‘aac_ltp ’
-Long Term Prediction (LTP)
-
-
-If not specified it is set to ‘aac_low ’.
-
-flags +qscale Set constant quality VBR (Variable Bit Rate) mode.
-
-global_quality Set quality in VBR mode as an integer number of lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-and used to set the quality value used by libfaac. A reasonable range
-for the option value in QP units is [10-500], the higher the value the
-higher the quality.
-
-q (-q ) Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value sets the quality value used by libfaac. A reasonable range
-for the option value is [10-500], the higher the value the higher the
-quality.
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
8.3.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to ABR 128 kbps AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfaac -b:a 128k -output.m4a
- Use ffmpeg to convert an audio file to VBR AAC, using the
-LTP AAC profile:
-
-
ffmpeg -i input.wav -c:a libfaac -profile:a aac_ltp -q:a 100 output.m4a
-
-
-
-
8.4 libfdk_aac# TOC
-
-
libfdk-aac AAC (Advanced Audio Coding) encoder wrapper.
-
-
The libfdk-aac library is based on the Fraunhofer FDK AAC code from
-the Android project.
-
-
Requires the presence of the libfdk-aac headers and library during
-configuration. You need to explicitly configure the build with
---enable-libfdk-aac. The library is also incompatible with GPL,
-so if you allow the use of GPL, you should configure with
---enable-gpl --enable-nonfree --enable-libfdk-aac.
-
-
This encoder is considered to be of higher quality with respect to
-both the native experimental FFmpeg AAC encoder and
-libfaac .
-
-
VBR encoding, enabled through the vbr or flags
-+qscale options, is experimental and only works with some
-combinations of parameters.
-
-
Support for encoding 7.1 audio is only available with libfdk-aac 0.1.3 or
-higher.
-
-
For more information see the fdk-aac project at
-http://sourceforge.net/p/opencore-amr/fdk-aac/ .
-
-
-
8.4.1 Options# TOC
-
-
The following options are mapped on the shared FFmpeg codec options.
-
-
-b Set bit rate in bits/s. If the bitrate is not explicitly specified, it
-is automatically set to a suitable value depending on the selected
-profile.
-
-In case VBR mode is enabled the option is ignored.
-
-ar Set audio sampling rate (in Hz).
-
-channels Set the number of audio channels.
-
-flags +qscale Enable fixed quality, VBR (Variable Bit Rate) mode.
-Note that VBR is implicitly enabled when the vbr value is
-positive.
-
-cutoff Set cutoff frequency. If not specified (or explicitly set to 0) it
-will use a value automatically computed by the library. Default value
-is 0.
-
-profile Set audio profile.
-
-The following profiles are recognized:
-
-‘aac_low ’
-Low Complexity AAC (LC)
-
-‘aac_he ’
-High Efficiency AAC (HE-AAC)
-
-‘aac_he_v2 ’
-High Efficiency AAC version 2 (HE-AACv2)
-
-‘aac_ld ’
-Low Delay AAC (LD)
-
-‘aac_eld ’
-Enhanced Low Delay AAC (ELD)
-
-
-If not specified it is set to ‘aac_low ’.
-
-
-
The following are private options of the libfdk_aac encoder.
-
-
-afterburner Enable afterburner feature if set to 1, disabled if set to 0. This
-improves the quality but also the required processing power.
-
-Default value is 1.
-
-eld_sbr Enable SBR (Spectral Band Replication) for ELD if set to 1, disabled
-if set to 0.
-
-Default value is 0.
-
-signaling Set SBR/PS signaling style.
-
-It can assume one of the following values:
-
-‘default ’
-choose signaling implicitly (explicit hierarchical by default,
-implicit if global header is disabled)
-
-‘implicit ’
-implicit backwards compatible signaling
-
-‘explicit_sbr ’
-explicit SBR, implicit PS signaling
-
-‘explicit_hierarchical ’
-explicit hierarchical signaling
-
-
-Default value is ‘default ’.
-
-latm Output LATM/LOAS encapsulated data if set to 1, disabled if set to 0.
-
-Default value is 0.
-
-header_period Set StreamMuxConfig and PCE repetition period (in frames) for sending
-in-band configuration buffers within LATM/LOAS transport layer.
-
-Must be a 16-bits non-negative integer.
-
-Default value is 0.
-
-vbr Set VBR mode, from 1 to 5. 1 is lowest quality (though still pretty
-good) and 5 is highest quality. A value of 0 will disable VBR, and CBR
-(Constant Bit Rate) is enabled.
-
-Currently only the ‘aac_low ’ profile supports VBR encoding.
-
-VBR modes 1-5 correspond to roughly the following average bit rates:
-
-
-‘1 ’
-32 kbps/channel
-
‘2 ’
-40 kbps/channel
-
‘3 ’
-48-56 kbps/channel
-
‘4 ’
-64 kbps/channel
-
‘5 ’
-about 80-96 kbps/channel
-
-
-Default value is 0.
-
-
-
-
8.4.2 Examples# TOC
-
-
- Use ffmpeg to convert an audio file to VBR AAC in an M4A (MP4)
-container:
-
-
ffmpeg -i input.wav -codec:a libfdk_aac -vbr 3 output.m4a
- Use ffmpeg to convert an audio file to CBR 64k kbps AAC, using the
-High-Efficiency AAC profile:
-
-
ffmpeg -i input.wav -c:a libfdk_aac -profile:a aac_he -b:a 64k output.m4a
-
-
-
-
8.5 libmp3lame# TOC
-
-
LAME (Lame Ain’t an MP3 Encoder) MP3 encoder wrapper.
-
-
Requires the presence of the libmp3lame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libmp3lame.
-
-
See libshine for a fixed-point MP3 encoder, although with a
-lower quality.
-
-
-
8.5.1 Options# TOC
-
-
The following options are supported by the libmp3lame wrapper. The
-lame-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR or ABR. LAME bitrate is
-expressed in kilobits/s.
-
-q (-V ) Set constant quality setting for VBR. This option is valid only
-using the ffmpeg command-line tool. For library interface
-users, use global_quality .
-
-compression_level (-q ) Set algorithm quality. Valid arguments are integers in the 0-9 range,
-with 0 meaning highest quality but slowest, and 9 meaning fastest
-while producing the worst quality.
-
-reservoir Enable use of bit reservoir when set to 1. Default value is 1. LAME
-has this enabled by default, but can be overridden by use
---nores option.
-
-joint_stereo (-m j ) Enable the encoder to use (on a frame by frame basis) either L/R
-stereo or mid/side stereo. Default value is 1.
-
-abr (--abr ) Enable the encoder to use ABR when set to 1. The lame
---abr sets the target bitrate, while this options only
-tells FFmpeg to use ABR still relies on b to set bitrate.
-
-
-
-
-
8.6 libopencore-amrnb# TOC
-
-
OpenCORE Adaptive Multi-Rate Narrowband encoder.
-
-
Requires the presence of the libopencore-amrnb headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopencore-amrnb --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 8000Hz sample rate,
-but you can override it by setting strict to ‘unofficial ’ or
-lower.
-
-
-
8.6.1 Options# TOC
-
-
-b Set bitrate in bits per second. Only the following bitrates are supported,
-otherwise libavcodec will round to the nearest valid bitrate.
-
-
-4750 5150 5900 6700 7400 7950 10200 12200
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
8.7 libshine# TOC
-
-
Shine Fixed-Point MP3 encoder wrapper.
-
-
Shine is a fixed-point MP3 encoder. It has a far better performance on
-platforms without an FPU, e.g. armel CPUs, and some phones and tablets.
-However, as it is more targeted on performance than quality, it is not on par
-with LAME and other production-grade encoders quality-wise. Also, according to
-the project’s homepage, this encoder may not be free of bugs as the code was
-written a long time ago and the project was dead for at least 5 years.
-
-
This encoder only supports stereo and mono input. This is also CBR-only.
-
-
The original project (last updated in early 2007) is at
-http://sourceforge.net/projects/libshine-fxp/ . We only support the
-updated fork by the Savonet/Liquidsoap project at https://github.com/savonet/shine .
-
-
Requires the presence of the libshine headers and library during
-configuration. You need to explicitly configure the build with
---enable-libshine.
-
-
See also libmp3lame .
-
-
-
8.7.1 Options# TOC
-
-
The following options are supported by the libshine wrapper. The
-shineenc-equivalent of the options are listed in parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. shineenc -b option
-is expressed in kilobits/s.
-
-
-
-
-
8.8 libtwolame# TOC
-
-
TwoLAME MP2 encoder wrapper.
-
-
Requires the presence of the libtwolame headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtwolame.
-
-
-
8.8.1 Options# TOC
-
-
The following options are supported by the libtwolame wrapper. The
-twolame-equivalent options follow the FFmpeg ones and are in
-parentheses.
-
-
-b (-b ) Set bitrate expressed in bits/s for CBR. twolame b
-option is expressed in kilobits/s. Default value is 128k.
-
-q (-V ) Set quality for experimental VBR support. Maximum value range is
-from -50 to 50, useful range is from -10 to 10. The higher the
-value, the better the quality. This option is valid only using the
-ffmpeg command-line tool. For library interface users,
-use global_quality .
-
-mode (--mode ) Set the mode of the resulting audio. Possible values:
-
-
-‘auto ’
-Choose mode automatically based on the input. This is the default.
-
‘stereo ’
-Stereo
-
‘joint_stereo ’
-Joint stereo
-
‘dual_channel ’
-Dual channel
-
‘mono ’
-Mono
-
-
-psymodel (--psyc-mode ) Set psychoacoustic model to use in encoding. The argument must be
-an integer between -1 and 4, inclusive. The higher the value, the
-better the quality. The default value is 3.
-
-energy_levels (--energy ) Enable energy levels extensions when set to 1. The default value is
-0 (disabled).
-
-error_protection (--protect ) Enable CRC error protection when set to 1. The default value is 0
-(disabled).
-
-copyright (--copyright ) Set MPEG audio copyright flag when set to 1. The default value is 0
-(disabled).
-
-original (--original ) Set MPEG audio original flag when set to 1. The default value is 0
-(disabled).
-
-
-
-
-
8.9 libvo-aacenc# TOC
-
-
VisualOn AAC encoder.
-
-
Requires the presence of the libvo-aacenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-aacenc --enable-version3.
-
-
This encoder is considered to be worse than the
-native experimental FFmpeg AAC encoder , according to
-multiple sources.
-
-
-
8.9.1 Options# TOC
-
-
The VisualOn AAC encoder only support encoding AAC-LC and up to 2
-channels. It is also CBR-only.
-
-
-b Set bit rate in bits/s.
-
-
-
-
-
8.10 libvo-amrwbenc# TOC
-
-
VisualOn Adaptive Multi-Rate Wideband encoder.
-
-
Requires the presence of the libvo-amrwbenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvo-amrwbenc --enable-version3.
-
-
This is a mono-only encoder. Officially it only supports 16000Hz sample
-rate, but you can override it by setting strict to
-‘unofficial ’ or lower.
-
-
-
8.10.1 Options# TOC
-
-
-b Set bitrate in bits/s. Only the following bitrates are supported, otherwise
-libavcodec will round to the nearest valid bitrate.
-
-
-‘6600 ’
-‘8850 ’
-‘12650 ’
-‘14250 ’
-‘15850 ’
-‘18250 ’
-‘19850 ’
-‘23050 ’
-‘23850 ’
-
-
-dtx Allow discontinuous transmission (generate comfort noise) when set to 1. The
-default value is 0 (disabled).
-
-
-
-
-
8.11 libopus# TOC
-
-
libopus Opus Interactive Audio Codec encoder wrapper.
-
-
Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
-
8.11.1 Option Mapping# TOC
-
-
Most libopus options are modelled after the opusenc utility from
-opus-tools. The following is an option mapping chart describing options
-supported by the libopus wrapper, and their opusenc-equivalent
-in parentheses.
-
-
-b (bitrate ) Set the bit rate in bits/s. FFmpeg’s b option is
-expressed in bits/s, while opusenc’s bitrate in
-kilobits/s.
-
-vbr (vbr , hard-cbr , and cvbr ) Set VBR mode. The FFmpeg vbr option has the following
-valid arguments, with the their opusenc equivalent options
-in parentheses:
-
-
-‘off (hard-cbr ) ’
-Use constant bit rate encoding.
-
-‘on (vbr ) ’
-Use variable bit rate encoding (the default).
-
-‘constrained (cvbr ) ’
-Use constrained variable bit rate encoding.
-
-
-compression_level (comp ) Set encoding algorithm complexity. Valid options are integers in
-the 0-10 range. 0 gives the fastest encodes but lower quality, while 10
-gives the highest quality but slowest encoding. The default is 10.
-
-frame_duration (framesize ) Set maximum frame size, or duration of a frame in milliseconds. The
-argument must be exactly the following: 2.5, 5, 10, 20, 40, 60. Smaller
-frame sizes achieve lower latency but less quality at a given bitrate.
-Sizes greater than 20ms are only interesting at fairly low bitrates.
-The default is 20ms.
-
-packet_loss (expect-loss ) Set expected packet loss percentage. The default is 0.
-
-application (N.A.) Set intended application type. Valid options are listed below:
-
-
-‘voip ’
-Favor improved speech intelligibility.
-
‘audio ’
-Favor faithfulness to the input (the default).
-
‘lowdelay ’
-Restrict to only the lowest delay modes.
-
-
-cutoff (N.A.) Set cutoff bandwidth in Hz. The argument must be exactly one of the
-following: 4000, 6000, 8000, 12000, or 20000, corresponding to
-narrowband, mediumband, wideband, super wideband, and fullband
-respectively. The default is 0 (cutoff disabled).
-
-
-
-
-
8.12 libvorbis# TOC
-
-
libvorbis encoder wrapper.
-
-
Requires the presence of the libvorbisenc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libvorbis.
-
-
-
8.12.1 Options# TOC
-
-
The following options are supported by the libvorbis wrapper. The
-oggenc-equivalent of the options are listed in parentheses.
-
-
To get a more accurate and extensive documentation of the libvorbis
-options, consult the libvorbisenc’s and oggenc’s documentations.
-See http://xiph.org/vorbis/ ,
-http://wiki.xiph.org/Vorbis-tools , and oggenc(1).
-
-
-b (-b ) Set bitrate expressed in bits/s for ABR. oggenc -b is
-expressed in kilobits/s.
-
-q (-q ) Set constant quality setting for VBR. The value should be a float
-number in the range of -1.0 to 10.0. The higher the value, the better
-the quality. The default value is ‘3.0 ’.
-
-This option is valid only using the ffmpeg command-line tool.
-For library interface users, use global_quality .
-
-cutoff (--advanced-encode-option lowpass_frequency=N ) Set cutoff bandwidth in Hz, a value of 0 disables cutoff. oggenc’s
-related option is expressed in kHz. The default value is ‘0 ’ (cutoff
-disabled).
-
-minrate (-m ) Set minimum bitrate expressed in bits/s. oggenc -m is
-expressed in kilobits/s.
-
-maxrate (-M ) Set maximum bitrate expressed in bits/s. oggenc -M is
-expressed in kilobits/s. This only has effect on ABR mode.
-
-iblock (--advanced-encode-option impulse_noisetune=N ) Set noise floor bias for impulse blocks. The value is a float number from
--15.0 to 0.0. A negative bias instructs the encoder to pay special attention
-to the crispness of transients in the encoded audio. The tradeoff for better
-transient response is a higher bitrate.
-
-
-
-
-
8.13 libwavpack# TOC
-
-
A wrapper providing WavPack encoding through libwavpack.
-
-
Only lossless mode using 32-bit integer samples is supported currently.
-
-
Requires the presence of the libwavpack headers and library during
-configuration. You need to explicitly configure the build with
---enable-libwavpack.
-
-
Note that a libavcodec-native encoder for the WavPack codec exists so users can
-encode audios with this codec without using this encoder. See wavpackenc .
-
-
-
8.13.1 Options# TOC
-
-
wavpack command line utility’s corresponding options are listed in
-parentheses, if any.
-
-
-frame_size (--blocksize ) Default is 32768.
-
-compression_level Set speed vs. compression tradeoff. Acceptable arguments are listed below:
-
-
-‘0 (-f ) ’
-Fast mode.
-
-‘1 ’
-Normal (default) settings.
-
-‘2 (-h ) ’
-High quality.
-
-‘3 (-hh ) ’
-Very high quality.
-
-‘4-8 (-hh -x EXTRAPROC ) ’
-Same as ‘3 ’, but with extra processing enabled.
-
-‘4 ’ is the same as -x2 and ‘8 ’ is the same as -x6 .
-
-
-
-
-
-
8.14 wavpack# TOC
-
-
WavPack lossless audio encoder.
-
-
This is a libavcodec-native WavPack encoder. There is also an encoder based on
-libwavpack, but there is virtually no reason to use that encoder.
-
-
See also libwavpack .
-
-
-
8.14.1 Options# TOC
-
-
The equivalent options for wavpack command line utility are listed in
-parentheses.
-
-
-
8.14.1.1 Shared options# TOC
-
-
The following shared options are effective for this encoder. Only special notes
-about this particular encoder will be documented here. For the general meaning
-of the options, see the Codec Options chapter .
-
-
-frame_size (--blocksize ) For this encoder, the range for this option is between 128 and 131072. Default
-is automatically decided based on sample rate and number of channel.
-
-For the complete formula of calculating default, see
-libavcodec/wavpackenc.c .
-
-compression_level (-f , -h , -hh , and -x ) This option’s syntax is consistent with libwavpack ’s.
-
-
-
-
8.14.1.2 Private options# TOC
-
-
-joint_stereo (-j ) Set whether to enable joint stereo. Valid values are:
-
-
-‘on (1 ) ’
-Force mid/side audio encoding.
-
‘off (0 ) ’
-Force left/right audio encoding.
-
‘auto ’
-Let the encoder decide automatically.
-
-
-optimize_mono Set whether to enable optimization for mono. This option is only effective for
-non-mono streams. Available values:
-
-
-‘on ’
-enabled
-
‘off ’
-disabled
-
-
-
-
-
-
-
9 Video Encoders# TOC
-
-
A description of some of the currently available video encoders
-follows.
-
-
-
9.1 libtheora# TOC
-
-
libtheora Theora encoder wrapper.
-
-
Requires the presence of the libtheora headers and library during
-configuration. You need to explicitly configure the build with
---enable-libtheora.
-
-
For more information about the libtheora project see
-http://www.theora.org/ .
-
-
-
9.1.1 Options# TOC
-
-
The following global options are mapped to internal libtheora options
-which affect the quality and the bitrate of the encoded stream.
-
-
-b Set the video bitrate in bit/s for CBR (Constant Bit Rate) mode. In
-case VBR (Variable Bit Rate) mode is enabled this option is ignored.
-
-flags Used to enable constant quality mode (VBR) encoding through the
-qscale flag, and to enable the pass1 and pass2
-modes.
-
-g Set the GOP size.
-
-global_quality Set the global quality as an integer in lambda units.
-
-Only relevant when VBR mode is enabled with flags +qscale. The
-value is converted to QP units by dividing it by FF_QP2LAMBDA,
-clipped in the [0 - 10] range, and then multiplied by 6.3 to get a
-value in the native libtheora range [0-63]. A higher value corresponds
-to a higher quality.
-
-q Enable VBR mode when set to a non-negative value, and set constant
-quality value as a double floating point value in QP units.
-
-The value is clipped in the [0-10] range, and then multiplied by 6.3
-to get a value in the native libtheora range [0-63].
-
-This option is valid only using the ffmpeg command-line
-tool. For library interface users, use global_quality .
-
-
-
-
9.1.2 Examples# TOC
-
-
- Set maximum constant quality (VBR) encoding with ffmpeg:
-
-
ffmpeg -i INPUT -codec:v libtheora -q:v 10 OUTPUT.ogg
- Use ffmpeg to convert a CBR 1000 kbps Theora video stream:
-
-
ffmpeg -i INPUT -codec:v libtheora -b:v 1000k OUTPUT.ogg
-
-
-
-
9.2 libvpx# TOC
-
-
VP8/VP9 format supported through libvpx.
-
-
Requires the presence of the libvpx headers and library during configuration.
-You need to explicitly configure the build with --enable-libvpx.
-
-
-
9.2.1 Options# TOC
-
-
Mapping from FFmpeg to libvpx options with conversion notes in parentheses.
-
-
-threads g_threads
-
-profile g_profile
-
-vb rc_target_bitrate
-
-g kf_max_dist
-
-keyint_min kf_min_dist
-
-qmin rc_min_quantizer
-
-qmax rc_max_quantizer
-
-bufsize, vb rc_buf_sz
-(bufsize * 1000 / vb)
-
-rc_buf_optimal_sz
-(bufsize * 1000 / vb * 5 / 6)
-
-rc_init_occupancy, vb rc_buf_initial_sz
-(rc_init_occupancy * 1000 / vb)
-
-rc_buffer_aggressivity rc_undershoot_pct
-
-skip_threshold rc_dropframe_thresh
-
-qcomp rc_2pass_vbr_bias_pct
-
-maxrate, vb rc_2pass_vbr_maxsection_pct
-(maxrate * 100 / vb)
-
-minrate, vb rc_2pass_vbr_minsection_pct
-(minrate * 100 / vb)
-
-minrate, maxrate, vb VPX_CBR
-(minrate == maxrate == vb)
-
-crf VPX_CQ, VP8E_SET_CQ_LEVEL
-
-quality
-best VPX_DL_BEST_QUALITY
-
good VPX_DL_GOOD_QUALITY
-
realtime VPX_DL_REALTIME
-
-
-speed VP8E_SET_CPUUSED
-
-nr VP8E_SET_NOISE_SENSITIVITY
-
-mb_threshold VP8E_SET_STATIC_THRESHOLD
-
-slices VP8E_SET_TOKEN_PARTITIONS
-
-max-intra-rate VP8E_SET_MAX_INTRA_BITRATE_PCT
-
-force_key_frames VPX_EFLAG_FORCE_KF
-
-Alternate reference frame related
-vp8flags altref VP8E_SET_ENABLEAUTOALTREF
-
arnr_max_frames VP8E_SET_ARNR_MAXFRAMES
-
arnr_type VP8E_SET_ARNR_TYPE
-
arnr_strength VP8E_SET_ARNR_STRENGTH
-
rc_lookahead g_lag_in_frames
-
-
-vp8flags error_resilient g_error_resilient
-
-aq_mode VP9E_SET_AQ_MODE
-
-
-
-
For more information about libvpx see:
-http://www.webmproject.org/
-
-
-
-
9.3 libwebp# TOC
-
-
libwebp WebP Image encoder wrapper
-
-
libwebp is Google’s official encoder for WebP images. It can encode in either
-lossy or lossless mode. Lossy images are essentially a wrapper around a VP8
-frame. Lossless images are a separate codec developed by Google.
-
-
-
9.3.1 Pixel Format# TOC
-
-
Currently, libwebp only supports YUV420 for lossy and RGB for lossless due
-to limitations of the format and libwebp. Alpha is supported for either mode.
-Because of API limitations, if RGB is passed in when encoding lossy or YUV is
-passed in for encoding lossless, the pixel format will automatically be
-converted using functions from libwebp. This is not ideal and is done only for
-convenience.
-
-
-
9.3.2 Options# TOC
-
-
--lossless boolean Enables/Disables use of lossless mode. Default is 0.
-
--compression_level integer For lossy, this is a quality/speed tradeoff. Higher values give better quality
-for a given size at the cost of increased encoding time. For lossless, this is
-a size/speed tradeoff. Higher values give smaller size at the cost of increased
-encoding time. More specifically, it controls the number of extra algorithms
-and compression tools used, and varies the combination of these tools. This
-maps to the method option in libwebp. The valid range is 0 to 6.
-Default is 4.
-
--qscale float For lossy encoding, this controls image quality, 0 to 100. For lossless
-encoding, this controls the effort and time spent at compressing more. The
-default value is 75. Note that for usage via libavcodec, this option is called
-global_quality and must be multiplied by FF_QP2LAMBDA .
-
--preset type Configuration preset. This does some automatic settings based on the general
-type of the image.
-
-none Do not use a preset.
-
default Use the encoder default.
-
picture Digital picture, like portrait, inner shot
-
photo Outdoor photograph, with natural lighting
-
drawing Hand or line drawing, with high-contrast details
-
icon Small-sized colorful images
-
text Text-like
-
-
-
-
-
-
9.4 libx264, libx264rgb# TOC
-
-
x264 H.264/MPEG-4 AVC encoder wrapper.
-
-
This encoder requires the presence of the libx264 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx264.
-
-
libx264 supports an impressive number of features, including 8x8 and
-4x4 adaptive spatial transform, adaptive B-frame placement, CAVLC/CABAC
-entropy coding, interlacing (MBAFF), lossless mode, psy optimizations
-for detail retention (adaptive quantization, psy-RD, psy-trellis).
-
-
Many libx264 encoder options are mapped to FFmpeg global codec
-options, while unique encoder options are provided through private
-options. Additionally the x264opts and x264-params
-private options allows one to pass a list of key=value tuples as accepted
-by the libx264 x264_param_parse function.
-
-
The x264 project website is at
-http://www.videolan.org/developers/x264.html .
-
-
The libx264rgb encoder is the same as libx264, except it accepts packed RGB
-pixel formats as input instead of YUV.
-
-
-
9.4.1 Supported Pixel Formats# TOC
-
-
x264 supports 8- to 10-bit color spaces. The exact bit depth is controlled at
-x264’s configure time. FFmpeg only supports one bit depth in one particular
-build. In other words, it is not possible to build one FFmpeg with multiple
-versions of x264 with different bit depths.
-
-
-
9.4.2 Options# TOC
-
-
The following options are supported by the libx264 wrapper. The
-x264-equivalent options or values are listed in parentheses
-for easy migration.
-
-
To reduce the duplication of documentation, only the private options
-and some others requiring special attention are documented here. For
-the documentation of the undocumented generic options, see
-the Codec Options chapter .
-
-
To get a more accurate and extensive documentation of the libx264
-options, invoke the command x264 --full-help or consult
-the libx264 documentation.
-
-
-b (bitrate ) Set bitrate in bits/s. Note that FFmpeg’s b option is
-expressed in bits/s, while x264’s bitrate is in
-kilobits/s.
-
-bf (bframes ) g (keyint ) qmin (qpmin ) Minimum quantizer scale.
-
-qmax (qpmax ) Maximum quantizer scale.
-
-qdiff (qpstep ) Maximum difference between quantizer scales.
-
-qblur (qblur ) Quantizer curve blur
-
-qcomp (qcomp ) Quantizer curve compression factor
-
-refs (ref ) Number of reference frames each P-frame can use. The range is from 0-16 .
-
-sc_threshold (scenecut ) Sets the threshold for the scene change detection.
-
-trellis (trellis ) Performs Trellis quantization to increase efficiency. Enabled by default.
-
-nr (nr ) me_range (merange ) Maximum range of the motion search in pixels.
-
-me_method (me ) Set motion estimation method. Possible values in the decreasing order
-of speed:
-
-
-‘dia (dia ) ’
-‘epzs (dia ) ’
-Diamond search with radius 1 (fastest). ‘epzs ’ is an alias for
-‘dia ’.
-
‘hex (hex ) ’
-Hexagonal search with radius 2.
-
‘umh (umh ) ’
-Uneven multi-hexagon search.
-
‘esa (esa ) ’
-Exhaustive search.
-
‘tesa (tesa ) ’
-Hadamard exhaustive search (slowest).
-
-
-subq (subme ) Sub-pixel motion estimation method.
-
-b_strategy (b-adapt ) Adaptive B-frame placement decision algorithm. Use only on first-pass.
-
-keyint_min (min-keyint ) Minimum GOP size.
-
-coder Set entropy encoder. Possible values:
-
-
-‘ac ’
-Enable CABAC.
-
-‘vlc ’
-Enable CAVLC and disable CABAC. It generates the same effect as
-x264’s --no-cabac option.
-
-
-cmp Set full pixel motion estimation comparation algorithm. Possible values:
-
-
-‘chroma ’
-Enable chroma in motion estimation.
-
-‘sad ’
-Ignore chroma in motion estimation. It generates the same effect as
-x264’s --no-chroma-me option.
-
-
-threads (threads ) Number of encoding threads.
-
-thread_type Set multithreading technique. Possible values:
-
-
-‘slice ’
-Slice-based multithreading. It generates the same effect as
-x264’s --sliced-threads option.
-
‘frame ’
-Frame-based multithreading.
-
-
-flags Set encoding flags. It can be used to disable closed GOP and enable
-open GOP by setting it to -cgop. The result is similar to
-the behavior of x264’s --open-gop option.
-
-rc_init_occupancy (vbv-init ) preset (preset ) Set the encoding preset.
-
-tune (tune ) Set tuning of the encoding params.
-
-profile (profile ) Set profile restrictions.
-
-fastfirstpass Enable fast settings when encoding first pass, when set to 1. When set
-to 0, it has the same effect of x264’s
---slow-firstpass option.
-
-crf (crf ) Set the quality for constant quality mode.
-
-crf_max (crf-max ) In CRF mode, prevents VBV from lowering quality beyond this point.
-
-qp (qp ) Set constant quantization rate control method parameter.
-
-aq-mode (aq-mode ) Set AQ method. Possible values:
-
-
-‘none (0 ) ’
-Disabled.
-
-‘variance (1 ) ’
-Variance AQ (complexity mask).
-
-‘autovariance (2 ) ’
-Auto-variance AQ (experimental).
-
-
-aq-strength (aq-strength ) Set AQ strength, reduce blocking and blurring in flat and textured areas.
-
-psy Use psychovisual optimizations when set to 1. When set to 0, it has the
-same effect as x264’s --no-psy option.
-
-psy-rd (psy-rd ) Set strength of psychovisual optimization, in
-psy-rd :psy-trellis format.
-
-rc-lookahead (rc-lookahead ) Set number of frames to look ahead for frametype and ratecontrol.
-
-weightb Enable weighted prediction for B-frames when set to 1. When set to 0,
-it has the same effect as x264’s --no-weightb option.
-
-weightp (weightp ) Set weighted prediction method for P-frames. Possible values:
-
-
-‘none (0 ) ’
-Disabled
-
‘simple (1 ) ’
-Enable only weighted refs
-
‘smart (2 ) ’
-Enable both weighted refs and duplicates
-
-
-ssim (ssim ) Enable calculation and printing SSIM stats after the encoding.
-
-intra-refresh (intra-refresh ) Enable the use of Periodic Intra Refresh instead of IDR frames when set
-to 1.
-
-avcintra-class (class ) Configure the encoder to generate AVC-Intra.
-Valid values are 50,100 and 200
-
-bluray-compat (bluray-compat ) Configure the encoder to be compatible with the bluray standard.
-It is a shorthand for setting "bluray-compat=1 force-cfr=1".
-
-b-bias (b-bias ) Set the influence on how often B-frames are used.
-
-b-pyramid (b-pyramid ) Set method for keeping of some B-frames as references. Possible values:
-
-
-‘none (none ) ’
-Disabled.
-
‘strict (strict ) ’
-Strictly hierarchical pyramid.
-
‘normal (normal ) ’
-Non-strict (not Blu-ray compatible).
-
-
-mixed-refs Enable the use of one reference per partition, as opposed to one
-reference per macroblock when set to 1. When set to 0, it has the
-same effect as x264’s --no-mixed-refs option.
-
-8x8dct Enable adaptive spatial transform (high profile 8x8 transform)
-when set to 1. When set to 0, it has the same effect as
-x264’s --no-8x8dct option.
-
-fast-pskip Enable early SKIP detection on P-frames when set to 1. When set
-to 0, it has the same effect as x264’s
---no-fast-pskip option.
-
-aud (aud ) Enable use of access unit delimiters when set to 1.
-
-mbtree Enable use macroblock tree ratecontrol when set to 1. When set
-to 0, it has the same effect as x264’s
---no-mbtree option.
-
-deblock (deblock ) Set loop filter parameters, in alpha :beta form.
-
-cplxblur (cplxblur ) Set fluctuations reduction in QP (before curve compression).
-
-partitions (partitions ) Set partitions to consider as a comma-separated list of. Possible
-values in the list:
-
-
-‘p8x8 ’
-8x8 P-frame partition.
-
‘p4x4 ’
-4x4 P-frame partition.
-
‘b8x8 ’
-4x4 B-frame partition.
-
‘i8x8 ’
-8x8 I-frame partition.
-
‘i4x4 ’
-4x4 I-frame partition.
-(Enabling ‘p4x4 ’ requires ‘p8x8 ’ to be enabled. Enabling
-‘i8x8 ’ requires adaptive spatial transform (8x8dct
-option) to be enabled.)
-
‘none (none ) ’
-Do not consider any partitions.
-
‘all (all ) ’
-Consider every partition.
-
-
-direct-pred (direct ) Set direct MV prediction mode. Possible values:
-
-
-‘none (none ) ’
-Disable MV prediction.
-
‘spatial (spatial ) ’
-Enable spatial predicting.
-
‘temporal (temporal ) ’
-Enable temporal predicting.
-
‘auto (auto ) ’
-Automatically decided.
-
-
-slice-max-size (slice-max-size ) Set the limit of the size of each slice in bytes. If not specified
-but RTP payload size (ps ) is specified, that is used.
-
-stats (stats ) Set the file name for multi-pass stats.
-
-nal-hrd (nal-hrd ) Set signal HRD information (requires vbv-bufsize to be set).
-Possible values:
-
-
-‘none (none ) ’
-Disable HRD information signaling.
-
‘vbr (vbr ) ’
-Variable bit rate.
-
‘cbr (cbr ) ’
-Constant bit rate (not allowed in MP4 container).
-
-
-x264opts (N.A.) Set any x264 option, see x264 --fullhelp for a list.
-
-Argument is a list of key =value couples separated by
-":". In filter and psy-rd options that use ":" as a separator
-themselves, use "," instead. They accept it as well since long ago but this
-is kept undocumented for some reason.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i foo.mpg -vcodec libx264 -x264opts keyint=123:min-keyint=20 -an out.mkv
- x264-params (N.A.) Override the x264 configuration using a :-separated list of key=value
-parameters.
-
-This option is functionally the same as the x264opts , but is
-duplicated for compatibility with the Libav fork.
-
-For example to specify libx264 encoding options with ffmpeg:
-
-
ffmpeg -i INPUT -c:v libx264 -x264-params level=30:bframes=0:weightp=0:\
-cabac=0:ref=1:vbv-maxrate=768:vbv-bufsize=2000:analyse=all:me=umh:\
-no-fast-pskip=1:subq=6:8x8dct=0:trellis=0 OUTPUT
-
-
-
Encoding ffpresets for common usages are provided so they can be used with the
-general presets system (e.g. passing the pre option).
-
-
-
9.5 libx265# TOC
-
-
x265 H.265/HEVC encoder wrapper.
-
-
This encoder requires the presence of the libx265 headers and library
-during configuration. You need to explicitly configure the build with
---enable-libx265 .
-
-
-
9.5.1 Options# TOC
-
-
-preset Set the x265 preset.
-
-tune Set the x265 tune parameter.
-
-x265-params Set x265 options using a list of key =value couples separated
-by ":". See x265 --help for a list of options.
-
-For example to specify libx265 encoding options with -x265-params :
-
-
-
ffmpeg -i input -c:v libx265 -x265-params crf=26:psy-rd=1 output.mp4
-
-
-
-
9.6 libxvid# TOC
-
-
Xvid MPEG-4 Part 2 encoder wrapper.
-
-
This encoder requires the presence of the libxvidcore headers and library
-during configuration. You need to explicitly configure the build with
---enable-libxvid --enable-gpl.
-
-
The native mpeg4 encoder supports the MPEG-4 Part 2 format, so
-users can encode to this format without this library.
-
-
-
9.6.1 Options# TOC
-
-
The following options are supported by the libxvid wrapper. Some of
-the following options are listed but are not documented, and
-correspond to shared codec options. See the Codec
-Options chapter for their documentation. The other shared options
-which are not listed have no effect for the libxvid encoder.
-
-
-b g qmin qmax mpeg_quant threads bf b_qfactor b_qoffset flags Set specific encoding flags. Possible values:
-
-
-‘mv4 ’
-Use four motion vector by macroblock.
-
-‘aic ’
-Enable high quality AC prediction.
-
-‘gray ’
-Only encode grayscale.
-
-‘gmc ’
-Enable the use of global motion compensation (GMC).
-
-‘qpel ’
-Enable quarter-pixel motion compensation.
-
-‘cgop ’
-Enable closed GOP.
-
-‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
-
-
-trellis me_method Set motion estimation method. Possible values in decreasing order of
-speed and increasing order of quality:
-
-
-‘zero ’
-Use no motion estimation (default).
-
-‘phods ’
-‘x1 ’
-‘log ’
-Enable advanced diamond zonal search for 16x16 blocks and half-pixel
-refinement for 16x16 blocks. ‘x1 ’ and ‘log ’ are aliases for
-‘phods ’.
-
-‘epzs ’
-Enable all of the things described above, plus advanced diamond zonal
-search for 8x8 blocks, half-pixel refinement for 8x8 blocks, and motion
-estimation on chroma planes.
-
-‘full ’
-Enable all of the things described above, plus extended 16x16 and 8x8
-blocks search.
-
-
-mbd Set macroblock decision algorithm. Possible values in the increasing
-order of quality:
-
-
-‘simple ’
-Use macroblock comparing function algorithm (default).
-
-‘bits ’
-Enable rate distortion-based half pixel and quarter pixel refinement for
-16x16 blocks.
-
-‘rd ’
-Enable all of the things described above, plus rate distortion-based
-half pixel and quarter pixel refinement for 8x8 blocks, and rate
-distortion-based search using square pattern.
-
-
-lumi_aq Enable lumi masking adaptive quantization when set to 1. Default is 0
-(disabled).
-
-variance_aq Enable variance adaptive quantization when set to 1. Default is 0
-(disabled).
-
-When combined with lumi_aq , the resulting quality will not
-be better than any of the two specified individually. In other
-words, the resulting quality will be the worse one of the two
-effects.
-
-ssim Set structural similarity (SSIM) displaying method. Possible values:
-
-
-‘off ’
-Disable displaying of SSIM information.
-
-‘avg ’
-Output average SSIM at the end of encoding to stdout. The format of
-showing the average SSIM is:
-
-
-
-For users who are not familiar with C, %f means a float number, or
-a decimal (e.g. 0.939232).
-
-‘frame ’
-Output both per-frame SSIM data during encoding and average SSIM at
-the end of encoding to stdout. The format of per-frame information
-is:
-
-
-
SSIM: avg: %1.3f min: %1.3f max: %1.3f
- For users who are not familiar with C, %1.3f means a float number
-rounded to 3 digits after the dot (e.g. 0.932).
-
-
-
-ssim_acc Set SSIM accuracy. Valid options are integers within the range of
-0-4, while 0 gives the most accurate result and 4 computes the
-fastest.
-
-
-
-
-
9.7 mpeg2# TOC
-
-
MPEG-2 video encoder.
-
-
-
9.7.1 Options# TOC
-
-
-seq_disp_ext integer Specifies if the encoder should write a sequence_display_extension to the
-output.
-
--1 auto Decide automatically to write it or not (this is the default) by checking if
-the data to be written is different from the default or unspecified values.
-
0 never Never write it.
-
1 always Always write it.
-
-
-
-
-
-
-
PNG image encoder.
-
-
-
9.8.1 Private options# TOC
-
-
-dpi integer Set physical density of pixels, in dots per inch, unset by default
-
dpm integer Set physical density of pixels, in dots per meter, unset by default
-
-
-
-
9.9 ProRes# TOC
-
-
Apple ProRes encoder.
-
-
FFmpeg contains 2 ProRes encoders, the prores-aw and prores-ks encoder.
-The used encoder can be chosen with the -vcodec option.
-
-
-
9.9.1 Private Options for prores-ks# TOC
-
-
-profile integer Select the ProRes profile to encode
-
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-‘4444 ’
-
-
-quant_mat integer Select quantization matrix.
-
-‘auto ’
-‘default ’
-‘proxy ’
-‘lt ’
-‘standard ’
-‘hq ’
-
-If set to auto , the matrix matching the profile will be picked.
-If not set, the matrix providing the highest quality, default , will be
-picked.
-
-bits_per_mb integer How many bits to allot for coding one macroblock. Different profiles use
-between 200 and 2400 bits per macroblock, the maximum is 8000.
-
-mbs_per_slice integer Number of macroblocks in each slice (1-8); the default value (8)
-should be good in almost all situations.
-
-vendor string Override the 4-byte vendor ID.
-A custom vendor ID like apl0 would claim the stream was produced by
-the Apple encoder.
-
-alpha_bits integer Specify number of bits for alpha component.
-Possible values are 0 , 8 and 16 .
-Use 0 to disable alpha plane coding.
-
-
-
-
-
9.9.2 Speed considerations# TOC
-
-
In the default mode of operation the encoder has to honor frame constraints
-(i.e. not produce frames with size bigger than requested) while still making
-output picture as good as possible.
-A frame containing a lot of small details is harder to compress and the encoder
-would spend more time searching for appropriate quantizers for each slice.
-
-
Setting a higher bits_per_mb limit will improve the speed.
-
-
For the fastest encoding speed set the qscale parameter (4 is the
-recommended value) and do not set a size constraint.
-
-
-
-
10 Subtitles Encoders# TOC
-
-
-
10.1 dvdsub# TOC
-
-
This codec encodes the bitmap subtitle format that is used in DVDs.
-Typically they are stored in VOBSUB file pairs (*.idx + *.sub),
-and they can also be used in Matroska files.
-
-
-
10.1.1 Options# TOC
-
-
-even_rows_fix When set to 1, enable a work-around that makes the number of pixel rows
-even in all subtitles. This fixes a problem with some players that
-cut off the bottom row if the number is odd. The work-around just adds
-a fully transparent row if needed. The overhead is low, typically
-one byte per subtitle on average.
-
-By default, this work-around is disabled.
-
-
-
-
-
11 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavcodec
-
-
-
-
12 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Devices Documentation
-
-
-
- FFmpeg Devices Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the input and output devices provided by the
-libavdevice library.
-
-
-
-
2 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
3 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
3.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
3.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
3.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
3.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
3.3 bktr# TOC
-
-
BSD video input device.
-
-
-
3.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
3.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
3.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
3.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
3.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
3.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
3.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
3.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
3.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
3.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
3.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
3.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
3.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
3.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
3.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
3.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
3.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
3.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
3.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
3.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
3.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
3.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
3.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
3.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
3.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
3.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
3.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
3.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
3.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
3.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
3.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
3.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
3.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
4 Output Devices# TOC
-
-
Output devices are configured elements in FFmpeg that can write
-multimedia data to an output device attached to your system.
-
-
When you configure your FFmpeg build, all the supported output devices
-are enabled by default. You can list all available ones using the
-configure option "–list-outdevs".
-
-
You can disable all the output devices using the configure option
-"–disable-outdevs", and selectively enable an output device using the
-option "–enable-outdev=OUTDEV ", or you can disable a particular
-input device using the option "–disable-outdev=OUTDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-enabled output devices.
-
-
A description of the currently available output devices follows.
-
-
-
4.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) output device.
-
-
-
4.1.1 Examples# TOC
-
-
- Play a file on default ALSA device:
-
-
ffmpeg -i INPUT -f alsa default
- Play a file on soundcard 1, audio device 7:
-
-
ffmpeg -i INPUT -f alsa hw:1,7
-
-
-
-
4.2 caca# TOC
-
-
CACA output device.
-
-
This output device allows one to show a video stream in CACA window.
-Only one CACA window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need to configure FFmpeg with
---enable-libcaca.
-libcaca is a graphics library that outputs text instead of pixels.
-
-
For more information about libcaca, check:
-http://caca.zoy.org/wiki/libcaca
-
-
-
4.2.1 Options# TOC
-
-
-window_title Set the CACA window title, if not specified default to the filename
-specified for the output device.
-
-window_size Set the CACA window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video.
-
-driver Set display driver.
-
-algorithm Set dithering algorithm. Dithering is necessary
-because the picture being rendered has usually far more colours than
-the available palette.
-The accepted values are listed with -list_dither algorithms.
-
-antialias Set antialias method. Antialiasing smoothens the rendered
-image and avoids the commonly seen staircase effect.
-The accepted values are listed with -list_dither antialiases.
-
-charset Set which characters are going to be used when rendering text.
-The accepted values are listed with -list_dither charsets.
-
-color Set color to be used when rendering text.
-The accepted values are listed with -list_dither colors.
-
-list_drivers If set to true , print a list of available drivers and exit.
-
-list_dither List available dither options related to the argument.
-The argument must be one of algorithms, antialiases,
-charsets, colors.
-
-
-
-
4.2.2 Examples# TOC
-
-
- The following command shows the ffmpeg output is an
-CACA window, forcing its size to 80x25:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt rgb24 -window_size 80x25 -f caca -
- Show the list of available drivers and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_drivers true -
- Show the list of available dither colors and exit:
-
-
ffmpeg -i INPUT -pix_fmt rgb24 -f caca -list_dither colors -
-
-
-
-
4.3 decklink# TOC
-
-
The decklink output device provides playback capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this output device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz.
-
-
-
4.3.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-preroll Amount of time to preroll video in seconds.
-Defaults to 0.5 .
-
-
-
-
-
4.3.2 Examples# TOC
-
-
- List output devices:
-
-
ffmpeg -i test.avi -f decklink -list_devices 1 dummy
- List supported formats:
-
-
ffmpeg -i test.avi -f decklink -list_formats 1 'DeckLink Mini Monitor'
- Play video clip:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 'DeckLink Mini Monitor'
- Play video clip with non-standard framerate or video size:
-
-
ffmpeg -i test.avi -f decklink -pix_fmt uyvy422 -s 720x486 -r 24000/1001 'DeckLink Mini Monitor'
-
-
-
-
4.4 fbdev# TOC
-
-
Linux framebuffer output device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
-
4.4.1 Options# TOC
-
-xoffset yoffset Set x/y coordinate of top left corner. Default is 0.
-
-
-
-
4.4.2 Examples# TOC
-
Play a file on framebuffer device /dev/fb0 .
-Required pixel format depends on current framebuffer settings.
-
-
ffmpeg -re -i INPUT -vcodec rawvideo -pix_fmt bgra -f fbdev /dev/fb0
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
4.5 opengl# TOC
-
OpenGL output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-opengl.
-
-
This output device allows one to render to OpenGL context.
-Context may be provided by application or default SDL window is created.
-
-
When device renders to external context, application must implement handlers for following messages:
-AV_DEV_TO_APP_CREATE_WINDOW_BUFFER - create OpenGL context on current thread.
-AV_DEV_TO_APP_PREPARE_WINDOW_BUFFER - make OpenGL context current.
-AV_DEV_TO_APP_DISPLAY_WINDOW_BUFFER - swap buffers.
-AV_DEV_TO_APP_DESTROY_WINDOW_BUFFER - destroy OpenGL context.
-Application is also required to inform a device about current resolution by sending AV_APP_TO_DEV_WINDOW_SIZE message.
-
-
-
4.5.1 Options# TOC
-
-background Set background color. Black is a default.
-
no_window Disables default SDL window when set to non-zero value.
-Application must provide OpenGL context and both window_size_cb and window_swap_buffers_cb callbacks when set.
-
window_title Set the SDL window title, if not specified default to the filename specified for the output device.
-Ignored when no_window is set.
-
window_size Set preferred window size, can be a string of the form widthxheight or a video size abbreviation.
-If not specified it defaults to the size of the input video, downscaled according to the aspect ratio.
-Mostly usable when no_window is not set.
-
-
-
-
-
4.5.2 Examples# TOC
-
Play a file on SDL window using OpenGL rendering:
-
-
ffmpeg -i INPUT -f opengl "window title"
-
-
-
-
-
-
OSS (Open Sound System) output device.
-
-
-
4.7 pulse# TOC
-
-
PulseAudio output device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org
-
-
-
4.7.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is set to the specified output name.
-
-device Specify the device to use. Default device is used when not provided.
-List of output devices can be obtained with command pactl list sinks.
-
-buffer_size buffer_duration Control the size and duration of the PulseAudio buffer. A small buffer
-gives more control, but requires more frequent updates.
-
-buffer_size specifies size in bytes while
-buffer_duration specifies duration in milliseconds.
-
-When both options are provided then the highest value is used
-(duration is recalculated to bytes using stream parameters). If they
-are set to 0 (which is default), the device will use the default
-PulseAudio duration value. By default PulseAudio set buffer duration
-to around 2 seconds.
-
-prebuf Specify pre-buffering size in bytes. The server does not start with
-playback before at least prebuf bytes are available in the
-buffer. By default this option is initialized to the same value as
-buffer_size or buffer_duration (whichever is bigger).
-
-minreq Specify minimum request size in bytes. The server does not request less
-than minreq bytes from the client, instead waits until the buffer
-is free enough to request more bytes at once. It is recommended to not set
-this option, which will initialize this to a value that is deemed sensible
-by the server.
-
-
-
-
-
4.7.2 Examples# TOC
-
Play a file on default device on default server:
-
-
ffmpeg -i INPUT -f pulse "stream name"
-
-
-
-
-
-
SDL (Simple DirectMedia Layer) output device.
-
-
This output device allows one to show a video stream in an SDL
-window. Only one SDL window is allowed per application, so you can
-have only one instance of this output device in an application.
-
-
To enable this output device you need libsdl installed on your system
-when configuring your build.
-
-
For more information about SDL, check:
-http://www.libsdl.org/
-
-
-
4.8.1 Options# TOC
-
-
-window_title Set the SDL window title, if not specified default to the filename
-specified for the output device.
-
-icon_title Set the name of the iconified SDL window, if not specified it is set
-to the same value of window_title .
-
-window_size Set the SDL window size, can be a string of the form
-width xheight or a video size abbreviation.
-If not specified it defaults to the size of the input video,
-downscaled according to the aspect ratio.
-
-window_fullscreen Set fullscreen mode when non-zero value is provided.
-Default value is zero.
-
-
-
-
4.8.2 Interactive commands# TOC
-
-
The window created by the device can be controlled through the
-following interactive commands.
-
-
-q, ESC Quit the device immediately.
-
-
-
-
4.8.3 Examples# TOC
-
-
The following command shows the ffmpeg output is an
-SDL window, forcing its size to the qcif format:
-
-
ffmpeg -i INPUT -vcodec rawvideo -pix_fmt yuv420p -window_size qcif -f sdl "SDL output"
-
-
-
-
4.9 sndio# TOC
-
-
sndio audio output device.
-
-
-
-
-
XV (XVideo) output device.
-
-
This output device allows one to show a video stream in a X Window System
-window.
-
-
-
4.10.1 Options# TOC
-
-
-display_name Specify the hardware display name, which determines the display and
-communications domain to be used.
-
-The display name or DISPLAY environment variable can be a string in
-the format hostname [:number [.screen_number ]].
-
-hostname specifies the name of the host machine on which the
-display is physically attached. number specifies the number of
-the display server on that host machine. screen_number specifies
-the screen to be used on that server.
-
-If unspecified, it defaults to the value of the DISPLAY environment
-variable.
-
-For example, dual-headed:0.1 would specify screen 1 of display
-0 on the machine named “dual-headed”.
-
-Check the X11 specification for more detailed information about the
-display name format.
-
-window_id When set to non-zero value then device doesn’t create new window,
-but uses existing one with provided window_id . By default
-this options is set to zero and device creates its own window.
-
-window_size Set the created window size, can be a string of the form
-width xheight or a video size abbreviation. If not
-specified it defaults to the size of the input video.
-Ignored when window_id is set.
-
-window_x window_y Set the X and Y window offsets for the created window. They are both
-set to 0 by default. The values may be ignored by the window manager.
-Ignored when window_id is set.
-
-window_title Set the window title, if not specified default to the filename
-specified for the output device. Ignored when window_id is set.
-
-
-
For more information about XVideo see http://www.x.org/ .
-
-
-
4.10.2 Examples# TOC
-
-
- Decode, display and encode video input with ffmpeg at the
-same time:
-
-
ffmpeg -i INPUT OUTPUT -f xv display
- Decode and display the input video to multiple X11 windows:
-
-
ffmpeg -i INPUT -f xv normal -vf negate -f xv negated
-
-
-
-
-
5 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavdevice
-
-
-
-
6 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Filters Documentation
-
-
-
- FFmpeg Filters Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes filters, sources, and sinks provided by the
-libavfilter library.
-
-
-
-
2 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
3 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
4 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
4.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
4.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
5 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
6 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
6.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
6.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
6.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
6.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
6.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
6.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
6.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
6.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
6.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
6.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
6.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
6.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
6.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
6.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
6.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
6.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
6.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
6.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
6.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
6.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
6.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
6.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
6.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
6.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
6.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
6.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
6.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
6.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
6.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
6.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
6.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
6.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
6.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
6.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
6.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
6.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
6.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
6.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
6.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
6.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
6.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
6.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
6.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
6.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
6.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
6.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
6.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
6.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
6.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
6.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
6.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
6.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
6.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
6.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
6.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
6.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
6.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
6.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
6.42.2 Examples# TOC
-
-
-
-
-
6.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
6.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
7 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
7.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
7.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
7.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
7.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
7.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
7.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
7.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
7.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
7.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
7.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
8 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
8.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
8.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
9 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
9.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
9.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
9.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
9.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
9.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
9.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
9.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
9.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
9.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
9.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
9.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
9.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
9.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
9.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
9.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
9.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
9.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
9.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
9.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
9.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
9.15.1 Examples# TOC
-
-
-
-
-
9.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
9.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
9.17.1 Examples# TOC
-
-
-
-
-
9.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
9.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
9.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
9.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
9.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
9.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
9.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
9.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
9.23.1 Examples# TOC
-
-
-
-
-
9.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
9.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
9.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
9.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
9.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
9.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
9.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
9.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
9.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
9.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
9.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
9.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
9.29.1 Examples# TOC
-
-
-
-
-
9.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
9.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
9.31.1 p/c/n/u/b meaning# TOC
-
-
-
9.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
9.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
9.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
9.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
9.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
9.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
9.34.1 Examples# TOC
-
-
-
-
-
9.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
9.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
9.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
9.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
9.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
9.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
9.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
9.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
9.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
9.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
9.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
9.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
9.42.1 Workflow examples# TOC
-
-
-
9.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
9.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
9.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
9.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
9.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
9.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
9.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
9.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
9.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
9.48.1 Examples# TOC
-
-
-
-
-
9.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
9.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
9.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
9.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
9.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
9.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
9.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
9.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
9.55.1 Examples# TOC
-
-
-
-
-
9.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
9.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
9.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
9.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
9.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
9.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
9.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
9.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
9.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
9.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
9.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
9.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
9.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
9.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
9.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
9.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
9.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.65.2 Examples# TOC
-
-
-
-
-
9.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
9.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.67.1 Examples# TOC
-
-
-
-
-
9.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
9.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
9.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
9.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
9.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
9.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
9.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
9.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
9.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
9.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
9.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
9.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
9.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
9.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
9.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.79.2 Examples# TOC
-
-
-
-
-
9.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
9.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
9.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
9.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
9.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
9.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
9.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
9.85.1 Examples# TOC
-
-
-
-
-
9.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
9.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
9.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
9.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
9.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
9.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
9.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
9.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
9.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
9.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
9.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
9.94.1 Examples# TOC
-
-
-
-
-
9.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
9.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
9.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
9.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
9.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
9.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
9.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
9.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
9.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
9.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
9.101.2 Examples# TOC
-
-
-
-
-
9.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
9.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
9.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
9.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
9.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
9.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
9.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
9.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
9.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
10 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
10.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
10.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
10.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
10.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
10.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
10.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
10.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
10.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
10.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
10.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
11 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
11.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
11.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
12 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
12.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
12.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
12.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
12.2.1 Examples# TOC
-
-
-
-
-
12.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
12.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
12.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
12.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
12.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
12.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
12.6.1 Examples# TOC
-
-
-
-
-
12.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
12.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
12.7.2 Examples# TOC
-
-
-
-
-
12.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
12.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
12.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
12.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
12.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
12.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
12.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
12.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
12.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
12.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
12.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
12.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
12.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
12.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
13 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
13.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
13.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
13.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
14 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavfilter
-
-
-
-
15 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Formats Documentation
-
-
-
- FFmpeg Formats Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the supported formats (muxers and demuxers)
-provided by the libavformat library.
-
-
-
-
2 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
2.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
3 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
3.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
3.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
3.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
3.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
3.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
3.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
3.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
3.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
3.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
3.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
3.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
3.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
3.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
4 Muxers# TOC
-
-
Muxers are configured elements in FFmpeg which allow writing
-multimedia streams to a particular type of file.
-
-
When you configure your FFmpeg build, all the supported muxers
-are enabled by default. You can list all available muxers using the
-configure option --list-muxers.
-
-
You can disable all the muxers with the configure option
---disable-muxers and selectively enable / disable single muxers
-with the options --enable-muxer=MUXER /
---disable-muxer=MUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled muxers.
-
-
A description of some of the currently available muxers follows.
-
-
-
4.1 aiff# TOC
-
-
Audio Interchange File Format muxer.
-
-
-
4.1.1 Options# TOC
-
-
It accepts the following options:
-
-
-write_id3v2 Enable ID3v2 tags writing when set to 1. Default is 0 (disabled).
-
-id3v2_version Select ID3v2 version to write. Currently only version 3 and 4 (aka.
-ID3v2.3 and ID3v2.4) are supported. The default is version 4.
-
-
-
-
-
-
-
CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a single line of the form:
-CRC=0xCRC , where CRC is a hexadecimal number 0-padded to
-8 digits containing the CRC for all the decoded input frames.
-
-
See also the framecrc muxer.
-
-
-
4.2.1 Examples# TOC
-
-
For example to compute the CRC of the input, and store it in the file
-out.crc :
-
-
ffmpeg -i INPUT -f crc out.crc
-
-
-
You can print the CRC to stdout with the command:
-
-
ffmpeg -i INPUT -f crc -
-
-
-
You can select the output format of each frame with ffmpeg by
-specifying the audio and video codec and format. For example to
-compute the CRC of the input audio converted to PCM unsigned 8-bit
-and the input video converted to MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f crc -
-
-
-
-
4.3 framecrc# TOC
-
-
Per-packet CRC (Cyclic Redundancy Check) testing format.
-
-
This muxer computes and prints the Adler-32 CRC for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-CRC.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , 0xCRC
-
-
-
CRC is a hexadecimal number 0-padded to 8 digits containing the
-CRC of the packet.
-
-
-
4.3.1 Examples# TOC
-
-
For example to compute the CRC of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.crc :
-
-
ffmpeg -i INPUT -f framecrc out.crc
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framecrc -
-
-
-
With ffmpeg, you can select the output format to which the
-audio and video frames are encoded before computing the CRC for each
-packet by specifying the audio and video codec. For example, to
-compute the CRC of each decoded input audio frame converted to PCM
-unsigned 8-bit and of each decoded input video frame converted to
-MPEG-2 video, use the command:
-
-
ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
-
-
-
See also the crc muxer.
-
-
-
4.4 framemd5# TOC
-
-
Per-packet MD5 testing format.
-
-
This muxer computes and prints the MD5 hash for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a line for each audio and video
-packet of the form:
-
-
stream_index , packet_dts , packet_pts , packet_duration , packet_size , MD5
-
-
-
MD5 is a hexadecimal number representing the computed MD5 hash
-for the packet.
-
-
-
4.4.1 Examples# TOC
-
-
For example to compute the MD5 of the audio and video frames in
-INPUT , converted to raw audio and video packets, and store it
-in the file out.md5 :
-
-
ffmpeg -i INPUT -f framemd5 out.md5
-
-
-
To print the information to stdout, use the command:
-
-
ffmpeg -i INPUT -f framemd5 -
-
-
-
See also the md5 muxer.
-
-
-
-
-
Animated GIF muxer.
-
-
It accepts the following options:
-
-
-loop Set the number of times to loop the output. Use -1 for no loop, 0
-for looping indefinitely (default).
-
-final_delay Force the delay (expressed in centiseconds) after the last frame. Each frame
-ends with a delay until the next frame. The default is -1, which is a
-special value to tell the muxer to re-use the previous delay. In case of a
-loop, you might want to customize this value to mark a pause for instance.
-
-
-
For example, to encode a gif looping 10 times, with a 5 seconds delay between
-the loops:
-
-
ffmpeg -i INPUT -loop 10 -final_delay 500 out.gif
-
-
-
Note 1: if you wish to extract the frames in separate GIF files, you need to
-force the image2 muxer:
-
-
ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
-
-
-
Note 2: the GIF format has a very small time base: the delay between two frames
-can not be smaller than one centi second.
-
-
-
-
-
Apple HTTP Live Streaming muxer that segments MPEG-TS according to
-the HTTP Live Streaming (HLS) specification.
-
-
It creates a playlist file, and one or more segment files. The output filename
-specifies the playlist filename.
-
-
By default, the muxer creates a file for each segment produced. These files
-have the same name as the playlist, followed by a sequential number and a
-.ts extension.
-
-
For example, to convert an input file with ffmpeg:
-
-
ffmpeg -i in.nut out.m3u8
-
-
This example will produce the playlist, out.m3u8 , and segment files:
-out0.ts , out1.ts , out2.ts , etc.
-
-
See also the segment muxer, which provides a more generic and
-flexible implementation of a segmenter, and can be used to perform HLS
-segmentation.
-
-
-
4.6.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-hls_time seconds Set the segment length in seconds. Default value is 2.
-
-hls_list_size size Set the maximum number of playlist entries. If set to 0 the list file
-will contain all the segments. Default value is 5.
-
-hls_ts_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing : special characters must be
-escaped.
-
-hls_wrap wrap Set the number after which the segment filename number (the number
-specified in each segment file) wraps. If set to 0 the number will be
-never wrapped. Default value is 0.
-
-This option is useful to avoid to fill the disk with many segment
-files, and limits the maximum number of segment files written to disk
-to wrap .
-
-start_number number Start the playlist sequence number from number . Default value is
-0.
-
-hls_allow_cache allowcache Explicitly set whether the client MAY (1) or MUST NOT (0) cache media segments.
-
-hls_base_url baseurl Append baseurl to every entry in the playlist.
-Useful to generate playlists with absolute paths.
-
-Note that the playlist sequence number must be unique for each segment
-and it is not to be confused with the segment filename sequence number
-which can be cyclic, for example if the wrap option is
-specified.
-
-hls_segment_filename filename Set the segment filename. Unless hls_flags single_file is set filename
-is used as a string format with the segment number:
-
-
ffmpeg in.nut -hls_segment_filename 'file%03d.ts' out.m3u8
- This example will produce the playlist, out.m3u8 , and segment files:
-file000.ts , file001.ts , file002.ts , etc.
-
-hls_flags single_file If this flag is set, the muxer will store all segments in a single MPEG-TS
-file, and will use byte ranges in the playlist. HLS playlists generated with
-this way will have the version number 4.
-For example:
-
-
ffmpeg -i in.nut -hls_flags single_file out.m3u8
- Will produce the playlist, out.m3u8 , and a single segment file,
-out.ts .
-
-hls_flags delete_segments Segment files removed from the playlist are deleted after a period of time
-equal to the duration of the segment plus the duration of the playlist.
-
-
-
-
-
-
ICO file muxer.
-
-
Microsoft’s icon file format (ICO) has some strict limitations that should be noted:
-
-
- Size cannot exceed 256 pixels in any dimension
-
- Only BMP and PNG images can be stored
-
- If a BMP image is used, it must be one of the following pixel formats:
-
-
BMP Bit Depth FFmpeg Pixel Format
-1bit pal8
-4bit pal8
-8bit pal8
-16bit rgb555le
-24bit bgr24
-32bit bgra
- If a BMP image is used, it must use the BITMAPINFOHEADER DIB header
-
- If a PNG image is used, it must use the rgba pixel format
-
-
-
-
4.8 image2# TOC
-
-
Image file muxer.
-
-
The image file muxer writes video frames to image files.
-
-
The output filenames are specified by a pattern, which can be used to
-produce sequentially numbered series of files.
-The pattern may contain the string "%d" or "%0N d", this string
-specifies the position of the characters representing a numbering in
-the filenames. If the form "%0N d" is used, the string
-representing the number in each filename is 0-padded to N
-digits. The literal character ’%’ can be specified in the pattern with
-the string "%%".
-
-
If the pattern contains "%d" or "%0N d", the first filename of
-the file list specified will contain the number 1, all the following
-numbers will be sequential.
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the image files to write.
-
-
For example the pattern "img-%03d.bmp" will specify a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.
-The pattern "img%%-%d.jpg" will specify a sequence of filenames of the
-form img%-1.jpg , img%-2.jpg , ..., img%-10.jpg ,
-etc.
-
-
-
4.8.1 Examples# TOC
-
-
The following example shows how to use ffmpeg for creating a
-sequence of files img-001.jpeg , img-002.jpeg , ...,
-taking one image every second from the input video:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 -f image2 'img-%03d.jpeg'
-
-
-
Note that with ffmpeg, if the format is not specified with the
--f option and the output filename specifies an image file
-format, the image2 muxer is automatically selected, so the previous
-command can be written as:
-
-
ffmpeg -i in.avi -vsync 1 -r 1 'img-%03d.jpeg'
-
-
-
Note also that the pattern must not necessarily contain "%d" or
-"%0N d", for example to create a single image file
-img.jpeg from the input video you can employ the command:
-
-
ffmpeg -i in.avi -f image2 -frames:v 1 img.jpeg
-
-
-
The strftime option allows you to expand the filename with
-date and time information. Check the documentation of
-the strftime() function for the syntax.
-
-
For example to generate image files from the strftime()
-"%Y-%m-%d_%H-%M-%S" pattern, the following ffmpeg command
-can be used:
-
-
ffmpeg -f v4l2 -r 1 -i /dev/video0 -f image2 -strftime 1 "%Y-%m-%d_%H-%M-%S.jpg"
-
-
-
-
4.8.2 Options# TOC
-
-
-start_number Start the sequence from the specified number. Default value is 1. Must
-be a non-negative number.
-
-update If set to 1, the filename will always be interpreted as just a
-filename, not a pattern, and the corresponding file will be continuously
-overwritten with new images. Default value is 0.
-
-strftime If set to 1, expand the filename with date and time information from
-strftime(). Default value is 0.
-
-
-
The image muxer supports the .Y.U.V image file format. This format is
-special in that that each image frame consists of three files, for
-each of the YUV420P components. To read or write this image file format,
-specify the name of the ’.Y’ file. The muxer will automatically open the
-’.U’ and ’.V’ files as required.
-
-
-
4.9 matroska# TOC
-
-
Matroska container muxer.
-
-
This muxer implements the matroska and webm container specs.
-
-
-
4.9.1 Metadata# TOC
-
-
The recognized metadata settings in this muxer are:
-
-
-title Set title name provided to a single track.
-
-language Specify the language of the track in the Matroska languages form.
-
-The language can be either the 3 letters bibliographic ISO-639-2 (ISO
-639-2/B) form (like "fre" for French), or a language code mixed with a
-country code for specialities in languages (like "fre-ca" for Canadian
-French).
-
-stereo_mode Set stereo 3D video layout of two views in a single video track.
-
-The following values are recognized:
-
-‘mono ’
-video is not stereo
-
‘left_right ’
-Both views are arranged side by side, Left-eye view is on the left
-
‘bottom_top ’
-Both views are arranged in top-bottom orientation, Left-eye view is at bottom
-
‘top_bottom ’
-Both views are arranged in top-bottom orientation, Left-eye view is on top
-
‘checkerboard_rl ’
-Each view is arranged in a checkerboard interleaved pattern, Left-eye view being first
-
‘checkerboard_lr ’
-Each view is arranged in a checkerboard interleaved pattern, Right-eye view being first
-
‘row_interleaved_rl ’
-Each view is constituted by a row based interleaving, Right-eye view is first row
-
‘row_interleaved_lr ’
-Each view is constituted by a row based interleaving, Left-eye view is first row
-
‘col_interleaved_rl ’
-Both views are arranged in a column based interleaving manner, Right-eye view is first column
-
‘col_interleaved_lr ’
-Both views are arranged in a column based interleaving manner, Left-eye view is first column
-
‘anaglyph_cyan_red ’
-All frames are in anaglyph format viewable through red-cyan filters
-
‘right_left ’
-Both views are arranged side by side, Right-eye view is on the left
-
‘anaglyph_green_magenta ’
-All frames are in anaglyph format viewable through green-magenta filters
-
‘block_lr ’
-Both eyes laced in one Block, Left-eye view is first
-
‘block_rl ’
-Both eyes laced in one Block, Right-eye view is first
-
-
-
-
For example a 3D WebM clip can be created using the following command line:
-
-
ffmpeg -i sample_left_right_clip.mpg -an -c:v libvpx -metadata stereo_mode=left_right -y stereo_clip.webm
-
-
-
-
4.9.2 Options# TOC
-
-
This muxer supports the following options:
-
-
-reserve_index_space By default, this muxer writes the index for seeking (called cues in Matroska
-terms) at the end of the file, because it cannot know in advance how much space
-to leave for the index at the beginning of the file. However for some use cases
-– e.g. streaming where seeking is possible but slow – it is useful to put the
-index at the beginning of the file.
-
-If this option is set to a non-zero value, the muxer will reserve a given amount
-of space in the file header and then try to write the cues there when the muxing
-finishes. If the available space does not suffice, muxing will fail. A safe size
-for most use cases should be about 50kB per hour of video.
-
-Note that cues are only written if the output is seekable and this option will
-have no effect if it is not.
-
-
-
-
4.10 md5# TOC
-
-
MD5 testing format.
-
-
This muxer computes and prints the MD5 hash of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
-
-
The output of the muxer consists of a single line of the form:
-MD5=MD5 , where MD5 is a hexadecimal number representing
-the computed MD5 hash.
-
-
For example to compute the MD5 hash of the input converted to raw
-audio and video, and store it in the file out.md5 :
-
-
ffmpeg -i INPUT -f md5 out.md5
-
-
-
You can print the MD5 to stdout with the command:
-
-
ffmpeg -i INPUT -f md5 -
-
-
-
See also the framemd5 muxer.
-
-
-
4.11 mov, mp4, ismv# TOC
-
-
MOV/MP4/ISMV (Smooth Streaming) muxer.
-
-
The mov/mp4/ismv muxer supports fragmentation. Normally, a MOV/MP4
-file has all the metadata about all packets stored in one location
-(written at the end of the file, it can be moved to the start for
-better playback by adding faststart to the movflags , or
-using the qt-faststart tool). A fragmented
-file consists of a number of fragments, where packets and metadata
-about these packets are stored together. Writing a fragmented
-file has the advantage that the file is decodable even if the
-writing is interrupted (while a normal MOV/MP4 is undecodable if
-it is not properly finished), and it requires less memory when writing
-very long files (since writing normal MOV/MP4 files stores info about
-every single packet in memory until the file is closed). The downside
-is that it is less compatible with other applications.
-
-
-
4.11.1 Options# TOC
-
-
Fragmentation is enabled by setting one of the AVOptions that define
-how to cut the file into fragments:
-
-
--moov_size bytes Reserves space for the moov atom at the beginning of the file instead of placing the
-moov atom at the end. If the space reserved is insufficient, muxing will fail.
-
-movflags frag_keyframe Start a new fragment at each video keyframe.
-
-frag_duration duration Create fragments that are duration microseconds long.
-
-frag_size size Create fragments that contain up to size bytes of payload data.
-
-movflags frag_custom Allow the caller to manually choose when to cut fragments, by
-calling av_write_frame(ctx, NULL) to write a fragment with
-the packets written so far. (This is only useful with other
-applications integrating libavformat, not from ffmpeg.)
-
-min_frag_duration duration Don’t create fragments that are shorter than duration microseconds long.
-
-
-
If more than one condition is specified, fragments are cut when
-one of the specified conditions is fulfilled. The exception to this is
--min_frag_duration, which has to be fulfilled for any of the other
-conditions to apply.
-
-
Additionally, the way the output file is written can be adjusted
-through a few other options:
-
-
--movflags empty_moov Write an initial moov atom directly at the start of the file, without
-describing any samples in it. Generally, an mdat/moov pair is written
-at the start of the file, as a normal MOV/MP4 file, containing only
-a short portion of the file. With this option set, there is no initial
-mdat atom, and the moov atom only describes the tracks but has
-a zero duration.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags separate_moof Write a separate moof (movie fragment) atom for each track. Normally,
-packets for all tracks are written in a moof atom (which is slightly
-more efficient), but with this option set, the muxer writes one moof/mdat
-pair for each track, making it easier to separate tracks.
-
-This option is implicitly set when writing ismv (Smooth Streaming) files.
-
-movflags faststart Run a second pass moving the index (moov atom) to the beginning of the file.
-This operation can take a while, and will not work in various situations such
-as fragmented output, thus it is not enabled by default.
-
-movflags rtphint Add RTP hinting tracks to the output file.
-
-movflags disable_chpl Disable Nero chapter markers (chpl atom). Normally, both Nero chapters
-and a QuickTime chapter track are written to the file. With this option
-set, only the QuickTime chapter track will be written. Nero chapters can
-cause failures when the file is reprocessed with certain tagging programs, like
-mp3Tag 2.61a and iTunes 11.3, most likely other versions are affected as well.
-
-movflags omit_tfhd_offset Do not write any absolute base_data_offset in tfhd atoms. This avoids
-tying fragments to absolute byte positions in the file/streams.
-
-movflags default_base_moof Similarly to the omit_tfhd_offset, this flag avoids writing the
-absolute base_data_offset field in tfhd atoms, but does so by using
-the new default-base-is-moof flag instead. This flag is new from
-14496-12:2012. This may make the fragments easier to parse in certain
-circumstances (avoiding basing track fragment location calculations
-on the implicit end of the previous track fragment).
-
-
-
-
4.11.2 Example# TOC
-
-
Smooth Streaming content can be pushed in real time to a publishing
-point on IIS with this muxer. Example:
-
-
ffmpeg -re <normal input/transcoding options> -movflags isml+frag_keyframe -f ismv http://server/publishingpoint.isml/Streams(Encoder1)
-
-
-
-
4.12 mp3# TOC
-
-
The MP3 muxer writes a raw MP3 stream with the following optional features:
-
- An ID3v2 metadata header at the beginning (enabled by default). Versions 2.3 and
-2.4 are supported, the id3v2_version private option controls which one is
-used (3 or 4). Setting id3v2_version to 0 disables the ID3v2 header
-completely.
-
-The muxer supports writing attached pictures (APIC frames) to the ID3v2 header.
-The pictures are supplied to the muxer in form of a video stream with a single
-packet. There can be any number of those streams, each will correspond to a
-single APIC frame. The stream metadata tags title and comment map
-to APIC description and picture type respectively. See
-http://id3.org/id3v2.4.0-frames for allowed picture types.
-
-Note that the APIC frames must be written at the beginning, so the muxer will
-buffer the audio frames until it gets all the pictures. It is therefore advised
-to provide the pictures as soon as possible to avoid excessive buffering.
-
- A Xing/LAME frame right after the ID3v2 header (if present). It is enabled by
-default, but will be written only if the output is seekable. The
-write_xing private option can be used to disable it. The frame contains
-various information that may be useful to the decoder, like the audio duration
-or encoder delay.
-
- A legacy ID3v1 tag at the end of the file (disabled by default). It may be
-enabled with the write_id3v1 private option, but as its capabilities are
-very limited, its usage is not recommended.
-
-
-
Examples:
-
-
Write an mp3 with an ID3v2.3 header and an ID3v1 footer:
-
-
ffmpeg -i INPUT -id3v2_version 3 -write_id3v1 1 out.mp3
-
-
-
To attach a picture to an mp3 file select both the audio and the picture stream
-with map:
-
-
ffmpeg -i input.mp3 -i cover.png -c copy -map 0 -map 1
--metadata:s:v title="Album cover" -metadata:s:v comment="Cover (Front)" out.mp3
-
-
-
Write a "clean" MP3 without any extra features:
-
-
ffmpeg -i input.wav -write_xing 0 -id3v2_version 0 out.mp3
-
-
-
-
4.13 mpegts# TOC
-
-
MPEG transport stream muxer.
-
-
This muxer implements ISO 13818-1 and part of ETSI EN 300 468.
-
-
The recognized metadata settings in mpegts muxer are service_provider
-and service_name. If they are not set the default for
-service_provider is "FFmpeg" and the default for
-service_name is "Service01".
-
-
-
4.13.1 Options# TOC
-
-
The muxer options are:
-
-
--mpegts_original_network_id number Set the original_network_id (default 0x0001). This is unique identifier
-of a network in DVB. Its main use is in the unique identification of a
-service through the path Original_Network_ID, Transport_Stream_ID.
-
-mpegts_transport_stream_id number Set the transport_stream_id (default 0x0001). This identifies a
-transponder in DVB.
-
-mpegts_service_id number Set the service_id (default 0x0001) also known as program in DVB.
-
-mpegts_pmt_start_pid number Set the first PID for PMT (default 0x1000, max 0x1f00).
-
-mpegts_start_pid number Set the first PID for data packets (default 0x0100, max 0x0f00).
-
-mpegts_m2ts_mode number Enable m2ts mode if set to 1. Default value is -1 which disables m2ts mode.
-
-muxrate number Set a constant muxrate (default VBR).
-
-pcr_period numer Override the default PCR retransmission time (default 20ms), ignored
-if variable muxrate is selected.
-
-pes_payload_size number Set minimum PES packet payload in bytes.
-
-mpegts_flags flags Set flags (see below).
-
-mpegts_copyts number Preserve original timestamps, if value is set to 1. Default value is -1, which
-results in shifting timestamps so that they start from 0.
-
-tables_version number Set PAT, PMT and SDT version (default 0, valid values are from 0 to 31, inclusively).
-This option allows updating stream structure so that standard consumer may
-detect the change. To do so, reopen output AVFormatContext (in case of API
-usage) or restart ffmpeg instance, cyclically changing tables_version value:
-
-
ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-ffmpeg -i source3.ts -codec copy -f mpegts -tables_version 31 udp://1.1.1.1:1111
-ffmpeg -i source1.ts -codec copy -f mpegts -tables_version 0 udp://1.1.1.1:1111
-ffmpeg -i source2.ts -codec copy -f mpegts -tables_version 1 udp://1.1.1.1:1111
-...
-
-
-
Option mpegts_flags may take a set of such flags:
-
-
-resend_headers Reemit PAT/PMT before writing the next packet.
-
latm Use LATM packetization for AAC.
-
-
-
-
4.13.2 Example# TOC
-
-
-
ffmpeg -i file.mpg -c copy \
- -mpegts_original_network_id 0x1122 \
- -mpegts_transport_stream_id 0x3344 \
- -mpegts_service_id 0x5566 \
- -mpegts_pmt_start_pid 0x1500 \
- -mpegts_start_pid 0x150 \
- -metadata service_provider="Some provider" \
- -metadata service_name="Some Channel" \
- -y out.ts
-
-
-
-
4.14 null# TOC
-
-
Null muxer.
-
-
This muxer does not generate any output file, it is mainly useful for
-testing or benchmarking purposes.
-
-
For example to benchmark decoding with ffmpeg you can use the
-command:
-
-
ffmpeg -benchmark -i INPUT -f null out.null
-
-
-
Note that the above command does not read or write the out.null
-file, but specifying the output file is required by the ffmpeg
-syntax.
-
-
Alternatively you can write the command as:
-
-
ffmpeg -benchmark -i INPUT -f null -
-
-
-
-
4.15 nut# TOC
-
-
--syncpoints flags Change the syncpoint usage in nut:
-
-default use the normal low-overhead seeking aids.none do not use the syncpoints at all, reducing the overhead but making the stream non-seekable;Use of this option is not recommended, as the resulting files are very damage
- sensitive and seeking is not possible. Also in general the overhead from
- syncpoints is negligible. Note, -write_index 0 can be used to disable
- all growing data tables, allowing to mux endless streams with limited memory
- and without these disadvantages.
-
timestamped extend the syncpoint with a wallclock field.
-The none and timestamped flags are experimental.
-
-write_index bool Write index at the end, the default is to write an index.
-
-
-
-
ffmpeg -i INPUT -f_strict experimental -syncpoints none - | processor
-
-
-
-
4.16 ogg# TOC
-
-
Ogg container muxer.
-
-
--page_duration duration Preferred page duration, in microseconds. The muxer will attempt to create
-pages that are approximately duration microseconds long. This allows the
-user to compromise between seek granularity and container overhead. The default
-is 1 second. A value of 0 will fill all segments, making pages as large as
-possible. A value of 1 will effectively use 1 packet-per-page in most
-situations, giving a small seek granularity at the cost of additional container
-overhead.
-
-
-
-
4.17 segment, stream_segment, ssegment# TOC
-
-
Basic stream segmenter.
-
-
This muxer outputs streams to a number of separate files of nearly
-fixed duration. Output filename pattern can be set in a fashion similar to
-image2 .
-
-
stream_segment is a variant of the muxer used to write to
-streaming output formats, i.e. which do not require global headers,
-and is recommended for outputting e.g. to MPEG transport stream segments.
-ssegment is a shorter alias for stream_segment.
-
-
Every segment starts with a keyframe of the selected reference stream,
-which is set through the reference_stream option.
-
-
Note that if you want accurate splitting for a video file, you need to
-make the input key frames correspond to the exact splitting times
-expected by the segmenter, or the segment muxer will start the new
-segment with the key frame found next after the specified start
-time.
-
-
The segment muxer works best with a single constant frame rate video.
-
-
Optionally it can generate a list of the created segments, by setting
-the option segment_list . The list type is specified by the
-segment_list_type option. The entry filenames in the segment
-list are set by default to the basename of the corresponding segment
-files.
-
-
See also the hls muxer, which provides a more specific
-implementation for HLS segmentation.
-
-
-
4.17.1 Options# TOC
-
-
The segment muxer supports the following options:
-
-
-reference_stream specifier Set the reference stream, as specified by the string specifier .
-If specifier is set to auto, the reference is chosen
-automatically. Otherwise it must be a stream specifier (see the “Stream
-specifiers” chapter in the ffmpeg manual) which specifies the
-reference stream. The default value is auto.
-
-segment_format format Override the inner container format, by default it is guessed by the filename
-extension.
-
-segment_format_options options_list Set output format options using a :-separated list of key=value
-parameters. Values containing the : special character must be
-escaped.
-
-segment_list name Generate also a listfile named name . If not specified no
-listfile is generated.
-
-segment_list_flags flags Set flags affecting the segment list generation.
-
-It currently supports the following flags:
-
-‘cache ’
-Allow caching (only affects M3U8 list files).
-
-‘live ’
-Allow live-friendly file generation.
-
-
-segment_list_type type Select the listing format.
-
-flat use a simple flat list of entries.hls use a m3u8-like structure.
-
-segment_list_size size Update the list file so that it contains at most size
-segments. If 0 the list file will contain all the segments. Default
-value is 0.
-
-segment_list_entry_prefix prefix Prepend prefix to each entry. Useful to generate absolute paths.
-By default no prefix is applied.
-
-The following values are recognized:
-
-‘flat ’
-Generate a flat list for the created segments, one segment per line.
-
-‘csv, ext ’
-Generate a list for the created segments, one segment per line,
-each line matching the format (comma-separated values):
-
-
segment_filename ,segment_start_time ,segment_end_time
-segment_filename is the name of the output file generated by the
-muxer according to the provided pattern. CSV escaping (according to
-RFC4180) is applied if required.
-
-segment_start_time and segment_end_time specify
-the segment start and end time expressed in seconds.
-
-A list file with the suffix ".csv" or ".ext" will
-auto-select this format.
-
-‘ext ’ is deprecated in favor or ‘csv ’.
-
-‘ffconcat ’
-Generate an ffconcat file for the created segments. The resulting file
-can be read using the FFmpeg concat demuxer.
-
-A list file with the suffix ".ffcat" or ".ffconcat" will
-auto-select this format.
-
-‘m3u8 ’
-Generate an extended M3U8 file, version 3, compliant with
-http://tools.ietf.org/id/draft-pantos-http-live-streaming .
-
-A list file with the suffix ".m3u8" will auto-select this format.
-
-
-If not specified the type is guessed from the list file name suffix.
-
-segment_time time Set segment duration to time , the value must be a duration
-specification. Default value is "2". See also the
-segment_times option.
-
-Note that splitting may not be accurate, unless you force the
-reference stream key-frames at the given time. See the introductory
-notice and the examples below.
-
-segment_atclocktime 1|0 If set to "1" split at regular clock time intervals starting from 00:00
-o’clock. The time value specified in segment_time is
-used for setting the length of the splitting interval.
-
-For example with segment_time set to "900" this makes it possible
-to create files at 12:00 o’clock, 12:15, 12:30, etc.
-
-Default value is "0".
-
-segment_time_delta delta Specify the accuracy time when selecting the start time for a
-segment, expressed as a duration specification. Default value is "0".
-
-When delta is specified a key-frame will start a new segment if its
-PTS satisfies the relation:
-
-
PTS >= start_time - time_delta
- This option is useful when splitting video content, which is always
-split at GOP boundaries, in case a key frame is found just before the
-specified split time.
-
-In particular may be used in combination with the ffmpeg option
-force_key_frames . The key frame times specified by
-force_key_frames may not be set accurately because of rounding
-issues, with the consequence that a key frame time may result set just
-before the specified time. For constant frame rate videos a value of
-1/(2*frame_rate ) should address the worst case mismatch between
-the specified time and the time set by force_key_frames .
-
-segment_times times Specify a list of split points. times contains a list of comma
-separated duration specifications, in increasing order. See also
-the segment_time option.
-
-segment_frames frames Specify a list of split video frame numbers. frames contains a
-list of comma separated integer numbers, in increasing order.
-
-This option specifies to start a new segment whenever a reference
-stream key frame is found and the sequential number (starting from 0)
-of the frame is greater or equal to the next value in the list.
-
-segment_wrap limit Wrap around segment index once it reaches limit .
-
-segment_start_number number Set the sequence number of the first segment. Defaults to 0.
-
-reset_timestamps 1|0 Reset timestamps at the begin of each segment, so that each segment
-will start with near-zero timestamps. It is meant to ease the playback
-of the generated segments. May not work with some combinations of
-muxers/codecs. It is set to 0 by default.
-
-initial_offset offset Specify timestamp offset to apply to the output packet timestamps. The
-argument must be a time duration specification, and defaults to 0.
-
-
-
-
4.17.2 Examples# TOC
-
-
-
-
-
4.18 smoothstreaming# TOC
-
-
Smooth Streaming muxer generates a set of files (Manifest, chunks) suitable for serving with conventional web server.
-
-
-window_size Specify the number of fragments kept in the manifest. Default 0 (keep all).
-
-extra_window_size Specify the number of fragments kept outside of the manifest before removing from disk. Default 5.
-
-lookahead_count Specify the number of lookahead fragments. Default 2.
-
-min_frag_duration Specify the minimum fragment duration (in microseconds). Default 5000000.
-
-remove_at_exit Specify whether to remove all fragments when finished. Default 0 (do not remove).
-
-
-
-
-
4.19 tee# TOC
-
-
The tee muxer can be used to write the same data to several files or any
-other kind of muxer. It can be used, for example, to both stream a video to
-the network and save it to disk at the same time.
-
-
It is different from specifying several outputs to the ffmpeg
-command-line tool because the audio and video data will be encoded only once
-with the tee muxer; encoding can be a very expensive process. It is not
-useful when using the libavformat API directly because it is then possible
-to feed the same packets to several muxers directly.
-
-
The slave outputs are specified in the file name given to the muxer,
-separated by ’|’. If any of the slave name contains the ’|’ separator,
-leading or trailing spaces or any special character, it must be
-escaped (see (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual ).
-
-
Muxer options can be specified for each slave by prepending them as a list of
-key =value pairs separated by ’:’, between square brackets. If
-the options values contain a special character or the ’:’ separator, they
-must be escaped; note that this is a second level escaping.
-
-
The following special options are also recognized:
-
-f Specify the format name. Useful if it cannot be guessed from the
-output name suffix.
-
-bsfs[/spec ] Specify a list of bitstream filters to apply to the specified
-output.
-
-It is possible to specify to which streams a given bitstream filter
-applies, by appending a stream specifier to the option separated by
-/. spec must be a stream specifier (see Format stream specifiers ). If the stream specifier is not specified, the
-bitstream filters will be applied to all streams in the output.
-
-Several bitstream filters can be specified, separated by ",".
-
-select Select the streams that should be mapped to the slave output,
-specified by a stream specifier. If not specified, this defaults to
-all the input streams.
-
-
-
-
4.19.1 Examples# TOC
-
-
- Encode something and both archive it in a WebM file and stream it
-as MPEG-TS over UDP (the streams need to be explicitly mapped):
-
-
ffmpeg -i ... -c:v libx264 -c:a mp2 -f tee -map 0:v -map 0:a
- "archive-20121107.mkv|[f=mpegts]udp://10.0.1.255:1234/"
- Use ffmpeg to encode the input, and send the output
-to three different destinations. The dump_extra bitstream
-filter is used to add extradata information to all the output video
-keyframes packets, as requested by the MPEG-TS format. The select
-option is applied to out.aac in order to make it contain only
-audio packets.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=a]out.aac"
- As below, but select only stream a:1 for the audio output. Note
-that a second level escaping must be performed, as ":" is a special
-character used to separate options.
-
-
ffmpeg -i ... -map 0 -flags +global_header -c:v libx264 -c:a aac -strict experimental
- -f tee "[bsfs/v=dump_extra]out.ts|[movflags=+faststart]out.mp4|[select=\'a:1\']out.aac"
-
-
-
Note: some codecs may need different options depending on the output format;
-the auto-detection of this can not work with the tee muxer. The main example
-is the global_header flag.
-
-
-
4.20 webm_dash_manifest# TOC
-
-
WebM DASH Manifest muxer.
-
-
This muxer implements the WebM DASH Manifest specification to generate the DASH manifest XML.
-
-
-
4.20.1 Options# TOC
-
-
This muxer supports the following options:
-
-
-adaptation_sets This option has the following syntax: "id=x,streams=a,b,c id=y,streams=d,e" where x and y are the
-unique identifiers of the adaptation sets and a,b,c,d and e are the indices of the corresponding
-audio and video streams. Any number of adaptation sets can be added using this option.
-
-
-
-
4.20.2 Example# TOC
-
-
ffmpeg -f webm_dash_manifest -i video1.webm \
- -f webm_dash_manifest -i video2.webm \
- -f webm_dash_manifest -i audio1.webm \
- -f webm_dash_manifest -i audio2.webm \
- -map 0 -map 1 -map 2 -map 3 \
- -c copy \
- -f webm_dash_manifest \
- -adaptation_sets "id=0,streams=0,1 id=1,streams=2,3" \
- manifest.xml
-
-
-
-
5 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
-
6 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavformat
-
-
-
-
7 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Protocols Documentation
-
-
-
- FFmpeg Protocols Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes the input and output protocols provided by the
-libavformat library.
-
-
-
-
2 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
2.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
2.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
2.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
2.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
2.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
2.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
2.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
2.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
2.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
2.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
2.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
2.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
2.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
2.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
2.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
2.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
2.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
2.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
2.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
2.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
2.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
2.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
2.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
2.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
2.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
2.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
2.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
2.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
2.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
2.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
2.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
2.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
2.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
2.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
2.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
2.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
2.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavformat
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Resampler Documentation
-
-
-
- FFmpeg Resampler Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The FFmpeg resampler provides a high-level interface to the
-libswresample library audio resampling utilities. In particular it
-allows one to perform audio resampling, audio channel layout rematrixing,
-and convert audio format and packing layout.
-
-
-
-
2 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libswresample
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Scaler Documentation
-
-
-
- FFmpeg Scaler Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The FFmpeg rescaler provides a high-level interface to the libswscale
-library image conversion utilities. In particular it allows one to perform
-image rescaling and pixel format conversion.
-
-
-
-
2 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
-
3 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libswscale
-
-
-
-
4 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- FFmpeg Utilities Documentation
-
-
-
- FFmpeg Utilities Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
This document describes some generic features and utilities provided
-by the libavutil library.
-
-
-
-
2 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
2.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
2.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
2.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
2.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
2.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
2.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
2.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
2.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
2.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
2.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
3 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
4 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
-
5 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-libavutil
-
-
-
-
6 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffmpeg Documentation
-
-
-
- ffmpeg Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffmpeg [global_options ] {[input_file_options ] -i input_file } ... {[output_file_options ] output_file } ...
-
-
-
2 Description# TOC
-
-
ffmpeg is a very fast video and audio converter that can also grab from
-a live audio/video source. It can also convert between arbitrary sample
-rates and resize video on the fly with a high quality polyphase filter.
-
-
ffmpeg reads from an arbitrary number of input "files" (which can be regular
-files, pipes, network streams, grabbing devices, etc.), specified by the
--i option, and writes to an arbitrary number of output "files", which are
-specified by a plain output filename. Anything found on the command line which
-cannot be interpreted as an option is considered to be an output filename.
-
-
Each input or output file can, in principle, contain any number of streams of
-different types (video/audio/subtitle/attachment/data). The allowed number and/or
-types of streams may be limited by the container format. Selecting which
-streams from which inputs will go into which output is either done automatically
-or with the -map option (see the Stream selection chapter).
-
-
To refer to input files in options, you must use their indices (0-based). E.g.
-the first input file is 0, the second is 1, etc. Similarly, streams
-within a file are referred to by their indices. E.g. 2:3 refers to the
-fourth stream in the third input file. Also see the Stream specifiers chapter.
-
-
As a general rule, options are applied to the next specified
-file. Therefore, order is important, and you can have the same
-option on the command line multiple times. Each occurrence is
-then applied to the next input or output file.
-Exceptions from this rule are the global options (e.g. verbosity level),
-which should be specified first.
-
-
Do not mix input and output files – first specify all input files, then all
-output files. Also do not mix options which belong to different files. All
-options apply ONLY to the next input or output file and are reset between files.
-
-
- To set the video bitrate of the output file to 64 kbit/s:
-
-
ffmpeg -i input.avi -b:v 64k -bufsize 64k output.avi
- To force the frame rate of the output file to 24 fps:
-
-
ffmpeg -i input.avi -r 24 output.avi
- To force the frame rate of the input file (valid for raw formats only)
-to 1 fps and the frame rate of the output file to 24 fps:
-
-
ffmpeg -r 1 -i input.m2v -r 24 output.avi
-
-
-
The format option may be needed for raw input files.
-
-
-
-
3 Detailed description# TOC
-
-
The transcoding process in ffmpeg for each output can be described by
-the following diagram:
-
-
-
_______ ______________
-| | | |
-| input | demuxer | encoded data | decoder
-| file | ---------> | packets | -----+
-|_______| |______________| |
- v
- _________
- | |
- | decoded |
- | frames |
- |_________|
- ________ ______________ |
-| | | | |
-| output | <-------- | encoded data | <----+
-| file | muxer | packets | encoder
-|________| |______________|
-
-
-
-
-
ffmpeg calls the libavformat library (containing demuxers) to read
-input files and get packets containing encoded data from them. When there are
-multiple input files, ffmpeg tries to keep them synchronized by
-tracking lowest timestamp on any active input stream.
-
-
Encoded packets are then passed to the decoder (unless streamcopy is selected
-for the stream, see further for a description). The decoder produces
-uncompressed frames (raw video/PCM audio/...) which can be processed further by
-filtering (see next section). After filtering, the frames are passed to the
-encoder, which encodes them and outputs encoded packets. Finally those are
-passed to the muxer, which writes the encoded packets to the output file.
-
-
-
3.1 Filtering# TOC
-
Before encoding, ffmpeg can process raw audio and video frames using
-filters from the libavfilter library. Several chained filters form a filter
-graph. ffmpeg distinguishes between two types of filtergraphs:
-simple and complex.
-
-
-
3.1.1 Simple filtergraphs# TOC
-
Simple filtergraphs are those that have exactly one input and output, both of
-the same type. In the above diagram they can be represented by simply inserting
-an additional step between decoding and encoding:
-
-
-
_________ ______________
-| | | |
-| decoded | | encoded data |
-| frames |\ _ | packets |
-|_________| \ /||______________|
- \ __________ /
- simple _\|| | / encoder
- filtergraph | filtered |/
- | frames |
- |__________|
-
-
-
-
Simple filtergraphs are configured with the per-stream -filter option
-(with -vf and -af aliases for video and audio respectively).
-A simple filtergraph for video can look for example like this:
-
-
-
_______ _____________ _______ ________
-| | | | | | | |
-| input | ---> | deinterlace | ---> | scale | ---> | output |
-|_______| |_____________| |_______| |________|
-
-
-
-
Note that some filters change frame properties but not frame contents. E.g. the
-fps filter in the example above changes number of frames, but does not
-touch the frame contents. Another example is the setpts filter, which
-only sets timestamps and otherwise passes the frames unchanged.
-
-
-
3.1.2 Complex filtergraphs# TOC
-
Complex filtergraphs are those which cannot be described as simply a linear
-processing chain applied to one stream. This is the case, for example, when the graph has
-more than one input and/or output, or when output stream type is different from
-input. They can be represented with the following diagram:
-
-
-
_________
-| |
-| input 0 |\ __________
-|_________| \ | |
- \ _________ /| output 0 |
- \ | | / |__________|
- _________ \| complex | /
-| | | |/
-| input 1 |---->| filter |\
-|_________| | | \ __________
- /| graph | \ | |
- / | | \| output 1 |
- _________ / |_________| |__________|
-| | /
-| input 2 |/
-|_________|
-
-
-
-
Complex filtergraphs are configured with the -filter_complex option.
-Note that this option is global, since a complex filtergraph, by its nature,
-cannot be unambiguously associated with a single stream or file.
-
-
The -lavfi option is equivalent to -filter_complex .
-
-
A trivial example of a complex filtergraph is the overlay filter, which
-has two video inputs and one video output, containing one video overlaid on top
-of the other. Its audio counterpart is the amix filter.
-
-
-
3.2 Stream copy# TOC
-
Stream copy is a mode selected by supplying the copy parameter to the
--codec option. It makes ffmpeg omit the decoding and encoding
-step for the specified stream, so it does only demuxing and muxing. It is useful
-for changing the container format or modifying container-level metadata. The
-diagram above will, in this case, simplify to this:
-
-
-
_______ ______________ ________
-| | | | | |
-| input | demuxer | encoded data | muxer | output |
-| file | ---------> | packets | -------> | file |
-|_______| |______________| |________|
-
-
-
-
Since there is no decoding or encoding, it is very fast and there is no quality
-loss. However, it might not work in some cases because of many factors. Applying
-filters is obviously also impossible, since filters work on uncompressed data.
-
-
-
-
4 Stream selection# TOC
-
-
By default, ffmpeg includes only one stream of each type (video, audio, subtitle)
-present in the input files and adds them to each output file. It picks the
-"best" of each based upon the following criteria: for video, it is the stream
-with the highest resolution, for audio, it is the stream with the most channels, for
-subtitles, it is the first subtitle stream. In the case where several streams of
-the same type rate equally, the stream with the lowest index is chosen.
-
-
You can disable some of those defaults by using the -vn/-an/-sn options. For
-full manual control, use the -map option, which disables the defaults just
-described.
-
-
-
-
5 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
5.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
5.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
5.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
5.4 Main options# TOC
-
-
--f fmt (input/output ) Force input or output file format. The format is normally auto detected for input
-files and guessed from the file extension for output files, so this option is not
-needed in most cases.
-
--i filename (input ) input file name
-
--y (global ) Overwrite output files without asking.
-
--n (global ) Do not overwrite output files, and exit immediately if a specified
-output file already exists.
-
--c[:stream_specifier ] codec (input/output,per-stream ) -codec[:stream_specifier ] codec (input/output,per-stream ) Select an encoder (when used before an output file) or a decoder (when used
-before an input file) for one or more streams. codec is the name of a
-decoder/encoder or a special value copy (output only) to indicate that
-the stream is not to be re-encoded.
-
-For example
-
-
ffmpeg -i INPUT -map 0 -c:v libx264 -c:a copy OUTPUT
- encodes all video streams with libx264 and copies all audio streams.
-
-For each stream, the last matching c option is applied, so
-
-
ffmpeg -i INPUT -map 0 -c copy -c:v:1 libx264 -c:a:137 libvorbis OUTPUT
- will copy all the streams except the second video, which will be encoded with
-libx264, and the 138th audio, which will be encoded with libvorbis.
-
--t duration (input/output ) When used as an input option (before -i), limit the duration of
-data read from the input file.
-
-When used as an output option (before an output filename), stop writing the
-output after its duration reaches duration .
-
-duration may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--to position (output ) Stop writing the output at position .
-position may be a number in seconds, or in hh:mm:ss[.xxx] form.
-
--to and -t are mutually exclusive and -t has priority.
-
--fs limit_size (output ) Set the file size limit, expressed in bytes.
-
--ss position (input/output ) When used as an input option (before -i), seeks in this input file to
-position . Note the in most formats it is not possible to seek exactly, so
-ffmpeg will seek to the closest seek point before position .
-When transcoding and -accurate_seek is enabled (the default), this
-extra segment between the seek point and position will be decoded and
-discarded. When doing stream copy or when -noaccurate_seek is used, it
-will be preserved.
-
-When used as an output option (before an output filename), decodes but discards
-input until the timestamps reach position .
-
-position may be either in seconds or in hh:mm:ss[.xxx] form.
-
--itsoffset offset (input ) Set the input time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added to the timestamps of the input files. Specifying
-a positive offset means that the corresponding streams are delayed by
-the time duration specified in offset .
-
--timestamp date (output ) Set the recording timestamp in the container.
-
-date must be a time duration specification,
-see (ffmpeg-utils)the Date section in the ffmpeg-utils(1) manual .
-
--metadata[:metadata_specifier] key =value (output,per-metadata ) Set a metadata key/value pair.
-
-An optional metadata_specifier may be given to set metadata
-on streams or chapters. See -map_metadata documentation for
-details.
-
-This option overrides metadata set with -map_metadata. It is
-also possible to delete metadata by using an empty value.
-
-For example, for setting the title in the output file:
-
-
ffmpeg -i in.avi -metadata title="my title" out.flv
- To set the language of the first audio stream:
-
-
ffmpeg -i INPUT -metadata:s:a:0 language=eng OUTPUT
- -target type (output ) Specify target file type (vcd, svcd, dvd, dv,
-dv50). type may be prefixed with pal-, ntsc- or
-film- to use the corresponding standard. All the format options
-(bitrate, codecs, buffer sizes) are then set automatically. You can just type:
-
-
-
ffmpeg -i myfile.avi -target vcd /tmp/vcd.mpg
- Nevertheless you can specify additional options as long as you know
-they do not conflict with the standard, as in:
-
-
-
ffmpeg -i myfile.avi -target vcd -bf 2 /tmp/vcd.mpg
- -dframes number (output ) Set the number of data frames to output. This is an alias for -frames:d.
-
--frames[:stream_specifier ] framecount (output,per-stream ) Stop writing to the stream after framecount frames.
-
--q[:stream_specifier ] q (output,per-stream ) -qscale[:stream_specifier ] q (output,per-stream ) Use fixed quality scale (VBR). The meaning of q /qscale is
-codec-dependent.
-If qscale is used without a stream_specifier then it applies only
-to the video stream, this is to maintain compatibility with previous behavior
-and as specifying the same codec specific value to 2 different codecs that is
-audio and video generally is not what is intended when no stream_specifier is
-used.
-
--filter[:stream_specifier ] filtergraph (output,per-stream ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single input and a single output of the
-same type of the stream. In the filtergraph, the input is associated
-to the label in, and the output to the label out. See
-the ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-See the -filter_complex option if you
-want to create filtergraphs with multiple inputs and/or outputs.
-
--filter_script[:stream_specifier ] filename (output,per-stream ) This option is similar to -filter , the only difference is that its
-argument is the name of the file from which a filtergraph description is to be
-read.
-
--pre[:stream_specifier ] preset_name (output,per-stream ) Specify the preset for matching stream(s).
-
--stats (global ) Print encoding progress/statistics. It is on by default, to explicitly
-disable it you need to specify -nostats.
-
--progress url (global ) Send program-friendly progress information to url .
-
-Progress information is written approximately every second and at the end of
-the encoding process. It is made of "key =value " lines. key
-consists of only alphanumeric characters. The last key of a sequence of
-progress information is always "progress".
-
--stdin Enable interaction on standard input. On by default unless standard input is
-used as an input. To explicitly disable interaction you need to specify
--nostdin.
-
-Disabling interaction on standard input is useful, for example, if
-ffmpeg is in the background process group. Roughly the same result can
-be achieved with ffmpeg ... < /dev/null but it requires a
-shell.
-
--debug_ts (global ) Print timestamp information. It is off by default. This option is
-mostly useful for testing and debugging purposes, and the output
-format may change from one version to another, so it should not be
-employed by portable scripts.
-
-See also the option -fdebug ts.
-
--attach filename (output ) Add an attachment to the output file. This is supported by a few formats
-like Matroska for e.g. fonts used in rendering subtitles. Attachments
-are implemented as a specific type of stream, so this option will add
-a new stream to the file. It is then possible to use per-stream options
-on this stream in the usual way. Attachment streams created with this
-option will be created after all the other streams (i.e. those created
-with -map or automatic mappings).
-
-Note that for Matroska you also have to set the mimetype metadata tag:
-
-
ffmpeg -i INPUT -attach DejaVuSans.ttf -metadata:s:2 mimetype=application/x-truetype-font out.mkv
- (assuming that the attachment stream will be third in the output file).
-
--dump_attachment[:stream_specifier ] filename (input,per-stream ) Extract the matching attachment stream into a file named filename . If
-filename is empty, then the value of the filename metadata tag
-will be used.
-
-E.g. to extract the first attachment to a file named ’out.ttf’:
-
-
ffmpeg -dump_attachment:t:0 out.ttf -i INPUT
- To extract all attachments to files determined by the filename tag:
-
-
ffmpeg -dump_attachment:t "" -i INPUT
- Technical note – attachments are implemented as codec extradata, so this
-option can actually be used to extract extradata from any stream, not just
-attachments.
-
-
-
-
-
5.5 Video Options# TOC
-
-
--vframes number (output ) Set the number of video frames to output. This is an alias for -frames:v.
-
-r[:stream_specifier ] fps (input/output,per-stream ) Set frame rate (Hz value, fraction or abbreviation).
-
-As an input option, ignore any timestamps stored in the file and instead
-generate timestamps assuming constant frame rate fps .
-This is not the same as the -framerate option used for some input formats
-like image2 or v4l2 (it used to be the same in older versions of FFmpeg).
-If in doubt use -framerate instead of the input option -r .
-
-As an output option, duplicate or drop input frames to achieve constant output
-frame rate fps .
-
--s[:stream_specifier ] size (input/output,per-stream ) Set frame size.
-
-As an input option, this is a shortcut for the video_size private
-option, recognized by some demuxers for which the frame size is either not
-stored in the file or is configurable – e.g. raw video or video grabbers.
-
-As an output option, this inserts the scale video filter to the
-end of the corresponding filtergraph. Please use the scale filter
-directly to insert it at the beginning or some other place.
-
-The format is ‘wxh ’ (default - same as source).
-
--aspect[:stream_specifier ] aspect (output,per-stream ) Set the video display aspect ratio specified by aspect .
-
-aspect can be a floating point number string, or a string of the
-form num :den , where num and den are the
-numerator and denominator of the aspect ratio. For example "4:3",
-"16:9", "1.3333", and "1.7777" are valid argument values.
-
-If used together with -vcodec copy , it will affect the aspect ratio
-stored at container level, but not the aspect ratio stored in encoded
-frames, if it exists.
-
--vn (output ) Disable video recording.
-
--vcodec codec (output ) Set the video codec. This is an alias for -codec:v.
-
--pass[:stream_specifier ] n (output,per-stream ) Select the pass number (1 or 2). It is used to do two-pass
-video encoding. The statistics of the video are recorded in the first
-pass into a log file (see also the option -passlogfile),
-and in the second pass that log file is used to generate the video
-at the exact requested bitrate.
-On pass 1, you may just deactivate audio and set output to null,
-examples for Windows and Unix:
-
-
ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y NUL
-ffmpeg -i foo.mov -c:v libxvid -pass 1 -an -f rawvideo -y /dev/null
- -passlogfile[:stream_specifier ] prefix (output,per-stream ) Set two-pass log file name prefix to prefix , the default file name
-prefix is “ffmpeg2pass”. The complete file name will be
-PREFIX-N.log , where N is a number specific to the output
-stream
-
--vf filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:v, see the -filter option .
-
-
-
-
5.6 Advanced Video options# TOC
-
-
--pix_fmt[:stream_specifier ] format (input/output,per-stream ) Set pixel format. Use -pix_fmts to show all the supported
-pixel formats.
-If the selected pixel format can not be selected, ffmpeg will print a
-warning and select the best pixel format supported by the encoder.
-If pix_fmt is prefixed by a +, ffmpeg will exit with an error
-if the requested pixel format can not be selected, and automatic conversions
-inside filtergraphs are disabled.
-If pix_fmt is a single +, ffmpeg selects the same pixel format
-as the input (or graph output) and automatic conversions are disabled.
-
--sws_flags flags (input/output ) Set SwScaler flags.
-
-vdt n Discard threshold.
-
--rc_override[:stream_specifier ] override (output,per-stream ) Rate control override for specific intervals, formatted as "int,int,int"
-list separated with slashes. Two first values are the beginning and
-end frame numbers, last one is quantizer to use if positive, or quality
-factor if negative.
-
--ilme Force interlacing support in encoder (MPEG-2 and MPEG-4 only).
-Use this option if your input file is interlaced and you want
-to keep the interlaced format for minimum losses.
-The alternative is to deinterlace the input stream with
--deinterlace , but deinterlacing introduces losses.
-
-psnr Calculate PSNR of compressed frames.
-
-vstats Dump video coding statistics to vstats_HHMMSS.log .
-
-vstats_file file Dump video coding statistics to file .
-
-top[:stream_specifier ] n (output,per-stream ) top=1/bottom=0/auto=-1 field first
-
-dc precision Intra_dc_precision.
-
-vtag fourcc/tag (output ) Force video tag/fourcc. This is an alias for -tag:v.
-
-qphist (global ) Show QP histogram
-
-vbsf bitstream_filter Deprecated see -bsf
-
--force_key_frames[:stream_specifier ] time [,time ...] (output,per-stream ) -force_key_frames[:stream_specifier ] expr:expr (output,per-stream ) Force key frames at the specified timestamps, more precisely at the first
-frames after each specified time.
-
-If the argument is prefixed with expr:, the string expr
-is interpreted like an expression and is evaluated for each frame. A
-key frame is forced in case the evaluation is non-zero.
-
-If one of the times is "chapters[delta ]", it is expanded into
-the time of the beginning of all chapters in the file, shifted by
-delta , expressed as a time in seconds.
-This option can be useful to ensure that a seek point is present at a
-chapter mark or any other designated place in the output file.
-
-For example, to insert a key frame at 5 minutes, plus key frames 0.1 second
-before the beginning of every chapter:
-
-
-force_key_frames 0:05:00,chapters-0.1
- The expression in expr can contain the following constants:
-
-n the number of current processed frame, starting from 0
-
n_forced the number of forced frames
-
prev_forced_n the number of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
prev_forced_t the time of the previous forced frame, it is NAN when no
-keyframe was forced yet
-
t the time of the current processed frame
-
-
-For example to force a key frame every 5 seconds, you can specify:
-
-
-force_key_frames expr:gte(t,n_forced*5)
- To force a key frame 5 seconds after the time of the last forced one,
-starting from second 13:
-
-
-force_key_frames expr:if(isnan(prev_forced_t),gte(t,13),gte(t,prev_forced_t+5))
- Note that forcing too many keyframes is very harmful for the lookahead
-algorithms of certain encoders: using fixed-GOP options or similar
-would be more efficient.
-
--copyinkf[:stream_specifier ] (output,per-stream ) When doing stream copy, copy also non-key frames found at the
-beginning.
-
--hwaccel[:stream_specifier ] hwaccel (input,per-stream ) Use hardware acceleration to decode the matching stream(s). The allowed values
-of hwaccel are:
-
-none Do not use any hardware acceleration (the default).
-
-auto Automatically select the hardware acceleration method.
-
-vda Use Apple VDA hardware acceleration.
-
-vdpau Use VDPAU (Video Decode and Presentation API for Unix) hardware acceleration.
-
-dxva2 Use DXVA2 (DirectX Video Acceleration) hardware acceleration.
-
-
-This option has no effect if the selected hwaccel is not available or not
-supported by the chosen decoder.
-
-Note that most acceleration methods are intended for playback and will not be
-faster than software decoding on modern CPUs. Additionally, ffmpeg
-will usually need to copy the decoded frames from the GPU memory into the system
-memory, resulting in further performance loss. This option is thus mainly
-useful for testing.
-
--hwaccel_device[:stream_specifier ] hwaccel_device (input,per-stream ) Select a device to use for hardware acceleration.
-
-This option only makes sense when the -hwaccel option is also
-specified. Its exact meaning depends on the specific hardware acceleration
-method chosen.
-
-
-vdpau For VDPAU, this option specifies the X11 display/screen to use. If this option
-is not specified, the value of the DISPLAY environment variable is used
-
-dxva2 For DXVA2, this option should contain the number of the display adapter to use.
-If this option is not specified, the default adapter is used.
-
-
-
-
-
5.7 Audio Options# TOC
-
-
--aframes number (output ) Set the number of audio frames to output. This is an alias for -frames:a.
-
-ar[:stream_specifier ] freq (input/output,per-stream ) Set the audio sampling frequency. For output streams it is set by
-default to the frequency of the corresponding input stream. For input
-streams this option only makes sense for audio grabbing devices and raw
-demuxers and is mapped to the corresponding demuxer options.
-
-aq q (output ) Set the audio quality (codec-specific, VBR). This is an alias for -q:a.
-
-ac[:stream_specifier ] channels (input/output,per-stream ) Set the number of audio channels. For output streams it is set by
-default to the number of input audio channels. For input streams
-this option only makes sense for audio grabbing devices and raw demuxers
-and is mapped to the corresponding demuxer options.
-
-an (output ) Disable audio recording.
-
-acodec codec (input/output ) Set the audio codec. This is an alias for -codec:a.
-
-sample_fmt[:stream_specifier ] sample_fmt (output,per-stream ) Set the audio sample format. Use -sample_fmts to get a list
-of supported sample formats.
-
--af filtergraph (output ) Create the filtergraph specified by filtergraph and use it to
-filter the stream.
-
-This is an alias for -filter:a, see the -filter option .
-
-
-
-
5.8 Advanced Audio options# TOC
-
-
--atag fourcc/tag (output ) Force audio tag/fourcc. This is an alias for -tag:a.
-
-absf bitstream_filter Deprecated, see -bsf
-
-guess_layout_max channels (input,per-stream ) If some input channel layout is not known, try to guess only if it
-corresponds to at most the specified number of channels. For example, 2
-tells to ffmpeg to recognize 1 channel as mono and 2 channels as
-stereo but not 6 channels as 5.1. The default is to always try to guess. Use
-0 to disable all guessing.
-
-
-
-
5.9 Subtitle options# TOC
-
-
--scodec codec (input/output ) Set the subtitle codec. This is an alias for -codec:s.
-
-sn (output ) Disable subtitle recording.
-
-sbsf bitstream_filter Deprecated, see -bsf
-
-
-
-
5.10 Advanced Subtitle options# TOC
-
-
--fix_sub_duration Fix subtitles durations. For each subtitle, wait for the next packet in the
-same stream and adjust the duration of the first to avoid overlap. This is
-necessary with some subtitles codecs, especially DVB subtitles, because the
-duration in the original packet is only a rough estimate and the end is
-actually marked by an empty subtitle frame. Failing to use this option when
-necessary can result in exaggerated durations or muxing failures due to
-non-monotonic timestamps.
-
-Note that this option will delay the output of all data until the next
-subtitle packet is decoded: it may increase memory consumption and latency a
-lot.
-
--canvas_size size Set the size of the canvas used to render subtitles.
-
-
-
-
-
5.11 Advanced options# TOC
-
-
--map [-]input_file_id [:stream_specifier ][,sync_file_id [:stream_specifier ]] | [linklabel] (output )
-Designate one or more input streams as a source for the output file. Each input
-stream is identified by the input file index input_file_id and
-the input stream index input_stream_id within the input
-file. Both indices start at 0. If specified,
-sync_file_id :stream_specifier sets which input stream
-is used as a presentation sync reference.
-
-The first -map option on the command line specifies the
-source for output stream 0, the second -map option specifies
-the source for output stream 1, etc.
-
-A - character before the stream identifier creates a "negative" mapping.
-It disables matching streams from already created mappings.
-
-An alternative [linklabel] form will map outputs from complex filter
-graphs (see the -filter_complex option) to the output file.
-linklabel must correspond to a defined output link label in the graph.
-
-For example, to map ALL streams from the first input file to output
-
-
ffmpeg -i INPUT -map 0 output
- For example, if you have two audio streams in the first input file,
-these streams are identified by "0:0" and "0:1". You can use
--map to select which streams to place in an output file. For
-example:
-
-
ffmpeg -i INPUT -map 0:1 out.wav
- will map the input stream in INPUT identified by "0:1" to
-the (single) output stream in out.wav .
-
-For example, to select the stream with index 2 from input file
-a.mov (specified by the identifier "0:2"), and stream with
-index 6 from input b.mov (specified by the identifier "1:6"),
-and copy them to the output file out.mov :
-
-
ffmpeg -i a.mov -i b.mov -c copy -map 0:2 -map 1:6 out.mov
- To select all video and the third audio stream from an input file:
-
-
ffmpeg -i INPUT -map 0:v -map 0:a:2 OUTPUT
- To map all the streams except the second audio, use negative mappings
-
-
ffmpeg -i INPUT -map 0 -map -0:a:1 OUTPUT
- To pick the English audio stream:
-
-
ffmpeg -i INPUT -map 0:m:language:eng OUTPUT
- Note that using this option disables the default mappings for this output file.
-
-
--map_channel [input_file_id .stream_specifier .channel_id |-1][:output_file_id .stream_specifier ] Map an audio channel from a given input to an output. If
-output_file_id .stream_specifier is not set, the audio channel will
-be mapped on all the audio streams.
-
-Using "-1" instead of
-input_file_id .stream_specifier .channel_id will map a muted
-channel.
-
-For example, assuming INPUT is a stereo audio file, you can switch the
-two audio channels with the following command:
-
-
ffmpeg -i INPUT -map_channel 0.0.1 -map_channel 0.0.0 OUTPUT
- If you want to mute the first channel and keep the second:
-
-
ffmpeg -i INPUT -map_channel -1 -map_channel 0.0.1 OUTPUT
- The order of the "-map_channel" option specifies the order of the channels in
-the output stream. The output channel layout is guessed from the number of
-channels mapped (mono if one "-map_channel", stereo if two, etc.). Using "-ac"
-in combination of "-map_channel" makes the channel gain levels to be updated if
-input and output channel layouts don’t match (for instance two "-map_channel"
-options and "-ac 6").
-
-You can also extract each channel of an input to specific outputs; the following
-command extracts two channels of the INPUT audio stream (file 0, stream 0)
-to the respective OUTPUT_CH0 and OUTPUT_CH1 outputs:
-
-
ffmpeg -i INPUT -map_channel 0.0.0 OUTPUT_CH0 -map_channel 0.0.1 OUTPUT_CH1
- The following example splits the channels of a stereo input into two separate
-streams, which are put into the same output file:
-
-
ffmpeg -i stereo.wav -map 0:0 -map 0:0 -map_channel 0.0.0:0.0 -map_channel 0.0.1:0.1 -y out.ogg
- Note that currently each output stream can only contain channels from a single
-input stream; you can’t for example use "-map_channel" to pick multiple input
-audio channels contained in different streams (from the same or different files)
-and merge them into a single output stream. It is therefore not currently
-possible, for example, to turn two separate mono streams into a single stereo
-stream. However splitting a stereo stream into two single channel mono streams
-is possible.
-
-If you need this feature, a possible workaround is to use the amerge
-filter. For example, if you need to merge a media (here input.mkv ) with 2
-mono audio streams into one single stereo channel audio stream (and keep the
-video stream), you can use the following command:
-
-
ffmpeg -i input.mkv -filter_complex "[0:1] [0:2] amerge" -c:a pcm_s16le -c:v copy output.mkv
- -map_metadata[:metadata_spec_out ] infile [:metadata_spec_in ] (output,per-metadata ) Set metadata information of the next output file from infile . Note that
-those are file indices (zero-based), not filenames.
-Optional metadata_spec_in/out parameters specify, which metadata to copy.
-A metadata specifier can have the following forms:
-
-g global metadata, i.e. metadata that applies to the whole file
-
-s [:stream_spec ]per-stream metadata. stream_spec is a stream specifier as described
-in the Stream specifiers chapter. In an input metadata specifier, the first
-matching stream is copied from. In an output metadata specifier, all matching
-streams are copied to.
-
-c :chapter_index per-chapter metadata. chapter_index is the zero-based chapter index.
-
-p :program_index per-program metadata. program_index is the zero-based program index.
-
-If metadata specifier is omitted, it defaults to global.
-
-By default, global metadata is copied from the first input file,
-per-stream and per-chapter metadata is copied along with streams/chapters. These
-default mappings are disabled by creating any mapping of the relevant type. A negative
-file index can be used to create a dummy mapping that just disables automatic copying.
-
-For example to copy metadata from the first stream of the input file to global metadata
-of the output file:
-
-
ffmpeg -i in.ogg -map_metadata 0:s:0 out.mp3
- To do the reverse, i.e. copy global metadata to all audio streams:
-
-
ffmpeg -i in.mkv -map_metadata:s:a 0:g out.mkv
- Note that simple 0 would work as well in this example, since global
-metadata is assumed by default.
-
--map_chapters input_file_index (output ) Copy chapters from input file with index input_file_index to the next
-output file. If no chapter mapping is specified, then chapters are copied from
-the first input file with at least one chapter. Use a negative file index to
-disable any chapter copying.
-
--benchmark (global ) Show benchmarking information at the end of an encode.
-Shows CPU time used and maximum memory consumption.
-Maximum memory consumption is not supported on all systems,
-it will usually display as 0 if not supported.
-
-benchmark_all (global ) Show benchmarking information during the encode.
-Shows CPU time used in various steps (audio/video encode/decode).
-
-timelimit duration (global ) Exit after ffmpeg has been running for duration seconds.
-
-dump (global ) Dump each input packet to stderr.
-
-hex (global ) When dumping packets, also dump the payload.
-
-re (input ) Read input at native frame rate. Mainly used to simulate a grab device.
-or live input stream (e.g. when reading from a file). Should not be used
-with actual grab devices or live input streams (where it can cause packet
-loss).
-By default ffmpeg attempts to read the input(s) as fast as possible.
-This option will slow down the reading of the input(s) to the native frame rate
-of the input(s). It is useful for real-time output (e.g. live streaming).
-
-loop_input Loop over the input stream. Currently it works only for image
-streams. This option is used for automatic FFserver testing.
-This option is deprecated, use -loop 1.
-
-loop_output number_of_times Repeatedly loop output for formats that support looping such as animated GIF
-(0 will loop the output infinitely).
-This option is deprecated, use -loop.
-
-vsync parameter Video sync method.
-For compatibility reasons old values can be specified as numbers.
-Newly added values will have to be specified as strings always.
-
-
-0, passthrough Each frame is passed with its timestamp from the demuxer to the muxer.
-
1, cfr Frames will be duplicated and dropped to achieve exactly the requested
-constant frame rate.
-
2, vfr Frames are passed through with their timestamp or dropped so as to
-prevent 2 frames from having the same timestamp.
-
drop As passthrough but destroys all timestamps, making the muxer generate
-fresh timestamps based on frame-rate.
-
-1, auto Chooses between 1 and 2 depending on muxer capabilities. This is the
-default method.
-
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-With -map you can select from which stream the timestamps should be
-taken. You can leave either video or audio unchanged and sync the
-remaining stream(s) to the unchanged one.
-
--async samples_per_second Audio sync method. "Stretches/squeezes" the audio stream to match the timestamps,
-the parameter is the maximum samples per second by which the audio is changed.
--async 1 is a special case where only the start of the audio stream is corrected
-without any later correction.
-
-Note that the timestamps may be further modified by the muxer, after this.
-For example, in the case that the format option avoid_negative_ts
-is enabled.
-
-This option has been deprecated. Use the aresample audio filter instead.
-
--copyts Do not process input timestamps, but keep their values without trying
-to sanitize them. In particular, do not remove the initial start time
-offset value.
-
-Note that, depending on the vsync option or on specific muxer
-processing (e.g. in case the format option avoid_negative_ts
-is enabled) the output timestamps may mismatch with the input
-timestamps even when this option is selected.
-
--start_at_zero When used with copyts , shift input timestamps so they start at zero.
-
-This means that using e.g. -ss 50 will make output timestamps start at
-50 seconds, regardless of what timestamp the input file started at.
-
--copytb mode Specify how to set the encoder timebase when stream copying. mode is an
-integer numeric value, and can assume one of the following values:
-
-
-1 Use the demuxer timebase.
-
-The time base is copied to the output encoder from the corresponding input
-demuxer. This is sometimes required to avoid non monotonically increasing
-timestamps when copying video streams with variable frame rate.
-
-0 Use the decoder timebase.
-
-The time base is copied to the output encoder from the corresponding input
-decoder.
-
--1 Try to make the choice automatically, in order to generate a sane output.
-
-
-Default value is -1.
-
--shortest (output ) Finish encoding when the shortest input stream ends.
-
-dts_delta_threshold Timestamp discontinuity delta threshold.
-
-muxdelay seconds (input ) Set the maximum demux-decode delay.
-
-muxpreload seconds (input ) Set the initial demux-decode delay.
-
-streamid output-stream-index :new-value (output ) Assign a new stream-id value to an output stream. This option should be
-specified prior to the output filename to which it applies.
-For the situation where multiple output files exist, a streamid
-may be reassigned to a different value.
-
-For example, to set the stream 0 PID to 33 and the stream 1 PID to 36 for
-an output mpegts file:
-
-
ffmpeg -i infile -streamid 0:33 -streamid 1:36 out.ts
- -bsf[:stream_specifier ] bitstream_filters (output,per-stream ) Set bitstream filters for matching streams. bitstream_filters is
-a comma-separated list of bitstream filters. Use the -bsfs option
-to get the list of bitstream filters.
-
-
ffmpeg -i h264.mp4 -c:v copy -bsf:v h264_mp4toannexb -an out.h264
-
-
ffmpeg -i file.mov -an -vn -bsf:s mov2textsub -c:s copy -f rawvideo sub.txt
- -tag[:stream_specifier ] codec_tag (input/output,per-stream ) Force a tag/fourcc for matching streams.
-
--timecode hh :mm :ss SEPff Specify Timecode for writing. SEP is ’:’ for non drop timecode and ’;’
-(or ’.’) for drop.
-
-
ffmpeg -i input.mpg -timecode 01:02:03.04 -r 30000/1001 -s ntsc output.mpg
- -filter_complex filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. For simple graphs – those with one input and one output of the same
-type – see the -filter options. filtergraph is a description of
-the filtergraph, as described in the “Filtergraph syntax” section of the
-ffmpeg-filters manual.
-
-Input link labels must refer to input streams using the
-[file_index:stream_specifier] syntax (i.e. the same as -map
-uses). If stream_specifier matches multiple streams, the first one will be
-used. An unlabeled input will be connected to the first unused input stream of
-the matching type.
-
-Output link labels are referred to with -map . Unlabeled outputs are
-added to the first output file.
-
-Note that with this option it is possible to use only lavfi sources without
-normal input files.
-
-For example, to overlay an image over video
-
-
ffmpeg -i video.mkv -i image.png -filter_complex '[0:v][1:v]overlay[out]' -map
-'[out]' out.mkv
- Here [0:v] refers to the first video stream in the first input file,
-which is linked to the first (main) input of the overlay filter. Similarly the
-first video stream in the second input is linked to the second (overlay) input
-of overlay.
-
-Assuming there is only one video stream in each input file, we can omit input
-labels, so the above is equivalent to
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay[out]' -map
-'[out]' out.mkv
- Furthermore we can omit the output label and the single output from the filter
-graph will be added to the output file automatically, so we can simply write
-
-
ffmpeg -i video.mkv -i image.png -filter_complex 'overlay' out.mkv
- To generate 5 seconds of pure red video using lavfi color source:
-
-
ffmpeg -filter_complex 'color=c=red' -t 5 out.mkv
- -lavfi filtergraph (global ) Define a complex filtergraph, i.e. one with arbitrary number of inputs and/or
-outputs. Equivalent to -filter_complex .
-
--filter_complex_script filename (global ) This option is similar to -filter_complex , the only difference is that
-its argument is the name of the file from which a complex filtergraph
-description is to be read.
-
--accurate_seek (input ) This option enables or disables accurate seeking in input files with the
--ss option. It is enabled by default, so seeking is accurate when
-transcoding. Use -noaccurate_seek to disable it, which may be useful
-e.g. when copying some streams and transcoding the others.
-
--override_ffserver (global ) Overrides the input specifications from ffserver. Using this
-option you can map any input stream to ffserver and control
-many aspects of the encoding from ffmpeg. Without this
-option ffmpeg will transmit to ffserver what is
-requested by ffserver.
-
-The option is intended for cases where features are needed that cannot be
-specified to ffserver but can be to ffmpeg.
-
--sdp_file file (global ) Print sdp information to file .
-This allows dumping sdp information when at least one output isn’t an
-rtp stream.
-
--discard (input ) Allows discarding specific streams or frames of streams at the demuxer.
-Not all demuxers support this.
-
-
-none Discard no frame.
-
-default Default, which discards no frames.
-
-noref Discard all non-reference frames.
-
-bidir Discard all bidirectional frames.
-
-nokey Discard all frames excepts keyframes.
-
-all Discard all frames.
-
-
-
-
-
As a special exception, you can use a bitmap subtitle stream as input: it
-will be converted into a video with the same size as the largest video in
-the file, or 720x576 if no video is present. Note that this is an
-experimental and temporary solution. It will be removed once libavfilter has
-proper support for subtitles.
-
-
For example, to hardcode subtitles on top of a DVB-T recording stored in
-MPEG-TS format, delaying the subtitles by 1 second:
-
-
ffmpeg -i input.ts -filter_complex \
- '[#0x2ef] setpts=PTS+1/TB [sub] ; [#0x2d0] [sub] overlay' \
- -sn -map '#0x2dc' output.mkv
-
-
(0x2d0, 0x2dc and 0x2ef are the MPEG-TS PIDs of respectively the video,
-audio and subtitles streams; 0:0, 0:3 and 0:7 would have worked too)
-
-
-
5.12 Preset files# TOC
-
A preset file contains a sequence of option =value pairs,
-one for each line, specifying a sequence of options which would be
-awkward to specify on the command line. Lines starting with the hash
-(’#’) character are ignored and are used to provide comments. Check
-the presets directory in the FFmpeg source tree for examples.
-
-
There are two types of preset files: ffpreset and avpreset files.
-
-
-
5.12.1 ffpreset files# TOC
-
ffpreset files are specified with the vpre, apre,
-spre, and fpre options. The fpre option takes the
-filename of the preset instead of a preset name as input and can be
-used for any kind of codec. For the vpre, apre, and
-spre options, the options specified in a preset file are
-applied to the currently selected codec of the same type as the preset
-option.
-
-
The argument passed to the vpre, apre, and spre
-preset options identifies the preset file to use according to the
-following rules:
-
-
First ffmpeg searches for a file named arg .ffpreset in the
-directories $FFMPEG_DATADIR (if set), and $HOME/.ffmpeg , and in
-the datadir defined at configuration time (usually PREFIX/share/ffmpeg )
-or in a ffpresets folder along the executable on win32,
-in that order. For example, if the argument is libvpx-1080p, it will
-search for the file libvpx-1080p.ffpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-codec_name -arg .ffpreset in the above-mentioned
-directories, where codec_name is the name of the codec to which
-the preset file options will be applied. For example, if you select
-the video codec with -vcodec libvpx and use -vpre 1080p,
-then it will search for the file libvpx-1080p.ffpreset .
-
-
-
5.12.2 avpreset files# TOC
-
avpreset files are specified with the pre option. They work similar to
-ffpreset files, but they only allow encoder- specific options. Therefore, an
-option =value pair specifying an encoder cannot be used.
-
-
When the pre option is specified, ffmpeg will look for files with the
-suffix .avpreset in the directories $AVCONV_DATADIR (if set), and
-$HOME/.avconv , and in the datadir defined at configuration time (usually
-PREFIX/share/ffmpeg ), in that order.
-
-
First ffmpeg searches for a file named codec_name -arg .avpreset in
-the above-mentioned directories, where codec_name is the name of the codec
-to which the preset file options will be applied. For example, if you select the
-video codec with -vcodec libvpx and use -pre 1080p, then it will
-search for the file libvpx-1080p.avpreset .
-
-
If no such file is found, then ffmpeg will search for a file named
-arg .avpreset in the same directories.
-
-
-
-
-
-
- For streaming at very low bitrates, use a low frame rate
-and a small GOP size. This is especially true for RealVideo where
-the Linux player does not seem to be very fast, so it can miss
-frames. An example is:
-
-
-
ffmpeg -g 3 -r 3 -t 10 -b:v 50k -s qcif -f rv10 /tmp/b.rm
- The parameter ’q’ which is displayed while encoding is the current
-quantizer. The value 1 indicates that a very good quality could
-be achieved. The value 31 indicates the worst quality. If q=31 appears
-too often, it means that the encoder cannot compress enough to meet
-your bitrate. You must either increase the bitrate, decrease the
-frame rate or decrease the frame size.
-
- If your computer is not fast enough, you can speed up the
-compression at the expense of the compression ratio. You can use
-’-me zero’ to speed up motion estimation, and ’-g 0’ to disable
-motion estimation completely (you have only I-frames, which means it
-is about as good as JPEG compression).
-
- To have very low audio bitrates, reduce the sampling frequency
-(down to 22050 Hz for MPEG audio, 22050 or 11025 for AC-3).
-
- To have a constant quality (but a variable bitrate), use the option
-’-qscale n’ when ’n’ is between 1 (excellent quality) and 31 (worst
-quality).
-
-
-
-
-
7 Examples# TOC
-
-
-
7.1 Video and Audio grabbing# TOC
-
-
If you specify the input format and device then ffmpeg can grab video
-and audio directly.
-
-
-
ffmpeg -f oss -i /dev/dsp -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Or with an ALSA audio source (mono input, card id 1) instead of OSS:
-
-
ffmpeg -f alsa -ac 1 -i hw:1 -f video4linux2 -i /dev/video0 /tmp/out.mpg
-
-
-
Note that you must activate the right video source and channel before
-launching ffmpeg with any TV viewer such as
-xawtv by Gerd Knorr. You also
-have to set the audio recording levels correctly with a
-standard mixer.
-
-
-
7.2 X11 grabbing# TOC
-
-
Grab the X11 display with ffmpeg via
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as
-the DISPLAY environment variable.
-
-
-
ffmpeg -f x11grab -video_size cif -framerate 25 -i :0.0+10,20 /tmp/out.mpg
-
-
-
0.0 is display.screen number of your X11 server, same as the DISPLAY environment
-variable. 10 is the x-offset and 20 the y-offset for the grabbing.
-
-
-
7.3 Video and Audio file format conversion# TOC
-
-
Any supported file format and protocol can serve as input to ffmpeg:
-
-
Examples:
-
- You can use YUV files as input:
-
-
-
ffmpeg -i /tmp/test%d.Y /tmp/out.mpg
- It will use the files:
-
-
/tmp/test0.Y, /tmp/test0.U, /tmp/test0.V,
-/tmp/test1.Y, /tmp/test1.U, /tmp/test1.V, etc...
- The Y files use twice the resolution of the U and V files. They are
-raw files, without header. They can be generated by all decent video
-decoders. You must specify the size of the image with the -s option
-if ffmpeg cannot guess it.
-
- You can input from a raw YUV420P file:
-
-
-
ffmpeg -i /tmp/test.yuv /tmp/out.avi
- test.yuv is a file containing raw YUV planar data. Each frame is composed
-of the Y plane followed by the U and V planes at half vertical and
-horizontal resolution.
-
- You can output to a raw YUV420P file:
-
-
-
ffmpeg -i mydivx.avi hugefile.yuv
- You can set several input files and output files:
-
-
-
ffmpeg -i /tmp/a.wav -s 640x480 -i /tmp/a.yuv /tmp/a.mpg
- Converts the audio file a.wav and the raw YUV video file a.yuv
-to MPEG file a.mpg.
-
- You can also do audio and video conversions at the same time:
-
-
-
ffmpeg -i /tmp/a.wav -ar 22050 /tmp/a.mp2
- Converts a.wav to MPEG audio at 22050 Hz sample rate.
-
- You can encode to several formats at the same time and define a
-mapping from input stream to output streams:
-
-
-
ffmpeg -i /tmp/a.wav -map 0:a -b:a 64k /tmp/a.mp2 -map 0:a -b:a 128k /tmp/b.mp2
- Converts a.wav to a.mp2 at 64 kbits and to b.mp2 at 128 kbits. ’-map
-file:index’ specifies which input stream is used for each output
-stream, in the order of the definition of output streams.
-
- You can transcode decrypted VOBs:
-
-
-
ffmpeg -i snatch_1.vob -f avi -c:v mpeg4 -b:v 800k -g 300 -bf 2 -c:a libmp3lame -b:a 128k snatch.avi
- This is a typical DVD ripping example; the input is a VOB file, the
-output an AVI file with MPEG-4 video and MP3 audio. Note that in this
-command we use B-frames so the MPEG-4 stream is DivX5 compatible, and
-GOP size is 300 which means one intra frame every 10 seconds for 29.97fps
-input video. Furthermore, the audio stream is MP3-encoded so you need
-to enable LAME support by passing --enable-libmp3lame to configure.
-The mapping is particularly useful for DVD transcoding
-to get the desired audio language.
-
-NOTE: To see the supported input formats, use ffmpeg -formats.
-
- You can extract images from a video, or create a video from many images:
-
-For extracting images from a video:
-
-
ffmpeg -i foo.avi -r 1 -s WxH -f image2 foo-%03d.jpeg
- This will extract one video frame per second from the video and will
-output them in files named foo-001.jpeg , foo-002.jpeg ,
-etc. Images will be rescaled to fit the new WxH values.
-
-If you want to extract just a limited number of frames, you can use the
-above command in combination with the -vframes or -t option, or in
-combination with -ss to start extracting from a certain point in time.
-
-For creating a video from many images:
-
-
ffmpeg -f image2 -i foo-%03d.jpeg -r 12 -s WxH foo.avi
- The syntax foo-%03d.jpeg specifies to use a decimal number
-composed of three digits padded with zeroes to express the sequence
-number. It is the same syntax supported by the C printf function, but
-only formats accepting a normal integer are suitable.
-
-When importing an image sequence, -i also supports expanding
-shell-like wildcard patterns (globbing) internally, by selecting the
-image2-specific -pattern_type glob option.
-
-For example, for creating a video from filenames matching the glob pattern
-foo-*.jpeg:
-
-
ffmpeg -f image2 -pattern_type glob -i 'foo-*.jpeg' -r 12 -s WxH foo.avi
- You can put many streams of the same type in the output:
-
-
-
ffmpeg -i test1.avi -i test2.avi -map 1:1 -map 1:0 -map 0:1 -map 0:0 -c copy -y test12.nut
- The resulting output file test12.nut will contain the first four streams
-from the input files in reverse order.
-
- To force CBR video output:
-
-
ffmpeg -i myfile.avi -b 4000k -minrate 4000k -maxrate 4000k -bufsize 1835k out.m2v
- The four options lmin, lmax, mblmin and mblmax use ’lambda’ units,
-but you may use the QP2LAMBDA constant to easily convert from ’q’ units:
-
-
ffmpeg -i src.ext -lmax 21*QP2LAMBDA dst.ext
-
-
-
-
-
8 See Also# TOC
-
-
ffmpeg-all ,
-ffplay , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
9 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffplay Documentation
-
-
-
- ffplay Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffplay [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
FFplay is a very simple and portable media player using the FFmpeg
-libraries and the SDL library. It is mostly used as a testbed for the
-various FFmpeg APIs.
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--x width Force displayed width.
-
-y height Force displayed height.
-
-s size Set frame size (WxH or abbreviation), needed for videos which do
-not contain a header with the frame size like raw YUV. This option
-has been deprecated in favor of private options, try -video_size.
-
-fs Start in fullscreen mode.
-
-an Disable audio.
-
-vn Disable video.
-
-sn Disable subtitles.
-
-ss pos Seek to a given position in seconds.
-
-t duration play <duration> seconds of audio/video
-
-bytes Seek by bytes.
-
-nodisp Disable graphical display.
-
-f fmt Force format.
-
-window_title title Set window title (default is the input filename).
-
-loop number Loops movie playback <number> times. 0 means forever.
-
-showmode mode Set the show mode to use.
-Available values for mode are:
-
-‘0, video ’
-show video
-
‘1, waves ’
-show audio waves
-
‘2, rdft ’
-show audio frequency band using RDFT ((Inverse) Real Discrete Fourier Transform)
-
-
-Default value is "video", if video is not present or cannot be played
-"rdft" is automatically selected.
-
-You can interactively cycle through the available show modes by
-pressing the key w .
-
--vf filtergraph Create the filtergraph specified by filtergraph and use it to
-filter the video stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single video input and a single video
-output. In the filtergraph, the input is associated to the label
-in, and the output to the label out. See the
-ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-You can specify this parameter multiple times and cycle through the specified
-filtergraphs along with the show modes by pressing the key w .
-
--af filtergraph filtergraph is a description of the filtergraph to apply to
-the input audio.
-Use the option "-filters" to show all the available filters (including
-sources and sinks).
-
--i input_file Read input_file .
-
-
-
-
3.5 Advanced options# TOC
-
--pix_fmt format Set pixel format.
-This option has been deprecated in favor of private options, try -pixel_format.
-
--stats Print several playback statistics, in particular show the stream
-duration, the codec parameters, the current position in the stream and
-the audio/video synchronisation drift. It is on by default, to
-explicitly disable it you need to specify -nostats.
-
--fast Non-spec-compliant optimizations.
-
-genpts Generate pts.
-
-sync type Set the master clock to audio (type=audio), video
-(type=video) or external (type=ext). Default is audio. The
-master clock is used to control audio-video synchronization. Most media
-players use audio as master clock, but in some cases (streaming or high
-quality broadcast) it is necessary to change that. This option is mainly
-used for debugging purposes.
-
-ast audio_stream_specifier Select the desired audio stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" audio stream is selected in the program of the
-already selected video stream.
-
-vst video_stream_specifier Select the desired video stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" video stream is selected.
-
-sst subtitle_stream_specifier Select the desired subtitle stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" subtitle stream is selected in the program of the
-already selected video or audio stream.
-
-autoexit Exit when video is done playing.
-
-exitonkeydown Exit if any key is pressed.
-
-exitonmousedown Exit if any mouse button is pressed.
-
--codec:media_specifier codec_name Force a specific decoder implementation for the stream identified by
-media_specifier , which can assume the values a (audio),
-v (video), and s subtitle.
-
--acodec codec_name Force a specific audio decoder.
-
--vcodec codec_name Force a specific video decoder.
-
--scodec codec_name Force a specific subtitle decoder.
-
--autorotate Automatically rotate the video according to presentation metadata. Enabled by
-default, use -noautorotate to disable it.
-
--framedrop Drop video frames if video is out of sync. Enabled by default if the master
-clock is not set to video. Use this option to enable frame dropping for all
-master clock sources, use -noframedrop to disable it.
-
--infbuf Do not limit the input buffer size, read as much data as possible from the
-input as soon as possible. Enabled by default for realtime streams, where data
-may be dropped if not read in time. Use this option to enable infinite buffers
-for all inputs, use -noinfbuf to disable it.
-
-
-
-
-
3.6 While playing# TOC
-
-
-q, ESC Quit.
-
-f Toggle full screen.
-
-p, SPC Pause.
-
-a Cycle audio channel in the current program.
-
-v Cycle video channel.
-
-t Cycle subtitle channel in the current program.
-
-c Cycle program.
-
-w Cycle video filters or show modes.
-
-s Step to the next frame.
-
-Pause if the stream is not already paused, step to the next video
-frame, and pause.
-
-left/right Seek backward/forward 10 seconds.
-
-down/up Seek backward/forward 1 minute.
-
-page down/page up Seek to the previous/next chapter.
-or if there are no chapters
-Seek backward/forward 10 minutes.
-
-mouse click Seek to percentage in file corresponding to fraction of width.
-
-
-
-
-
-
4 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
4.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
4.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
4.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
4.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
4.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
4.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
4.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
4.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
4.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
4.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
5 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
6 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
7 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
8 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
9 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
9.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
9.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
10 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
10.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
10.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
10.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
10.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
10.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
10.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
10.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
10.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
10.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
10.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
11 Subtitles Decoders# TOC
-
-
-
11.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
11.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
11.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
11.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
12 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
12.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
12.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
12.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
12.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
12.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
12.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
12.7 mjpega_dump_header# TOC
-
-
-
12.8 movsub# TOC
-
-
-
12.9 mp3_header_decompress# TOC
-
-
-
12.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
12.11 remove_extra# TOC
-
-
-
13 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
13.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
14 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
14.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
14.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
14.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
14.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
14.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
14.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
14.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
14.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
14.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
14.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
14.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
14.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
14.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
14.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
14.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
14.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
15 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
16 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
16.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
16.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
16.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
16.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
16.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
16.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
16.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
16.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
16.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
16.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
16.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
16.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
16.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
16.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
16.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
16.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
16.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
16.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
16.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
16.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
16.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
16.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
16.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
16.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
16.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
16.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
16.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
16.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
16.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
16.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
16.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
16.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
16.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
16.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
16.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
16.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
16.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
16.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
16.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
17 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
18 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
18.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
18.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
18.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
18.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
18.3 bktr# TOC
-
-
BSD video input device.
-
-
-
18.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
18.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
18.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
18.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
18.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
18.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
18.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
18.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
18.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
18.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
18.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
18.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
18.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
18.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
18.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
18.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
18.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
18.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
18.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
18.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
18.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
18.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
18.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
18.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
18.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
18.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
18.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
18.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
18.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
18.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
18.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
18.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
18.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
19 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
20 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
21 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
22 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
23 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
23.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
23.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
24 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
25 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
25.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
25.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
25.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
25.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
25.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
25.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
25.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
25.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
25.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
25.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
25.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
25.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
25.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
25.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
25.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
25.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
25.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
25.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
25.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
25.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
25.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
25.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
25.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
25.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
25.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
25.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
25.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
25.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
25.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
25.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
25.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
25.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
25.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
25.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
25.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
25.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
25.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
25.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
25.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
25.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
25.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
25.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
25.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
25.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
25.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
25.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
25.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
25.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
25.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
25.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
25.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
25.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
25.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
25.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
25.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
25.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
25.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
25.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
25.42.2 Examples# TOC
-
-
-
-
-
25.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
25.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
26 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
26.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
26.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
26.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
26.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
26.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
26.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
26.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
26.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
26.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
26.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
27 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
27.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
27.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
28 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
28.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
28.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
28.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
28.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
28.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
28.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
28.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
28.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
28.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
28.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
28.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
28.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
28.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
28.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
28.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
28.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
28.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
28.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
28.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
28.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
28.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
28.15.1 Examples# TOC
-
-
-
-
-
28.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
28.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
28.17.1 Examples# TOC
-
-
-
-
-
28.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
28.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
28.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
28.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
28.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
28.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
28.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
28.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
28.23.1 Examples# TOC
-
-
-
-
-
28.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
28.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
28.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
28.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
28.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
28.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
28.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
28.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
28.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
28.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
28.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
28.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
28.29.1 Examples# TOC
-
-
-
-
-
28.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
28.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
28.31.1 p/c/n/u/b meaning# TOC
-
-
-
28.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
28.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
28.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
28.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
28.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
28.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
28.34.1 Examples# TOC
-
-
-
-
-
28.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
28.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
28.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
28.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
28.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
28.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
28.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
28.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
28.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
28.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
28.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
28.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
28.42.1 Workflow examples# TOC
-
-
-
28.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
28.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
28.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
28.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
28.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
28.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
28.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
28.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
28.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
28.48.1 Examples# TOC
-
-
-
-
-
28.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
28.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
28.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
28.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
28.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
28.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
28.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
28.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
28.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
28.55.1 Examples# TOC
-
-
-
-
-
28.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
28.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
28.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
28.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
28.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
28.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
28.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
28.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
28.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
28.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
28.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
28.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
28.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
28.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
28.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
28.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
28.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
28.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.65.2 Examples# TOC
-
-
-
-
-
28.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
28.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.67.1 Examples# TOC
-
-
-
-
-
28.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
28.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
28.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
28.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
28.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
28.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
28.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
28.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
28.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
28.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
28.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
28.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
28.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
28.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
28.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
28.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
28.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.79.2 Examples# TOC
-
-
-
-
-
28.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
28.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
28.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
28.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
28.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
28.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
28.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
28.85.1 Examples# TOC
-
-
-
-
-
28.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
28.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
28.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
28.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
28.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
28.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
28.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
28.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
28.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
28.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
28.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
28.94.1 Examples# TOC
-
-
-
-
-
28.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
28.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
28.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
28.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
28.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
28.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
28.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
28.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
28.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
28.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
28.101.2 Examples# TOC
-
-
-
-
-
28.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
28.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
28.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
28.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
28.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
28.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
28.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
28.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
28.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
29 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
29.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
29.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
29.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
29.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
29.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
29.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
29.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
29.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
29.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
29.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
30 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
30.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
30.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
31 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
31.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
31.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
31.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
31.2.1 Examples# TOC
-
-
-
-
-
31.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
31.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
31.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
31.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
31.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
31.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
31.6.1 Examples# TOC
-
-
-
-
-
31.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
31.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
31.7.2 Examples# TOC
-
-
-
-
-
31.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
31.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
31.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
31.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
31.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
31.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
31.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
31.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
31.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
31.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
31.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
31.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
31.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
31.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
32 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
32.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
32.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
32.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
33 See Also# TOC
-
-
ffplay ,
-ffmpeg , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
34 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffplay Documentation
-
-
-
- ffplay Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffplay [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
FFplay is a very simple and portable media player using the FFmpeg
-libraries and the SDL library. It is mostly used as a testbed for the
-various FFmpeg APIs.
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--x width Force displayed width.
-
-y height Force displayed height.
-
-s size Set frame size (WxH or abbreviation), needed for videos which do
-not contain a header with the frame size like raw YUV. This option
-has been deprecated in favor of private options, try -video_size.
-
-fs Start in fullscreen mode.
-
-an Disable audio.
-
-vn Disable video.
-
-sn Disable subtitles.
-
-ss pos Seek to a given position in seconds.
-
-t duration play <duration> seconds of audio/video
-
-bytes Seek by bytes.
-
-nodisp Disable graphical display.
-
-f fmt Force format.
-
-window_title title Set window title (default is the input filename).
-
-loop number Loops movie playback <number> times. 0 means forever.
-
-showmode mode Set the show mode to use.
-Available values for mode are:
-
-‘0, video ’
-show video
-
‘1, waves ’
-show audio waves
-
‘2, rdft ’
-show audio frequency band using RDFT ((Inverse) Real Discrete Fourier Transform)
-
-
-Default value is "video", if video is not present or cannot be played
-"rdft" is automatically selected.
-
-You can interactively cycle through the available show modes by
-pressing the key w .
-
--vf filtergraph Create the filtergraph specified by filtergraph and use it to
-filter the video stream.
-
-filtergraph is a description of the filtergraph to apply to
-the stream, and must have a single video input and a single video
-output. In the filtergraph, the input is associated to the label
-in, and the output to the label out. See the
-ffmpeg-filters manual for more information about the filtergraph
-syntax.
-
-You can specify this parameter multiple times and cycle through the specified
-filtergraphs along with the show modes by pressing the key w .
-
--af filtergraph filtergraph is a description of the filtergraph to apply to
-the input audio.
-Use the option "-filters" to show all the available filters (including
-sources and sinks).
-
--i input_file Read input_file .
-
-
-
-
3.5 Advanced options# TOC
-
--pix_fmt format Set pixel format.
-This option has been deprecated in favor of private options, try -pixel_format.
-
--stats Print several playback statistics, in particular show the stream
-duration, the codec parameters, the current position in the stream and
-the audio/video synchronisation drift. It is on by default, to
-explicitly disable it you need to specify -nostats.
-
--fast Non-spec-compliant optimizations.
-
-genpts Generate pts.
-
-sync type Set the master clock to audio (type=audio), video
-(type=video) or external (type=ext). Default is audio. The
-master clock is used to control audio-video synchronization. Most media
-players use audio as master clock, but in some cases (streaming or high
-quality broadcast) it is necessary to change that. This option is mainly
-used for debugging purposes.
-
-ast audio_stream_specifier Select the desired audio stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" audio stream is selected in the program of the
-already selected video stream.
-
-vst video_stream_specifier Select the desired video stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" video stream is selected.
-
-sst subtitle_stream_specifier Select the desired subtitle stream using the given stream specifier. The stream
-specifiers are described in the Stream specifiers chapter. If this option
-is not specified, the "best" subtitle stream is selected in the program of the
-already selected video or audio stream.
-
-autoexit Exit when video is done playing.
-
-exitonkeydown Exit if any key is pressed.
-
-exitonmousedown Exit if any mouse button is pressed.
-
--codec:media_specifier codec_name Force a specific decoder implementation for the stream identified by
-media_specifier , which can assume the values a (audio),
-v (video), and s subtitle.
-
--acodec codec_name Force a specific audio decoder.
-
--vcodec codec_name Force a specific video decoder.
-
--scodec codec_name Force a specific subtitle decoder.
-
--autorotate Automatically rotate the video according to presentation metadata. Enabled by
-default, use -noautorotate to disable it.
-
--framedrop Drop video frames if video is out of sync. Enabled by default if the master
-clock is not set to video. Use this option to enable frame dropping for all
-master clock sources, use -noframedrop to disable it.
-
--infbuf Do not limit the input buffer size, read as much data as possible from the
-input as soon as possible. Enabled by default for realtime streams, where data
-may be dropped if not read in time. Use this option to enable infinite buffers
-for all inputs, use -noinfbuf to disable it.
-
-
-
-
-
3.6 While playing# TOC
-
-
-q, ESC Quit.
-
-f Toggle full screen.
-
-p, SPC Pause.
-
-a Cycle audio channel in the current program.
-
-v Cycle video channel.
-
-t Cycle subtitle channel in the current program.
-
-c Cycle program.
-
-w Cycle video filters or show modes.
-
-s Step to the next frame.
-
-Pause if the stream is not already paused, step to the next video
-frame, and pause.
-
-left/right Seek backward/forward 10 seconds.
-
-down/up Seek backward/forward 1 minute.
-
-page down/page up Seek to the previous/next chapter.
-or if there are no chapters
-Seek backward/forward 10 minutes.
-
-mouse click Seek to percentage in file corresponding to fraction of width.
-
-
-
-
-
-
-
4 See Also# TOC
-
-
ffmpeg-all ,
-ffmpeg , ffprobe , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
5 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffprobe Documentation
-
-
-
- ffprobe Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffprobe [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
ffprobe gathers information from multimedia streams and prints it in
-human- and machine-readable fashion.
-
-
For example it can be used to check the format of the container used
-by a multimedia stream and the format and type of each media stream
-contained in it.
-
-
If a filename is specified in input, ffprobe will try to open and
-probe the file content. If the file cannot be opened or recognized as
-a multimedia file, a positive exit code is returned.
-
-
ffprobe may be employed both as a standalone application or in
-combination with a textual filter, which may perform more
-sophisticated processing, e.g. statistical processing or plotting.
-
-
Options are used to list some of the formats supported by ffprobe or
-for specifying which information to display, and for setting how
-ffprobe will show it.
-
-
ffprobe output is designed to be easily parsable by a textual filter,
-and consists of one or more sections of a form defined by the selected
-writer, which is specified by the print_format option.
-
-
Sections may contain other nested sections, and are identified by a
-name (which may be shared by other sections), and an unique
-name. See the output of sections .
-
-
Metadata tags stored in the container or in the streams are recognized
-and printed in the corresponding "FORMAT", "STREAM" or "PROGRAM_STREAM"
-section.
-
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--f format Force format to use.
-
--unit Show the unit of the displayed values.
-
--prefix Use SI prefixes for the displayed values.
-Unless the "-byte_binary_prefix" option is used all the prefixes
-are decimal.
-
--byte_binary_prefix Force the use of binary prefixes for byte values.
-
--sexagesimal Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.
-
--pretty Prettify the format of the displayed values, it corresponds to the
-options "-unit -prefix -byte_binary_prefix -sexagesimal".
-
--of, -print_format writer_name [=writer_options ] Set the output printing format.
-
-writer_name specifies the name of the writer, and
-writer_options specifies the options to be passed to the writer.
-
-For example for printing the output in JSON format, specify:
-
-
-For more details on the available output printing formats, see the
-Writers section below.
-
--sections Print sections structure and section information, and exit. The output
-is not meant to be parsed by a machine.
-
--select_streams stream_specifier Select only the streams specified by stream_specifier . This
-option affects only the options related to streams
-(e.g. show_streams, show_packets, etc.).
-
-For example to show only audio streams, you can use the command:
-
-
ffprobe -show_streams -select_streams a INPUT
- To show only video packets belonging to the video stream with index 1:
-
-
ffprobe -show_packets -select_streams v:1 INPUT
- -show_data Show payload data, as a hexadecimal and ASCII dump. Coupled with
--show_packets , it will dump the packets’ data. Coupled with
--show_streams , it will dump the codec extradata.
-
-The dump is printed as the "data" field. It may contain newlines.
-
--show_data_hash algorithm Show a hash of payload data, for packets with -show_packets and for
-codec extradata with -show_streams .
-
--show_error Show information about the error found when trying to probe the input.
-
-The error information is printed within a section with name "ERROR".
-
--show_format Show information about the container format of the input multimedia
-stream.
-
-All the container format information is printed within a section with
-name "FORMAT".
-
--show_format_entry name Like -show_format , but only prints the specified entry of the
-container format information, rather than all. This option may be given more
-than once, then all specified entries will be shown.
-
-This option is deprecated, use show_entries instead.
-
--show_entries section_entries Set list of entries to show.
-
-Entries are specified according to the following
-syntax. section_entries contains a list of section entries
-separated by :. Each section entry is composed by a section
-name (or unique name), optionally followed by a list of entries local
-to that section, separated by ,.
-
-If section name is specified but is followed by no =, all
-entries are printed to output, together with all the contained
-sections. Otherwise only the entries specified in the local section
-entries list are printed. In particular, if = is specified but
-the list of local entries is empty, then no entries will be shown for
-that section.
-
-Note that the order of specification of the local section entries is
-not honored in the output, and the usual display order will be
-retained.
-
-The formal syntax is given by:
-
-
LOCAL_SECTION_ENTRIES ::= SECTION_ENTRY_NAME [,LOCAL_SECTION_ENTRIES ]
-SECTION_ENTRY ::= SECTION_NAME [=[LOCAL_SECTION_ENTRIES ]]
-SECTION_ENTRIES ::= SECTION_ENTRY [:SECTION_ENTRIES ]
-For example, to show only the index and type of each stream, and the PTS
-time, duration time, and stream index of the packets, you can specify
-the argument:
-
-
packet=pts_time,duration_time,stream_index : stream=index,codec_type
- To show all the entries in the section "format", but only the codec
-type in the section "stream", specify the argument:
-
-
format : stream=codec_type
- To show all the tags in the stream and format sections:
-
-
stream_tags : format_tags
- To show only the title tag (if available) in the stream
-sections:
-
-
--show_packets Show information about each packet contained in the input multimedia
-stream.
-
-The information for each single packet is printed within a dedicated
-section with name "PACKET".
-
--show_frames Show information about each frame and subtitle contained in the input
-multimedia stream.
-
-The information for each single frame is printed within a dedicated
-section with name "FRAME" or "SUBTITLE".
-
--show_streams Show information about each media stream contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "STREAM".
-
--show_programs Show information about programs and their streams contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "PROGRAM_STREAM".
-
--show_chapters Show information about chapters stored in the format.
-
-Each chapter is printed within a dedicated section with name "CHAPTER".
-
--count_frames Count the number of frames per stream and report it in the
-corresponding stream section.
-
--count_packets Count the number of packets per stream and report it in the
-corresponding stream section.
-
--read_intervals read_intervals
-Read only the specified intervals. read_intervals must be a
-sequence of interval specifications separated by ",".
-ffprobe will seek to the interval starting point, and will
-continue reading from that.
-
-Each interval is specified by two optional parts, separated by "%".
-
-The first part specifies the interval start position. It is
-interpreted as an abolute position, or as a relative offset from the
-current position if it is preceded by the "+" character. If this first
-part is not specified, no seeking will be performed when reading this
-interval.
-
-The second part specifies the interval end position. It is interpreted
-as an absolute position, or as a relative offset from the current
-position if it is preceded by the "+" character. If the offset
-specification starts with "#", it is interpreted as the number of
-packets to read (not including the flushing packets) from the interval
-start. If no second part is specified, the program will read until the
-end of the input.
-
-Note that seeking is not accurate, thus the actual interval start
-point may be different from the specified position. Also, when an
-interval duration is specified, the absolute end time will be computed
-by adding the duration to the interval start point found by seeking
-the file, rather than to the specified start value.
-
-The formal syntax is given by:
-
-
INTERVAL ::= [START |+START_OFFSET ][%[END |+END_OFFSET ]]
-INTERVALS ::= INTERVAL [,INTERVALS ]
-A few examples follow.
-
- Seek to time 10, read packets until 20 seconds after the found seek
-point, then seek to position 01:30 (1 minute and thirty
-seconds) and read packets until position 01:45.
-
-
- Read only 42 packets after seeking to position 01:23:
-
-
- Read only the first 20 seconds from the start:
-
-
- Read from the start until position 02:30:
-
-
-
-
--show_private_data, -private Show private data, that is data depending on the format of the
-particular shown element.
-This option is enabled by default, but you may need to disable it
-for specific uses, for example when creating XSD-compliant XML output.
-
--show_program_version Show information related to program version.
-
-Version information is printed within a section with name
-"PROGRAM_VERSION".
-
--show_library_versions Show information related to library versions.
-
-Version information for each library is printed within a section with
-name "LIBRARY_VERSION".
-
--show_versions Show information related to program and library versions. This is the
-equivalent of setting both -show_program_version and
--show_library_versions options.
-
--show_pixel_formats Show information about all pixel formats supported by FFmpeg.
-
-Pixel format information for each format is printed within a section
-with name "PIXEL_FORMAT".
-
--bitexact Force bitexact output, useful to produce output which is not dependent
-on the specific build.
-
--i input_file Read input_file .
-
-
-
-
-
4 Writers# TOC
-
-
A writer defines the output format adopted by ffprobe, and will be
-used for printing all the parts of the output.
-
-
A writer may accept one or more arguments, which specify the options
-to adopt. The options are specified as a list of key =value
-pairs, separated by ":".
-
-
All writers support the following options:
-
-
-string_validation, sv Set string validation mode.
-
-The following values are accepted.
-
-‘fail ’
-The writer will fail immediately in case an invalid string (UTF-8)
-sequence or code point is found in the input. This is especially
-useful to validate input metadata.
-
-‘ignore ’
-Any validation error will be ignored. This will result in possibly
-broken output, especially with the json or xml writer.
-
-‘replace ’
-The writer will substitute invalid UTF-8 sequences or code points with
-the string specified with the string_validation_replacement .
-
-
-Default value is ‘replace ’.
-
-string_validation_replacement, svr Set replacement string to use in case string_validation is
-set to ‘replace ’.
-
-In case the option is not specified, the writer will assume the empty
-string, that is it will remove the invalid sequences from the input
-strings.
-
-
-
A description of the currently available writers follows.
-
-
-
4.1 default# TOC
-
Default format.
-
-
Print each section in the form:
-
-
[SECTION]
-key1=val1
-...
-keyN=valN
-[/SECTION]
-
-
-
Metadata tags are printed as a line in the corresponding FORMAT, STREAM or
-PROGRAM_STREAM section, and are prefixed by the string "TAG:".
-
-
A description of the accepted options follows.
-
-
-nokey, nk If set to 1 specify not to print the key of each field. Default value
-is 0.
-
-noprint_wrappers, nw If set to 1 specify not to print the section header and footer.
-Default value is 0.
-
-
-
-
4.2 compact, csv# TOC
-
Compact and CSV format.
-
-
The csv writer is equivalent to compact, but supports
-different defaults.
-
-
Each section is printed on a single line.
-If no option is specifid, the output has the form:
-
-
section|key1=val1| ... |keyN=valN
-
-
-
Metadata tags are printed in the corresponding "format" or "stream"
-section. A metadata tag key, if printed, is prefixed by the string
-"tag:".
-
-
The description of the accepted options follows.
-
-
-item_sep, s Specify the character to use for separating fields in the output line.
-It must be a single printable character, it is "|" by default ("," for
-the csv writer).
-
-nokey, nk If set to 1 specify not to print the key of each field. Its default
-value is 0 (1 for the csv writer).
-
-escape, e Set the escape mode to use, default to "c" ("csv" for the csv
-writer).
-
-It can assume one of the following values:
-
-c Perform C-like escaping. Strings containing a newline (’\n’), carriage
-return (’\r’), a tab (’\t’), a form feed (’\f’), the escaping
-character (’\’) or the item separator character SEP are escaped using C-like fashioned
-escaping, so that a newline is converted to the sequence "\n", a
-carriage return to "\r", ’\’ to "\\" and the separator SEP is
-converted to "\SEP ".
-
-csv Perform CSV-like escaping, as described in RFC4180. Strings
-containing a newline (’\n’), a carriage return (’\r’), a double quote
-(’"’), or SEP are enclosed in double-quotes.
-
-none Perform no escaping.
-
-
-print_section, p Print the section name at the begin of each line if the value is
-1, disable it with value set to 0. Default value is
-1.
-
-
-
-
-
4.3 flat# TOC
-
Flat format.
-
-
A free-form output where each line contains an explicit key=value, such as
-"streams.stream.3.tags.foo=bar". The output is shell escaped, so it can be
-directly embedded in sh scripts as long as the separator character is an
-alphanumeric character or an underscore (see sep_char option).
-
-
The description of the accepted options follows.
-
-
-sep_char, s Separator character used to separate the chapter, the section name, IDs and
-potential tags in the printed field key.
-
-Default value is ’.’.
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
-
INI format output.
-
-
Print output in an INI based format.
-
-
The following conventions are adopted:
-
-
- all key and values are UTF-8
- ’.’ is the subgroup separator
- newline, ’\t’, ’\f’, ’\b’ and the following characters are escaped
- ’\’ is the escape character
- ’#’ is the comment indicator
- ’=’ is the key/value separator
- ’:’ is not used but usually parsed as key/value separator
-
-
-
This writer accepts options as a list of key =value pairs,
-separated by ":".
-
-
The description of the accepted options follows.
-
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
4.5 json# TOC
-
JSON based format.
-
-
Each section is printed using JSON notation.
-
-
The description of the accepted options follows.
-
-
-compact, c If set to 1 enable compact output, that is each section will be
-printed on a single line. Default value is 0.
-
-
-
For more information about JSON, see http://www.json.org/ .
-
-
-
-
XML based format.
-
-
The XML output is described in the XML schema description file
-ffprobe.xsd installed in the FFmpeg datadir.
-
-
An updated version of the schema can be retrieved at the url
-http://www.ffmpeg.org/schema/ffprobe.xsd , which redirects to the
-latest schema committed into the FFmpeg development source code tree.
-
-
Note that the output issued will be compliant to the
-ffprobe.xsd schema only when no special global output options
-(unit , prefix , byte_binary_prefix ,
-sexagesimal etc.) are specified.
-
-
The description of the accepted options follows.
-
-
-fully_qualified, q If set to 1 specify if the output should be fully qualified. Default
-value is 0.
-This is required for generating an XML file which can be validated
-through an XSD file.
-
-xsd_compliant, x If set to 1 perform more checks for ensuring that the output is XSD
-compliant. Default value is 0.
-This option automatically sets fully_qualified to 1.
-
-
-
For more information about the XML format, see
-http://www.w3.org/XML/ .
-
-
-
5 Timecode# TOC
-
-
ffprobe supports Timecode extraction:
-
-
- MPEG1/2 timecode is extracted from the GOP, and is available in the video
-stream details (-show_streams , see timecode ).
-
- MOV timecode is extracted from tmcd track, so is available in the tmcd
-stream metadata (-show_streams , see TAG:timecode ).
-
- DV, GXF and AVI timecodes are available in format metadata
-(-show_format , see TAG:timecode ).
-
-
-
-
-
6 Syntax# TOC
-
-
This section documents the syntax and formats employed by the FFmpeg
-libraries and tools.
-
-
-
6.1 Quoting and escaping# TOC
-
-
FFmpeg adopts the following quoting and escaping mechanism, unless
-explicitly specified. The following rules are applied:
-
-
- ' and \ are special characters (respectively used for
-quoting and escaping). In addition to them, there might be other
-special characters depending on the specific syntax where the escaping
-and quoting are employed.
-
- A special character is escaped by prefixing it with a ’\’.
-
- All characters enclosed between ” are included literally in the
-parsed string. The quote character ' itself cannot be quoted,
-so you may need to close the quote and escape it.
-
- Leading and trailing whitespaces, unless escaped or quoted, are
-removed from the parsed string.
-
-
-
Note that you may need to add a second level of escaping when using
-the command line or a script, which depends on the syntax of the
-adopted shell language.
-
-
The function av_get_token defined in
-libavutil/avstring.h can be used to parse a token quoted or
-escaped according to the rules defined above.
-
-
The tool tools/ffescape in the FFmpeg source tree can be used
-to automatically quote or escape a string in a script.
-
-
-
6.1.1 Examples# TOC
-
-
- Escape the string Crime d'Amour containing the ' special
-character:
-
-
- The string above contains a quote, so the ' needs to be escaped
-when quoting it:
-
-
- Include leading or trailing whitespaces using quoting:
-
-
' this string starts and ends with whitespaces '
- Escaping and quoting can be mixed together:
-
-
' The string '\'string\'' is a string '
- To include a literal \ you can use either escaping or quoting:
-
-
'c:\foo' can be written as c:\\foo
-
-
-
-
6.2 Date# TOC
-
-
The accepted syntax is:
-
-
[(YYYY-MM-DD|YYYYMMDD)[T|t| ]]((HH:MM:SS[.m...]]])|(HHMMSS[.m...]]]))[Z]
-now
-
-
-
If the value is "now" it takes the current time.
-
-
Time is local time unless Z is appended, in which case it is
-interpreted as UTC.
-If the year-month-day part is not specified it takes the current
-year-month-day.
-
-
-
6.3 Time duration# TOC
-
-
There are two accepted syntaxes for expressing time duration.
-
-
-
-
HH expresses the number of hours, MM the number of minutes
-for a maximum of 2 digits, and SS the number of seconds for a
-maximum of 2 digits. The m at the end expresses decimal value for
-SS .
-
-
or
-
-
-
-
S expresses the number of seconds, with the optional decimal part
-m .
-
-
In both expressions, the optional ‘- ’ indicates negative duration.
-
-
-
6.3.1 Examples# TOC
-
-
The following examples are all valid time duration:
-
-
-‘55 ’
-55 seconds
-
-‘12:03:45 ’
-12 hours, 03 minutes and 45 seconds
-
-‘23.189 ’
-23.189 seconds
-
-
-
-
6.4 Video size# TOC
-
Specify the size of the sourced video, it may be a string of the form
-width xheight , or the name of a size abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-720x480
-
‘pal ’
-720x576
-
‘qntsc ’
-352x240
-
‘qpal ’
-352x288
-
‘sntsc ’
-640x480
-
‘spal ’
-768x576
-
‘film ’
-352x240
-
‘ntsc-film ’
-352x240
-
‘sqcif ’
-128x96
-
‘qcif ’
-176x144
-
‘cif ’
-352x288
-
‘4cif ’
-704x576
-
‘16cif ’
-1408x1152
-
‘qqvga ’
-160x120
-
‘qvga ’
-320x240
-
‘vga ’
-640x480
-
‘svga ’
-800x600
-
‘xga ’
-1024x768
-
‘uxga ’
-1600x1200
-
‘qxga ’
-2048x1536
-
‘sxga ’
-1280x1024
-
‘qsxga ’
-2560x2048
-
‘hsxga ’
-5120x4096
-
‘wvga ’
-852x480
-
‘wxga ’
-1366x768
-
‘wsxga ’
-1600x1024
-
‘wuxga ’
-1920x1200
-
‘woxga ’
-2560x1600
-
‘wqsxga ’
-3200x2048
-
‘wquxga ’
-3840x2400
-
‘whsxga ’
-6400x4096
-
‘whuxga ’
-7680x4800
-
‘cga ’
-320x200
-
‘ega ’
-640x350
-
‘hd480 ’
-852x480
-
‘hd720 ’
-1280x720
-
‘hd1080 ’
-1920x1080
-
‘2k ’
-2048x1080
-
‘2kflat ’
-1998x1080
-
‘2kscope ’
-2048x858
-
‘4k ’
-4096x2160
-
‘4kflat ’
-3996x2160
-
‘4kscope ’
-4096x1716
-
‘nhd ’
-640x360
-
‘hqvga ’
-240x160
-
‘wqvga ’
-400x240
-
‘fwqvga ’
-432x240
-
‘hvga ’
-480x320
-
‘qhd ’
-960x540
-
-
-
-
6.5 Video rate# TOC
-
-
Specify the frame rate of a video, expressed as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a float
-number or a valid video frame rate abbreviation.
-
-
The following abbreviations are recognized:
-
-‘ntsc ’
-30000/1001
-
‘pal ’
-25/1
-
‘qntsc ’
-30000/1001
-
‘qpal ’
-25/1
-
‘sntsc ’
-30000/1001
-
‘spal ’
-25/1
-
‘film ’
-24/1
-
‘ntsc-film ’
-24000/1001
-
-
-
-
6.6 Ratio# TOC
-
-
A ratio can be expressed as an expression, or in the form
-numerator :denominator .
-
-
Note that a ratio with infinite (1/0) or negative value is
-considered valid, so you should check on the returned value if you
-want to exclude those values.
-
-
The undefined value can be expressed using the "0:0" string.
-
-
-
6.7 Color# TOC
-
-
It can be the name of a color as defined below (case insensitive match) or a
-[0x|#]RRGGBB[AA] sequence, possibly followed by @ and a string
-representing the alpha component.
-
-
The alpha component may be a string composed by "0x" followed by an
-hexadecimal number or a decimal number between 0.0 and 1.0, which
-represents the opacity value (‘0x00 ’ or ‘0.0 ’ means completely
-transparent, ‘0xff ’ or ‘1.0 ’ completely opaque). If the alpha
-component is not specified then ‘0xff ’ is assumed.
-
-
The string ‘random ’ will result in a random color.
-
-
The following names of colors are recognized:
-
-‘AliceBlue ’
-0xF0F8FF
-
‘AntiqueWhite ’
-0xFAEBD7
-
‘Aqua ’
-0x00FFFF
-
‘Aquamarine ’
-0x7FFFD4
-
‘Azure ’
-0xF0FFFF
-
‘Beige ’
-0xF5F5DC
-
‘Bisque ’
-0xFFE4C4
-
‘Black ’
-0x000000
-
‘BlanchedAlmond ’
-0xFFEBCD
-
‘Blue ’
-0x0000FF
-
‘BlueViolet ’
-0x8A2BE2
-
‘Brown ’
-0xA52A2A
-
‘BurlyWood ’
-0xDEB887
-
‘CadetBlue ’
-0x5F9EA0
-
‘Chartreuse ’
-0x7FFF00
-
‘Chocolate ’
-0xD2691E
-
‘Coral ’
-0xFF7F50
-
‘CornflowerBlue ’
-0x6495ED
-
‘Cornsilk ’
-0xFFF8DC
-
‘Crimson ’
-0xDC143C
-
‘Cyan ’
-0x00FFFF
-
‘DarkBlue ’
-0x00008B
-
‘DarkCyan ’
-0x008B8B
-
‘DarkGoldenRod ’
-0xB8860B
-
‘DarkGray ’
-0xA9A9A9
-
‘DarkGreen ’
-0x006400
-
‘DarkKhaki ’
-0xBDB76B
-
‘DarkMagenta ’
-0x8B008B
-
‘DarkOliveGreen ’
-0x556B2F
-
‘Darkorange ’
-0xFF8C00
-
‘DarkOrchid ’
-0x9932CC
-
‘DarkRed ’
-0x8B0000
-
‘DarkSalmon ’
-0xE9967A
-
‘DarkSeaGreen ’
-0x8FBC8F
-
‘DarkSlateBlue ’
-0x483D8B
-
‘DarkSlateGray ’
-0x2F4F4F
-
‘DarkTurquoise ’
-0x00CED1
-
‘DarkViolet ’
-0x9400D3
-
‘DeepPink ’
-0xFF1493
-
‘DeepSkyBlue ’
-0x00BFFF
-
‘DimGray ’
-0x696969
-
‘DodgerBlue ’
-0x1E90FF
-
‘FireBrick ’
-0xB22222
-
‘FloralWhite ’
-0xFFFAF0
-
‘ForestGreen ’
-0x228B22
-
‘Fuchsia ’
-0xFF00FF
-
‘Gainsboro ’
-0xDCDCDC
-
‘GhostWhite ’
-0xF8F8FF
-
‘Gold ’
-0xFFD700
-
‘GoldenRod ’
-0xDAA520
-
‘Gray ’
-0x808080
-
‘Green ’
-0x008000
-
‘GreenYellow ’
-0xADFF2F
-
‘HoneyDew ’
-0xF0FFF0
-
‘HotPink ’
-0xFF69B4
-
‘IndianRed ’
-0xCD5C5C
-
‘Indigo ’
-0x4B0082
-
‘Ivory ’
-0xFFFFF0
-
‘Khaki ’
-0xF0E68C
-
‘Lavender ’
-0xE6E6FA
-
‘LavenderBlush ’
-0xFFF0F5
-
‘LawnGreen ’
-0x7CFC00
-
‘LemonChiffon ’
-0xFFFACD
-
‘LightBlue ’
-0xADD8E6
-
‘LightCoral ’
-0xF08080
-
‘LightCyan ’
-0xE0FFFF
-
‘LightGoldenRodYellow ’
-0xFAFAD2
-
‘LightGreen ’
-0x90EE90
-
‘LightGrey ’
-0xD3D3D3
-
‘LightPink ’
-0xFFB6C1
-
‘LightSalmon ’
-0xFFA07A
-
‘LightSeaGreen ’
-0x20B2AA
-
‘LightSkyBlue ’
-0x87CEFA
-
‘LightSlateGray ’
-0x778899
-
‘LightSteelBlue ’
-0xB0C4DE
-
‘LightYellow ’
-0xFFFFE0
-
‘Lime ’
-0x00FF00
-
‘LimeGreen ’
-0x32CD32
-
‘Linen ’
-0xFAF0E6
-
‘Magenta ’
-0xFF00FF
-
‘Maroon ’
-0x800000
-
‘MediumAquaMarine ’
-0x66CDAA
-
‘MediumBlue ’
-0x0000CD
-
‘MediumOrchid ’
-0xBA55D3
-
‘MediumPurple ’
-0x9370D8
-
‘MediumSeaGreen ’
-0x3CB371
-
‘MediumSlateBlue ’
-0x7B68EE
-
‘MediumSpringGreen ’
-0x00FA9A
-
‘MediumTurquoise ’
-0x48D1CC
-
‘MediumVioletRed ’
-0xC71585
-
‘MidnightBlue ’
-0x191970
-
‘MintCream ’
-0xF5FFFA
-
‘MistyRose ’
-0xFFE4E1
-
‘Moccasin ’
-0xFFE4B5
-
‘NavajoWhite ’
-0xFFDEAD
-
‘Navy ’
-0x000080
-
‘OldLace ’
-0xFDF5E6
-
‘Olive ’
-0x808000
-
‘OliveDrab ’
-0x6B8E23
-
‘Orange ’
-0xFFA500
-
‘OrangeRed ’
-0xFF4500
-
‘Orchid ’
-0xDA70D6
-
‘PaleGoldenRod ’
-0xEEE8AA
-
‘PaleGreen ’
-0x98FB98
-
‘PaleTurquoise ’
-0xAFEEEE
-
‘PaleVioletRed ’
-0xD87093
-
‘PapayaWhip ’
-0xFFEFD5
-
‘PeachPuff ’
-0xFFDAB9
-
‘Peru ’
-0xCD853F
-
‘Pink ’
-0xFFC0CB
-
‘Plum ’
-0xDDA0DD
-
‘PowderBlue ’
-0xB0E0E6
-
‘Purple ’
-0x800080
-
‘Red ’
-0xFF0000
-
‘RosyBrown ’
-0xBC8F8F
-
‘RoyalBlue ’
-0x4169E1
-
‘SaddleBrown ’
-0x8B4513
-
‘Salmon ’
-0xFA8072
-
‘SandyBrown ’
-0xF4A460
-
‘SeaGreen ’
-0x2E8B57
-
‘SeaShell ’
-0xFFF5EE
-
‘Sienna ’
-0xA0522D
-
‘Silver ’
-0xC0C0C0
-
‘SkyBlue ’
-0x87CEEB
-
‘SlateBlue ’
-0x6A5ACD
-
‘SlateGray ’
-0x708090
-
‘Snow ’
-0xFFFAFA
-
‘SpringGreen ’
-0x00FF7F
-
‘SteelBlue ’
-0x4682B4
-
‘Tan ’
-0xD2B48C
-
‘Teal ’
-0x008080
-
‘Thistle ’
-0xD8BFD8
-
‘Tomato ’
-0xFF6347
-
‘Turquoise ’
-0x40E0D0
-
‘Violet ’
-0xEE82EE
-
‘Wheat ’
-0xF5DEB3
-
‘White ’
-0xFFFFFF
-
‘WhiteSmoke ’
-0xF5F5F5
-
‘Yellow ’
-0xFFFF00
-
‘YellowGreen ’
-0x9ACD32
-
-
-
-
6.8 Channel Layout# TOC
-
-
A channel layout specifies the spatial disposition of the channels in
-a multi-channel audio stream. To specify a channel layout, FFmpeg
-makes use of a special syntax.
-
-
Individual channels are identified by an id, as given by the table
-below:
-
-‘FL ’
-front left
-
‘FR ’
-front right
-
‘FC ’
-front center
-
‘LFE ’
-low frequency
-
‘BL ’
-back left
-
‘BR ’
-back right
-
‘FLC ’
-front left-of-center
-
‘FRC ’
-front right-of-center
-
‘BC ’
-back center
-
‘SL ’
-side left
-
‘SR ’
-side right
-
‘TC ’
-top center
-
‘TFL ’
-top front left
-
‘TFC ’
-top front center
-
‘TFR ’
-top front right
-
‘TBL ’
-top back left
-
‘TBC ’
-top back center
-
‘TBR ’
-top back right
-
‘DL ’
-downmix left
-
‘DR ’
-downmix right
-
‘WL ’
-wide left
-
‘WR ’
-wide right
-
‘SDL ’
-surround direct left
-
‘SDR ’
-surround direct right
-
‘LFE2 ’
-low frequency 2
-
-
-
Standard channel layout compositions can be specified by using the
-following identifiers:
-
-‘mono ’
-FC
-
‘stereo ’
-FL+FR
-
‘2.1 ’
-FL+FR+LFE
-
‘3.0 ’
-FL+FR+FC
-
‘3.0(back) ’
-FL+FR+BC
-
‘4.0 ’
-FL+FR+FC+BC
-
‘quad ’
-FL+FR+BL+BR
-
‘quad(side) ’
-FL+FR+SL+SR
-
‘3.1 ’
-FL+FR+FC+LFE
-
‘5.0 ’
-FL+FR+FC+BL+BR
-
‘5.0(side) ’
-FL+FR+FC+SL+SR
-
‘4.1 ’
-FL+FR+FC+LFE+BC
-
‘5.1 ’
-FL+FR+FC+LFE+BL+BR
-
‘5.1(side) ’
-FL+FR+FC+LFE+SL+SR
-
‘6.0 ’
-FL+FR+FC+BC+SL+SR
-
‘6.0(front) ’
-FL+FR+FLC+FRC+SL+SR
-
‘hexagonal ’
-FL+FR+FC+BL+BR+BC
-
‘6.1 ’
-FL+FR+FC+LFE+BC+SL+SR
-
‘6.1 ’
-FL+FR+FC+LFE+BL+BR+BC
-
‘6.1(front) ’
-FL+FR+LFE+FLC+FRC+SL+SR
-
‘7.0 ’
-FL+FR+FC+BL+BR+SL+SR
-
‘7.0(front) ’
-FL+FR+FC+FLC+FRC+SL+SR
-
‘7.1 ’
-FL+FR+FC+LFE+BL+BR+SL+SR
-
‘7.1(wide) ’
-FL+FR+FC+LFE+BL+BR+FLC+FRC
-
‘7.1(wide-side) ’
-FL+FR+FC+LFE+FLC+FRC+SL+SR
-
‘octagonal ’
-FL+FR+FC+BL+BR+BC+SL+SR
-
‘downmix ’
-DL+DR
-
-
-
A custom channel layout can be specified as a sequence of terms, separated by
-’+’ or ’|’. Each term can be:
-
- the name of a standard channel layout (e.g. ‘mono ’,
-‘stereo ’, ‘4.0 ’, ‘quad ’, ‘5.0 ’, etc.)
-
- the name of a single channel (e.g. ‘FL ’, ‘FR ’, ‘FC ’, ‘LFE ’, etc.)
-
- a number of channels, in decimal, optionally followed by ’c’, yielding
-the default channel layout for that number of channels (see the
-function av_get_default_channel_layout)
-
- a channel layout mask, in hexadecimal starting with "0x" (see the
-AV_CH_* macros in libavutil/channel_layout.h .
-
-
-
Starting from libavutil version 53 the trailing character "c" to
-specify a number of channels will be required, while a channel layout
-mask could also be specified as a decimal number (if and only if not
-followed by "c").
-
-
See also the function av_get_channel_layout defined in
-libavutil/channel_layout.h .
-
-
-
7 Expression Evaluation# TOC
-
-
When evaluating an arithmetic expression, FFmpeg uses an internal
-formula evaluator, implemented through the libavutil/eval.h
-interface.
-
-
An expression may contain unary, binary operators, constants, and
-functions.
-
-
Two expressions expr1 and expr2 can be combined to form
-another expression "expr1 ;expr2 ".
-expr1 and expr2 are evaluated in turn, and the new
-expression evaluates to the value of expr2 .
-
-
The following binary operators are available: +, -,
-*, /, ^.
-
-
The following unary operators are available: +, -.
-
-
The following functions are available:
-
-abs(x) Compute absolute value of x .
-
-acos(x) Compute arccosine of x .
-
-asin(x) Compute arcsine of x .
-
-atan(x) Compute arctangent of x .
-
-between(x, min, max) Return 1 if x is greater than or equal to min and lesser than or
-equal to max , 0 otherwise.
-
-bitand(x, y) bitor(x, y) Compute bitwise and/or operation on x and y .
-
-The results of the evaluation of x and y are converted to
-integers before executing the bitwise operation.
-
-Note that both the conversion to integer and the conversion back to
-floating point can lose precision. Beware of unexpected results for
-large numbers (usually 2^53 and larger).
-
-ceil(expr) Round the value of expression expr upwards to the nearest
-integer. For example, "ceil(1.5)" is "2.0".
-
-clip(x, min, max) Return the value of x clipped between min and max .
-
-cos(x) Compute cosine of x .
-
-cosh(x) Compute hyperbolic cosine of x .
-
-eq(x, y) Return 1 if x and y are equivalent, 0 otherwise.
-
-exp(x) Compute exponential of x (with base e, the Euler’s number).
-
-floor(expr) Round the value of expression expr downwards to the nearest
-integer. For example, "floor(-1.5)" is "-2.0".
-
-gauss(x) Compute Gauss function of x , corresponding to
-exp(-x*x/2) / sqrt(2*PI).
-
-gcd(x, y) Return the greatest common divisor of x and y . If both x and
-y are 0 or either or both are less than zero then behavior is undefined.
-
-gt(x, y) Return 1 if x is greater than y , 0 otherwise.
-
-gte(x, y) Return 1 if x is greater than or equal to y , 0 otherwise.
-
-hypot(x, y) This function is similar to the C function with the same name; it returns
-"sqrt(x *x + y *y )", the length of the hypotenuse of a
-right triangle with sides of length x and y , or the distance of the
-point (x , y ) from the origin.
-
-if(x, y) Evaluate x , and if the result is non-zero return the result of
-the evaluation of y , return 0 otherwise.
-
-if(x, y, z) Evaluate x , and if the result is non-zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-ifnot(x, y) Evaluate x , and if the result is zero return the result of the
-evaluation of y , return 0 otherwise.
-
-ifnot(x, y, z) Evaluate x , and if the result is zero return the evaluation
-result of y , otherwise the evaluation result of z .
-
-isinf(x) Return 1.0 if x is +/-INFINITY, 0.0 otherwise.
-
-isnan(x) Return 1.0 if x is NAN, 0.0 otherwise.
-
-ld(var) Allow to load the value of the internal variable with number
-var , which was previously stored with st(var , expr ).
-The function returns the loaded value.
-
-log(x) Compute natural logarithm of x .
-
-lt(x, y) Return 1 if x is lesser than y , 0 otherwise.
-
-lte(x, y) Return 1 if x is lesser than or equal to y , 0 otherwise.
-
-max(x, y) Return the maximum between x and y .
-
-min(x, y) Return the maximum between x and y .
-
-mod(x, y) Compute the remainder of division of x by y .
-
-not(expr) Return 1.0 if expr is zero, 0.0 otherwise.
-
-pow(x, y) Compute the power of x elevated y , it is equivalent to
-"(x )^(y )".
-
-print(t) print(t, l) Print the value of expression t with loglevel l . If
-l is not specified then a default log level is used.
-Returns the value of the expression printed.
-
-Prints t with loglevel l
-
-random(x) Return a pseudo random value between 0.0 and 1.0. x is the index of the
-internal variable which will be used to save the seed/state.
-
-root(expr, max) Find an input value for which the function represented by expr
-with argument ld(0) is 0 in the interval 0..max .
-
-The expression in expr must denote a continuous function or the
-result is undefined.
-
-ld(0) is used to represent the function input value, which means
-that the given expression will be evaluated multiple times with
-various input values that the expression can access through
-ld(0). When the expression evaluates to 0 then the
-corresponding input value will be returned.
-
-sin(x) Compute sine of x .
-
-sinh(x) Compute hyperbolic sine of x .
-
-sqrt(expr) Compute the square root of expr . This is equivalent to
-"(expr )^.5".
-
-squish(x) Compute expression 1/(1 + exp(4*x)).
-
-st(var, expr) Allow to store the value of the expression expr in an internal
-variable. var specifies the number of the variable where to
-store the value, and it is a value ranging from 0 to 9. The function
-returns the value stored in the internal variable.
-Note, Variables are currently not shared between expressions.
-
-tan(x) Compute tangent of x .
-
-tanh(x) Compute hyperbolic tangent of x .
-
-taylor(expr, x) taylor(expr, x, id) Evaluate a Taylor series at x , given an expression representing
-the ld(id)-th derivative of a function at 0.
-
-When the series does not converge the result is undefined.
-
-ld(id) is used to represent the derivative order in expr ,
-which means that the given expression will be evaluated multiple times
-with various input values that the expression can access through
-ld(id). If id is not specified then 0 is assumed.
-
-Note, when you have the derivatives at y instead of 0,
-taylor(expr, x-y) can be used.
-
-time(0) Return the current (wallclock) time in seconds.
-
-trunc(expr) Round the value of expression expr towards zero to the nearest
-integer. For example, "trunc(-1.5)" is "-1.0".
-
-while(cond, expr) Evaluate expression expr while the expression cond is
-non-zero, and returns the value of the last expr evaluation, or
-NAN if cond was always false.
-
-
-
The following constants are available:
-
-PI area of the unit disc, approximately 3.14
-
E exp(1) (Euler’s number), approximately 2.718
-
PHI golden ratio (1+sqrt(5))/2, approximately 1.618
-
-
-
Assuming that an expression is considered "true" if it has a non-zero
-value, note that:
-
-
* works like AND
-
-
+ works like OR
-
-
For example the construct:
-
-
is equivalent to:
-
-
-
In your C code, you can extend the list of unary and binary functions,
-and define recognized constants, so that they are available for your
-expressions.
-
-
The evaluator also recognizes the International System unit prefixes.
-If ’i’ is appended after the prefix, binary prefixes are used, which
-are based on powers of 1024 instead of powers of 1000.
-The ’B’ postfix multiplies the value by 8, and can be appended after a
-unit prefix or used alone. This allows using for example ’KB’, ’MiB’,
-’G’ and ’B’ as number postfix.
-
-
The list of available International System prefixes follows, with
-indication of the corresponding powers of 10 and of 2.
-
-y 10^-24 / 2^-80
-
z 10^-21 / 2^-70
-
a 10^-18 / 2^-60
-
f 10^-15 / 2^-50
-
p 10^-12 / 2^-40
-
n 10^-9 / 2^-30
-
u 10^-6 / 2^-20
-
m 10^-3 / 2^-10
-
c 10^-2
-
d 10^-1
-
h 10^2
-
k 10^3 / 2^10
-
K 10^3 / 2^10
-
M 10^6 / 2^20
-
G 10^9 / 2^30
-
T 10^12 / 2^40
-
P 10^15 / 2^40
-
E 10^18 / 2^50
-
Z 10^21 / 2^60
-
Y 10^24 / 2^70
-
-
-
-
-
8 OpenCL Options# TOC
-
-
When FFmpeg is configured with --enable-opencl, it is possible
-to set the options for the global OpenCL context.
-
-
The list of supported options follows:
-
-
-build_options Set build options used to compile the registered kernels.
-
-See reference "OpenCL Specification Version: 1.2 chapter 5.6.4".
-
-platform_idx Select the index of the platform to run OpenCL code.
-
-The specified index must be one of the indexes in the device list
-which can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-device_idx Select the index of the device used to run OpenCL code.
-
-The specified index must be one of the indexes in the device list which
-can be obtained with ffmpeg -opencl_bench or av_opencl_get_device_list().
-
-
-
-
-
9 Codec Options# TOC
-
-
libavcodec provides some generic global options, which can be set on
-all the encoders and decoders. In addition each codec may support
-so-called private options, which are specific for a given codec.
-
-
Sometimes, a global option may only affect a specific kind of codec,
-and may be nonsensical or ignored by another, so you need to be aware
-of the meaning of the specified options. Also some options are
-meant only for decoding or encoding.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVCodecContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follow:
-
-
-b integer (encoding,audio,video ) Set bitrate in bits/s. Default value is 200K.
-
-ab integer (encoding,audio ) Set audio bitrate (in bits/s). Default value is 128K.
-
-bt integer (encoding,video ) Set video bitrate tolerance (in bits/s). In 1-pass mode, bitrate
-tolerance specifies how far ratecontrol is willing to deviate from the
-target average bitrate value. This is not related to min/max
-bitrate. Lowering tolerance too much has an adverse effect on quality.
-
-flags flags (decoding/encoding,audio,video,subtitles ) Set generic flags.
-
-Possible values:
-
-‘mv4 ’
-Use four motion vector by macroblock (mpeg4).
-
‘qpel ’
-Use 1/4 pel motion compensation.
-
‘loop ’
-Use loop filter.
-
‘qscale ’
-Use fixed qscale.
-
‘gmc ’
-Use gmc.
-
‘mv0 ’
-Always try a mb with mv=<0,0>.
-
‘input_preserved ’
-‘pass1 ’
-Use internal 2pass ratecontrol in first pass mode.
-
‘pass2 ’
-Use internal 2pass ratecontrol in second pass mode.
-
‘gray ’
-Only decode/encode grayscale.
-
‘emu_edge ’
-Do not draw edges.
-
‘psnr ’
-Set error[?] variables during encoding.
-
‘truncated ’
-‘naq ’
-Normalize adaptive quantization.
-
‘ildct ’
-Use interlaced DCT.
-
‘low_delay ’
-Force low delay.
-
‘global_header ’
-Place global headers in extradata instead of every keyframe.
-
‘bitexact ’
-Only write platform-, build- and time-independent data. (except (I)DCT).
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
‘aic ’
-Apply H263 advanced intra coding / mpeg4 ac prediction.
-
‘cbp ’
-Deprecated, use mpegvideo private options instead.
-
‘qprd ’
-Deprecated, use mpegvideo private options instead.
-
‘ilme ’
-Apply interlaced motion estimation.
-
‘cgop ’
-Use closed gop.
-
-
-me_method integer (encoding,video ) Set motion estimation method.
-
-Possible values:
-
-‘zero ’
-zero motion estimation (fastest)
-
‘full ’
-full motion estimation (slowest)
-
‘epzs ’
-EPZS motion estimation (default)
-
‘esa ’
-esa motion estimation (alias for full)
-
‘tesa ’
-tesa motion estimation
-
‘dia ’
-dia motion estimation (alias for epzs)
-
‘log ’
-log motion estimation
-
‘phods ’
-phods motion estimation
-
‘x1 ’
-X1 motion estimation
-
‘hex ’
-hex motion estimation
-
‘umh ’
-umh motion estimation
-
‘iter ’
-iter motion estimation
-
-
-extradata_size integer Set extradata size.
-
-time_base rational number Set codec time base.
-
-It is the fundamental unit of time (in seconds) in terms of which
-frame timestamps are represented. For fixed-fps content, timebase
-should be 1 / frame_rate and timestamp increments should be
-identically 1.
-
-g integer (encoding,video ) Set the group of picture size. Default value is 12.
-
-ar integer (decoding/encoding,audio ) Set audio sampling rate (in Hz).
-
-ac integer (decoding/encoding,audio ) Set number of audio channels.
-
-cutoff integer (encoding,audio ) Set cutoff bandwidth.
-
-frame_size integer (encoding,audio ) Set audio frame size.
-
-Each submitted frame except the last must contain exactly frame_size
-samples per channel. May be 0 when the codec has
-CODEC_CAP_VARIABLE_FRAME_SIZE set, in that case the frame size is not
-restricted. It is set by some decoders to indicate constant frame
-size.
-
-frame_number integer Set the frame number.
-
-delay integer qcomp float (encoding,video ) Set video quantizer scale compression (VBR). It is used as a constant
-in the ratecontrol equation. Recommended range for default rc_eq:
-0.0-1.0.
-
-qblur float (encoding,video ) Set video quantizer scale blur (VBR).
-
-qmin integer (encoding,video ) Set min video quantizer scale (VBR). Must be included between -1 and
-69, default value is 2.
-
-qmax integer (encoding,video ) Set max video quantizer scale (VBR). Must be included between -1 and
-1024, default value is 31.
-
-qdiff integer (encoding,video ) Set max difference between the quantizer scale (VBR).
-
-bf integer (encoding,video ) Set max number of B frames between non-B-frames.
-
-Must be an integer between -1 and 16. 0 means that B-frames are
-disabled. If a value of -1 is used, it will choose an automatic value
-depending on the encoder.
-
-Default value is 0.
-
-b_qfactor float (encoding,video ) Set qp factor between P and B frames.
-
-rc_strategy integer (encoding,video ) Set ratecontrol method.
-
-b_strategy integer (encoding,video ) Set strategy to choose between I/P/B-frames.
-
-ps integer (encoding,video ) Set RTP payload size in bytes.
-
-mv_bits integer header_bits integer i_tex_bits integer p_tex_bits integer i_count integer p_count integer skip_count integer misc_bits integer frame_bits integer codec_tag integer bug flags (decoding,video ) Workaround not auto detected encoder bugs.
-
-Possible values:
-
-‘autodetect ’
-‘old_msmpeg4 ’
-some old lavc generated msmpeg4v3 files (no autodetection)
-
‘xvid_ilace ’
-Xvid interlacing bug (autodetected if fourcc==XVIX)
-
‘ump4 ’
-(autodetected if fourcc==UMP4)
-
‘no_padding ’
-padding bug (autodetected)
-
‘amv ’
-‘ac_vlc ’
-illegal vlc bug (autodetected per fourcc)
-
‘qpel_chroma ’
-‘std_qpel ’
-old standard qpel (autodetected per fourcc/version)
-
‘qpel_chroma2 ’
-‘direct_blocksize ’
-direct-qpel-blocksize bug (autodetected per fourcc/version)
-
‘edge ’
-edge padding bug (autodetected per fourcc/version)
-
‘hpel_chroma ’
-‘dc_clip ’
-‘ms ’
-Workaround various bugs in microsoft broken decoders.
-
‘trunc ’
-trancated frames
-
-
-lelim integer (encoding,video ) Set single coefficient elimination threshold for luminance (negative
-values also consider DC coefficient).
-
-celim integer (encoding,video ) Set single coefficient elimination threshold for chrominance (negative
-values also consider dc coefficient)
-
-strict integer (decoding/encoding,audio,video ) Specify how strictly to follow the standards.
-
-Possible values:
-
-‘very ’
-strictly conform to a older more strict version of the spec or reference software
-
‘strict ’
-strictly conform to all the things in the spec no matter what consequences
-
‘normal ’
-‘unofficial ’
-allow unofficial extensions
-
‘experimental ’
-allow non standardized experimental things, experimental
-(unfinished/work in progress/not well tested) decoders and encoders.
-Note: experimental decoders can pose a security risk, do not use this for
-decoding untrusted input.
-
-
-b_qoffset float (encoding,video ) Set QP offset between P and B frames.
-
-err_detect flags (decoding,audio,video ) Set error detection flags.
-
-Possible values:
-
-‘crccheck ’
-verify embedded CRCs
-
‘bitstream ’
-detect bitstream specification deviations
-
‘buffer ’
-detect improper bitstream length
-
‘explode ’
-abort decoding on minor error detection
-
‘ignore_err ’
-ignore decoding errors, and continue decoding.
-This is useful if you want to analyze the content of a video and thus want
-everything to be decoded no matter what. This option will not result in a video
-that is pleasing to watch in case of errors.
-
‘careful ’
-consider things that violate the spec and have not been seen in the wild as errors
-
‘compliant ’
-consider all spec non compliancies as errors
-
‘aggressive ’
-consider things that a sane encoder should not do as an error
-
-
-has_b_frames integer block_align integer mpeg_quant integer (encoding,video ) Use MPEG quantizers instead of H.263.
-
-qsquish float (encoding,video ) How to keep quantizer between qmin and qmax (0 = clip, 1 = use
-differentiable function).
-
-rc_qmod_amp float (encoding,video ) Set experimental quantizer modulation.
-
-rc_qmod_freq integer (encoding,video ) Set experimental quantizer modulation.
-
-rc_override_count integer rc_eq string (encoding,video ) Set rate control equation. When computing the expression, besides the
-standard functions defined in the section ’Expression Evaluation’, the
-following functions are available: bits2qp(bits), qp2bits(qp). Also
-the following constants are available: iTex pTex tex mv fCode iCount
-mcVar var isI isP isB avgQP qComp avgIITex avgPITex avgPPTex avgBPTex
-avgTex.
-
-maxrate integer (encoding,audio,video ) Set max bitrate tolerance (in bits/s). Requires bufsize to be set.
-
-minrate integer (encoding,audio,video ) Set min bitrate tolerance (in bits/s). Most useful in setting up a CBR
-encode. It is of little use elsewise.
-
-bufsize integer (encoding,audio,video ) Set ratecontrol buffer size (in bits).
-
-rc_buf_aggressivity float (encoding,video ) Currently useless.
-
-i_qfactor float (encoding,video ) Set QP factor between P and I frames.
-
-i_qoffset float (encoding,video ) Set QP offset between P and I frames.
-
-rc_init_cplx float (encoding,video ) Set initial complexity for 1-pass encoding.
-
-dct integer (encoding,video ) Set DCT algorithm.
-
-Possible values:
-
-‘auto ’
-autoselect a good one (default)
-
‘fastint ’
-fast integer
-
‘int ’
-accurate integer
-
‘mmx ’
-‘altivec ’
-‘faan ’
-floating point AAN DCT
-
-
-lumi_mask float (encoding,video ) Compress bright areas stronger than medium ones.
-
-tcplx_mask float (encoding,video ) Set temporal complexity masking.
-
-scplx_mask float (encoding,video ) Set spatial complexity masking.
-
-p_mask float (encoding,video ) Set inter masking.
-
-dark_mask float (encoding,video ) Compress dark areas stronger than medium ones.
-
-idct integer (decoding/encoding,video ) Select IDCT implementation.
-
-Possible values:
-
-‘auto ’
-‘int ’
-‘simple ’
-‘simplemmx ’
-‘simpleauto ’
-Automatically pick a IDCT compatible with the simple one
-
-‘arm ’
-‘altivec ’
-‘sh4 ’
-‘simplearm ’
-‘simplearmv5te ’
-‘simplearmv6 ’
-‘simpleneon ’
-‘simplealpha ’
-‘ipp ’
-‘xvidmmx ’
-‘faani ’
-floating point AAN IDCT
-
-
-slice_count integer ec flags (decoding,video ) Set error concealment strategy.
-
-Possible values:
-
-‘guess_mvs ’
-iterative motion vector (MV) search (slow)
-
‘deblock ’
-use strong deblock filter for damaged MBs
-
‘favor_inter ’
-favor predicting from the previous frame instead of the current
-
-
-bits_per_coded_sample integer pred integer (encoding,video ) Set prediction method.
-
-Possible values:
-
-‘left ’
-‘plane ’
-‘median ’
-
-
-aspect rational number (encoding,video ) Set sample aspect ratio.
-
-debug flags (decoding/encoding,audio,video,subtitles ) Print specific debug info.
-
-Possible values:
-
-‘pict ’
-picture info
-
‘rc ’
-rate control
-
‘bitstream ’
-‘mb_type ’
-macroblock (MB) type
-
‘qp ’
-per-block quantization parameter (QP)
-
‘mv ’
-motion vector
-
‘dct_coeff ’
-‘skip ’
-‘startcode ’
-‘pts ’
-‘er ’
-error recognition
-
‘mmco ’
-memory management control operations (H.264)
-
‘bugs ’
-‘vis_qp ’
-visualize quantization parameter (QP), lower QP are tinted greener
-
‘vis_mb_type ’
-visualize block types
-
‘buffers ’
-picture buffer allocations
-
‘thread_ops ’
-threading operations
-
‘nomc ’
-skip motion compensation
-
-
-vismv integer (decoding,video ) Visualize motion vectors (MVs).
-
-This option is deprecated, see the codecview filter instead.
-
-Possible values:
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-cmp integer (encoding,video ) Set full pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-subcmp integer (encoding,video ) Set sub pel me compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-mbcmp integer (encoding,video ) Set macroblock compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-ildctcmp integer (encoding,video ) Set interlaced dct compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-dia_size integer (encoding,video ) Set diamond type & size for motion estimation.
-
-last_pred integer (encoding,video ) Set amount of motion predictors from the previous frame.
-
-preme integer (encoding,video ) Set pre motion estimation.
-
-precmp integer (encoding,video ) Set pre motion estimation compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-pre_dia_size integer (encoding,video ) Set diamond type & size for motion estimation pre-pass.
-
-subq integer (encoding,video ) Set sub pel motion estimation quality.
-
-dtg_active_format integer me_range integer (encoding,video ) Set limit motion vectors range (1023 for DivX player).
-
-ibias integer (encoding,video ) Set intra quant bias.
-
-pbias integer (encoding,video ) Set inter quant bias.
-
-color_table_id integer global_quality integer (encoding,audio,video ) coder integer (encoding,video )
-Possible values:
-
-‘vlc ’
-variable length coder / huffman coder
-
‘ac ’
-arithmetic coder
-
‘raw ’
-raw (no encoding)
-
‘rle ’
-run-length coder
-
‘deflate ’
-deflate-based coder
-
-
-
-context integer (encoding,video ) Set context model.
-
-slice_flags integer xvmc_acceleration integer mbd integer (encoding,video ) Set macroblock decision algorithm (high quality mode).
-
-Possible values:
-
-‘simple ’
-use mbcmp (default)
-
‘bits ’
-use fewest bits
-
‘rd ’
-use best rate distortion
-
-
-stream_codec_tag integer sc_threshold integer (encoding,video ) Set scene change threshold.
-
-lmin integer (encoding,video ) Set min lagrange factor (VBR).
-
-lmax integer (encoding,video ) Set max lagrange factor (VBR).
-
-nr integer (encoding,video ) Set noise reduction.
-
-rc_init_occupancy integer (encoding,video ) Set number of bits which should be loaded into the rc buffer before
-decoding starts.
-
-flags2 flags (decoding/encoding,audio,video )
-Possible values:
-
-‘fast ’
-Allow non spec compliant speedup tricks.
-
‘sgop ’
-Deprecated, use mpegvideo private options instead.
-
‘noout ’
-Skip bitstream encoding.
-
‘ignorecrop ’
-Ignore cropping information from sps.
-
‘local_header ’
-Place global headers at every keyframe instead of in extradata.
-
‘chunks ’
-Frame data might be split into multiple chunks.
-
‘showall ’
-Show all frames before the first keyframe.
-
‘skiprd ’
-Deprecated, use mpegvideo private options instead.
-
‘export_mvs ’
-Export motion vectors into frame side-data (see AV_FRAME_DATA_MOTION_VECTORS)
-for codecs that support it. See also doc/examples/export_mvs.c .
-
-
-
-error integer (encoding,video ) qns integer (encoding,video ) Deprecated, use mpegvideo private options instead.
-
-threads integer (decoding/encoding,video )
-Possible values:
-
-‘auto ’
-detect a good number of threads
-
-
-
-me_threshold integer (encoding,video ) Set motion estimation threshold.
-
-mb_threshold integer (encoding,video ) Set macroblock threshold.
-
-dc integer (encoding,video ) Set intra_dc_precision.
-
-nssew integer (encoding,video ) Set nsse weight.
-
-skip_top integer (decoding,video ) Set number of macroblock rows at the top which are skipped.
-
-skip_bottom integer (decoding,video ) Set number of macroblock rows at the bottom which are skipped.
-
-profile integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-‘aac_main ’
-‘aac_low ’
-‘aac_ssr ’
-‘aac_ltp ’
-‘aac_he ’
-‘aac_he_v2 ’
-‘aac_ld ’
-‘aac_eld ’
-‘mpeg2_aac_low ’
-‘mpeg2_aac_he ’
-‘mpeg4_sp ’
-‘mpeg4_core ’
-‘mpeg4_main ’
-‘mpeg4_asp ’
-‘dts ’
-‘dts_es ’
-‘dts_96_24 ’
-‘dts_hd_hra ’
-‘dts_hd_ma ’
-
-
-
-level integer (encoding,audio,video )
-Possible values:
-
-‘unknown ’
-
-
-
-lowres integer (decoding,audio,video ) Decode at 1= 1/2, 2=1/4, 3=1/8 resolutions.
-
-skip_threshold integer (encoding,video ) Set frame skip threshold.
-
-skip_factor integer (encoding,video ) Set frame skip factor.
-
-skip_exp integer (encoding,video ) Set frame skip exponent.
-Negative values behave identical to the corresponding positive ones, except
-that the score is normalized.
-Positive values exist primarily for compatibility reasons and are not so useful.
-
-skipcmp integer (encoding,video ) Set frame skip compare function.
-
-Possible values:
-
-‘sad ’
-sum of absolute differences, fast (default)
-
‘sse ’
-sum of squared errors
-
‘satd ’
-sum of absolute Hadamard transformed differences
-
‘dct ’
-sum of absolute DCT transformed differences
-
‘psnr ’
-sum of squared quantization errors (avoid, low quality)
-
‘bit ’
-number of bits needed for the block
-
‘rd ’
-rate distortion optimal, slow
-
‘zero ’
-0
-
‘vsad ’
-sum of absolute vertical differences
-
‘vsse ’
-sum of squared vertical differences
-
‘nsse ’
-noise preserving sum of squared differences
-
‘w53 ’
-5/3 wavelet, only used in snow
-
‘w97 ’
-9/7 wavelet, only used in snow
-
‘dctmax ’
-‘chroma ’
-
-
-border_mask float (encoding,video ) Increase the quantizer for macroblocks close to borders.
-
-mblmin integer (encoding,video ) Set min macroblock lagrange factor (VBR).
-
-mblmax integer (encoding,video ) Set max macroblock lagrange factor (VBR).
-
-mepc integer (encoding,video ) Set motion estimation bitrate penalty compensation (1.0 = 256).
-
-skip_loop_filter integer (decoding,video ) skip_idct integer (decoding,video ) skip_frame integer (decoding,video )
-Make decoder discard processing depending on the frame type selected
-by the option value.
-
-skip_loop_filter skips frame loop filtering, skip_idct
-skips frame IDCT/dequantization, skip_frame skips decoding.
-
-Possible values:
-
-‘none ’
-Discard no frame.
-
-‘default ’
-Discard useless frames like 0-sized frames.
-
-‘noref ’
-Discard all non-reference frames.
-
-‘bidir ’
-Discard all bidirectional frames.
-
-‘nokey ’
-Discard all frames excepts keyframes.
-
-‘all ’
-Discard all frames.
-
-
-Default value is ‘default ’.
-
-
-bidir_refine integer (encoding,video ) Refine the two motion vectors used in bidirectional macroblocks.
-
-brd_scale integer (encoding,video ) Downscale frames for dynamic B-frame decision.
-
-keyint_min integer (encoding,video ) Set minimum interval between IDR-frames.
-
-refs integer (encoding,video ) Set reference frames to consider for motion compensation.
-
-chromaoffset integer (encoding,video ) Set chroma qp offset from luma.
-
-trellis integer (encoding,audio,video ) Set rate-distortion optimal quantization.
-
-sc_factor integer (encoding,video ) Set value multiplied by qscale for each frame and added to
-scene_change_score.
-
-mv0_threshold integer (encoding,video ) b_sensitivity integer (encoding,video ) Adjust sensitivity of b_frame_strategy 1.
-
-compression_level integer (encoding,audio,video ) min_prediction_order integer (encoding,audio ) max_prediction_order integer (encoding,audio ) timecode_frame_start integer (encoding,video ) Set GOP timecode frame start number, in non drop frame format.
-
-request_channels integer (decoding,audio ) Set desired number of audio channels.
-
-bits_per_raw_sample integer channel_layout integer (decoding/encoding,audio )
-Possible values:
-
-request_channel_layout integer (decoding,audio )
-Possible values:
-
-rc_max_vbv_use float (encoding,video ) rc_min_vbv_use float (encoding,video ) ticks_per_frame integer (decoding/encoding,audio,video ) color_primaries integer (decoding/encoding,video ) color_trc integer (decoding/encoding,video ) colorspace integer (decoding/encoding,video ) color_range integer (decoding/encoding,video ) chroma_sample_location integer (decoding/encoding,video ) log_level_offset integer Set the log level offset.
-
-slices integer (encoding,video ) Number of slices, used in parallelized encoding.
-
-thread_type flags (decoding/encoding,video ) Select which multithreading methods to use.
-
-Use of ‘frame ’ will increase decoding delay by one frame per
-thread, so clients which cannot provide future frames should not use
-it.
-
-Possible values:
-
-‘slice ’
-Decode more than one part of a single frame at once.
-
-Multithreading using slices works only when the video was encoded with
-slices.
-
-‘frame ’
-Decode more than one frame at once.
-
-
-Default value is ‘slice+frame ’.
-
-audio_service_type integer (encoding,audio ) Set audio service type.
-
-Possible values:
-
-‘ma ’
-Main Audio Service
-
‘ef ’
-Effects
-
‘vi ’
-Visually Impaired
-
‘hi ’
-Hearing Impaired
-
‘di ’
-Dialogue
-
‘co ’
-Commentary
-
‘em ’
-Emergency
-
‘vo ’
-Voice Over
-
‘ka ’
-Karaoke
-
-
-request_sample_fmt sample_fmt (decoding,audio ) Set sample format audio decoders should prefer. Default value is
-none.
-
-pkt_timebase rational number sub_charenc encoding (decoding,subtitles ) Set the input subtitles character encoding.
-
-field_order field_order (video ) Set/override the field order of the video.
-Possible values:
-
-‘progressive ’
-Progressive video
-
‘tt ’
-Interlaced video, top field coded and displayed first
-
‘bb ’
-Interlaced video, bottom field coded and displayed first
-
‘tb ’
-Interlaced video, top coded first, bottom displayed first
-
‘bt ’
-Interlaced video, bottom coded first, top displayed first
-
-
-skip_alpha integer (decoding,video ) Set to 1 to disable processing alpha (transparency). This works like the
-‘gray ’ flag in the flags option which skips chroma information
-instead of alpha. Default is 0.
-
-codec_whitelist list (input ) "," separated List of allowed decoders. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
10 Decoders# TOC
-
-
Decoders are configured elements in FFmpeg which allow the decoding of
-multimedia streams.
-
-
When you configure your FFmpeg build, all the supported native decoders
-are enabled by default. Decoders requiring an external library must be enabled
-manually via the corresponding --enable-lib option. You can list all
-available decoders using the configure option --list-decoders.
-
-
You can disable all the decoders with the configure option
---disable-decoders and selectively enable / disable single decoders
-with the options --enable-decoder=DECODER /
---disable-decoder=DECODER .
-
-
The option -decoders of the ff* tools will display the list of
-enabled decoders.
-
-
-
-
11 Video Decoders# TOC
-
-
A description of some of the currently available video decoders
-follows.
-
-
-
11.1 rawvideo# TOC
-
-
Raw video decoder.
-
-
This decoder decodes rawvideo streams.
-
-
-
11.1.1 Options# TOC
-
-
-top top_field_first Specify the assumed field type of the input video.
-
--1 the video is assumed to be progressive (default)
-
0 bottom-field-first is assumed
-
1 top-field-first is assumed
-
-
-
-
-
-
-
12 Audio Decoders# TOC
-
-
A description of some of the currently available audio decoders
-follows.
-
-
-
12.1 ac3# TOC
-
-
AC-3 audio decoder.
-
-
This decoder implements part of ATSC A/52:2010 and ETSI TS 102 366, as well as
-the undocumented RealAudio 3 (a.k.a. dnet).
-
-
-
12.1.1 AC-3 Decoder Options# TOC
-
-
--drc_scale value Dynamic Range Scale Factor. The factor to apply to dynamic range values
-from the AC-3 stream. This factor is applied exponentially.
-There are 3 notable scale factor ranges:
-
-drc_scale == 0 DRC disabled. Produces full range audio.
-
0 < drc_scale <= 1 DRC enabled. Applies a fraction of the stream DRC value.
-Audio reproduction is between full range and full compression.
-
drc_scale > 1 DRC enabled. Applies drc_scale asymmetrically.
-Loud sounds are fully compressed. Soft sounds are enhanced.
-
-
-
-
-
-
12.2 ffwavesynth# TOC
-
-
Internal wave synthetizer.
-
-
This decoder generates wave patterns according to predefined sequences. Its
-use is purely internal and the format of the data it accepts is not publicly
-documented.
-
-
-
12.3 libcelt# TOC
-
-
libcelt decoder wrapper.
-
-
libcelt allows libavcodec to decode the Xiph CELT ultra-low delay audio codec.
-Requires the presence of the libcelt headers and library during configuration.
-You need to explicitly configure the build with --enable-libcelt.
-
-
-
12.4 libgsm# TOC
-
-
libgsm decoder wrapper.
-
-
libgsm allows libavcodec to decode the GSM full rate audio codec. Requires
-the presence of the libgsm headers and library during configuration. You need
-to explicitly configure the build with --enable-libgsm.
-
-
This decoder supports both the ordinary GSM and the Microsoft variant.
-
-
-
12.5 libilbc# TOC
-
-
libilbc decoder wrapper.
-
-
libilbc allows libavcodec to decode the Internet Low Bitrate Codec (iLBC)
-audio codec. Requires the presence of the libilbc headers and library during
-configuration. You need to explicitly configure the build with
---enable-libilbc.
-
-
-
12.5.1 Options# TOC
-
-
The following option is supported by the libilbc wrapper.
-
-
-enhance
-Enable the enhancement of the decoded audio when set to 1. The default
-value is 0 (disabled).
-
-
-
-
-
-
12.6 libopencore-amrnb# TOC
-
-
libopencore-amrnb decoder wrapper.
-
-
libopencore-amrnb allows libavcodec to decode the Adaptive Multi-Rate
-Narrowband audio codec. Using it requires the presence of the
-libopencore-amrnb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrnb.
-
-
An FFmpeg native decoder for AMR-NB exists, so users can decode AMR-NB
-without this library.
-
-
-
12.7 libopencore-amrwb# TOC
-
-
libopencore-amrwb decoder wrapper.
-
-
libopencore-amrwb allows libavcodec to decode the Adaptive Multi-Rate
-Wideband audio codec. Using it requires the presence of the
-libopencore-amrwb headers and library during configuration. You need to
-explicitly configure the build with --enable-libopencore-amrwb.
-
-
An FFmpeg native decoder for AMR-WB exists, so users can decode AMR-WB
-without this library.
-
-
-
12.8 libopus# TOC
-
-
libopus decoder wrapper.
-
-
libopus allows libavcodec to decode the Opus Interactive Audio Codec.
-Requires the presence of the libopus headers and library during
-configuration. You need to explicitly configure the build with
---enable-libopus.
-
-
An FFmpeg native decoder for Opus exists, so users can decode Opus
-without this library.
-
-
-
-
13 Subtitles Decoders# TOC
-
-
-
13.1 dvdsub# TOC
-
-
This codec decodes the bitmap subtitles used in DVDs; the same subtitles can
-also be found in VobSub file pairs and in some Matroska files.
-
-
-
13.1.1 Options# TOC
-
-
-palette Specify the global palette used by the bitmaps. When stored in VobSub, the
-palette is normally specified in the index file; in Matroska, the palette is
-stored in the codec extra-data in the same format as in VobSub. In DVDs, the
-palette is stored in the IFO file, and therefore not available when reading
-from dumped VOB files.
-
-The format for this option is a string containing 16 24-bits hexadecimal
-numbers (without 0x prefix) separated by comas, for example 0d00ee,
-ee450d, 101010, eaeaea, 0ce60b, ec14ed, ebff0b, 0d617a, 7b7b7b, d1d1d1,
-7b2a0e, 0d950c, 0f007b, cf0dec, cfa80c, 7c127b.
-
-ifo_palette Specify the IFO file from which the global palette is obtained.
-(experimental)
-
-forced_subs_only Only decode subtitle entries marked as forced. Some titles have forced
-and non-forced subtitles in the same track. Setting this flag to 1
-will only keep the forced subtitles. Default value is 0.
-
-
-
-
13.2 libzvbi-teletext# TOC
-
-
Libzvbi allows libavcodec to decode DVB teletext pages and DVB teletext
-subtitles. Requires the presence of the libzvbi headers and library during
-configuration. You need to explicitly configure the build with
---enable-libzvbi.
-
-
-
13.2.1 Options# TOC
-
-
-txt_page List of teletext page numbers to decode. You may use the special * string to
-match all pages. Pages that do not match the specified list are dropped.
-Default value is *.
-
txt_chop_top Discards the top teletext line. Default value is 1.
-
txt_format Specifies the format of the decoded subtitles. The teletext decoder is capable
-of decoding the teletext pages to bitmaps or to simple text, you should use
-"bitmap" for teletext pages, because certain graphics and colors cannot be
-expressed in simple text. You might use "text" for teletext based subtitles if
-your application can handle simple text based subtitles. Default value is
-bitmap.
-
txt_left X offset of generated bitmaps, default is 0.
-
txt_top Y offset of generated bitmaps, default is 0.
-
txt_chop_spaces Chops leading and trailing spaces and removes empty lines from the generated
-text. This option is useful for teletext based subtitles where empty spaces may
-be present at the start or at the end of the lines or empty lines may be
-present between the subtitle lines because of double-sized teletext charactes.
-Default value is 1.
-
txt_duration Sets the display duration of the decoded teletext pages or subtitles in
-miliseconds. Default value is 30000 which is 30 seconds.
-
txt_transparent Force transparent background of the generated teletext bitmaps. Default value
-is 0 which means an opaque (black) background.
-
-
-
-
14 Bitstream Filters# TOC
-
-
When you configure your FFmpeg build, all the supported bitstream
-filters are enabled by default. You can list all available ones using
-the configure option --list-bsfs.
-
-
You can disable all the bitstream filters using the configure option
---disable-bsfs, and selectively enable any bitstream filter using
-the option --enable-bsf=BSF, or you can disable a particular
-bitstream filter using the option --disable-bsf=BSF.
-
-
The option -bsfs of the ff* tools will display the list of
-all the supported bitstream filters included in your build.
-
-
The ff* tools have a -bsf option applied per stream, taking a
-comma-separated list of filters, whose parameters follow the filter
-name after a ’=’.
-
-
-
ffmpeg -i INPUT -c:v copy -bsf:v filter1[=opt1=str1/opt2=str2][,filter2] OUTPUT
-
-
-
Below is a description of the currently available bitstream filters,
-with their parameters, if any.
-
-
-
14.1 aac_adtstoasc# TOC
-
-
Convert MPEG-2/4 AAC ADTS to MPEG-4 Audio Specific Configuration
-bitstream filter.
-
-
This filter creates an MPEG-4 AudioSpecificConfig from an MPEG-2/4
-ADTS header and removes the ADTS header.
-
-
This is required for example when copying an AAC stream from a raw
-ADTS AAC container to a FLV or a MOV/MP4 file.
-
-
-
14.2 chomp# TOC
-
-
Remove zero padding at the end of a packet.
-
-
-
14.3 dump_extra# TOC
-
-
Add extradata to the beginning of the filtered packets.
-
-
The additional argument specifies which packets should be filtered.
-It accepts the values:
-
-‘a ’
-add extradata to all key packets, but only if local_header is
-set in the flags2 codec context field
-
-‘k ’
-add extradata to all key packets
-
-‘e ’
-add extradata to all packets
-
-
-
If not specified it is assumed ‘k ’.
-
-
For example the following ffmpeg command forces a global
-header (thus disabling individual packet headers) in the H.264 packets
-generated by the libx264 encoder, but corrects them by adding
-the header stored in extradata to the key packets:
-
-
ffmpeg -i INPUT -map 0 -flags:v +global_header -c:v libx264 -bsf:v dump_extra out.ts
-
-
-
-
14.4 h264_mp4toannexb# TOC
-
-
Convert an H.264 bitstream from length prefixed mode to start code
-prefixed mode (as defined in the Annex B of the ITU-T H.264
-specification).
-
-
This is required by some streaming formats, typically the MPEG-2
-transport stream format ("mpegts").
-
-
For example to remux an MP4 file containing an H.264 stream to mpegts
-format with ffmpeg, you can use the command:
-
-
-
ffmpeg -i INPUT.mp4 -codec copy -bsf:v h264_mp4toannexb OUTPUT.ts
-
-
-
-
14.5 imxdump# TOC
-
-
Modifies the bitstream to fit in MOV and to be usable by the Final Cut
-Pro decoder. This filter only applies to the mpeg2video codec, and is
-likely not needed for Final Cut Pro 7 and newer with the appropriate
--tag:v .
-
-
For example, to remux 30 MB/sec NTSC IMX to MOV:
-
-
-
ffmpeg -i input.mxf -c copy -bsf:v imxdump -tag:v mx3n output.mov
-
-
-
-
14.6 mjpeg2jpeg# TOC
-
-
Convert MJPEG/AVI1 packets to full JPEG/JFIF packets.
-
-
MJPEG is a video codec wherein each video frame is essentially a
-JPEG image. The individual frames can be extracted without loss,
-e.g. by
-
-
-
ffmpeg -i ../some_mjpeg.avi -c:v copy frames_%d.jpg
-
-
-
Unfortunately, these chunks are incomplete JPEG images, because
-they lack the DHT segment required for decoding. Quoting from
-http://www.digitalpreservation.gov/formats/fdd/fdd000063.shtml :
-
-
Avery Lee, writing in the rec.video.desktop newsgroup in 2001,
-commented that "MJPEG, or at least the MJPEG in AVIs having the
-MJPG fourcc, is restricted JPEG with a fixed – and *omitted* –
-Huffman table. The JPEG must be YCbCr colorspace, it must be 4:2:2,
-and it must use basic Huffman encoding, not arithmetic or
-progressive. . . . You can indeed extract the MJPEG frames and
-decode them with a regular JPEG decoder, but you have to prepend
-the DHT segment to them, or else the decoder won’t have any idea
-how to decompress the data. The exact table necessary is given in
-the OpenDML spec."
-
-
This bitstream filter patches the header of frames extracted from an MJPEG
-stream (carrying the AVI1 header ID and lacking a DHT segment) to
-produce fully qualified JPEG images.
-
-
-
ffmpeg -i mjpeg-movie.avi -c:v copy -bsf:v mjpeg2jpeg frame_%d.jpg
-exiftran -i -9 frame*.jpg
-ffmpeg -i frame_%d.jpg -c:v copy rotated.avi
-
-
-
-
14.7 mjpega_dump_header# TOC
-
-
-
14.8 movsub# TOC
-
-
-
14.9 mp3_header_decompress# TOC
-
-
-
14.10 noise# TOC
-
-
Damages the contents of packets without damaging the container. Can be
-used for fuzzing or testing error resilience/concealment.
-
-
Parameters:
-A numeral string, whose value is related to how often output bytes will
-be modified. Therefore, values below or equal to 0 are forbidden, and
-the lower the more frequent bytes will be modified, with 1 meaning
-every byte is modified.
-
-
-
ffmpeg -i INPUT -c copy -bsf noise[=1] output.mkv
-
-
applies the modification to every byte.
-
-
-
14.11 remove_extra# TOC
-
-
-
15 Format Options# TOC
-
-
The libavformat library provides some generic global options, which
-can be set on all the muxers and demuxers. In addition each muxer or
-demuxer may support so-called private options, which are specific for
-that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
The list of supported options follows:
-
-
-avioflags flags (input/output ) Possible values:
-
-‘direct ’
-Reduce buffering.
-
-
-probesize integer (input ) Set probing size in bytes, i.e. the size of the data to analyze to get
-stream information. A higher value will allow to detect more
-information in case it is dispersed into the stream, but will increase
-latency. Must be an integer not lesser than 32. It is 5000000 by default.
-
-packetsize integer (output ) Set packet size.
-
-fflags flags (input/output ) Set format flags.
-
-Possible values:
-
-‘ignidx ’
-Ignore index.
-
‘genpts ’
-Generate PTS.
-
‘nofillin ’
-Do not fill in missing values that can be exactly calculated.
-
‘noparse ’
-Disable AVParsers, this needs +nofillin too.
-
‘igndts ’
-Ignore DTS.
-
‘discardcorrupt ’
-Discard corrupted frames.
-
‘sortdts ’
-Try to interleave output packets by DTS.
-
‘keepside ’
-Do not merge side data.
-
‘latm ’
-Enable RTP MP4A-LATM payload.
-
‘nobuffer ’
-Reduce the latency introduced by optional buffering
-
‘bitexact ’
-Only write platform-, build- and time-independent data.
-This ensures that file and data checksums are reproducible and match between
-platforms. Its primary use is for regression testing.
-
-
-seek2any integer (input ) Allow seeking to non-keyframes on demuxer level when supported if set to 1.
-Default is 0.
-
-analyzeduration integer (input ) Specify how many microseconds are analyzed to probe the input. A
-higher value will allow to detect more accurate information, but will
-increase latency. It defaults to 5,000,000 microseconds = 5 seconds.
-
-cryptokey hexadecimal string (input ) Set decryption key.
-
-indexmem integer (input ) Set max memory used for timestamp index (per stream).
-
-rtbufsize integer (input ) Set max memory used for buffering real-time frames.
-
-fdebug flags (input/output ) Print specific debug info.
-
-Possible values:
-
-‘ts ’
-
-
-max_delay integer (input/output ) Set maximum muxing or demuxing delay in microseconds.
-
-fpsprobesize integer (input ) Set number of frames used to probe fps.
-
-audio_preload integer (output ) Set microseconds by which audio packets should be interleaved earlier.
-
-chunk_duration integer (output ) Set microseconds for each chunk.
-
-chunk_size integer (output ) Set size in bytes for each chunk.
-
-err_detect, f_err_detect flags (input ) Set error detection flags. f_err_detect is deprecated and
-should be used only via the ffmpeg tool.
-
-Possible values:
-
-‘crccheck ’
-Verify embedded CRCs.
-
‘bitstream ’
-Detect bitstream specification deviations.
-
‘buffer ’
-Detect improper bitstream length.
-
‘explode ’
-Abort decoding on minor error detection.
-
‘careful ’
-Consider things that violate the spec and have not been seen in the
-wild as errors.
-
‘compliant ’
-Consider all spec non compliancies as errors.
-
‘aggressive ’
-Consider things that a sane encoder should not do as an error.
-
-
-use_wallclock_as_timestamps integer (input ) Use wallclock as timestamps.
-
-avoid_negative_ts integer (output )
-Possible values:
-
-‘make_non_negative ’
-Shift timestamps to make them non-negative.
-Also note that this affects only leading negative timestamps, and not
-non-monotonic negative timestamps.
-
‘make_zero ’
-Shift timestamps so that the first timestamp is 0.
-
‘auto (default) ’
-Enables shifting when required by the target format.
-
‘disabled ’
-Disables shifting of timestamp.
-
-
-When shifting is enabled, all output timestamps are shifted by the
-same amount. Audio, video, and subtitles desynching and relative
-timestamp differences are preserved compared to how they would have
-been without shifting.
-
-
-skip_initial_bytes integer (input ) Set number of bytes to skip before reading header and frames if set to 1.
-Default is 0.
-
-correct_ts_overflow integer (input ) Correct single timestamp overflows if set to 1. Default is 1.
-
-flush_packets integer (output ) Flush the underlying I/O stream after each packet. Default 1 enables it, and
-has the effect of reducing the latency; 0 disables it and may slightly
-increase performance in some cases.
-
-output_ts_offset offset (output ) Set the output time offset.
-
-offset must be a time duration specification,
-see (ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-The offset is added by the muxer to the output timestamps.
-
-Specifying a positive offset means that the corresponding streams are
-delayed bt the time duration specified in offset . Default value
-is 0 (meaning that no offset is applied).
-
-format_whitelist list (input ) "," separated List of allowed demuxers. By default all are allowed.
-
-dump_separator string (input ) Separator used to separate the fields printed on the command line about the
-Stream parameters.
-For example to separate the fields with newlines and indention:
-
-
ffprobe -dump_separator "
- " -i ~/videos/matrixbench_mpeg2.mpg
-
-
-
-
-
15.1 Format stream specifiers# TOC
-
-
Format stream specifiers allow selection of one or more streams that
-match specific properties.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index.
-
-stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio,
-’s’ for subtitle, ’d’ for data, and ’t’ for attachments. If
-stream_index is given, then it matches the stream number
-stream_index of this type. Otherwise, it matches all streams of
-this type.
-
-p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number
-stream_index in the program with the id
-program_id . Otherwise, it matches all streams in the program.
-
-#stream_id Matches the stream by a format-specific ID.
-
-
-
The exact semantics of stream specifiers is defined by the
-avformat_match_stream_specifier() function declared in the
-libavformat/avformat.h header.
-
-
-
16 Demuxers# TOC
-
-
Demuxers are configured elements in FFmpeg that can read the
-multimedia streams from a particular type of file.
-
-
When you configure your FFmpeg build, all the supported demuxers
-are enabled by default. You can list all available ones using the
-configure option --list-demuxers.
-
-
You can disable all the demuxers using the configure option
---disable-demuxers, and selectively enable a single demuxer with
-the option --enable-demuxer=DEMUXER , or disable it
-with the option --disable-demuxer=DEMUXER .
-
-
The option -formats of the ff* tools will display the list of
-enabled demuxers.
-
-
The description of some of the currently available demuxers follows.
-
-
-
16.1 applehttp# TOC
-
-
Apple HTTP Live Streaming demuxer.
-
-
This demuxer presents all AVStreams from all variant streams.
-The id field is set to the bitrate variant index number. By setting
-the discard flags on AVStreams (by pressing ’a’ or ’v’ in ffplay),
-the caller can decide which variant streams to actually receive.
-The total bitrate of the variant that the stream belongs to is
-available in a metadata key named "variant_bitrate".
-
-
-
16.2 apng# TOC
-
-
Animated Portable Network Graphics demuxer.
-
-
This demuxer is used to demux APNG files.
-All headers, but the PNG signature, up to (but not including) the first
-fcTL chunk are transmitted as extradata.
-Frames are then split as being all the chunks between two fcTL ones, or
-between the last fcTL and IEND chunks.
-
-
--ignore_loop bool Ignore the loop variable in the file if set.
-
-max_fps int Maximum framerate in frames per second (0 for no limit).
-
-default_fps int Default framerate in frames per second when none is specified in the file
-(0 meaning as fast as possible).
-
-
-
-
16.3 asf# TOC
-
-
Advanced Systems Format demuxer.
-
-
This demuxer is used to demux ASF files and MMS network streams.
-
-
--no_resync_search bool Do not try to resynchronize by looking for a certain optional start code.
-
-
-
-
16.4 concat# TOC
-
-
Virtual concatenation script demuxer.
-
-
This demuxer reads a list of files and other directives from a text file and
-demuxes them one after the other, as if all their packet had been muxed
-together.
-
-
The timestamps in the files are adjusted so that the first file starts at 0
-and each next file starts where the previous one finishes. Note that it is
-done globally and may cause gaps if all streams do not have exactly the same
-length.
-
-
All files must have the same streams (same codecs, same time base, etc.).
-
-
The duration of each file is used to adjust the timestamps of the next file:
-if the duration is incorrect (because it was computed using the bit-rate or
-because the file is truncated, for example), it can cause artifacts. The
-duration directive can be used to override the duration stored in
-each file.
-
-
-
16.4.1 Syntax# TOC
-
-
The script is a text file in extended-ASCII, with one directive per line.
-Empty lines, leading spaces and lines starting with ’#’ are ignored. The
-following directive is recognized:
-
-
-file path Path to a file to read; special characters and spaces must be escaped with
-backslash or single quotes.
-
-All subsequent file-related directives apply to that file.
-
-ffconcat version 1.0Identify the script type and version. It also sets the safe option
-to 1 if it was to its default -1.
-
-To make FFmpeg recognize the format automatically, this directive must
-appears exactly as is (no extra space or byte-order-mark) on the very first
-line of the script.
-
-duration dur Duration of the file. This information can be specified from the file;
-specifying it here may be more efficient or help if the information from the
-file is not available or accurate.
-
-If the duration is set for all files, then it is possible to seek in the
-whole concatenated video.
-
-streamIntroduce a stream in the virtual file.
-All subsequent stream-related directives apply to the last introduced
-stream.
-Some streams properties must be set in order to allow identifying the
-matching streams in the subfiles.
-If no streams are defined in the script, the streams from the first file are
-copied.
-
-exact_stream_id id Set the id of the stream.
-If this directive is given, the string with the corresponding id in the
-subfiles will be used.
-This is especially useful for MPEG-PS (VOB) files, where the order of the
-streams is not reliable.
-
-
-
-
-
16.4.2 Options# TOC
-
-
This demuxer accepts the following option:
-
-
-safe If set to 1, reject unsafe file paths. A file path is considered safe if it
-does not contain a protocol specification and is relative and all components
-only contain characters from the portable character set (letters, digits,
-period, underscore and hyphen) and have no period at the beginning of a
-component.
-
-If set to 0, any file name is accepted.
-
-The default is -1, it is equivalent to 1 if the format was automatically
-probed and 0 otherwise.
-
-auto_convert If set to 1, try to perform automatic conversions on packet data to make the
-streams concatenable.
-
-Currently, the only conversion is adding the h264_mp4toannexb bitstream
-filter to H.264 streams in MP4 format. This is necessary in particular if
-there are resolution changes.
-
-
-
-
-
16.5 flv# TOC
-
-
Adobe Flash Video Format demuxer.
-
-
This demuxer is used to demux FLV files and RTMP network streams.
-
-
--flv_metadata bool Allocate the streams according to the onMetaData array content.
-
-
-
-
16.6 libgme# TOC
-
-
The Game Music Emu library is a collection of video game music file emulators.
-
-
See http://code.google.com/p/game-music-emu/ for more information.
-
-
Some files have multiple tracks. The demuxer will pick the first track by
-default. The track_index option can be used to select a different
-track. Track indexes start at 0. The demuxer exports the number of tracks as
-tracks meta data entry.
-
-
For very large files, the max_size option may have to be adjusted.
-
-
-
16.7 libquvi# TOC
-
-
Play media from Internet services using the quvi project.
-
-
The demuxer accepts a format option to request a specific quality. It
-is by default set to best .
-
-
See http://quvi.sourceforge.net/ for more information.
-
-
FFmpeg needs to be built with --enable-libquvi for this demuxer to be
-enabled.
-
-
-
16.8 gif# TOC
-
-
Animated GIF demuxer.
-
-
It accepts the following options:
-
-
-min_delay Set the minimum valid delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 2.
-
-default_delay Set the default delay between frames in hundredths of seconds.
-Range is 0 to 6000. Default value is 10.
-
-ignore_loop GIF files can contain information to loop a certain number of times (or
-infinitely). If ignore_loop is set to 1, then the loop setting
-from the input will be ignored and looping will not occur. If set to 0,
-then looping will occur and will cycle the number of times according to
-the GIF. Default value is 1.
-
-
-
For example, with the overlay filter, place an infinitely looping GIF
-over another video:
-
-
ffmpeg -i input.mp4 -ignore_loop 0 -i input.gif -filter_complex overlay=shortest=1 out.mkv
-
-
-
Note that in the above example the shortest option for overlay filter is
-used to end the output video at the length of the shortest input file,
-which in this case is input.mp4 as the GIF in this example loops
-infinitely.
-
-
-
16.9 image2# TOC
-
-
Image file demuxer.
-
-
This demuxer reads from a list of image files specified by a pattern.
-The syntax and meaning of the pattern is specified by the
-option pattern_type .
-
-
The pattern may contain a suffix which is used to automatically
-determine the format of the images contained in the files.
-
-
The size, the pixel format, and the format of each image must be the
-same for all the files in the sequence.
-
-
This demuxer accepts the following options:
-
-framerate Set the frame rate for the video stream. It defaults to 25.
-
loop If set to 1, loop over the input. Default value is 0.
-
pattern_type Select the pattern type used to interpret the provided filename.
-
-pattern_type accepts one of the following values.
-
-sequence Select a sequence pattern type, used to specify a sequence of files
-indexed by sequential numbers.
-
-A sequence pattern may contain the string "%d" or "%0N d", which
-specifies the position of the characters representing a sequential
-number in each filename matched by the pattern. If the form
-"%d0N d" is used, the string representing the number in each
-filename is 0-padded and N is the total number of 0-padded
-digits representing the number. The literal character ’%’ can be
-specified in the pattern with the string "%%".
-
-If the sequence pattern contains "%d" or "%0N d", the first filename of
-the file list specified by the pattern must contain a number
-inclusively contained between start_number and
-start_number +start_number_range -1, and all the following
-numbers must be sequential.
-
-For example the pattern "img-%03d.bmp" will match a sequence of
-filenames of the form img-001.bmp , img-002.bmp , ...,
-img-010.bmp , etc.; the pattern "i%%m%%g-%d.jpg" will match a
-sequence of filenames of the form i%m%g-1.jpg ,
-i%m%g-2.jpg , ..., i%m%g-10.jpg , etc.
-
-Note that the pattern must not necessarily contain "%d" or
-"%0N d", for example to convert a single image file
-img.jpeg you can employ the command:
-
-
ffmpeg -i img.jpeg img.png
- glob Select a glob wildcard pattern type.
-
-The pattern is interpreted like a glob() pattern. This is only
-selectable if libavformat was compiled with globbing support.
-
-glob_sequence (deprecated, will be removed) Select a mixed glob wildcard/sequence pattern.
-
-If your version of libavformat was compiled with globbing support, and
-the provided pattern contains at least one glob meta character among
-%*?[]{} that is preceded by an unescaped "%", the pattern is
-interpreted like a glob() pattern, otherwise it is interpreted
-like a sequence pattern.
-
-All glob special characters %*?[]{} must be prefixed
-with "%". To escape a literal "%" you shall use "%%".
-
-For example the pattern foo-%*.jpeg will match all the
-filenames prefixed by "foo-" and terminating with ".jpeg", and
-foo-%?%?%?.jpeg will match all the filenames prefixed with
-"foo-", followed by a sequence of three characters, and terminating
-with ".jpeg".
-
-This pattern type is deprecated in favor of glob and
-sequence .
-
-
-Default value is glob_sequence .
-
pixel_format Set the pixel format of the images to read. If not specified the pixel
-format is guessed from the first image file in the sequence.
-
start_number Set the index of the file matched by the image file pattern to start
-to read from. Default value is 0.
-
start_number_range Set the index interval range to check when looking for the first image
-file in the sequence, starting from start_number . Default value
-is 5.
-
ts_from_file If set to 1, will set frame timestamp to modification time of image file. Note
-that monotonity of timestamps is not provided: images go in the same order as
-without this option. Default value is 0.
-If set to 2, will set frame timestamp to the modification time of the image file in
-nanosecond precision.
-
video_size Set the video size of the images to read. If not specified the video
-size is guessed from the first image file in the sequence.
-
-
-
-
16.9.1 Examples# TOC
-
-
- Use ffmpeg for creating a video from the images in the file
-sequence img-001.jpeg , img-002.jpeg , ..., assuming an
-input frame rate of 10 frames per second:
-
-
ffmpeg -framerate 10 -i 'img-%03d.jpeg' out.mkv
- As above, but start by reading from a file with index 100 in the sequence:
-
-
ffmpeg -framerate 10 -start_number 100 -i 'img-%03d.jpeg' out.mkv
- Read images matching the "*.png" glob pattern , that is all the files
-terminating with the ".png" suffix:
-
-
ffmpeg -framerate 10 -pattern_type glob -i "*.png" out.mkv
-
-
-
-
16.10 mpegts# TOC
-
-
MPEG-2 transport stream demuxer.
-
-
-fix_teletext_pts Overrides teletext packet PTS and DTS values with the timestamps calculated
-from the PCR of the first program which the teletext stream is part of and is
-not discarded. Default value is 1, set this option to 0 if you want your
-teletext packet PTS and DTS values untouched.
-
-
-
-
16.11 rawvideo# TOC
-
-
Raw video demuxer.
-
-
This demuxer allows one to read raw video data. Since there is no header
-specifying the assumed video parameters, the user must specify them
-in order to be able to decode the data correctly.
-
-
This demuxer accepts the following options:
-
-framerate Set input video frame rate. Default value is 25.
-
-pixel_format Set the input video pixel format. Default value is yuv420p.
-
-video_size Set the input video size. This value must be specified explicitly.
-
-
-
For example to read a rawvideo file input.raw with
-ffplay, assuming a pixel format of rgb24, a video
-size of 320x240, and a frame rate of 10 images per second, use
-the command:
-
-
ffplay -f rawvideo -pixel_format rgb24 -video_size 320x240 -framerate 10 input.raw
-
-
-
-
16.12 sbg# TOC
-
-
SBaGen script demuxer.
-
-
This demuxer reads the script language used by SBaGen
-http://uazu.net/sbagen/ to generate binaural beats sessions. A SBG
-script looks like that:
-
-
-SE
-a: 300-2.5/3 440+4.5/0
-b: 300-2.5/0 440+4.5/3
-off: -
-NOW == a
-+0:07:00 == b
-+0:14:00 == a
-+0:21:00 == b
-+0:30:00 off
-
-
-
A SBG script can mix absolute and relative timestamps. If the script uses
-either only absolute timestamps (including the script start time) or only
-relative ones, then its layout is fixed, and the conversion is
-straightforward. On the other hand, if the script mixes both kind of
-timestamps, then the NOW reference for relative timestamps will be
-taken from the current time of day at the time the script is read, and the
-script layout will be frozen according to that reference. That means that if
-the script is directly played, the actual times will match the absolute
-timestamps up to the sound controller’s clock accuracy, but if the user
-somehow pauses the playback or seeks, all times will be shifted accordingly.
-
-
-
16.13 tedcaptions# TOC
-
-
JSON captions used for TED Talks .
-
-
TED does not provide links to the captions, but they can be guessed from the
-page. The file tools/bookmarklets.html from the FFmpeg source tree
-contains a bookmarklet to expose them.
-
-
This demuxer accepts the following option:
-
-start_time Set the start time of the TED talk, in milliseconds. The default is 15000
-(15s). It is used to sync the captions with the downloadable videos, because
-they include a 15s intro.
-
-
-
Example: convert the captions to a format most players understand:
-
-
ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
-
-
-
-
17 Metadata# TOC
-
-
FFmpeg is able to dump metadata from media files into a simple UTF-8-encoded
-INI-like text file and then load it back using the metadata muxer/demuxer.
-
-
The file format is as follows:
-
- A file consists of a header and a number of metadata tags divided into sections,
-each on its own line.
-
- The header is a ’;FFMETADATA’ string, followed by a version number (now 1).
-
- Metadata tags are of the form ’key=value’
-
- Immediately after header follows global metadata
-
- After global metadata there may be sections with per-stream/per-chapter
-metadata.
-
- A section starts with the section name in uppercase (i.e. STREAM or CHAPTER) in
-brackets (’[’, ’]’) and ends with next section or end of file.
-
- At the beginning of a chapter section there may be an optional timebase to be
-used for start/end values. It must be in form ’TIMEBASE=num/den’, where num and
-den are integers. If the timebase is missing then start/end times are assumed to
-be in milliseconds.
-Next a chapter section must contain chapter start and end times in form
-’START=num’, ’END=num’, where num is a positive integer.
-
- Empty lines and lines starting with ’;’ or ’#’ are ignored.
-
- Metadata keys or values containing special characters (’=’, ’;’, ’#’, ’\’ and a
-newline) must be escaped with a backslash ’\’.
-
- Note that whitespace in metadata (e.g. foo = bar) is considered to be a part of
-the tag (in the example above key is ’foo ’, value is ’ bar’).
-
-
-
A ffmetadata file might look like this:
-
-
;FFMETADATA1
-title=bike\\shed
-;this is a comment
-artist=FFmpeg troll team
-
-[CHAPTER]
-TIMEBASE=1/1000
-START=0
-#chapter ends at 0:01:00
-END=60000
-title=chapter \#1
-[STREAM]
-title=multi\
-line
-
-
-
By using the ffmetadata muxer and demuxer it is possible to extract
-metadata from an input file to an ffmetadata file, and then transcode
-the file into an output file with the edited ffmetadata file.
-
-
Extracting an ffmetadata file with ffmpeg goes as follows:
-
-
ffmpeg -i INPUT -f ffmetadata FFMETADATAFILE
-
-
-
Reinserting edited metadata information from the FFMETADATAFILE file can
-be done as:
-
-
ffmpeg -i INPUT -i FFMETADATAFILE -map_metadata 1 -codec copy OUTPUT
-
-
-
-
18 Protocols# TOC
-
-
Protocols are configured elements in FFmpeg that enable access to
-resources that require specific protocols.
-
-
When you configure your FFmpeg build, all the supported protocols are
-enabled by default. You can list all available ones using the
-configure option "–list-protocols".
-
-
You can disable all the protocols using the configure option
-"–disable-protocols", and selectively enable a protocol using the
-option "–enable-protocol=PROTOCOL ", or you can disable a
-particular protocol using the option
-"–disable-protocol=PROTOCOL ".
-
-
The option "-protocols" of the ff* tools will display the list of
-supported protocols.
-
-
A description of the currently available protocols follows.
-
-
-
18.1 bluray# TOC
-
-
Read BluRay playlist.
-
-
The accepted options are:
-
-angle BluRay angle
-
-chapter Start chapter (1...N)
-
-playlist Playlist to read (BDMV/PLAYLIST/?????.mpls)
-
-
-
-
Examples:
-
-
Read longest playlist from BluRay mounted to /mnt/bluray:
-
-
-
Read angle 2 of playlist 4 from BluRay mounted to /mnt/bluray, start from chapter 2:
-
-
-playlist 4 -angle 2 -chapter 2 bluray:/mnt/bluray
-
-
-
-
18.2 cache# TOC
-
-
Caching wrapper for input stream.
-
-
Cache the input stream to temporary file. It brings seeking capability to live streams.
-
-
-
-
-
18.3 concat# TOC
-
-
Physical concatenation protocol.
-
-
Allow to read and seek from many resource in sequence as if they were
-a unique resource.
-
-
A URL accepted by this protocol has the syntax:
-
-
concat:URL1 |URL2 |...|URLN
-
-
-
where URL1 , URL2 , ..., URLN are the urls of the
-resource to be concatenated, each one possibly specifying a distinct
-protocol.
-
-
For example to read a sequence of files split1.mpeg ,
-split2.mpeg , split3.mpeg with ffplay use the
-command:
-
-
ffplay concat:split1.mpeg\|split2.mpeg\|split3.mpeg
-
-
-
Note that you may need to escape the character "|" which is special for
-many shells.
-
-
-
18.4 crypto# TOC
-
-
AES-encrypted stream reading protocol.
-
-
The accepted options are:
-
-key Set the AES decryption key binary block from given hexadecimal representation.
-
-iv Set the AES decryption initialization vector binary block from given hexadecimal representation.
-
-
-
Accepted URL formats:
-
-
crypto:URL
-crypto+URL
-
-
-
-
18.5 data# TOC
-
-
Data in-line in the URI. See http://en.wikipedia.org/wiki/Data_URI_scheme .
-
-
For example, to convert a GIF file given inline with ffmpeg:
-
-
ffmpeg -i "data:image/gif;base64,R0lGODdhCAAIAMIEAAAAAAAA//8AAP//AP///////////////ywAAAAACAAIAAADF0gEDLojDgdGiJdJqUX02iB4E8Q9jUMkADs=" smiley.png
-
-
-
-
18.6 file# TOC
-
-
File access protocol.
-
-
Allow to read from or write to a file.
-
-
A file URL can have the form:
-
-
-
where filename is the path of the file to read.
-
-
An URL that does not have a protocol prefix will be assumed to be a
-file URL. Depending on the build, an URL that looks like a Windows
-path with the drive letter at the beginning will also be assumed to be
-a file URL (usually not the case in builds for unix-like systems).
-
-
For example to read from a file input.mpeg with ffmpeg
-use the command:
-
-
ffmpeg -i file:input.mpeg output.mpeg
-
-
-
This protocol accepts the following options:
-
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable for files on slow medium.
-
-
-
-
18.7 ftp# TOC
-
-
FTP (File Transfer Protocol).
-
-
Allow to read from or write to remote resources using FTP protocol.
-
-
Following syntax is required.
-
-
ftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-ftp-anonymous-password Password used when login as anonymous user. Typically an e-mail address
-should be used.
-
-ftp-write-seekable Control seekability of connection during encoding. If set to 1 the
-resource is supposed to be seekable, if set to 0 it is assumed not
-to be seekable. Default value is 0.
-
-
-
NOTE: Protocol can be used as output, but it is recommended to not do
-it, unless special care is taken (tests, customized server configuration
-etc.). Different FTP servers behave in different way during seek
-operation. ff* tools may produce incomplete content due to server limitations.
-
-
-
18.8 gopher# TOC
-
-
Gopher protocol.
-
-
-
18.9 hls# TOC
-
-
Read Apple HTTP Live Streaming compliant segmented stream as
-a uniform one. The M3U8 playlists describing the segments can be
-remote HTTP resources or local files, accessed using the standard
-file protocol.
-The nested protocol is declared by specifying
-"+proto " after the hls URI scheme name, where proto
-is either "file" or "http".
-
-
-
hls+http://host/path/to/remote/resource.m3u8
-hls+file://path/to/local/resource.m3u8
-
-
-
Using this protocol is discouraged - the hls demuxer should work
-just as well (if not, please report the issues) and is more complete.
-To use the hls demuxer instead, simply use the direct URLs to the
-m3u8 files.
-
-
-
18.10 http# TOC
-
-
HTTP (Hyper Text Transfer Protocol).
-
-
This protocol accepts the following options:
-
-
-seekable Control seekability of connection. If set to 1 the resource is
-supposed to be seekable, if set to 0 it is assumed not to be seekable,
-if set to -1 it will try to autodetect if it is seekable. Default
-value is -1.
-
-chunked_post If set to 1 use chunked Transfer-Encoding for posts, default is 1.
-
-content_type Set a specific content type for the POST messages.
-
-headers Set custom HTTP headers, can override built in default headers. The
-value must be a string encoding the headers.
-
-multiple_requests Use persistent connections if set to 1, default is 0.
-
-post_data Set custom HTTP post data.
-
-user-agent user_agent Override the User-Agent header. If not specified the protocol will use a
-string describing the libavformat build. ("Lavf/<version>")
-
-timeout Set timeout in microseconds of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout is
-not specified.
-
-mime_type Export the MIME type.
-
-icy If set to 1 request ICY (SHOUTcast) metadata from the server. If the server
-supports this, the metadata has to be retrieved by the application by reading
-the icy_metadata_headers and icy_metadata_packet options.
-The default is 1.
-
-icy_metadata_headers If the server supports ICY metadata, this contains the ICY-specific HTTP reply
-headers, separated by newline characters.
-
-icy_metadata_packet If the server supports ICY metadata, and icy was set to 1, this
-contains the last non-empty metadata packet sent by the server. It should be
-polled in regular intervals by applications interested in mid-stream metadata
-updates.
-
-cookies Set the cookies to be sent in future requests. The format of each cookie is the
-same as the value of a Set-Cookie HTTP response field. Multiple cookies can be
-delimited by a newline character.
-
-offset Set initial byte offset.
-
-end_offset Try to limit the request to bytes preceding this offset.
-
-
-
-
18.10.1 HTTP Cookies# TOC
-
-
Some HTTP requests will be denied unless cookie values are passed in with the
-request. The cookies option allows these cookies to be specified. At
-the very least, each cookie must specify a value along with a path and domain.
-HTTP requests that match both the domain and path will automatically include the
-cookie value in the HTTP Cookie header field. Multiple cookies can be delimited
-by a newline.
-
-
The required syntax to play a stream specifying a cookie is:
-
-
ffplay -cookies "nlqptid=nltid=tsn; path=/; domain=somedomain.com;" http://somedomain.com/somestream.m3u8
-
-
-
-
18.11 Icecast# TOC
-
-
Icecast protocol (stream to Icecast servers)
-
-
This protocol accepts the following options:
-
-
-ice_genre Set the stream genre.
-
-ice_name Set the stream name.
-
-ice_description Set the stream description.
-
-ice_url Set the stream website URL.
-
-ice_public Set if the stream should be public.
-The default is 0 (not public).
-
-user_agent Override the User-Agent header. If not specified a string of the form
-"Lavf/<version>" will be used.
-
-password Set the Icecast mountpoint password.
-
-content_type Set the stream content type. This must be set if it is different from
-audio/mpeg.
-
-legacy_icecast This enables support for Icecast versions < 2.4.0, that do not support the
-HTTP PUT method but the SOURCE method.
-
-
-
-
-
icecast://[username [:password ]@]server :port /mountpoint
-
-
-
-
18.12 mmst# TOC
-
-
MMS (Microsoft Media Server) protocol over TCP.
-
-
-
18.13 mmsh# TOC
-
-
MMS (Microsoft Media Server) protocol over HTTP.
-
-
The required syntax is:
-
-
mmsh://server [:port ][/app ][/playpath ]
-
-
-
-
18.14 md5# TOC
-
-
MD5 output protocol.
-
-
Computes the MD5 hash of the data to be written, and on close writes
-this to the designated output or stdout if none is specified. It can
-be used to test muxers without writing an actual file.
-
-
Some examples follow.
-
-
# Write the MD5 hash of the encoded AVI file to the file output.avi.md5.
-ffmpeg -i input.flv -f avi -y md5:output.avi.md5
-
-# Write the MD5 hash of the encoded AVI file to stdout.
-ffmpeg -i input.flv -f avi -y md5:
-
-
-
Note that some formats (typically MOV) require the output protocol to
-be seekable, so they will fail with the MD5 output protocol.
-
-
-
18.15 pipe# TOC
-
-
UNIX pipe access protocol.
-
-
Allow to read and write from UNIX pipes.
-
-
The accepted syntax is:
-
-
-
number is the number corresponding to the file descriptor of the
-pipe (e.g. 0 for stdin, 1 for stdout, 2 for stderr). If number
-is not specified, by default the stdout file descriptor will be used
-for writing, stdin for reading.
-
-
For example to read from stdin with ffmpeg:
-
-
cat test.wav | ffmpeg -i pipe:0
-# ...this is the same as...
-cat test.wav | ffmpeg -i pipe:
-
-
-
For writing to stdout with ffmpeg:
-
-
ffmpeg -i test.wav -f avi pipe:1 | cat > test.avi
-# ...this is the same as...
-ffmpeg -i test.wav -f avi pipe: | cat > test.avi
-
-
-
This protocol accepts the following options:
-
-
-blocksize Set I/O operation maximum block size, in bytes. Default value is
-INT_MAX, which results in not limiting the requested block size.
-Setting this value reasonably low improves user termination request reaction
-time, which is valuable if data transmission is slow.
-
-
-
Note that some formats (typically MOV), require the output protocol to
-be seekable, so they will fail with the pipe output protocol.
-
-
-
18.16 rtmp# TOC
-
-
Real-Time Messaging Protocol.
-
-
The Real-Time Messaging Protocol (RTMP) is used for streaming multimedia
-content across a TCP/IP network.
-
-
The required syntax is:
-
-
rtmp://[username :password @]server [:port ][/app ][/instance ][/playpath ]
-
-
-
The accepted parameters are:
-
-username An optional username (mostly for publishing).
-
-password An optional password (mostly for publishing).
-
-server The address of the RTMP server.
-
-port The number of the TCP port to use (by default is 1935).
-
-app It is the name of the application to access. It usually corresponds to
-the path where the application is installed on the RTMP server
-(e.g. /ondemand/ , /flash/live/ , etc.). You can override
-the value parsed from the URI through the rtmp_app option, too.
-
-playpath It is the path or name of the resource to play with reference to the
-application specified in app , may be prefixed by "mp4:". You
-can override the value parsed from the URI through the rtmp_playpath
-option, too.
-
-listen Act as a server, listening for an incoming connection.
-
-timeout Maximum time to wait for the incoming connection. Implies listen.
-
-
-
Additionally, the following parameters can be set via command line options
-(or in code via AVOptions):
-
-rtmp_app Name of application to connect on the RTMP server. This option
-overrides the parameter specified in the URI.
-
-rtmp_buffer Set the client buffer time in milliseconds. The default is 3000.
-
-rtmp_conn Extra arbitrary AMF connection parameters, parsed from a string,
-e.g. like B:1 S:authMe O:1 NN:code:1.23 NS:flag:ok O:0.
-Each value is prefixed by a single character denoting the type,
-B for Boolean, N for number, S for string, O for object, or Z for null,
-followed by a colon. For Booleans the data must be either 0 or 1 for
-FALSE or TRUE, respectively. Likewise for Objects the data must be 0 or
-1 to end or begin an object, respectively. Data items in subobjects may
-be named, by prefixing the type with ’N’ and specifying the name before
-the value (i.e. NB:myFlag:1). This option may be used multiple
-times to construct arbitrary AMF sequences.
-
-rtmp_flashver Version of the Flash plugin used to run the SWF player. The default
-is LNX 9,0,124,2. (When publishing, the default is FMLE/3.0 (compatible;
-<libavformat version>).)
-
-rtmp_flush_interval Number of packets flushed in the same request (RTMPT only). The default
-is 10.
-
-rtmp_live Specify that the media is a live stream. No resuming or seeking in
-live streams is possible. The default value is any, which means the
-subscriber first tries to play the live stream specified in the
-playpath. If a live stream of that name is not found, it plays the
-recorded stream. The other possible values are live and
-recorded.
-
-rtmp_pageurl URL of the web page in which the media was embedded. By default no
-value will be sent.
-
-rtmp_playpath Stream identifier to play or to publish. This option overrides the
-parameter specified in the URI.
-
-rtmp_subscribe Name of live stream to subscribe to. By default no value will be sent.
-It is only sent if the option is specified or if rtmp_live
-is set to live.
-
-rtmp_swfhash SHA256 hash of the decompressed SWF file (32 bytes).
-
-rtmp_swfsize Size of the decompressed SWF file, required for SWFVerification.
-
-rtmp_swfurl URL of the SWF player for the media. By default no value will be sent.
-
-rtmp_swfverify URL to player swf file, compute hash/size automatically.
-
-rtmp_tcurl URL of the target stream. Defaults to proto://host[:port]/app.
-
-
-
-
For example to read with ffplay a multimedia resource named
-"sample" from the application "vod" from an RTMP server "myserver":
-
-
ffplay rtmp://myserver/vod/sample
-
-
-
To publish to a password protected server, passing the playpath and
-app names separately:
-
-
ffmpeg -re -i <input> -f flv -rtmp_playpath some/long/path -rtmp_app long/app/name rtmp://username:password@myserver/
-
-
-
-
18.17 rtmpe# TOC
-
-
Encrypted Real-Time Messaging Protocol.
-
-
The Encrypted Real-Time Messaging Protocol (RTMPE) is used for
-streaming multimedia content within standard cryptographic primitives,
-consisting of Diffie-Hellman key exchange and HMACSHA256, generating
-a pair of RC4 keys.
-
-
-
18.18 rtmps# TOC
-
-
Real-Time Messaging Protocol over a secure SSL connection.
-
-
The Real-Time Messaging Protocol (RTMPS) is used for streaming
-multimedia content across an encrypted connection.
-
-
-
18.19 rtmpt# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Real-Time Messaging Protocol tunneled through HTTP (RTMPT) is used
-for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
18.20 rtmpte# TOC
-
-
Encrypted Real-Time Messaging Protocol tunneled through HTTP.
-
-
The Encrypted Real-Time Messaging Protocol tunneled through HTTP (RTMPTE)
-is used for streaming multimedia content within HTTP requests to traverse
-firewalls.
-
-
-
18.21 rtmpts# TOC
-
-
Real-Time Messaging Protocol tunneled through HTTPS.
-
-
The Real-Time Messaging Protocol tunneled through HTTPS (RTMPTS) is used
-for streaming multimedia content within HTTPS requests to traverse
-firewalls.
-
-
-
18.22 libsmbclient# TOC
-
-
libsmbclient permits one to manipulate CIFS/SMB network resources.
-
-
Following syntax is required.
-
-
-
smb://[[domain:]user[:password@]]server[/share[/path[/file]]]
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout in miliseconds of socket I/O operations used by the underlying
-low level operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-workgroup Set the workgroup used for making connections. By default workgroup is not specified.
-
-
-
-
For more information see: http://www.samba.org/ .
-
-
-
18.23 libssh# TOC
-
-
Secure File Transfer Protocol via libssh
-
-
Allow to read from or write to remote resources using SFTP protocol.
-
-
Following syntax is required.
-
-
-
sftp://[user[:password]@]server[:port]/path/to/remote/resource.mpeg
-
-
-
This protocol accepts the following options.
-
-
-timeout Set timeout of socket I/O operations used by the underlying low level
-operation. By default it is set to -1, which means that the timeout
-is not specified.
-
-truncate Truncate existing files on write, if set to 1. A value of 0 prevents
-truncating. Default value is 1.
-
-private_key Specify the path of the file containing private key to use during authorization.
-By default libssh searches for keys in the ~/.ssh/ directory.
-
-
-
-
Example: Play a file stored on remote server.
-
-
-
ffplay sftp://user:password@server_address:22/home/user/resource.mpeg
-
-
-
-
18.24 librtmp rtmp, rtmpe, rtmps, rtmpt, rtmpte# TOC
-
-
Real-Time Messaging Protocol and its variants supported through
-librtmp.
-
-
Requires the presence of the librtmp headers and library during
-configuration. You need to explicitly configure the build with
-"–enable-librtmp". If enabled this will replace the native RTMP
-protocol.
-
-
This protocol provides most client functions and a few server
-functions needed to support RTMP, RTMP tunneled in HTTP (RTMPT),
-encrypted RTMP (RTMPE), RTMP over SSL/TLS (RTMPS) and tunneled
-variants of these encrypted types (RTMPTE, RTMPTS).
-
-
The required syntax is:
-
-
rtmp_proto ://server [:port ][/app ][/playpath ] options
-
-
-
where rtmp_proto is one of the strings "rtmp", "rtmpt", "rtmpe",
-"rtmps", "rtmpte", "rtmpts" corresponding to each RTMP variant, and
-server , port , app and playpath have the same
-meaning as specified for the RTMP native protocol.
-options contains a list of space-separated options of the form
-key =val .
-
-
See the librtmp manual page (man 3 librtmp) for more information.
-
-
For example, to stream a file in real-time to an RTMP server using
-ffmpeg:
-
-
ffmpeg -re -i myfile -f flv rtmp://myserver/live/mystream
-
-
-
To play the same stream using ffplay:
-
-
ffplay "rtmp://myserver/live/mystream live=1"
-
-
-
-
18.25 rtp# TOC
-
-
Real-time Transport Protocol.
-
-
The required syntax for an RTP URL is:
-rtp://hostname [:port ][?option =val ...]
-
-
port specifies the RTP port to use.
-
-
The following URL options are supported:
-
-
-ttl=n Set the TTL (Time-To-Live) value (for multicast only).
-
-rtcpport=n Set the remote RTCP port to n .
-
-localrtpport=n Set the local RTP port to n .
-
-localrtcpport=n ' Set the local RTCP port to n .
-
-pkt_size=n Set max packet size (in bytes) to n .
-
-connect=0|1 Do a connect() on the UDP socket (if set to 1) or not (if set
-to 0).
-
-sources=ip [,ip ] List allowed source IP addresses.
-
-block=ip [,ip ] List disallowed (blocked) source IP addresses.
-
-write_to_source=0|1 Send packets to the source address of the latest received packet (if
-set to 1) or to a default remote address (if set to 0).
-
-localport=n Set the local RTP port to n .
-
-This is a deprecated option. Instead, localrtpport should be
-used.
-
-
-
-
Important notes:
-
-
- If rtcpport is not set the RTCP port will be set to the RTP
-port value plus 1.
-
- If localrtpport (the local RTP port) is not set any available
-port will be used for the local RTP and RTCP ports.
-
- If localrtcpport (the local RTCP port) is not set it will be
-set to the local RTP port value plus 1.
-
-
-
-
18.26 rtsp# TOC
-
-
Real-Time Streaming Protocol.
-
-
RTSP is not technically a protocol handler in libavformat, it is a demuxer
-and muxer. The demuxer supports both normal RTSP (with data transferred
-over RTP; this is used by e.g. Apple and Microsoft) and Real-RTSP (with
-data transferred over RDT).
-
-
The muxer can be used to send a stream using RTSP ANNOUNCE to a server
-supporting it (currently Darwin Streaming Server and Mischa Spiegelmock’s
-RTSP server ).
-
-
The required syntax for a RTSP url is:
-
-
rtsp://hostname [:port ]/path
-
-
-
Options can be set on the ffmpeg/ffplay command
-line, or set in code via AVOptions or in
-avformat_open_input.
-
-
The following options are supported.
-
-
-initial_pause Do not start playing the stream immediately if set to 1. Default value
-is 0.
-
-rtsp_transport Set RTSP transport protocols.
-
-It accepts the following values:
-
-‘udp ’
-Use UDP as lower transport protocol.
-
-‘tcp ’
-Use TCP (interleaving within the RTSP control channel) as lower
-transport protocol.
-
-‘udp_multicast ’
-Use UDP multicast as lower transport protocol.
-
-‘http ’
-Use HTTP tunneling as lower transport protocol, which is useful for
-passing proxies.
-
-
-Multiple lower transport protocols may be specified, in that case they are
-tried one at a time (if the setup of one fails, the next one is tried).
-For the muxer, only the ‘tcp ’ and ‘udp ’ options are supported.
-
-rtsp_flags Set RTSP flags.
-
-The following values are accepted:
-
-‘filter_src ’
-Accept packets only from negotiated peer address and port.
-
‘listen ’
-Act as a server, listening for an incoming connection.
-
‘prefer_tcp ’
-Try TCP for RTP transport first, if TCP is available as RTSP RTP transport.
-
-
-Default value is ‘none ’.
-
-allowed_media_types Set media types to accept from the server.
-
-The following flags are accepted:
-
-‘video ’
-‘audio ’
-‘data ’
-
-
-By default it accepts all media types.
-
-min_port Set minimum local UDP port. Default value is 5000.
-
-max_port Set maximum local UDP port. Default value is 65000.
-
-timeout Set maximum timeout (in seconds) to wait for incoming connections.
-
-A value of -1 means infinite (default). This option implies the
-rtsp_flags set to ‘listen ’.
-
-reorder_queue_size Set number of packets to buffer for handling of reordered packets.
-
-stimeout Set socket TCP I/O timeout in microseconds.
-
-user-agent Override User-Agent header. If not specified, it defaults to the
-libavformat identifier string.
-
-
-
When receiving data over UDP, the demuxer tries to reorder received packets
-(since they may arrive out of order, or packets may get lost totally). This
-can be disabled by setting the maximum demuxing delay to zero (via
-the max_delay field of AVFormatContext).
-
-
When watching multi-bitrate Real-RTSP streams with ffplay, the
-streams to display can be chosen with -vst n and
--ast n for video and audio respectively, and can be switched
-on the fly by pressing v and a.
-
-
-
18.26.1 Examples# TOC
-
-
The following examples all make use of the ffplay and
-ffmpeg tools.
-
-
- Watch a stream over UDP, with a max reordering delay of 0.5 seconds:
-
-
ffplay -max_delay 500000 -rtsp_transport udp rtsp://server/video.mp4
- Watch a stream tunneled over HTTP:
-
-
ffplay -rtsp_transport http rtsp://server/video.mp4
- Send a stream in realtime to a RTSP server, for others to watch:
-
-
ffmpeg -re -i input -f rtsp -muxdelay 0.1 rtsp://server/live.sdp
- Receive a stream in realtime:
-
-
ffmpeg -rtsp_flags listen -i rtsp://ownaddress/live.sdp output
-
-
-
-
18.27 sap# TOC
-
-
Session Announcement Protocol (RFC 2974). This is not technically a
-protocol handler in libavformat, it is a muxer and demuxer.
-It is used for signalling of RTP streams, by announcing the SDP for the
-streams regularly on a separate port.
-
-
-
18.27.1 Muxer# TOC
-
-
The syntax for a SAP url given to the muxer is:
-
-
sap://destination [:port ][?options ]
-
-
-
The RTP packets are sent to destination on port port ,
-or to port 5004 if no port is specified.
-options is a &-separated list. The following options
-are supported:
-
-
-announce_addr=address Specify the destination IP address for sending the announcements to.
-If omitted, the announcements are sent to the commonly used SAP
-announcement multicast address 224.2.127.254 (sap.mcast.net), or
-ff0e::2:7ffe if destination is an IPv6 address.
-
-announce_port=port Specify the port to send the announcements on, defaults to
-9875 if not specified.
-
-ttl=ttl Specify the time to live value for the announcements and RTP packets,
-defaults to 255.
-
-same_port=0|1 If set to 1, send all RTP streams on the same port pair. If zero (the
-default), all streams are sent on unique ports, with each stream on a
-port 2 numbers higher than the previous.
-VLC/Live555 requires this to be set to 1, to be able to receive the stream.
-The RTP stack in libavformat for receiving requires all streams to be sent
-on unique ports.
-
-
-
Example command lines follow.
-
-
To broadcast a stream on the local subnet, for watching in VLC:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255?same_port=1
-
-
-
Similarly, for watching in ffplay:
-
-
-
ffmpeg -re -i input -f sap sap://224.0.0.255
-
-
-
And for watching in ffplay, over IPv6:
-
-
-
ffmpeg -re -i input -f sap sap://[ff0e::1:2:3:4]
-
-
-
-
18.27.2 Demuxer# TOC
-
-
The syntax for a SAP url given to the demuxer is:
-
-
sap://[address ][:port ]
-
-
-
address is the multicast address to listen for announcements on,
-if omitted, the default 224.2.127.254 (sap.mcast.net) is used. port
-is the port that is listened on, 9875 if omitted.
-
-
The demuxers listens for announcements on the given address and port.
-Once an announcement is received, it tries to receive that particular stream.
-
-
Example command lines follow.
-
-
To play back the first stream announced on the normal SAP multicast address:
-
-
-
-
To play back the first stream announced on one the default IPv6 SAP multicast address:
-
-
-
ffplay sap://[ff0e::2:7ffe]
-
-
-
-
18.28 sctp# TOC
-
-
Stream Control Transmission Protocol.
-
-
The accepted URL syntax is:
-
-
sctp://host :port [?options ]
-
-
-
The protocol accepts the following options:
-
-listen If set to any value, listen for an incoming connection. Outgoing connection is done by default.
-
-max_streams Set the maximum number of streams. By default no limit is set.
-
-
-
-
18.29 srtp# TOC
-
-
Secure Real-time Transport Protocol.
-
-
The accepted options are:
-
-srtp_in_suite srtp_out_suite Select input and output encoding suites.
-
-Supported values:
-
-‘AES_CM_128_HMAC_SHA1_80 ’
-‘SRTP_AES128_CM_HMAC_SHA1_80 ’
-‘AES_CM_128_HMAC_SHA1_32 ’
-‘SRTP_AES128_CM_HMAC_SHA1_32 ’
-
-
-srtp_in_params srtp_out_params Set input and output encoding parameters, which are expressed by a
-base64-encoded representation of a binary block. The first 16 bytes of
-this binary block are used as master key, the following 14 bytes are
-used as master salt.
-
-
-
-
18.30 subfile# TOC
-
-
Virtually extract a segment of a file or another stream.
-The underlying stream must be seekable.
-
-
Accepted options:
-
-start Start offset of the extracted segment, in bytes.
-
end End offset of the extracted segment, in bytes.
-
-
-
Examples:
-
-
Extract a chapter from a DVD VOB file (start and end sectors obtained
-externally and multiplied by 2048):
-
-
subfile,,start,153391104,end,268142592,,:/media/dvd/VIDEO_TS/VTS_08_1.VOB
-
-
-
Play an AVI file directly from a TAR archive:
-subfile,,start,183241728,end,366490624,,:archive.tar
-
-
-
18.31 tcp# TOC
-
-
Transmission Control Protocol.
-
-
The required syntax for a TCP url is:
-
-
tcp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form
-key =val .
-
-
The list of supported options follows.
-
-
-listen=1|0 Listen for an incoming connection. Default value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-listen_timeout=microseconds Set listen timeout, expressed in microseconds.
-
-
-
The following example shows how to setup a listening TCP connection
-with ffmpeg, which is then accessed with ffplay:
-
-
ffmpeg -i input -f format tcp://hostname :port ?listen
-ffplay tcp://hostname :port
-
-
-
-
18.32 tls# TOC
-
-
Transport Layer Security (TLS) / Secure Sockets Layer (SSL)
-
-
The required syntax for a TLS/SSL url is:
-
-
tls://hostname :port [?options ]
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-ca_file, cafile=filename A file containing certificate authority (CA) root certificates to treat
-as trusted. If the linked TLS library contains a default this might not
-need to be specified for verification to work, but not all libraries and
-setups have defaults built in.
-The file must be in OpenSSL PEM format.
-
-tls_verify=1|0 If enabled, try to verify the peer that we are communicating with.
-Note, if using OpenSSL, this currently only makes sure that the
-peer certificate is signed by one of the root certificates in the CA
-database, but it does not validate that the certificate actually
-matches the host name we are trying to connect to. (With GnuTLS,
-the host name is validated as well.)
-
-This is disabled by default since it requires a CA database to be
-provided by the caller in many cases.
-
-cert_file, cert=filename A file containing a certificate to use in the handshake with the peer.
-(When operating as server, in listen mode, this is more often required
-by the peer, while client certificates only are mandated in certain
-setups.)
-
-key_file, key=filename A file containing the private key for the certificate.
-
-listen=1|0 If enabled, listen for connections on the provided port, and assume
-the server role in the handshake instead of the client role.
-
-
-
-
Example command lines:
-
-
To create a TLS/SSL server that serves an input stream.
-
-
-
ffmpeg -i input -f format tls://hostname :port ?listen&cert=server.crt &key=server.key
-
-
-
To play back a stream from the TLS/SSL server using ffplay:
-
-
-
ffplay tls://hostname :port
-
-
-
-
18.33 udp# TOC
-
-
User Datagram Protocol.
-
-
The required syntax for an UDP URL is:
-
-
udp://hostname :port [?options ]
-
-
-
options contains a list of &-separated options of the form key =val .
-
-
In case threading is enabled on the system, a circular buffer is used
-to store the incoming data, which allows one to reduce loss of data due to
-UDP socket buffer overruns. The fifo_size and
-overrun_nonfatal options are related to this buffer.
-
-
The list of supported options follows.
-
-
-buffer_size=size Set the UDP maximum socket buffer size in bytes. This is used to set either
-the receive or send buffer size, depending on what the socket is used for.
-Default is 64KB. See also fifo_size .
-
-localport=port Override the local UDP port to bind with.
-
-localaddr=addr Choose the local IP address. This is useful e.g. if sending multicast
-and the host has multiple interfaces, where the user can choose
-which interface to send on by specifying the IP address of that interface.
-
-pkt_size=size Set the size in bytes of UDP packets.
-
-reuse=1|0 Explicitly allow or disallow reusing UDP sockets.
-
-ttl=ttl Set the time to live value (for multicast only).
-
-connect=1|0 Initialize the UDP socket with connect(). In this case, the
-destination address can’t be changed with ff_udp_set_remote_url later.
-If the destination address isn’t known at the start, this option can
-be specified in ff_udp_set_remote_url, too.
-This allows finding out the source address for the packets with getsockname,
-and makes writes return with AVERROR(ECONNREFUSED) if "destination
-unreachable" is received.
-For receiving, this gives the benefit of only receiving packets from
-the specified peer address/port.
-
-sources=address [,address ] Only receive packets sent to the multicast group from one of the
-specified sender IP addresses.
-
-block=address [,address ] Ignore packets sent to the multicast group from the specified
-sender IP addresses.
-
-fifo_size=units Set the UDP receiving circular buffer size, expressed as a number of
-packets with size of 188 bytes. If not specified defaults to 7*4096.
-
-overrun_nonfatal=1|0 Survive in case of UDP receiving circular buffer overrun. Default
-value is 0.
-
-timeout=microseconds Set raise error timeout, expressed in microseconds.
-
-This option is only relevant in read mode: if no data arrived in more
-than this time interval, raise error.
-
-broadcast=1|0 Explicitly allow or disallow UDP broadcasting.
-
-Note that broadcasting may not work properly on networks having
-a broadcast storm protection.
-
-
-
-
18.33.1 Examples# TOC
-
-
- Use ffmpeg to stream over UDP to a remote endpoint:
-
-
ffmpeg -i input -f format udp://hostname :port
- Use ffmpeg to stream in mpegts format over UDP using 188
-sized UDP packets, using a large input buffer:
-
-
ffmpeg -i input -f mpegts udp://hostname :port ?pkt_size=188&buffer_size=65535
- Use ffmpeg to receive over UDP from a remote endpoint:
-
-
ffmpeg -i udp://[multicast-address ]:port ...
-
-
-
-
18.34 unix# TOC
-
-
Unix local socket
-
-
The required syntax for a Unix socket URL is:
-
-
-
-
The following parameters can be set via command line options
-(or in code via AVOptions):
-
-
-timeout Timeout in ms.
-
listen Create the Unix socket in listening mode.
-
-
-
-
19 Device Options# TOC
-
-
The libavdevice library provides the same interface as
-libavformat. Namely, an input device is considered like a demuxer, and
-an output device like a muxer, and the interface and generic device
-options are the same provided by libavformat (see the ffmpeg-formats
-manual).
-
-
In addition each input or output device may support so-called private
-options, which are specific for that component.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, or by setting the value explicitly in the device
-AVFormatContext options or using the libavutil/opt.h API
-for programmatic use.
-
-
-
-
20 Input Devices# TOC
-
-
Input devices are configured elements in FFmpeg which allow to access
-the data coming from a multimedia device attached to your system.
-
-
When you configure your FFmpeg build, all the supported input devices
-are enabled by default. You can list all available ones using the
-configure option "–list-indevs".
-
-
You can disable all the input devices using the configure option
-"–disable-indevs", and selectively enable an input device using the
-option "–enable-indev=INDEV ", or you can disable a particular
-input device using the option "–disable-indev=INDEV ".
-
-
The option "-devices" of the ff* tools will display the list of
-supported input devices.
-
-
A description of the currently available input devices follows.
-
-
-
20.1 alsa# TOC
-
-
ALSA (Advanced Linux Sound Architecture) input device.
-
-
To enable this input device during configuration you need libasound
-installed on your system.
-
-
This device allows capturing from an ALSA device. The name of the
-device to capture has to be an ALSA card identifier.
-
-
An ALSA identifier has the syntax:
-
-
hw:CARD [,DEV [,SUBDEV ]]
-
-
-
where the DEV and SUBDEV components are optional.
-
-
The three arguments (in order: CARD ,DEV ,SUBDEV )
-specify card number or identifier, device number and subdevice number
-(-1 means any).
-
-
To see the list of cards currently recognized by your system check the
-files /proc/asound/cards and /proc/asound/devices .
-
-
For example to capture with ffmpeg from an ALSA device with
-card id 0, you may run the command:
-
-
ffmpeg -f alsa -i hw:0 alsaout.wav
-
-
-
For more information see:
-http://www.alsa-project.org/alsa-doc/alsa-lib/pcm.html
-
-
-
20.2 avfoundation# TOC
-
-
AVFoundation input device.
-
-
AVFoundation is the currently recommended framework by Apple for streamgrabbing on OSX >= 10.7 as well as on iOS.
-The older QTKit framework has been marked deprecated since OSX version 10.7.
-
-
The input filename has to be given in the following syntax:
-
-
-i "[[VIDEO]:[AUDIO]]"
-
-
The first entry selects the video input while the latter selects the audio input.
-The stream has to be specified by the device name or the device index as shown by the device list.
-Alternatively, the video and/or audio input device can be chosen by index using the
-
- -video_device_index <INDEX>
-
-and/or
-
- -audio_device_index <INDEX>
-
-, overriding any
-device name or index given in the input filename.
-
-
All available devices can be enumerated by using -list_devices true , listing
-all device names and corresponding indices.
-
-
There are two device name aliases:
-
-defaultSelect the AVFoundation default device of the corresponding type.
-
-noneDo not record the corresponding media type.
-This is equivalent to specifying an empty device name or index.
-
-
-
-
-
20.2.1 Options# TOC
-
-
AVFoundation supports the following options:
-
-
--list_devices <TRUE|FALSE> If set to true, a list of all available input devices is given showing all
-device names and indices.
-
--video_device_index <INDEX> Specify the video device by its index. Overrides anything given in the input filename.
-
--audio_device_index <INDEX> Specify the audio device by its index. Overrides anything given in the input filename.
-
--pixel_format <FORMAT> Request the video device to use a specific pixel format.
-If the specified format is not supported, a list of available formats is given
-und the first one in this list is used instead. Available pixel formats are:
-monob, rgb555be, rgb555le, rgb565be, rgb565le, rgb24, bgr24, 0rgb, bgr0, 0bgr, rgb0,
- bgr48be, uyvy422, yuva444p, yuva444p16le, yuv444p, yuv422p16, yuv422p10, yuv444p10,
- yuv420p, nv12, yuyv422, gray
-
-
-
-
-
20.2.2 Examples# TOC
-
-
- Print the list of AVFoundation supported devices and exit:
-
-
$ ffmpeg -f avfoundation -list_devices true -i ""
- Record video from video device 0 and audio from audio device 0 into out.avi:
-
-
$ ffmpeg -f avfoundation -i "0:0" out.avi
- Record video from video device 2 and audio from audio device 1 into out.avi:
-
-
$ ffmpeg -f avfoundation -video_device_index 2 -i ":1" out.avi
- Record video from the system default video device using the pixel format bgr0 and do not record any audio into out.avi:
-
-
$ ffmpeg -f avfoundation -pixel_format bgr0 -i "default:none" out.avi
-
-
-
-
20.3 bktr# TOC
-
-
BSD video input device.
-
-
-
20.4 dshow# TOC
-
-
Windows DirectShow input device.
-
-
DirectShow support is enabled when FFmpeg is built with the mingw-w64 project.
-Currently only audio and video devices are supported.
-
-
Multiple devices may be opened as separate inputs, but they may also be
-opened on the same input, which should improve synchronism between them.
-
-
The input name should be in the format:
-
-
-
-
where TYPE can be either audio or video ,
-and NAME is the device’s name.
-
-
-
20.4.1 Options# TOC
-
-
If no options are specified, the device’s defaults are used.
-If the device does not support the requested options, it will
-fail to open.
-
-
-video_size Set the video size in the captured video.
-
-framerate Set the frame rate in the captured video.
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-
-sample_size Set the sample size (in bits) of the captured audio.
-
-channels Set the number of channels in the captured audio.
-
-list_devices If set to true , print a list of devices and exit.
-
-list_options If set to true , print a list of selected device’s options
-and exit.
-
-video_device_number Set video device number for devices with same name (starts at 0,
-defaults to 0).
-
-audio_device_number Set audio device number for devices with same name (starts at 0,
-defaults to 0).
-
-pixel_format Select pixel format to be used by DirectShow. This may only be set when
-the video codec is not set or set to rawvideo.
-
-audio_buffer_size Set audio device buffer size in milliseconds (which can directly
-impact latency, depending on the device).
-Defaults to using the audio device’s
-default buffer size (typically some multiple of 500ms).
-Setting this value too low can degrade performance.
-See also
-http://msdn.microsoft.com/en-us/library/windows/desktop/dd377582(v=vs.85).aspx
-
-
-
-
-
20.4.2 Examples# TOC
-
-
- Print the list of DirectShow supported devices and exit:
-
-
$ ffmpeg -list_devices true -f dshow -i dummy
- Open video device Camera :
-
-
$ ffmpeg -f dshow -i video="Camera"
- Open second video device with name Camera :
-
-
$ ffmpeg -f dshow -video_device_number 1 -i video="Camera"
- Open video device Camera and audio device Microphone :
-
-
$ ffmpeg -f dshow -i video="Camera":audio="Microphone"
- Print the list of supported options in selected device and exit:
-
-
$ ffmpeg -list_options true -f dshow -i video="Camera"
-
-
-
-
20.5 dv1394# TOC
-
-
Linux DV 1394 input device.
-
-
-
20.6 fbdev# TOC
-
-
Linux framebuffer input device.
-
-
The Linux framebuffer is a graphic hardware-independent abstraction
-layer to show graphics on a computer monitor, typically on the
-console. It is accessed through a file device node, usually
-/dev/fb0 .
-
-
For more detailed information read the file
-Documentation/fb/framebuffer.txt included in the Linux source tree.
-
-
To record from the framebuffer device /dev/fb0 with
-ffmpeg:
-
-
ffmpeg -f fbdev -r 10 -i /dev/fb0 out.avi
-
-
-
You can take a single screenshot image with the command:
-
-
ffmpeg -f fbdev -frames:v 1 -r 1 -i /dev/fb0 screenshot.jpeg
-
-
-
See also http://linux-fbdev.sourceforge.net/ , and fbset(1).
-
-
-
20.7 gdigrab# TOC
-
-
Win32 GDI-based screen capture device.
-
-
This device allows you to capture a region of the display on Windows.
-
-
There are two options for the input filename:
-
-
or
-
-
-
The first option will capture the entire desktop, or a fixed region of the
-desktop. The second option will instead capture the contents of a single
-window, regardless of its position on the screen.
-
-
For example, to grab the entire desktop using ffmpeg:
-
-
ffmpeg -f gdigrab -framerate 6 -i desktop out.mpg
-
-
-
Grab a 640x480 region at position 10,20:
-
-
ffmpeg -f gdigrab -framerate 6 -offset_x 10 -offset_y 20 -video_size vga -i desktop out.mpg
-
-
-
Grab the contents of the window named "Calculator"
-
-
ffmpeg -f gdigrab -framerate 6 -i title=Calculator out.mpg
-
-
-
-
20.7.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. Use the value 0 to
-not draw the pointer. Default value is 1.
-
-framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-Note that show_region is incompatible with grabbing the contents
-of a single window.
-
-For example:
-
-
ffmpeg -f gdigrab -show_region 1 -framerate 6 -video_size cif -offset_x 10 -offset_y 20 -i desktop out.mpg
- video_size Set the video frame size. The default is to capture the full screen if desktop is selected, or the full window size if title=window_title is selected.
-
-offset_x When capturing a region with video_size , set the distance from the left edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned to the left of your primary monitor, you will need to use a negative offset_x value to move the region to that monitor.
-
-offset_y When capturing a region with video_size , set the distance from the top edge of the screen or desktop.
-
-Note that the offset calculation is from the top left corner of the primary monitor on Windows. If you have a monitor positioned above your primary monitor, you will need to use a negative offset_y value to move the region to that monitor.
-
-
-
-
-
20.8 iec61883# TOC
-
-
FireWire DV/HDV input device using libiec61883.
-
-
To enable this input device, you need libiec61883, libraw1394 and
-libavc1394 installed on your system. Use the configure option
---enable-libiec61883 to compile with the device enabled.
-
-
The iec61883 capture device supports capturing from a video device
-connected via IEEE1394 (FireWire), using libiec61883 and the new Linux
-FireWire stack (juju). This is the default DV/HDV input method in Linux
-Kernel 2.6.37 and later, since the old FireWire stack was removed.
-
-
Specify the FireWire port to be used as input file, or "auto"
-to choose the first port connected.
-
-
-
20.8.1 Options# TOC
-
-
-dvtype Override autodetection of DV/HDV. This should only be used if auto
-detection does not work, or if usage of a different device type
-should be prohibited. Treating a DV device as HDV (or vice versa) will
-not work and result in undefined behavior.
-The values auto , dv and hdv are supported.
-
-dvbuffer Set maximum size of buffer for incoming data, in frames. For DV, this
-is an exact value. For HDV, it is not frame exact, since HDV does
-not have a fixed frame size.
-
-dvguid Select the capture device by specifying it’s GUID. Capturing will only
-be performed from the specified device and fails if no device with the
-given GUID is found. This is useful to select the input if multiple
-devices are connected at the same time.
-Look at /sys/bus/firewire/devices to find out the GUIDs.
-
-
-
-
-
20.8.2 Examples# TOC
-
-
- Grab and show the input of a FireWire DV/HDV device.
-
-
ffplay -f iec61883 -i auto
- Grab and record the input of a FireWire DV/HDV device,
-using a packet buffer of 100000 packets if the source is HDV.
-
-
ffmpeg -f iec61883 -i auto -hdvbuffer 100000 out.mpg
-
-
-
-
20.9 jack# TOC
-
-
JACK input device.
-
-
To enable this input device during configuration you need libjack
-installed on your system.
-
-
A JACK input device creates one or more JACK writable clients, one for
-each audio channel, with name client_name :input_N , where
-client_name is the name provided by the application, and N
-is a number which identifies the channel.
-Each writable client will send the acquired data to the FFmpeg input
-device.
-
-
Once you have created one or more JACK readable clients, you need to
-connect them to one or more JACK writable clients.
-
-
To connect or disconnect JACK clients you can use the jack_connect
-and jack_disconnect programs, or do it through a graphical interface,
-for example with qjackctl.
-
-
To list the JACK clients and their properties you can invoke the command
-jack_lsp.
-
-
Follows an example which shows how to capture a JACK readable client
-with ffmpeg.
-
-
# Create a JACK writable client with name "ffmpeg".
-$ ffmpeg -f jack -i ffmpeg -y out.wav
-
-# Start the sample jack_metro readable client.
-$ jack_metro -b 120 -d 0.2 -f 4000
-
-# List the current JACK clients.
-$ jack_lsp -c
-system:capture_1
-system:capture_2
-system:playback_1
-system:playback_2
-ffmpeg:input_1
-metro:120_bpm
-
-# Connect metro to the ffmpeg writable client.
-$ jack_connect metro:120_bpm ffmpeg:input_1
-
-
-
For more information read:
-http://jackaudio.org/
-
-
-
20.10 lavfi# TOC
-
-
Libavfilter input virtual device.
-
-
This input device reads data from the open output pads of a libavfilter
-filtergraph.
-
-
For each filtergraph open output, the input device will create a
-corresponding stream which is mapped to the generated output. Currently
-only video data is supported. The filtergraph is specified through the
-option graph .
-
-
-
20.10.1 Options# TOC
-
-
-graph Specify the filtergraph to use as input. Each video open output must be
-labelled by a unique string of the form "outN ", where N is a
-number starting from 0 corresponding to the mapped input stream
-generated by the device.
-The first unlabelled output is automatically assigned to the "out0"
-label, but all the others need to be specified explicitly.
-
-The suffix "+subcc" can be appended to the output label to create an extra
-stream with the closed captions packets attached to that output
-(experimental; only for EIA-608 / CEA-708 for now).
-The subcc streams are created after all the normal streams, in the order of
-the corresponding stream.
-For example, if there is "out19+subcc", "out7+subcc" and up to "out42", the
-stream #43 is subcc for stream #7 and stream #44 is subcc for stream #19.
-
-If not specified defaults to the filename specified for the input
-device.
-
-graph_file Set the filename of the filtergraph to be read and sent to the other
-filters. Syntax of the filtergraph is the same as the one specified by
-the option graph .
-
-
-
-
-
20.10.2 Examples# TOC
-
-
- Create a color video stream and play it back with ffplay:
-
-
ffplay -f lavfi -graph "color=c=pink [out0]" dummy
- As the previous example, but use filename for specifying the graph
-description, and omit the "out0" label:
-
-
ffplay -f lavfi color=c=pink
- Create three different video test filtered sources and play them:
-
-
ffplay -f lavfi -graph "testsrc [out0]; testsrc,hflip [out1]; testsrc,negate [out2]" test3
- Read an audio stream from a file using the amovie source and play it
-back with ffplay:
-
-
ffplay -f lavfi "amovie=test.wav"
- Read an audio stream and a video stream and play it back with
-ffplay:
-
-
ffplay -f lavfi "movie=test.avi[out0];amovie=test.wav[out1]"
- Dump decoded frames to images and closed captions to a file (experimental):
-
-
ffmpeg -f lavfi -i "movie=test.ts[out0+subcc]" -map v frame%08d.png -map s -c copy -f rawvideo subcc.bin
-
-
-
-
20.11 libcdio# TOC
-
-
Audio-CD input device based on cdio.
-
-
To enable this input device during configuration you need libcdio
-installed on your system. Requires the configure option
---enable-libcdio.
-
-
This device allows playing and grabbing from an Audio-CD.
-
-
For example to copy with ffmpeg the entire Audio-CD in /dev/sr0,
-you may run the command:
-
-
ffmpeg -f libcdio -i /dev/sr0 cd.wav
-
-
-
-
20.12 libdc1394# TOC
-
-
IIDC1394 input device, based on libdc1394 and libraw1394.
-
-
Requires the configure option --enable-libdc1394.
-
-
-
20.13 openal# TOC
-
-
The OpenAL input device provides audio capture on all systems with a
-working OpenAL 1.1 implementation.
-
-
To enable this input device during configuration, you need OpenAL
-headers and libraries installed on your system, and need to configure
-FFmpeg with --enable-openal.
-
-
OpenAL headers and libraries should be provided as part of your OpenAL
-implementation, or as an additional download (an SDK). Depending on your
-installation you may need to specify additional flags via the
---extra-cflags and --extra-ldflags for allowing the build
-system to locate the OpenAL headers and libraries.
-
-
An incomplete list of OpenAL implementations follows:
-
-
-Creative The official Windows implementation, providing hardware acceleration
-with supported devices and software fallback.
-See http://openal.org/ .
-
OpenAL Soft Portable, open source (LGPL) software implementation. Includes
-backends for the most common sound APIs on the Windows, Linux,
-Solaris, and BSD operating systems.
-See http://kcat.strangesoft.net/openal.html .
-
Apple OpenAL is part of Core Audio, the official Mac OS X Audio interface.
-See http://developer.apple.com/technologies/mac/audio-and-video.html
-
-
-
This device allows one to capture from an audio input device handled
-through OpenAL.
-
-
You need to specify the name of the device to capture in the provided
-filename. If the empty string is provided, the device will
-automatically select the default device. You can get the list of the
-supported devices by using the option list_devices .
-
-
-
20.13.1 Options# TOC
-
-
-channels Set the number of channels in the captured audio. Only the values
-1 (monaural) and 2 (stereo) are currently supported.
-Defaults to 2 .
-
-sample_size Set the sample size (in bits) of the captured audio. Only the values
-8 and 16 are currently supported. Defaults to
-16 .
-
-sample_rate Set the sample rate (in Hz) of the captured audio.
-Defaults to 44.1k .
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-
-
-
-
20.13.2 Examples# TOC
-
-
Print the list of OpenAL supported devices and exit:
-
-
$ ffmpeg -list_devices true -f openal -i dummy out.ogg
-
-
-
Capture from the OpenAL device DR-BT101 via PulseAudio :
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out.ogg
-
-
-
Capture from the default device (note the empty string ” as filename):
-
-
$ ffmpeg -f openal -i '' out.ogg
-
-
-
Capture from two devices simultaneously, writing to two different files,
-within the same ffmpeg command:
-
-
$ ffmpeg -f openal -i 'DR-BT101 via PulseAudio' out1.ogg -f openal -i 'ALSA Default' out2.ogg
-
-
Note: not all OpenAL implementations support multiple simultaneous capture -
-try the latest OpenAL Soft if the above does not work.
-
-
-
20.14 oss# TOC
-
-
Open Sound System input device.
-
-
The filename to provide to the input device is the device node
-representing the OSS input device, and is usually set to
-/dev/dsp .
-
-
For example to grab from /dev/dsp using ffmpeg use the
-command:
-
-
ffmpeg -f oss -i /dev/dsp /tmp/oss.wav
-
-
-
For more information about OSS see:
-http://manuals.opensound.com/usersguide/dsp.html
-
-
-
20.15 pulse# TOC
-
-
PulseAudio input device.
-
-
To enable this output device you need to configure FFmpeg with --enable-libpulse.
-
-
The filename to provide to the input device is a source device or the
-string "default"
-
-
To list the PulseAudio source devices and their properties you can invoke
-the command pactl list sources.
-
-
More information about PulseAudio can be found on http://www.pulseaudio.org .
-
-
-
20.15.1 Options# TOC
-
-server Connect to a specific PulseAudio server, specified by an IP address.
-Default server is used when not provided.
-
-name Specify the application name PulseAudio will use when showing active clients,
-by default it is the LIBAVFORMAT_IDENT string.
-
-stream_name Specify the stream name PulseAudio will use when showing active streams,
-by default it is "record".
-
-sample_rate Specify the samplerate in Hz, by default 48kHz is used.
-
-channels Specify the channels in use, by default 2 (stereo) is set.
-
-frame_size Specify the number of bytes per frame, by default it is set to 1024.
-
-fragment_size Specify the minimal buffering fragment in PulseAudio, it will affect the
-audio latency. By default it is unset.
-
-
-
-
20.15.2 Examples# TOC
-
Record a stream from default device:
-
-
ffmpeg -f pulse -i default /tmp/pulse.wav
-
-
-
-
20.16 qtkit# TOC
-
-
QTKit input device.
-
-
The filename passed as input is parsed to contain either a device name or index.
-The device index can also be given by using -video_device_index.
-A given device index will override any given device name.
-If the desired device consists of numbers only, use -video_device_index to identify it.
-The default device will be chosen if an empty string or the device name "default" is given.
-The available devices can be enumerated by using -list_devices.
-
-
-
ffmpeg -f qtkit -i "0" out.mpg
-
-
-
-
ffmpeg -f qtkit -video_device_index 0 -i "" out.mpg
-
-
-
-
ffmpeg -f qtkit -i "default" out.mpg
-
-
-
-
ffmpeg -f qtkit -list_devices true -i ""
-
-
-
-
20.17 sndio# TOC
-
-
sndio input device.
-
-
To enable this input device during configuration you need libsndio
-installed on your system.
-
-
The filename to provide to the input device is the device node
-representing the sndio input device, and is usually set to
-/dev/audio0 .
-
-
For example to grab from /dev/audio0 using ffmpeg use the
-command:
-
-
ffmpeg -f sndio -i /dev/audio0 /tmp/oss.wav
-
-
-
-
20.18 video4linux2, v4l2# TOC
-
-
Video4Linux2 input video device.
-
-
"v4l2" can be used as alias for "video4linux2".
-
-
If FFmpeg is built with v4l-utils support (by using the
---enable-libv4l2 configure option), it is possible to use it with the
--use_libv4l2 input device option.
-
-
The name of the device to grab is a file device node, usually Linux
-systems tend to automatically create such nodes when the device
-(e.g. an USB webcam) is plugged into the system, and has a name of the
-kind /dev/videoN , where N is a number associated to
-the device.
-
-
Video4Linux2 devices usually support a limited set of
-width xheight sizes and frame rates. You can check which are
-supported using -list_formats all for Video4Linux2 devices.
-Some devices, like TV cards, support one or more standards. It is possible
-to list all the supported standards using -list_standards all.
-
-
The time base for the timestamps is 1 microsecond. Depending on the kernel
-version and configuration, the timestamps may be derived from the real time
-clock (origin at the Unix Epoch) or the monotonic clock (origin usually at
-boot time, unaffected by NTP or manual changes to the clock). The
--timestamps abs or -ts abs option can be used to force
-conversion into the real time clock.
-
-
Some usage examples of the video4linux2 device with ffmpeg
-and ffplay:
-
- Grab and show the input of a video4linux2 device:
-
-
ffplay -f video4linux2 -framerate 30 -video_size hd720 /dev/video0
- Grab and record the input of a video4linux2 device, leave the
-frame rate and size as previously set:
-
-
ffmpeg -f video4linux2 -input_format mjpeg -i /dev/video0 out.mpeg
-
-
-
For more information about Video4Linux, check http://linuxtv.org/ .
-
-
-
20.18.1 Options# TOC
-
-
-standard Set the standard. Must be the name of a supported standard. To get a
-list of the supported standards, use the list_standards
-option.
-
-channel Set the input channel number. Default to -1, which means using the
-previously selected channel.
-
-video_size Set the video frame size. The argument must be a string in the form
-WIDTH xHEIGHT or a valid size abbreviation.
-
-pixel_format Select the pixel format (only valid for raw video input).
-
-input_format Set the preferred pixel format (for raw video) or a codec name.
-This option allows one to select the input format, when several are
-available.
-
-framerate Set the preferred video frame rate.
-
-list_formats List available formats (supported pixel formats, codecs, and frame
-sizes) and exit.
-
-Available values are:
-
-‘all ’
-Show all available (compressed and non-compressed) formats.
-
-‘raw ’
-Show only raw video (non-compressed) formats.
-
-‘compressed ’
-Show only compressed formats.
-
-
-list_standards List supported standards and exit.
-
-Available values are:
-
-‘all ’
-Show all supported standards.
-
-
-timestamps, ts Set type of timestamps for grabbed frames.
-
-Available values are:
-
-‘default ’
-Use timestamps from the kernel.
-
-‘abs ’
-Use absolute timestamps (wall clock).
-
-‘mono2abs ’
-Force conversion from monotonic to absolute timestamps.
-
-
-Default value is default.
-
-
-
-
20.19 vfwcap# TOC
-
-
VfW (Video for Windows) capture input device.
-
-
The filename passed as input is the capture driver number, ranging from
-0 to 9. You may use "list" as filename to print a list of drivers. Any
-other filename will be interpreted as device number 0.
-
-
-
20.20 x11grab# TOC
-
-
X11 video input device.
-
-
Depends on X11, Xext, and Xfixes. Requires the configure option
---enable-x11grab.
-
-
This device allows one to capture a region of an X11 display.
-
-
The filename passed as input has the syntax:
-
-
[hostname ]:display_number .screen_number [+x_offset ,y_offset ]
-
-
-
hostname :display_number .screen_number specifies the
-X11 display name of the screen to grab from. hostname can be
-omitted, and defaults to "localhost". The environment variable
-DISPLAY contains the default display name.
-
-
x_offset and y_offset specify the offsets of the grabbed
-area with respect to the top-left border of the X11 screen. They
-default to 0.
-
-
Check the X11 documentation (e.g. man X) for more detailed information.
-
-
Use the dpyinfo program for getting basic information about the
-properties of your X11 display (e.g. grep for "name" or "dimensions").
-
-
For example to grab from :0.0 using ffmpeg:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0 out.mpg
-
-
-
Grab at position 10,20:
-
-
ffmpeg -f x11grab -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
-
-
-
-
20.20.1 Options# TOC
-
-
-draw_mouse Specify whether to draw the mouse pointer. A value of 0 specify
-not to draw the pointer. Default value is 1.
-
-follow_mouse Make the grabbed area follow the mouse. The argument can be
-centered or a number of pixels PIXELS .
-
-When it is specified with "centered", the grabbing region follows the mouse
-pointer and keeps the pointer at the center of region; otherwise, the region
-follows only when the mouse pointer reaches within PIXELS (greater than
-zero) to the edge of region.
-
-For example:
-
-
ffmpeg -f x11grab -follow_mouse centered -framerate 25 -video_size cif -i :0.0 out.mpg
- To follow only when the mouse pointer reaches within 100 pixels to edge:
-
-
ffmpeg -f x11grab -follow_mouse 100 -framerate 25 -video_size cif -i :0.0 out.mpg
- framerate Set the grabbing frame rate. Default value is ntsc,
-corresponding to a frame rate of 30000/1001.
-
-show_region Show grabbed region on screen.
-
-If show_region is specified with 1, then the grabbing
-region will be indicated on screen. With this option, it is easy to
-know what is being grabbed if only a portion of the screen is grabbed.
-
-For example:
-
-
ffmpeg -f x11grab -show_region 1 -framerate 25 -video_size cif -i :0.0+10,20 out.mpg
- With follow_mouse :
-
-
ffmpeg -f x11grab -follow_mouse centered -show_region 1 -framerate 25 -video_size cif -i :0.0 out.mpg
- video_size Set the video frame size. Default value is vga.
-
-use_shm Use the MIT-SHM extension for shared memory. Default value is 1.
-It may be necessary to disable it for remote displays.
-
-
-
-
20.21 decklink# TOC
-
-
The decklink input device provides capture capabilities for Blackmagic
-DeckLink devices.
-
-
To enable this input device, you need the Blackmagic DeckLink SDK and you
-need to configure with the appropriate --extra-cflags
-and --extra-ldflags.
-On Windows, you need to run the IDL files through widl.
-
-
DeckLink is very picky about the formats it supports. Pixel format is always
-uyvy422, framerate and video size must be determined for your device with
--list_formats 1. Audio sample rate is always 48 kHz and the number
-of channels currently is limited to 2 (stereo).
-
-
-
20.21.1 Options# TOC
-
-
-list_devices If set to true , print a list of devices and exit.
-Defaults to false .
-
-list_formats If set to true , print a list of supported formats and exit.
-Defaults to false .
-
-
-
-
-
20.21.2 Examples# TOC
-
-
- List input devices:
-
-
ffmpeg -f decklink -list_devices 1 -i dummy
- List supported formats:
-
-
ffmpeg -f decklink -list_formats 1 -i 'Intensity Pro'
- Capture video clip at 1080i50 (format 11):
-
-
ffmpeg -f decklink -i 'Intensity Pro@11' -acodec copy -vcodec copy output.avi
-
-
-
-
-
21 Resampler Options# TOC
-
-
The audio resampler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools, option =value for the aresample filter,
-by setting the value explicitly in the
-SwrContext options or using the libavutil/opt.h API for
-programmatic use.
-
-
-ich, in_channel_count Set the number of input channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-in_channel_layout is set.
-
-och, out_channel_count Set the number of output channels. Default value is 0. Setting this
-value is not mandatory if the corresponding channel layout
-out_channel_layout is set.
-
-uch, used_channel_count Set the number of used input channels. Default value is 0. This option is
-only used for special remapping.
-
-isr, in_sample_rate Set the input sample rate. Default value is 0.
-
-osr, out_sample_rate Set the output sample rate. Default value is 0.
-
-isf, in_sample_fmt Specify the input sample format. It is set by default to none.
-
-osf, out_sample_fmt Specify the output sample format. It is set by default to none.
-
-tsf, internal_sample_fmt Set the internal sample format. Default value is none.
-This will automatically be chosen when it is not explicitly set.
-
-icl, in_channel_layout ocl, out_channel_layout Set the input/output channel layout.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-clev, center_mix_level Set the center mix level. It is a value expressed in deciBel, and must be
-in the interval [-32,32].
-
-slev, surround_mix_level Set the surround mix level. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-lfe_mix_level Set LFE mix into non LFE level. It is used when there is a LFE input but no
-LFE output. It is a value expressed in deciBel, and must
-be in the interval [-32,32].
-
-rmvol, rematrix_volume Set rematrix volume. Default value is 1.0.
-
-rematrix_maxval Set maximum output value for rematrixing.
-This can be used to prevent clipping vs. preventing volumn reduction
-A value of 1.0 prevents cliping.
-
-flags, swr_flags Set flags used by the converter. Default value is 0.
-
-It supports the following individual flags:
-
-res force resampling, this flag forces resampling to be used even when the
-input and output sample rates match.
-
-
-dither_scale Set the dither scale. Default value is 1.
-
-dither_method Set dither method. Default value is 0.
-
-Supported values:
-
-‘rectangular ’
-select rectangular dither
-
‘triangular ’
-select triangular dither
-
‘triangular_hp ’
-select triangular dither with high pass
-
‘lipshitz ’
-select lipshitz noise shaping dither
-
‘shibata ’
-select shibata noise shaping dither
-
‘low_shibata ’
-select low shibata noise shaping dither
-
‘high_shibata ’
-select high shibata noise shaping dither
-
‘f_weighted ’
-select f-weighted noise shaping dither
-
‘modified_e_weighted ’
-select modified-e-weighted noise shaping dither
-
‘improved_e_weighted ’
-select improved-e-weighted noise shaping dither
-
-
-
-resampler Set resampling engine. Default value is swr.
-
-Supported values:
-
-‘swr ’
-select the native SW Resampler; filter options precision and cheby are not
-applicable in this case.
-
‘soxr ’
-select the SoX Resampler (where available); compensation, and filter options
-filter_size, phase_shift, filter_type & kaiser_beta, are not applicable in this
-case.
-
-
-filter_size For swr only, set resampling filter size, default value is 32.
-
-phase_shift For swr only, set resampling phase shift, default value is 10, and must be in
-the interval [0,30].
-
-linear_interp Use Linear Interpolation if set to 1, default value is 0.
-
-cutoff Set cutoff frequency (swr: 6dB point; soxr: 0dB point) ratio; must be a float
-value between 0 and 1. Default value is 0.97 with swr, and 0.91 with soxr
-(which, with a sample-rate of 44100, preserves the entire audio band to 20kHz).
-
-precision For soxr only, the precision in bits to which the resampled signal will be
-calculated. The default value of 20 (which, with suitable dithering, is
-appropriate for a destination bit-depth of 16) gives SoX’s ’High Quality’; a
-value of 28 gives SoX’s ’Very High Quality’.
-
-cheby For soxr only, selects passband rolloff none (Chebyshev) & higher-precision
-approximation for ’irrational’ ratios. Default value is 0.
-
-async For swr only, simple 1 parameter audio sync to timestamps using stretching,
-squeezing, filling and trimming. Setting this to 1 will enable filling and
-trimming, larger values represent the maximum amount in samples that the data
-may be stretched or squeezed for each second.
-Default value is 0, thus no compensation is applied to make the samples match
-the audio timestamps.
-
-first_pts For swr only, assume the first pts should be this value. The time unit is 1 / sample rate.
-This allows for padding/trimming at the start of stream. By default, no
-assumption is made about the first frame’s expected pts, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative pts due to encoder delay.
-
-min_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger stretching/squeezing/filling or trimming of the
-data to make it match the timestamps. The default is that
-stretching/squeezing/filling and trimming is disabled
-(min_comp = FLT_MAX).
-
-min_hard_comp For swr only, set the minimum difference between timestamps and audio data (in
-seconds) to trigger adding/dropping samples to make it match the
-timestamps. This option effectively is a threshold to select between
-hard (trim/fill) and soft (squeeze/stretch) compensation. Note that
-all compensation is by default disabled through min_comp .
-The default is 0.1.
-
-comp_duration For swr only, set duration (in seconds) over which data is stretched/squeezed
-to make it match the timestamps. Must be a non-negative double float value,
-default value is 1.0.
-
-max_soft_comp For swr only, set maximum factor by which data is stretched/squeezed to make it
-match the timestamps. Must be a non-negative double float value, default value
-is 0.
-
-matrix_encoding Select matrixed stereo encoding.
-
-It accepts the following values:
-
-‘none ’
-select none
-
‘dolby ’
-select Dolby
-
‘dplii ’
-select Dolby Pro Logic II
-
-
-Default value is none.
-
-filter_type For swr only, select resampling filter type. This only affects resampling
-operations.
-
-It accepts the following values:
-
-‘cubic ’
-select cubic
-
‘blackman_nuttall ’
-select Blackman Nuttall Windowed Sinc
-
‘kaiser ’
-select Kaiser Windowed Sinc
-
-
-kaiser_beta For swr only, set Kaiser Window Beta value. Must be an integer in the
-interval [2,16], default value is 9.
-
-output_sample_bits For swr only, set number of used output sample bits for dithering. Must be an integer in the
-interval [0,64], default value is 0, which means it’s not used.
-
-
-
-
-
22 Scaler Options# TOC
-
-
The video scaler supports the following named options.
-
-
Options may be set by specifying -option value in the
-FFmpeg tools. For programmatic use, they can be set explicitly in the
-SwsContext options or through the libavutil/opt.h API.
-
-
-
-
-sws_flags Set the scaler flags. This is also used to set the scaling
-algorithm. Only a single algorithm should be selected.
-
-It accepts the following values:
-
-‘fast_bilinear ’
-Select fast bilinear scaling algorithm.
-
-‘bilinear ’
-Select bilinear scaling algorithm.
-
-‘bicubic ’
-Select bicubic scaling algorithm.
-
-‘experimental ’
-Select experimental scaling algorithm.
-
-‘neighbor ’
-Select nearest neighbor rescaling algorithm.
-
-‘area ’
-Select averaging area rescaling algorithm.
-
-‘bicublin ’
-Select bicubic scaling algorithm for the luma component, bilinear for
-chroma components.
-
-‘gauss ’
-Select Gaussian rescaling algorithm.
-
-‘sinc ’
-Select sinc rescaling algorithm.
-
-‘lanczos ’
-Select lanczos rescaling algorithm.
-
-‘spline ’
-Select natural bicubic spline rescaling algorithm.
-
-‘print_info ’
-Enable printing/debug logging.
-
-‘accurate_rnd ’
-Enable accurate rounding.
-
-‘full_chroma_int ’
-Enable full chroma interpolation.
-
-‘full_chroma_inp ’
-Select full chroma input.
-
-‘bitexact ’
-Enable bitexact output.
-
-
-srcw Set source width.
-
-srch Set source height.
-
-dstw Set destination width.
-
-dsth Set destination height.
-
-src_format Set source pixel format (must be expressed as an integer).
-
-dst_format Set destination pixel format (must be expressed as an integer).
-
-src_range Select source range.
-
-dst_range Select destination range.
-
-param0, param1 Set scaling algorithm parameters. The specified values are specific of
-some scaling algorithms and ignored by others. The specified values
-are floating point number values.
-
-sws_dither Set the dithering algorithm. Accepts one of the following
-values. Default value is ‘auto ’.
-
-
-‘auto ’
-automatic choice
-
-‘none ’
-no dithering
-
-‘bayer ’
-bayer dither
-
-‘ed ’
-error diffusion dither
-
-‘a_dither ’
-arithmetic dither, based using addition
-
-‘x_dither ’
-arithmetic dither, based using xor (more random/less apparent patterning that
-a_dither).
-
-
-
-
-
-
-
23 Filtering Introduction# TOC
-
-
Filtering in FFmpeg is enabled through the libavfilter library.
-
-
In libavfilter, a filter can have multiple inputs and multiple
-outputs.
-To illustrate the sorts of things that are possible, we consider the
-following filtergraph.
-
-
-
[main]
-input --> split ---------------------> overlay --> output
- | ^
- |[tmp] [flip]|
- +-----> crop --> vflip -------+
-
-
-
This filtergraph splits the input stream in two streams, then sends one
-stream through the crop filter and the vflip filter, before merging it
-back with the other stream by overlaying it on top. You can use the
-following command to achieve this:
-
-
-
ffmpeg -i INPUT -vf "split [main][tmp]; [tmp] crop=iw:ih/2:0:0, vflip [flip]; [main][flip] overlay=0:H/2" OUTPUT
-
-
-
The result will be that the top half of the video is mirrored
-onto the bottom half of the output video.
-
-
Filters in the same linear chain are separated by commas, and distinct
-linear chains of filters are separated by semicolons. In our example,
-crop,vflip are in one linear chain, split and
-overlay are separately in another. The points where the linear
-chains join are labelled by names enclosed in square brackets. In the
-example, the split filter generates two outputs that are associated to
-the labels [main] and [tmp] .
-
-
The stream sent to the second output of split , labelled as
-[tmp] , is processed through the crop filter, which crops
-away the lower half part of the video, and then vertically flipped. The
-overlay filter takes in input the first unchanged output of the
-split filter (which was labelled as [main] ), and overlay on its
-lower half the output generated by the crop,vflip filterchain.
-
-
Some filters take in input a list of parameters: they are specified
-after the filter name and an equal sign, and are separated from each other
-by a colon.
-
-
There exist so-called source filters that do not have an
-audio/video input, and sink filters that will not have audio/video
-output.
-
-
-
-
24 graph2dot# TOC
-
-
The graph2dot program included in the FFmpeg tools
-directory can be used to parse a filtergraph description and issue a
-corresponding textual representation in the dot language.
-
-
Invoke the command:
-
-
-
to see how to use graph2dot .
-
-
You can then pass the dot description to the dot program (from
-the graphviz suite of programs) and obtain a graphical representation
-of the filtergraph.
-
-
For example the sequence of commands:
-
-
echo GRAPH_DESCRIPTION | \
-tools/graph2dot -o graph.tmp && \
-dot -Tpng graph.tmp -o graph.png && \
-display graph.png
-
-
-
can be used to create and display an image representing the graph
-described by the GRAPH_DESCRIPTION string. Note that this string must be
-a complete self-contained graph, with its inputs and outputs explicitly defined.
-For example if your command line is of the form:
-
-
ffmpeg -i infile -vf scale=640:360 outfile
-
-
your GRAPH_DESCRIPTION string will need to be of the form:
-
-
nullsrc,scale=640:360,nullsink
-
-
you may also need to set the nullsrc parameters and add a format
-filter in order to simulate a specific input file.
-
-
-
-
25 Filtergraph description# TOC
-
-
A filtergraph is a directed graph of connected filters. It can contain
-cycles, and there can be multiple links between a pair of
-filters. Each link has one input pad on one side connecting it to one
-filter from which it takes its input, and one output pad on the other
-side connecting it to one filter accepting its output.
-
-
Each filter in a filtergraph is an instance of a filter class
-registered in the application, which defines the features and the
-number of input and output pads of the filter.
-
-
A filter with no input pads is called a "source", and a filter with no
-output pads is called a "sink".
-
-
-
25.1 Filtergraph syntax# TOC
-
-
A filtergraph has a textual representation, which is
-recognized by the -filter /-vf and -filter_complex
-options in ffmpeg and -vf in ffplay, and by the
-avfilter_graph_parse()/avfilter_graph_parse2() functions defined in
-libavfilter/avfilter.h .
-
-
A filterchain consists of a sequence of connected filters, each one
-connected to the previous one in the sequence. A filterchain is
-represented by a list of ","-separated filter descriptions.
-
-
A filtergraph consists of a sequence of filterchains. A sequence of
-filterchains is represented by a list of ";"-separated filterchain
-descriptions.
-
-
A filter is represented by a string of the form:
-[in_link_1 ]...[in_link_N ]filter_name =arguments [out_link_1 ]...[out_link_M ]
-
-
filter_name is the name of the filter class of which the
-described filter is an instance of, and has to be the name of one of
-the filter classes registered in the program.
-The name of the filter class is optionally followed by a string
-"=arguments ".
-
-
arguments is a string which contains the parameters used to
-initialize the filter instance. It may have one of two forms:
-
- A ’:’-separated list of key=value pairs.
-
- A ’:’-separated list of value . In this case, the keys are assumed to be
-the option names in the order they are declared. E.g. the fade filter
-declares three options in this order – type , start_frame and
-nb_frames . Then the parameter list in:0:30 means that the value
-in is assigned to the option type , 0 to
-start_frame and 30 to nb_frames .
-
- A ’:’-separated list of mixed direct value and long key=value
-pairs. The direct value must precede the key=value pairs, and
-follow the same constraints order of the previous point. The following
-key=value pairs can be set in any preferred order.
-
-
-
-
If the option value itself is a list of items (e.g. the format filter
-takes a list of pixel formats), the items in the list are usually separated by
-’|’.
-
-
The list of arguments can be quoted using the character "’" as initial
-and ending mark, and the character ’\’ for escaping the characters
-within the quoted text; otherwise the argument string is considered
-terminated when the next special character (belonging to the set
-"[]=;,") is encountered.
-
-
The name and arguments of the filter are optionally preceded and
-followed by a list of link labels.
-A link label allows one to name a link and associate it to a filter output
-or input pad. The preceding labels in_link_1
-... in_link_N , are associated to the filter input pads,
-the following labels out_link_1 ... out_link_M , are
-associated to the output pads.
-
-
When two link labels with the same name are found in the
-filtergraph, a link between the corresponding input and output pad is
-created.
-
-
If an output pad is not labelled, it is linked by default to the first
-unlabelled input pad of the next filter in the filterchain.
-For example in the filterchain
-
-
nullsrc, split[L1], [L2]overlay, nullsink
-
-
the split filter instance has two output pads, and the overlay filter
-instance two input pads. The first output pad of split is labelled
-"L1", the first input pad of overlay is labelled "L2", and the second
-output pad of split is linked to the second input pad of overlay,
-which are both unlabelled.
-
-
In a complete filterchain all the unlabelled filter input and output
-pads must be connected. A filtergraph is considered valid if all the
-filter input and output pads of all the filterchains are connected.
-
-
Libavfilter will automatically insert scale filters where format
-conversion is required. It is possible to specify swscale flags
-for those automatically inserted scalers by prepending
-sws_flags=flags ;
-to the filtergraph description.
-
-
Here is a BNF description of the filtergraph syntax:
-
-
NAME ::= sequence of alphanumeric characters and '_'
-LINKLABEL ::= "[" NAME "]"
-LINKLABELS ::= LINKLABEL [LINKLABELS ]
-FILTER_ARGUMENTS ::= sequence of chars (possibly quoted)
-FILTER ::= [LINKLABELS ] NAME ["=" FILTER_ARGUMENTS ] [LINKLABELS ]
-FILTERCHAIN ::= FILTER [,FILTERCHAIN ]
-FILTERGRAPH ::= [sws_flags=flags ;] FILTERCHAIN [;FILTERGRAPH ]
-
-
-
-
25.2 Notes on filtergraph escaping# TOC
-
-
Filtergraph description composition entails several levels of
-escaping. See (ffmpeg-utils)the "Quoting and escaping"
-section in the ffmpeg-utils(1) manual for more
-information about the employed escaping procedure.
-
-
A first level escaping affects the content of each filter option
-value, which may contain the special character : used to
-separate values, or one of the escaping characters \'.
-
-
A second level escaping affects the whole filter description, which
-may contain the escaping characters \' or the special
-characters [],; used by the filtergraph description.
-
-
Finally, when you specify a filtergraph on a shell commandline, you
-need to perform a third level escaping for the shell special
-characters contained within it.
-
-
For example, consider the following string to be embedded in
-the drawtext filter description text value:
-
-
this is a 'string': may contain one, or more, special characters
-
-
-
This string contains the ' special escaping character, and the
-: special character, so it needs to be escaped in this way:
-
-
text=this is a \'string\'\: may contain one, or more, special characters
-
-
-
A second level of escaping is required when embedding the filter
-description in a filtergraph description, in order to escape all the
-filtergraph special characters. Thus the example above becomes:
-
-
drawtext=text=this is a \\\'string\\\'\\: may contain one\, or more\, special characters
-
-
(note that in addition to the \' escaping special characters,
-also , needs to be escaped).
-
-
Finally an additional level of escaping is needed when writing the
-filtergraph description in a shell command, which depends on the
-escaping rules of the adopted shell. For example, assuming that
-\ is special and needs to be escaped with another \, the
-previous string will finally result in:
-
-
-vf "drawtext=text=this is a \\\\\\'string\\\\\\'\\\\: may contain one\\, or more\\, special characters"
-
-
-
-
26 Timeline editing# TOC
-
-
Some filters support a generic enable option. For the filters
-supporting timeline editing, this option can be set to an expression which is
-evaluated before sending a frame to the filter. If the evaluation is non-zero,
-the filter will be enabled, otherwise the frame will be sent unchanged to the
-next filter in the filtergraph.
-
-
The expression accepts the following values:
-
-‘t ’
-timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-‘n ’
-sequential number of the input frame, starting from 0
-
-‘pos ’
-the position in the file of the input frame, NAN if unknown
-
-‘w ’
-‘h ’
-width and height of the input frame if video
-
-
-
Additionally, these filters support an enable command that can be used
-to re-define the expression.
-
-
Like any other filtering option, the enable option follows the same
-rules.
-
-
For example, to enable a blur filter (smartblur ) from 10 seconds to 3
-minutes, and a curves filter starting at 3 seconds:
-
-
smartblur = enable='between(t,10,3*60)',
-curves = enable='gte(t,3)' : preset=cross_process
-
-
-
-
-
27 Audio Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the audio filters included in your
-build.
-
-
Below is a description of the currently available audio filters.
-
-
-
27.1 adelay# TOC
-
-
Delay one or more audio channels.
-
-
Samples in delayed channel are filled with silence.
-
-
The filter accepts the following option:
-
-
-delays Set list of delays in milliseconds for each channel separated by ’|’.
-At least one delay greater than 0 should be provided.
-Unused delays will be silently ignored. If number of given delays is
-smaller than number of channels all remaining channels will not be delayed.
-
-
-
-
27.1.1 Examples# TOC
-
-
- Delay first channel by 1.5 seconds, the third channel by 0.5 seconds and leave
-the second channel (and any other channels that may be present) unchanged.
-
-
-
-
-
27.2 aecho# TOC
-
-
Apply echoing to the input audio.
-
-
Echoes are reflected sound and can occur naturally amongst mountains
-(and sometimes large buildings) when talking or shouting; digital echo
-effects emulate this behaviour and are often used to help fill out the
-sound of a single instrument or vocal. The time difference between the
-original signal and the reflection is the delay, and the
-loudness of the reflected signal is the decay.
-Multiple echoes can have different delays and decays.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain of reflected signal. Default is 0.6.
-
-out_gain Set output gain of reflected signal. Default is 0.3.
-
-delays Set list of time intervals in milliseconds between original signal and reflections
-separated by ’|’. Allowed range for each delay is (0 - 90000.0].
-Default is 1000.
-
-decays Set list of loudnesses of reflected signals separated by ’|’.
-Allowed range for each decay is (0 - 1.0].
-Default is 0.5.
-
-
-
-
27.2.1 Examples# TOC
-
-
- Make it sound as if there are twice as many instruments as are actually playing:
-
-
- If delay is very short, then it sound like a (metallic) robot playing music:
-
-
- A longer delay will sound like an open air concert in the mountains:
-
-
aecho=0.8:0.9:1000:0.3
- Same as above but with one more mountain:
-
-
aecho=0.8:0.9:1000|1800:0.3|0.25
-
-
-
-
27.3 aeval# TOC
-
-
Modify an audio signal according to the specified expressions.
-
-
This filter accepts one or more expressions (one for each channel),
-which are evaluated and used to modify a corresponding audio signal.
-
-
It accepts the following parameters:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. If
-the number of input channels is greater than the number of
-expressions, the last specified expression is used for the remaining
-output channels.
-
-channel_layout, c Set output channel layout. If not specified, the channel layout is
-specified by the number of expressions. If set to ‘same ’, it will
-use by default the same input channel layout.
-
-
-
Each expression in exprs can contain the following constants and functions:
-
-
-ch channel number of the current expression
-
-n number of the evaluated sample, starting from 0
-
-s sample rate
-
-t time of the evaluated sample expressed in seconds
-
-nb_in_channels nb_out_channels input and output number of channels
-
-val(CH) the value of input channel with number CH
-
-
-
Note: this filter is slow. For faster processing you should use a
-dedicated filter.
-
-
-
27.3.1 Examples# TOC
-
-
- Half volume:
-
-
aeval=val(ch)/2:c=same
- Invert phase of the second channel:
-
-
-
-
-
27.4 afade# TOC
-
-
Apply fade-in/out effect to input audio.
-
-
A description of the accepted parameters follows.
-
-
-type, t Specify the effect type, can be either in for fade-in, or
-out for a fade-out effect. Default is in.
-
-start_sample, ss Specify the number of the start sample for starting to apply the fade
-effect. Default is 0.
-
-nb_samples, ns Specify the number of samples for which the fade effect has to last. At
-the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence. Default is 44100.
-
-start_time, st Specify the start time of the fade effect. Default is 0.
-The value must be specified as a time duration; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-If set this option is used instead of start_sample .
-
-duration, d Specify the duration of the fade effect. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-At the end of the fade-in effect the output audio will have the same
-volume as the input audio, at the end of the fade-out transition
-the output audio will be silence.
-By default the duration is determined by nb_samples .
-If set this option is used instead of nb_samples .
-
-curve Set curve for fade transition.
-
-It accepts the following values:
-
-tri select triangular, linear slope (default)
-
qsin select quarter of sine wave
-
hsin select half of sine wave
-
esin select exponential sine wave
-
log select logarithmic
-
par select inverted parabola
-
qua select quadratic
-
cub select cubic
-
squ select square root
-
cbr select cubic root
-
-
-
-
-
27.4.1 Examples# TOC
-
-
- Fade in first 15 seconds of audio:
-
-
- Fade out last 25 seconds of a 900 seconds audio:
-
-
afade=t=out:st=875:d=25
-
-
-
-
27.5 aformat# TOC
-
-
Set output format constraints for the input audio. The framework will
-negotiate the most appropriate format to minimize conversions.
-
-
It accepts the following parameters:
-
-sample_fmts A ’|’-separated list of requested sample formats.
-
-sample_rates A ’|’-separated list of requested sample rates.
-
-channel_layouts A ’|’-separated list of requested channel layouts.
-
-See (ffmpeg-utils)the Channel Layout section in the ffmpeg-utils(1) manual
-for the required syntax.
-
-
-
If a parameter is omitted, all values are allowed.
-
-
Force the output to either unsigned 8-bit or signed 16-bit stereo
-
-
aformat=sample_fmts=u8|s16:channel_layouts=stereo
-
-
-
-
27.6 allpass# TOC
-
-
Apply a two-pole all-pass filter with central frequency (in Hz)
-frequency , and filter-width width .
-An all-pass filter changes the audio’s frequency to phase relationship
-without changing its frequency to amplitude relationship.
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.7 amerge# TOC
-
-
Merge two or more audio streams into a single multi-channel stream.
-
-
The filter accepts the following options:
-
-
-inputs Set the number of inputs. Default is 2.
-
-
-
-
If the channel layouts of the inputs are disjoint, and therefore compatible,
-the channel layout of the output will be set accordingly and the channels
-will be reordered as necessary. If the channel layouts of the inputs are not
-disjoint, the output will have all the channels of the first input then all
-the channels of the second input, in that order, and the channel layout of
-the output will be the default value corresponding to the total number of
-channels.
-
-
For example, if the first input is in 2.1 (FL+FR+LF) and the second input
-is FC+BL+BR, then the output will be in 5.1, with the channels in the
-following order: a1, a2, b1, a3, b2, b3 (a1 is the first channel of the
-first input, b1 is the first channel of the second input).
-
-
On the other hand, if both input are in stereo, the output channels will be
-in the default order: a1, a2, b1, b2, and the channel layout will be
-arbitrarily set to 4.0, which may or may not be the expected value.
-
-
All inputs must have the same sample rate, and format.
-
-
If inputs do not have the same duration, the output will stop with the
-shortest.
-
-
-
27.7.1 Examples# TOC
-
-
- Merge two mono files into a stereo stream:
-
-
amovie=left.wav [l] ; amovie=right.mp3 [r] ; [l] [r] amerge
- Multiple merges assuming 1 video stream and 6 audio streams in input.mkv :
-
-
ffmpeg -i input.mkv -filter_complex "[0:1][0:2][0:3][0:4][0:5][0:6] amerge=inputs=6" -c:a pcm_s16le output.mkv
-
-
-
-
27.8 amix# TOC
-
-
Mixes multiple audio inputs into a single output.
-
-
Note that this filter only supports float samples (the amerge
-and pan audio filters support many formats). If the amix
-input has integer samples then aresample will be automatically
-inserted to perform the conversion to float samples.
-
-
For example
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex amix=inputs=3:duration=first:dropout_transition=3 OUTPUT
-
-
will mix 3 input audio streams to a single output with the same duration as the
-first input and a dropout transition time of 3 seconds.
-
-
It accepts the following parameters:
-
-inputs The number of inputs. If unspecified, it defaults to 2.
-
-duration How to determine the end-of-stream.
-
-longest The duration of the longest input. (default)
-
-shortest The duration of the shortest input.
-
-first The duration of the first input.
-
-
-
-dropout_transition The transition time, in seconds, for volume renormalization when an input
-stream ends. The default value is 2 seconds.
-
-
-
-
-
27.9 anull# TOC
-
-
Pass the audio source unchanged to the output.
-
-
-
27.10 apad# TOC
-
-
Pad the end of an audio stream with silence.
-
-
This can be used together with ffmpeg -shortest to
-extend audio streams to the same length as the video stream.
-
-
A description of the accepted options follows.
-
-
-packet_size Set silence packet size. Default value is 4096.
-
-pad_len Set the number of samples of silence to add to the end. After the
-value is reached, the stream is terminated. This option is mutually
-exclusive with whole_len .
-
-whole_len Set the minimum total number of samples in the output audio stream. If
-the value is longer than the input audio length, silence is added to
-the end, until the value is reached. This option is mutually exclusive
-with pad_len .
-
-
-
If neither the pad_len nor the whole_len option is
-set, the filter will add silence to the end of the input stream
-indefinitely.
-
-
-
27.10.1 Examples# TOC
-
-
- Add 1024 samples of silence to the end of the input:
-
-
- Make sure the audio output will contain at least 10000 samples, pad
-the input with silence if required:
-
-
- Use ffmpeg to pad the audio input with silence, so that the
-video stream will always result the shortest and will be converted
-until the end in the output file when using the shortest
-option:
-
-
ffmpeg -i VIDEO -i AUDIO -filter_complex "[1:0]apad" -shortest OUTPUT
-
-
-
-
27.11 aphaser# TOC
-
Add a phasing effect to the input audio.
-
-
A phaser filter creates series of peaks and troughs in the frequency spectrum.
-The position of the peaks and troughs are modulated so that they vary over time, creating a sweeping effect.
-
-
A description of the accepted parameters follows.
-
-
-in_gain Set input gain. Default is 0.4.
-
-out_gain Set output gain. Default is 0.74
-
-delay Set delay in milliseconds. Default is 3.0.
-
-decay Set decay. Default is 0.4.
-
-speed Set modulation speed in Hz. Default is 0.5.
-
-type Set modulation type. Default is triangular.
-
-It accepts the following values:
-
-‘triangular, t ’
-‘sinusoidal, s ’
-
-
-
-
-
27.12 aresample# TOC
-
-
Resample the input audio to the specified parameters, using the
-libswresample library. If none are specified then the filter will
-automatically convert between its input and output.
-
-
This filter is also able to stretch/squeeze the audio data to make it match
-the timestamps or to inject silence / cut out audio to make it match the
-timestamps, do a combination of both or do neither.
-
-
The filter accepts the syntax
-[sample_rate :]resampler_options , where sample_rate
-expresses a sample rate and resampler_options is a list of
-key =value pairs, separated by ":". See the
-ffmpeg-resampler manual for the complete list of supported options.
-
-
-
27.12.1 Examples# TOC
-
-
- Resample the input audio to 44100Hz:
-
-
- Stretch/squeeze samples to the given timestamps, with a maximum of 1000
-samples per second compensation:
-
-
-
-
-
27.13 asetnsamples# TOC
-
-
Set the number of samples per each output audio frame.
-
-
The last output packet may contain a different number of samples, as
-the filter will flush all the remaining samples when the input audio
-signal its end.
-
-
The filter accepts the following options:
-
-
-nb_out_samples, n Set the number of frames per each output audio frame. The number is
-intended as the number of samples per each channel .
-Default value is 1024.
-
-pad, p If set to 1, the filter will pad the last audio frame with zeroes, so
-that the last frame will contain the same number of samples as the
-previous ones. Default value is 1.
-
-
-
For example, to set the number of per-frame samples to 1234 and
-disable padding for the last frame, use:
-
-
asetnsamples=n=1234:p=0
-
-
-
-
27.14 asetrate# TOC
-
-
Set the sample rate without altering the PCM data.
-This will result in a change of speed and pitch.
-
-
The filter accepts the following options:
-
-
-sample_rate, r Set the output sample rate. Default is 44100 Hz.
-
-
-
-
27.15 ashowinfo# TOC
-
-
Show a line containing various information for each input audio frame.
-The input audio is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The presentation timestamp of the input frame, in time base units; the time base
-depends on the filter input pad, and is usually 1/sample_rate .
-
-pts_time The presentation timestamp of the input frame in seconds.
-
-pos position of the frame in the input stream, -1 if this information in
-unavailable and/or meaningless (for example in case of synthetic audio)
-
-fmt The sample format.
-
-chlayout The channel layout.
-
-rate The sample rate for the audio frame.
-
-nb_samples The number of samples (per channel) in the frame.
-
-checksum The Adler-32 checksum (printed in hexadecimal) of the audio data. For planar
-audio, the data is treated as if all the planes were concatenated.
-
-plane_checksums A list of Adler-32 checksums for each data plane.
-
-
-
-
27.16 astats# TOC
-
-
Display time domain statistical information about the audio channels.
-Statistics are calculated and displayed for each audio channel and,
-where applicable, an overall figure is also given.
-
-
It accepts the following option:
-
-length Short window length in seconds, used for peak and trough RMS measurement.
-Default is 0.05 (50 milliseconds). Allowed range is [0.1 - 10].
-
-
-
A description of each shown parameter follows:
-
-
-DC offset Mean amplitude displacement from zero.
-
-Min level Minimal sample level.
-
-Max level Maximal sample level.
-
-Peak level dB RMS level dB Standard peak and RMS level measured in dBFS.
-
-RMS peak dB RMS trough dB Peak and trough values for RMS level measured over a short window.
-
-Crest factor Standard ratio of peak to RMS level (note: not in dB).
-
-Flat factor Flatness (i.e. consecutive samples with the same value) of the signal at its peak levels
-(i.e. either Min level or Max level ).
-
-Peak count Number of occasions (not the number of samples) that the signal attained either
-Min level or Max level .
-
-
-
-
27.17 astreamsync# TOC
-
-
Forward two audio streams and control the order the buffers are forwarded.
-
-
The filter accepts the following options:
-
-
-expr, e Set the expression deciding which stream should be
-forwarded next: if the result is negative, the first stream is forwarded; if
-the result is positive or zero, the second stream is forwarded. It can use
-the following variables:
-
-
-b1 b2 number of buffers forwarded so far on each stream
-
s1 s2 number of samples forwarded so far on each stream
-
t1 t2 current timestamp of each stream
-
-
-The default value is t1-t2, which means to always forward the stream
-that has a smaller timestamp.
-
-
-
-
27.17.1 Examples# TOC
-
-
Stress-test amerge by randomly sending buffers on the wrong
-input, while avoiding too much of a desynchronization:
-
-
amovie=file.ogg [a] ; amovie=file.mp3 [b] ;
-[a] [b] astreamsync=(2*random(1))-1+tanh(5*(t1-t2)) [a2] [b2] ;
-[a2] [b2] amerge
-
-
-
-
27.18 asyncts# TOC
-
-
Synchronize audio data with timestamps by squeezing/stretching it and/or
-dropping samples/adding silence when needed.
-
-
This filter is not built by default, please use aresample to do squeezing/stretching.
-
-
It accepts the following parameters:
-
-compensate Enable stretching/squeezing the data to make it match the timestamps. Disabled
-by default. When disabled, time gaps are covered with silence.
-
-min_delta The minimum difference between timestamps and audio data (in seconds) to trigger
-adding/dropping samples. The default value is 0.1. If you get an imperfect
-sync with this filter, try setting this parameter to 0.
-
-max_comp The maximum compensation in samples per second. Only relevant with compensate=1.
-The default value is 500.
-
-first_pts Assume that the first PTS should be this value. The time base is 1 / sample
-rate. This allows for padding/trimming at the start of the stream. By default,
-no assumption is made about the first frame’s expected PTS, so no padding or
-trimming is done. For example, this could be set to 0 to pad the beginning with
-silence if an audio stream starts after the video stream or to trim any samples
-with a negative PTS due to encoder delay.
-
-
-
-
-
27.19 atempo# TOC
-
-
Adjust audio tempo.
-
-
The filter accepts exactly one parameter, the audio tempo. If not
-specified then the filter will assume nominal 1.0 tempo. Tempo must
-be in the [0.5, 2.0] range.
-
-
-
27.19.1 Examples# TOC
-
-
- Slow down audio to 80% tempo:
-
-
- To speed up audio to 125% tempo:
-
-
-
-
-
27.20 atrim# TOC
-
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Timestamp (in seconds) of the start of the section to keep. I.e. the audio
-sample with the timestamp start will be the first sample in the output.
-
-end Specify time of the first audio sample that will be dropped, i.e. the
-audio sample immediately preceding the one with the timestamp end will be
-the last sample in the output.
-
-start_pts Same as start , except this option sets the start timestamp in samples
-instead of seconds.
-
-end_pts Same as end , except this option sets the end timestamp in samples instead
-of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_sample The number of the first sample that should be output.
-
-end_sample The number of the first sample that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual .
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _sample options simply count the
-samples that pass through the filter. So start/end_pts and start/end_sample will
-give different results when the timestamps are wrong, inexact or do not start at
-zero. Also note that this filter does not modify the timestamps. If you wish
-to have the output timestamps start at zero, insert the asetpts filter after the
-atrim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all samples that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple atrim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -af atrim=60:120
- Keep only the first 1000 samples:
-
-
ffmpeg -i INPUT -af atrim=end_sample=1000
-
-
-
-
27.21 bandpass# TOC
-
-
Apply a two-pole Butterworth band-pass filter with central
-frequency frequency , and (3dB-point) band-width width.
-The csg option selects a constant skirt gain (peak gain = Q)
-instead of the default: constant 0dB peak gain.
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-csg Constant skirt gain if set to 1. Defaults to 0.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.22 bandreject# TOC
-
-
Apply a two-pole Butterworth band-reject filter with central
-frequency frequency , and (3dB-point) band-width width .
-The filter roll off at 6dB per octave (20dB per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency. Default is 3000.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-
-
-
27.23 bass# TOC
-
-
Boost or cut the bass (lower) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at 0 Hz. Its useful range is about -20
-(for a large cut) to +20 (for a large boost).
-Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 100 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
27.24 biquad# TOC
-
-
Apply a biquad IIR filter with the given coefficients.
-Where b0 , b1 , b2 and a0 , a1 , a2
-are the numerator and denominator coefficients respectively.
-
-
-
27.25 bs2b# TOC
-
Bauer stereo to binaural transformation, which improves headphone listening of
-stereo audio records.
-
-
It accepts the following parameters:
-
-profile Pre-defined crossfeed level.
-
-default Default level (fcut=700, feed=50).
-
-cmoy Chu Moy circuit (fcut=700, feed=60).
-
-jmeier Jan Meier circuit (fcut=650, feed=95).
-
-
-
-fcut Cut frequency (in Hz).
-
-feed Feed level (in Hz).
-
-
-
-
-
27.26 channelmap# TOC
-
-
Remap input channels to new locations.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the output stream.
-
-map Map channels from input to output. The argument is a ’|’-separated list of
-mappings, each in the in_channel -out_channel in_channel form. in_channel can be either the name of the input
-channel (e.g. FL for front left) or its index in the input channel layout.
-out_channel is the name of the output channel or its index in the output
-channel layout. If out_channel is not given then it is implicitly an
-index, starting with zero and increasing by one for each mapping.
-
-
-
If no mapping is present, the filter will implicitly map input channels to
-output channels, preserving indices.
-
-
For example, assuming a 5.1+downmix input MOV file,
-
-
ffmpeg -i in.mov -filter 'channelmap=map=DL-FL|DR-FR' out.wav
-
-
will create an output WAV file tagged as stereo from the downmix channels of
-the input.
-
-
To fix a 5.1 WAV improperly encoded in AAC’s native channel order
-
-
ffmpeg -i in.wav -filter 'channelmap=1|2|0|5|3|4:channel_layout=5.1' out.wav
-
-
-
-
27.27 channelsplit# TOC
-
-
Split each channel from an input audio stream into a separate output stream.
-
-
It accepts the following parameters:
-
-channel_layout The channel layout of the input stream. The default is "stereo".
-
-
-
For example, assuming a stereo input MP3 file,
-
-
ffmpeg -i in.mp3 -filter_complex channelsplit out.mkv
-
-
will create an output Matroska file with two audio streams, one containing only
-the left channel and the other the right channel.
-
-
Split a 5.1 WAV file into per-channel files:
-
-
ffmpeg -i in.wav -filter_complex
-'channelsplit=channel_layout=5.1[FL][FR][FC][LFE][SL][SR]'
--map '[FL]' front_left.wav -map '[FR]' front_right.wav -map '[FC]'
-front_center.wav -map '[LFE]' lfe.wav -map '[SL]' side_left.wav -map '[SR]'
-side_right.wav
-
-
-
-
27.28 compand# TOC
-
Compress or expand the audio’s dynamic range.
-
-
It accepts the following parameters:
-
-
-attacks decays A list of times in seconds for each channel over which the instantaneous level
-of the input signal is averaged to determine its volume. attacks refers to
-increase of volume and decays refers to decrease of volume. For most
-situations, the attack time (response to the audio getting louder) should be
-shorter than the decay time, because the human ear is more sensitive to sudden
-loud audio than sudden soft audio. A typical value for attack is 0.3 seconds and
-a typical value for decay is 0.8 seconds.
-
-points A list of points for the transfer function, specified in dB relative to the
-maximum possible signal amplitude. Each key points list must be defined using
-the following syntax: x0/y0|x1/y1|x2/y2|.... or
-x0/y0 x1/y1 x2/y2 ....
-
-The input values must be in strictly increasing order but the transfer function
-does not have to be monotonically rising. The point 0/0 is assumed but
-may be overridden (by 0/out-dBn). Typical values for the transfer
-function are -70/-70|-60/-20.
-
-soft-knee Set the curve radius in dB for all joints. It defaults to 0.01.
-
-gain Set the additional gain in dB to be applied at all points on the transfer
-function. This allows for easy adjustment of the overall gain.
-It defaults to 0.
-
-volume Set an initial volume, in dB, to be assumed for each channel when filtering
-starts. This permits the user to supply a nominal level initially, so that, for
-example, a very large gain is not applied to initial signal levels before the
-companding has begun to operate. A typical value for audio which is initially
-quiet is -90 dB. It defaults to 0.
-
-delay Set a delay, in seconds. The input audio is analyzed immediately, but audio is
-delayed before being fed to the volume adjuster. Specifying a delay
-approximately equal to the attack/decay times allows the filter to effectively
-operate in predictive rather than reactive mode. It defaults to 0.
-
-
-
-
-
27.28.1 Examples# TOC
-
-
- Make music with both quiet and loud passages suitable for listening to in a
-noisy environment:
-
-
compand=.3|.3:1|1:-90/-60|-60/-40|-40/-30|-20/-20:6:0:-90:0.2
- A noise gate for when the noise is at a lower level than the signal:
-
-
compand=.1|.1:.2|.2:-900/-900|-50.1/-900|-50/-50:.01:0:-90:.1
- Here is another noise gate, this time for when the noise is at a higher level
-than the signal (making it, in some ways, similar to squelch):
-
-
compand=.1|.1:.1|.1:-45.1/-45.1|-45/-900|0/-900:.01:45:-90:.1
-
-
-
-
27.29 earwax# TOC
-
-
Make audio easier to listen to on headphones.
-
-
This filter adds ‘cues’ to 44.1kHz stereo (i.e. audio CD format) audio
-so that when listened to on headphones the stereo image is moved from
-inside your head (standard for headphones) to outside and in front of
-the listener (standard for speakers).
-
-
Ported from SoX.
-
-
-
27.30 equalizer# TOC
-
-
Apply a two-pole peaking equalisation (EQ) filter. With this
-filter, the signal-level at and around a selected frequency can
-be increased or decreased, whilst (unlike bandpass and bandreject
-filters) that at all other frequencies is unchanged.
-
-
In order to produce complex equalisation curves, this filter can
-be given several times, each with a different central frequency.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the filter’s central frequency in Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-
-gain, g Set the required gain or attenuation in dB.
-Beware of clipping when using a positive gain.
-
-
-
-
27.30.1 Examples# TOC
-
- Attenuate 10 dB at 1000 Hz, with a bandwidth of 200 Hz:
-
-
equalizer=f=1000:width_type=h:width=200:g=-10
- Apply 2 dB gain at 1000 Hz with Q 1 and attenuate 5 dB at 100 Hz with Q 2:
-
-
equalizer=f=1000:width_type=q:width=1:g=2,equalizer=f=100:width_type=q:width=2:g=-5
-
-
-
-
27.31 flanger# TOC
-
Apply a flanging effect to the audio.
-
-
The filter accepts the following options:
-
-
-delay Set base delay in milliseconds. Range from 0 to 30. Default value is 0.
-
-depth Set added swep delay in milliseconds. Range from 0 to 10. Default value is 2.
-
-regen Set percentage regeneration (delayed signal feedback). Range from -95 to 95.
-Default value is 0.
-
-width Set percentage of delayed signal mixed with original. Range from 0 to 100.
-Default value is 71.
-
-speed Set sweeps per second (Hz). Range from 0.1 to 10. Default value is 0.5.
-
-shape Set swept wave shape, can be triangular or sinusoidal .
-Default value is sinusoidal .
-
-phase Set swept wave percentage-shift for multi channel. Range from 0 to 100.
-Default value is 25.
-
-interp Set delay-line interpolation, linear or quadratic .
-Default is linear .
-
-
-
-
27.32 highpass# TOC
-
-
Apply a high-pass filter with 3dB point frequency.
-The filter can be either single-pole, or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 3000.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
27.33 join# TOC
-
-
Join multiple input streams into one multi-channel stream.
-
-
It accepts the following parameters:
-
-inputs The number of input streams. It defaults to 2.
-
-channel_layout The desired output channel layout. It defaults to stereo.
-
-map Map channels from inputs to output. The argument is a ’|’-separated list of
-mappings, each in the input_idx .in_channel -out_channel input_idx is the 0-based index of the input stream. in_channel
-can be either the name of the input channel (e.g. FL for front left) or its
-index in the specified input stream. out_channel is the name of the output
-channel.
-
-
-
The filter will attempt to guess the mappings when they are not specified
-explicitly. It does so by first trying to find an unused matching input channel
-and if that fails it picks the first unused input channel.
-
-
Join 3 inputs (with properly set channel layouts):
-
-
ffmpeg -i INPUT1 -i INPUT2 -i INPUT3 -filter_complex join=inputs=3 OUTPUT
-
-
-
Build a 5.1 output from 6 single-channel streams:
-
-
ffmpeg -i fl -i fr -i fc -i sl -i sr -i lfe -filter_complex
-'join=inputs=6:channel_layout=5.1:map=0.0-FL|1.0-FR|2.0-FC|3.0-SL|4.0-SR|5.0-LFE'
-out
-
-
-
-
27.34 ladspa# TOC
-
-
Load a LADSPA (Linux Audio Developer’s Simple Plugin API) plugin.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-ladspa.
-
-
-file, f Specifies the name of LADSPA plugin library to load. If the environment
-variable LADSPA_PATH is defined, the LADSPA plugin is searched in
-each one of the directories specified by the colon separated list in
-LADSPA_PATH, otherwise in the standard LADSPA paths, which are in
-this order: HOME/.ladspa/lib/ , /usr/local/lib/ladspa/ ,
-/usr/lib/ladspa/ .
-
-plugin, p Specifies the plugin within the library. Some libraries contain only
-one plugin, but others contain many of them. If this is not set filter
-will list all available plugins within the specified library.
-
-controls, c Set the ’|’ separated list of controls which are zero or more floating point
-values that determine the behavior of the loaded plugin (for example delay,
-threshold or gain).
-Controls need to be defined using the following syntax:
-c0=value0 |c1=value1 |c2=value2 |..., where
-valuei is the value set on the i -th control.
-If controls is set to help, all available controls and
-their valid ranges are printed.
-
-sample_rate, s Specify the sample rate, default to 44100. Only used if plugin have
-zero inputs.
-
-nb_samples, n Set the number of samples per channel per each output frame, default
-is 1024. Only used if plugin have zero inputs.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified duration,
-as the generated audio is always cut at the end of a complete frame.
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-Only used if plugin have zero inputs.
-
-
-
-
-
27.34.1 Examples# TOC
-
-
- List all available plugins within amp (LADSPA example plugin) library:
-
-
- List all available controls and their valid ranges for vcf_notch
-plugin from VCF library:
-
-
ladspa=f=vcf:p=vcf_notch:c=help
- Simulate low quality audio equipment using Computer Music Toolkit (CMT)
-plugin library:
-
-
ladspa=file=cmt:plugin=lofi:controls=c0=22|c1=12|c2=12
- Add reverberation to the audio using TAP-plugins
-(Tom’s Audio Processing plugins):
-
-
ladspa=file=tap_reverb:tap_reverb
- Generate white noise, with 0.2 amplitude:
-
-
ladspa=file=cmt:noise_source_white:c=c0=.2
- Generate 20 bpm clicks using plugin C* Click - Metronome from the
-C* Audio Plugin Suite (CAPS) library:
-
-
ladspa=file=caps:Click:c=c1=20'
- Apply C* Eq10X2 - Stereo 10-band equaliser effect:
-
-
ladspa=caps:Eq10X2:c=c0=-48|c9=-24|c3=12|c4=2
-
-
-
-
27.34.2 Commands# TOC
-
-
This filter supports the following commands:
-
-cN Modify the N -th control value.
-
-If the specified value is not valid, it is ignored and prior one is kept.
-
-
-
-
27.35 lowpass# TOC
-
-
Apply a low-pass filter with 3dB point frequency.
-The filter can be either single-pole or double-pole (the default).
-The filter roll off at 6dB per pole per octave (20dB per pole per decade).
-
-
The filter accepts the following options:
-
-
-frequency, f Set frequency in Hz. Default is 500.
-
-poles, p Set number of poles. Default is 2.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Specify the band-width of a filter in width_type units.
-Applies only to double-pole filter.
-The default is 0.707q and gives a Butterworth response.
-
-
-
-
27.36 pan# TOC
-
-
Mix channels with specific gain levels. The filter accepts the output
-channel layout followed by a set of channels definitions.
-
-
This filter is also designed to efficiently remap the channels of an audio
-stream.
-
-
The filter accepts parameters of the form:
-"l |outdef |outdef |..."
-
-
-l output channel layout or number of channels
-
-outdef output channel specification, of the form:
-"out_name =[gain *]in_name [+[gain *]in_name ...]"
-
-out_name output channel to define, either a channel name (FL, FR, etc.) or a channel
-number (c0, c1, etc.)
-
-gain multiplicative coefficient for the channel, 1 leaving the volume unchanged
-
-in_name input channel to use, see out_name for details; it is not possible to mix
-named and numbered input channels
-
-
-
If the ‘=’ in a channel specification is replaced by ‘<’, then the gains for
-that specification will be renormalized so that the total is 1, thus
-avoiding clipping noise.
-
-
-
27.36.1 Mixing examples# TOC
-
-
For example, if you want to down-mix from stereo to mono, but with a bigger
-factor for the left channel:
-
-
pan=1c|c0=0.9*c0+0.1*c1
-
-
-
A customized down-mix to stereo that works automatically for 3-, 4-, 5- and
-7-channels surround:
-
-
pan=stereo| FL < FL + 0.5*FC + 0.6*BL + 0.6*SL | FR < FR + 0.5*FC + 0.6*BR + 0.6*SR
-
-
-
Note that ffmpeg integrates a default down-mix (and up-mix) system
-that should be preferred (see "-ac" option) unless you have very specific
-needs.
-
-
-
27.36.2 Remapping examples# TOC
-
-
The channel remapping will be effective if, and only if:
-
-
- gain coefficients are zeroes or ones,
- only one input per channel output,
-
-
-
If all these conditions are satisfied, the filter will notify the user ("Pure
-channel mapping detected"), and use an optimized and lossless method to do the
-remapping.
-
-
For example, if you have a 5.1 source and want a stereo audio stream by
-dropping the extra channels:
-
-
pan="stereo| c0=FL | c1=FR"
-
-
-
Given the same source, you can also switch front left and front right channels
-and keep the input channel layout:
-
-
pan="5.1| c0=c1 | c1=c0 | c2=c2 | c3=c3 | c4=c4 | c5=c5"
-
-
-
If the input is a stereo audio stream, you can mute the front left channel (and
-still keep the stereo channel layout) with:
-
-
-
Still with a stereo audio stream input, you can copy the right channel in both
-front left and right:
-
-
pan="stereo| c0=FR | c1=FR"
-
-
-
-
27.37 replaygain# TOC
-
-
ReplayGain scanner filter. This filter takes an audio stream as an input and
-outputs it unchanged.
-At end of filtering it displays track_gain and track_peak.
-
-
-
27.38 resample# TOC
-
-
Convert the audio sample format, sample rate and channel layout. It is
-not meant to be used directly.
-
-
-
27.39 silencedetect# TOC
-
-
Detect silence in an audio stream.
-
-
This filter logs a message when it detects that the input audio volume is less
-or equal to a noise tolerance value for a duration greater or equal to the
-minimum detected noise duration.
-
-
The printed times and duration are expressed in seconds.
-
-
The filter accepts the following options:
-
-
-duration, d Set silence duration until notification (default is 2 seconds).
-
-noise, n Set noise tolerance. Can be specified in dB (in case "dB" is appended to the
-specified value) or amplitude ratio. Default is -60dB, or 0.001.
-
-
-
-
27.39.1 Examples# TOC
-
-
- Detect 5 seconds of silence with -50dB noise tolerance:
-
-
silencedetect=n=-50dB:d=5
- Complete example with ffmpeg to detect silence with 0.0001 noise
-tolerance in silence.mp3 :
-
-
ffmpeg -i silence.mp3 -af silencedetect=noise=0.0001 -f null -
-
-
-
-
27.40 silenceremove# TOC
-
-
Remove silence from the beginning, middle or end of the audio.
-
-
The filter accepts the following options:
-
-
-start_periods This value is used to indicate if audio should be trimmed at beginning of
-the audio. A value of zero indicates no silence should be trimmed from the
-beginning. When specifying a non-zero value, it trims audio up until it
-finds non-silence. Normally, when trimming silence from beginning of audio
-the start_periods will be 1 but it can be increased to higher
-values to trim all audio up to specific count of non-silence periods.
-Default value is 0.
-
-start_duration Specify the amount of time that non-silence must be detected before it stops
-trimming audio. By increasing the duration, bursts of noises can be treated
-as silence and trimmed off. Default value is 0.
-
-start_threshold This indicates what sample value should be treated as silence. For digital
-audio, a value of 0 may be fine but for audio recorded from analog,
-you may wish to increase the value to account for background noise.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-stop_periods Set the count for trimming silence from the end of audio.
-To remove silence from the middle of a file, specify a stop_periods
-that is negative. This value is then treated as a positive value and is
-used to indicate the effect should restart processing as specified by
-start_periods , making it suitable for removing periods of silence
-in the middle of the audio.
-Default value is 0.
-
-stop_duration Specify a duration of silence that must exist before audio is not copied any
-more. By specifying a higher duration, silence that is wanted can be left in
-the audio.
-Default value is 0.
-
-stop_threshold This is the same as start_threshold but for trimming silence from
-the end of audio.
-Can be specified in dB (in case "dB" is appended to the specified value)
-or amplitude ratio. Default value is 0.
-
-leave_silence This indicate that stop_duration length of audio should be left intact
-at the beginning of each period of silence.
-For example, if you want to remove long pauses between words but do not want
-to remove the pauses completely. Default value is 0.
-
-
-
-
-
27.40.1 Examples# TOC
-
-
- The following example shows how this filter can be used to start a recording
-that does not contain the delay at the start which usually occurs between
-pressing the record button and the start of the performance:
-
-
silenceremove=1:5:0.02
-
-
-
-
27.41 treble# TOC
-
-
Boost or cut treble (upper) frequencies of the audio using a two-pole
-shelving filter with a response similar to that of a standard
-hi-fi’s tone-controls. This is also known as shelving equalisation (EQ).
-
-
The filter accepts the following options:
-
-
-gain, g Give the gain at whichever is the lower of ~22 kHz and the
-Nyquist frequency. Its useful range is about -20 (for a large cut)
-to +20 (for a large boost). Beware of clipping when using a positive gain.
-
-frequency, f Set the filter’s central frequency and so can be used
-to extend or reduce the frequency range to be boosted or cut.
-The default value is 3000 Hz.
-
-width_type Set method to specify band-width of filter.
-
-h Hz
-
q Q-Factor
-
o octave
-
s slope
-
-
-width, w Determine how steep is the filter’s shelf transition.
-
-
-
-
27.42 volume# TOC
-
-
Adjust the input audio volume.
-
-
It accepts the following parameters:
-
-volume Set audio volume expression.
-
-Output values are clipped to the maximum value.
-
-The output audio volume is given by the relation:
-
-
output_volume = volume * input_volume
-The default value for volume is "1.0".
-
-precision This parameter represents the mathematical precision.
-
-It determines which input sample formats will be allowed, which affects the
-precision of the volume scaling.
-
-
-fixed 8-bit fixed-point; this limits input sample format to U8, S16, and S32.
-
float 32-bit floating-point; this limits input sample format to FLT. (default)
-
double 64-bit floating-point; this limits input sample format to DBL.
-
-
-replaygain Choose the behaviour on encountering ReplayGain side data in input frames.
-
-
-drop Remove ReplayGain side data, ignoring its contents (the default).
-
-ignore Ignore ReplayGain side data, but leave it in the frame.
-
-track Prefer the track gain, if present.
-
-album Prefer the album gain, if present.
-
-
-replaygain_preamp Pre-amplification gain in dB to apply to the selected replaygain gain.
-
-Default value for replaygain_preamp is 0.0.
-
-eval Set when the volume expression is evaluated.
-
-It accepts the following values:
-
-‘once ’
-only evaluate expression once during the filter initialization, or
-when the ‘volume ’ command is sent
-
-‘frame ’
-evaluate expression for each incoming frame
-
-
-Default value is ‘once ’.
-
-
-
The volume expression can contain the following parameters.
-
-
-n frame number (starting at zero)
-
nb_channels number of channels
-
nb_consumed_samples number of samples consumed by the filter
-
nb_samples number of samples in the current frame
-
pos original frame position in the file
-
pts frame PTS
-
sample_rate sample rate
-
startpts PTS at start of stream
-
startt time at start of stream
-
t frame time
-
tb timestamp timebase
-
volume last set volume value
-
-
-
Note that when eval is set to ‘once ’ only the
-sample_rate and tb variables are available, all other
-variables will evaluate to NAN.
-
-
-
27.42.1 Commands# TOC
-
-
This filter supports the following commands:
-
-volume Modify the volume expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
replaygain_noclip Prevent clipping by limiting the gain applied.
-
-Default value for replaygain_noclip is 1.
-
-
-
-
-
27.42.2 Examples# TOC
-
-
-
-
-
27.43 volumedetect# TOC
-
-
Detect the volume of the input video.
-
-
The filter has no parameters. The input is not modified. Statistics about
-the volume will be printed in the log when the input stream end is reached.
-
-
In particular it will show the mean volume (root mean square), maximum
-volume (on a per-sample basis), and the beginning of a histogram of the
-registered volume values (from the maximum value to a cumulated 1/1000 of
-the samples).
-
-
All volumes are in decibels relative to the maximum PCM value.
-
-
-
27.43.1 Examples# TOC
-
-
Here is an excerpt of the output:
-
-
[Parsed_volumedetect_0 0xa23120] mean_volume: -27 dB
-[Parsed_volumedetect_0 0xa23120] max_volume: -4 dB
-[Parsed_volumedetect_0 0xa23120] histogram_4db: 6
-[Parsed_volumedetect_0 0xa23120] histogram_5db: 62
-[Parsed_volumedetect_0 0xa23120] histogram_6db: 286
-[Parsed_volumedetect_0 0xa23120] histogram_7db: 1042
-[Parsed_volumedetect_0 0xa23120] histogram_8db: 2551
-[Parsed_volumedetect_0 0xa23120] histogram_9db: 4609
-[Parsed_volumedetect_0 0xa23120] histogram_10db: 8409
-
-
-
It means that:
-
- The mean square energy is approximately -27 dB, or 10^-2.7.
- The largest sample is at -4 dB, or more precisely between -4 dB and -5 dB.
- There are 6 samples at -4 dB, 62 at -5 dB, 286 at -6 dB, etc.
-
-
-
In other words, raising the volume by +4 dB does not cause any clipping,
-raising it by +5 dB causes clipping for 6 samples, etc.
-
-
-
-
28 Audio Sources# TOC
-
-
Below is a description of the currently available audio sources.
-
-
-
28.1 abuffer# TOC
-
-
Buffer audio frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/asrc_abuffer.h .
-
-
It accepts the following parameters:
-
-time_base The timebase which will be used for timestamps of submitted frames. It must be
-either a floating-point number or in numerator /denominator form.
-
-sample_rate The sample rate of the incoming audio buffers.
-
-sample_fmt The sample format of the incoming audio buffers.
-Either a sample format name or its corresponding integer representation from
-the enum AVSampleFormat in libavutil/samplefmt.h
-
-channel_layout The channel layout of the incoming audio buffers.
-Either a channel layout name from channel_layout_map in
-libavutil/channel_layout.c or its corresponding integer representation
-from the AV_CH_LAYOUT_* macros in libavutil/channel_layout.h
-
-channels The number of channels of the incoming audio buffers.
-If both channels and channel_layout are specified, then they
-must be consistent.
-
-
-
-
-
28.1.1 Examples# TOC
-
-
-
abuffer=sample_rate=44100:sample_fmt=s16p:channel_layout=stereo
-
-
-
will instruct the source to accept planar 16bit signed stereo at 44100Hz.
-Since the sample format with name "s16p" corresponds to the number
-6 and the "stereo" channel layout corresponds to the value 0x3, this is
-equivalent to:
-
-
abuffer=sample_rate=44100:sample_fmt=6:channel_layout=0x3
-
-
-
-
28.2 aevalsrc# TOC
-
-
Generate an audio signal specified by an expression.
-
-
This source accepts in input one or more expressions (one for each
-channel), which are evaluated and used to generate a corresponding
-audio signal.
-
-
This source accepts the following options:
-
-
-exprs Set the ’|’-separated expressions list for each separate channel. In case the
-channel_layout option is not specified, the selected channel layout
-depends on the number of provided expressions. Otherwise the last
-specified expression is applied to the remaining output channels.
-
-channel_layout, c Set the channel layout. The number of channels in the specified layout
-must be equal to the number of specified expressions.
-
-duration, d Set the minimum duration of the sourced audio. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-Note that the resulting duration may be greater than the specified
-duration, as the generated audio is always cut at the end of a
-complete frame.
-
-If not specified, or the expressed duration is negative, the audio is
-supposed to be generated forever.
-
-nb_samples, n Set the number of samples per channel per each output frame,
-default to 1024.
-
-sample_rate, s Specify the sample rate, default to 44100.
-
-
-
Each expression in exprs can contain the following constants:
-
-
-n number of the evaluated sample, starting from 0
-
-t time of the evaluated sample expressed in seconds, starting from 0
-
-s sample rate
-
-
-
-
-
28.2.1 Examples# TOC
-
-
- Generate silence:
-
-
- Generate a sin signal with frequency of 440 Hz, set sample rate to
-8000 Hz:
-
-
aevalsrc="sin(440*2*PI*t):s=8000"
- Generate a two channels signal, specify the channel layout (Front
-Center + Back Center) explicitly:
-
-
aevalsrc="sin(420*2*PI*t)|cos(430*2*PI*t):c=FC|BC"
- Generate white noise:
-
-
aevalsrc="-2+random(0)"
- Generate an amplitude modulated signal:
-
-
aevalsrc="sin(10*2*PI*t)*sin(880*2*PI*t)"
- Generate 2.5 Hz binaural beats on a 360 Hz carrier:
-
-
aevalsrc="0.1*sin(2*PI*(360-2.5/2)*t) | 0.1*sin(2*PI*(360+2.5/2)*t)"
-
-
-
-
28.3 anullsrc# TOC
-
-
The null audio source, return unprocessed audio frames. It is mainly useful
-as a template and to be employed in analysis / debugging tools, or as
-the source for filters which ignore the input data (for example the sox
-synth filter).
-
-
This source accepts the following options:
-
-
-channel_layout, cl
-Specifies the channel layout, and can be either an integer or a string
-representing a channel layout. The default value of channel_layout
-is "stereo".
-
-Check the channel_layout_map definition in
-libavutil/channel_layout.c for the mapping between strings and
-channel layout values.
-
-
-sample_rate, r Specifies the sample rate, and defaults to 44100.
-
-nb_samples, n Set the number of samples per requested frames.
-
-
-
-
-
28.3.1 Examples# TOC
-
-
- Set the sample rate to 48000 Hz and the channel layout to AV_CH_LAYOUT_MONO.
-
-
- Do the same operation with a more obvious syntax:
-
-
anullsrc=r=48000:cl=mono
-
-
-
All the parameters need to be explicitly defined.
-
-
-
28.4 flite# TOC
-
-
Synthesize a voice utterance using the libflite library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libflite.
-
-
Note that the flite library is not thread-safe.
-
-
The filter accepts the following options:
-
-
-list_voices If set to 1, list the names of the available voices and exit
-immediately. Default value is 0.
-
-nb_samples, n Set the maximum number of samples per frame. Default value is 512.
-
-textfile Set the filename containing the text to speak.
-
-text Set the text to speak.
-
-voice, v Set the voice to use for the speech synthesis. Default value is
-kal. See also the list_voices option.
-
-
-
-
28.4.1 Examples# TOC
-
-
- Read from file speech.txt , and synthesize the text using the
-standard flite voice:
-
-
flite=textfile=speech.txt
- Read the specified text selecting the slt voice:
-
-
flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Input text to ffmpeg:
-
-
ffmpeg -f lavfi -i flite=text='So fare thee well, poor devil of a Sub-Sub, whose commentator I am':voice=slt
- Make ffplay speak the specified text, using flite and
-the lavfi device:
-
-
ffplay -f lavfi flite=text='No more be grieved for which that thou hast done.'
-
-
-
For more information about libflite, check:
-http://www.speech.cs.cmu.edu/flite/
-
-
-
28.5 sine# TOC
-
-
Generate an audio signal made of a sine wave with amplitude 1/8.
-
-
The audio signal is bit-exact.
-
-
The filter accepts the following options:
-
-
-frequency, f Set the carrier frequency. Default is 440 Hz.
-
-beep_factor, b Enable a periodic beep every second with frequency beep_factor times
-the carrier frequency. Default is 0, meaning the beep is disabled.
-
-sample_rate, r Specify the sample rate, default is 44100.
-
-duration, d Specify the duration of the generated audio stream.
-
-samples_per_frame Set the number of samples per output frame, default is 1024.
-
-
-
-
28.5.1 Examples# TOC
-
-
- Generate a simple 440 Hz sine wave:
-
-
- Generate a 220 Hz sine wave with a 880 Hz beep each second, for 5 seconds:
-
-
sine=220:4:d=5
-sine=f=220:b=4:d=5
-sine=frequency=220:beep_factor=4:duration=5
-
-
-
-
-
29 Audio Sinks# TOC
-
-
Below is a description of the currently available audio sinks.
-
-
-
29.1 abuffersink# TOC
-
-
Buffer audio frames, and make them available to the end of filter chain.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVABufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
29.2 anullsink# TOC
-
-
Null audio sink; do absolutely nothing with the input audio. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
30 Video Filters# TOC
-
-
When you configure your FFmpeg build, you can disable any of the
-existing filters using --disable-filters.
-The configure output will show the video filters included in your
-build.
-
-
Below is a description of the currently available video filters.
-
-
-
30.1 alphaextract# TOC
-
-
Extract the alpha component from the input as a grayscale video. This
-is especially useful with the alphamerge filter.
-
-
-
30.2 alphamerge# TOC
-
-
Add or replace the alpha component of the primary input with the
-grayscale value of a second input. This is intended for use with
-alphaextract to allow the transmission or storage of frame
-sequences that have alpha in a format that doesn’t support an alpha
-channel.
-
-
For example, to reconstruct full frames from a normal YUV-encoded video
-and a separate video created with alphaextract , you might use:
-
-
movie=in_alpha.mkv [alpha]; [in][alpha] alphamerge [out]
-
-
-
Since this filter is designed for reconstruction, it operates on frame
-sequences without considering timestamps, and terminates when either
-input reaches end of stream. This will cause problems if your encoding
-pipeline drops frames. If you’re trying to apply an image as an
-overlay to a video stream, consider the overlay filter instead.
-
-
-
30.3 ass# TOC
-
-
Same as the subtitles filter, except that it doesn’t require libavcodec
-and libavformat to work. On the other hand, it is limited to ASS (Advanced
-Substation Alpha) subtitles files.
-
-
This filter accepts the following option in addition to the common options from
-the subtitles filter:
-
-
-shaping Set the shaping engine
-
-Available values are:
-
-‘auto ’
-The default libass shaping engine, which is the best available.
-
‘simple ’
-Fast, font-agnostic shaper that can do only substitutions
-
‘complex ’
-Slower shaper using OpenType for substitutions and positioning
-
-
-The default is auto.
-
-
-
-
30.4 bbox# TOC
-
-
Compute the bounding box for the non-black pixels in the input frame
-luminance plane.
-
-
This filter computes the bounding box containing all the pixels with a
-luminance value greater than the minimum allowed value.
-The parameters describing the bounding box are printed on the filter
-log.
-
-
The filter accepts the following option:
-
-
-min_val Set the minimal luminance value. Default is 16.
-
-
-
-
30.5 blackdetect# TOC
-
-
Detect video intervals that are (almost) completely black. Can be
-useful to detect chapter transitions, commercials, or invalid
-recordings. Output lines contains the time for the start, end and
-duration of the detected black interval expressed in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
The filter accepts the following options:
-
-
-black_min_duration, d Set the minimum detected black duration expressed in seconds. It must
-be a non-negative floating point number.
-
-Default value is 2.0.
-
-picture_black_ratio_th, pic_th Set the threshold for considering a picture "black".
-Express the minimum value for the ratio:
-
-
nb_black_pixels / nb_pixels
-for which a picture is considered black.
-Default value is 0.98.
-
-pixel_black_th, pix_th Set the threshold for considering a pixel "black".
-
-The threshold expresses the maximum pixel luminance value for which a
-pixel is considered "black". The provided value is scaled according to
-the following equation:
-
-
absolute_threshold = luminance_minimum_value + pixel_black_th * luminance_range_size
-luminance_range_size and luminance_minimum_value depend on
-the input video format, the range is [0-255] for YUV full-range
-formats and [16-235] for YUV non full-range formats.
-
-Default value is 0.10.
-
-
-
The following example sets the maximum pixel threshold to the minimum
-value, and detects only black intervals of 2 or more seconds:
-
-
blackdetect=d=2:pix_th=0.00
-
-
-
-
30.6 blackframe# TOC
-
-
Detect frames that are (almost) completely black. Can be useful to
-detect chapter transitions or commercials. Output lines consist of
-the frame number of the detected frame, the percentage of blackness,
-the position in the file if known or -1 and the timestamp in seconds.
-
-
In order to display the output lines, you need to set the loglevel at
-least to the AV_LOG_INFO value.
-
-
It accepts the following parameters:
-
-
-amount The percentage of the pixels that have to be below the threshold; it defaults to
-98.
-
-threshold, thresh The threshold below which a pixel value is considered black; it defaults to
-32.
-
-
-
-
-
30.7 blend, tblend# TOC
-
-
Blend two video frames into each other.
-
-
The blend filter takes two input streams and outputs one
-stream, the first input is the "top" layer and second input is
-"bottom" layer. Output terminates when shortest input terminates.
-
-
The tblend (time blend) filter takes two consecutive frames
-from one single stream, and outputs the result obtained by blending
-the new frame on top of the old frame.
-
-
A description of the accepted options follows.
-
-
-c0_mode c1_mode c2_mode c3_mode all_mode Set blend mode for specific pixel component or all pixel components in case
-of all_mode . Default value is normal.
-
-Available values for component modes are:
-
-‘addition ’
-‘and ’
-‘average ’
-‘burn ’
-‘darken ’
-‘difference ’
-‘difference128 ’
-‘divide ’
-‘dodge ’
-‘exclusion ’
-‘hardlight ’
-‘lighten ’
-‘multiply ’
-‘negation ’
-‘normal ’
-‘or ’
-‘overlay ’
-‘phoenix ’
-‘pinlight ’
-‘reflect ’
-‘screen ’
-‘softlight ’
-‘subtract ’
-‘vividlight ’
-‘xor ’
-
-
-c0_opacity c1_opacity c2_opacity c3_opacity all_opacity Set blend opacity for specific pixel component or all pixel components in case
-of all_opacity . Only used in combination with pixel component blend modes.
-
-c0_expr c1_expr c2_expr c3_expr all_expr Set blend expression for specific pixel component or all pixel components in case
-of all_expr . Note that related mode options will be ignored if those are set.
-
-The expressions can use the following variables:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y the coordinates of the current sample
-
-W H the width and height of currently filtered plane
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-TOP, A Value of pixel component at current location for first video frame (top layer).
-
-BOTTOM, B Value of pixel component at current location for second video frame (bottom layer).
-
-
-shortest Force termination when the shortest input terminates. Default is
-0. This option is only defined for the blend filter.
-
-repeatlast Continue applying the last bottom frame after the end of the stream. A value of
-0 disable the filter after the last frame of the bottom layer is reached.
-Default is 1. This option is only defined for the blend filter.
-
-
-
-
30.7.1 Examples# TOC
-
-
- Apply transition from bottom layer to top layer in first 10 seconds:
-
-
blend=all_expr='A*(if(gte(T,10),1,T/10))+B*(1-(if(gte(T,10),1,T/10)))'
- Apply 1x1 checkerboard effect:
-
-
blend=all_expr='if(eq(mod(X,2),mod(Y,2)),A,B)'
- Apply uncover left effect:
-
-
blend=all_expr='if(gte(N*SW+X,W),A,B)'
- Apply uncover down effect:
-
-
blend=all_expr='if(gte(Y-N*SH,0),A,B)'
- Apply uncover up-left effect:
-
-
blend=all_expr='if(gte(T*SH*40+Y,H)*gte((T*40*SW+X)*W/H,W),A,B)'
- Display differences between the current and the previous frame:
-
-
tblend=all_mode=difference128
-
-
-
-
30.8 boxblur# TOC
-
-
Apply a boxblur algorithm to the input video.
-
-
It accepts the following parameters:
-
-
-luma_radius, lr luma_power, lp chroma_radius, cr chroma_power, cp alpha_radius, ar alpha_power, ap
-
-
A description of the accepted options follows.
-
-
-luma_radius, lr chroma_radius, cr alpha_radius, ar Set an expression for the box radius in pixels used for blurring the
-corresponding input plane.
-
-The radius value must be a non-negative number, and must not be
-greater than the value of the expression min(w,h)/2 for the
-luma and alpha planes, and of min(cw,ch)/2 for the chroma
-planes.
-
-Default value for luma_radius is "2". If not specified,
-chroma_radius and alpha_radius default to the
-corresponding value set for luma_radius .
-
-The expressions can contain the following constants:
-
-w h The input width and height in pixels.
-
-cw ch The input chroma image width and height in pixels.
-
-hsub vsub The horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p", hsub is 2 and vsub is 1.
-
-
-luma_power, lp chroma_power, cp alpha_power, ap Specify how many times the boxblur filter is applied to the
-corresponding plane.
-
-Default value for luma_power is 2. If not specified,
-chroma_power and alpha_power default to the
-corresponding value set for luma_power .
-
-A value of 0 will disable the effect.
-
-
-
-
30.8.1 Examples# TOC
-
-
- Apply a boxblur filter with the luma, chroma, and alpha radii
-set to 2:
-
-
boxblur=luma_radius=2:luma_power=1
-boxblur=2:1
- Set the luma radius to 2, and alpha and chroma radius to 0:
-
-
- Set the luma and chroma radii to a fraction of the video dimension:
-
-
boxblur=luma_radius=min(h\,w)/10:luma_power=1:chroma_radius=min(cw\,ch)/10:chroma_power=1
-
-
-
-
30.9 codecview# TOC
-
-
Visualize information exported by some codecs.
-
-
Some codecs can export information through frames using side-data or other
-means. For example, some MPEG based codecs export motion vectors through the
-export_mvs flag in the codec flags2 option.
-
-
The filter accepts the following option:
-
-
-mv Set motion vectors to visualize.
-
-Available flags for mv are:
-
-
-‘pf ’
-forward predicted MVs of P-frames
-
‘bf ’
-forward predicted MVs of B-frames
-
‘bb ’
-backward predicted MVs of B-frames
-
-
-
-
-
30.9.1 Examples# TOC
-
-
- Visualizes multi-directionals MVs from P and B-Frames using ffplay:
-
-
ffplay -flags2 +export_mvs input.mpg -vf codecview=mv=pf+bf+bb
-
-
-
-
30.10 colorbalance# TOC
-
Modify intensity of primary colors (red, green and blue) of input frames.
-
-
The filter allows an input frame to be adjusted in the shadows, midtones or highlights
-regions for the red-cyan, green-magenta or blue-yellow balance.
-
-
A positive adjustment value shifts the balance towards the primary color, a negative
-value towards the complementary color.
-
-
The filter accepts the following options:
-
-
-rs gs bs Adjust red, green and blue shadows (darkest pixels).
-
-rm gm bm Adjust red, green and blue midtones (medium pixels).
-
-rh gh bh Adjust red, green and blue highlights (brightest pixels).
-
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-
-
-
30.10.1 Examples# TOC
-
-
- Add red color cast to shadows:
-
-
-
-
-
30.11 colorlevels# TOC
-
-
Adjust video input frames using levels.
-
-
The filter accepts the following options:
-
-
-rimin gimin bimin aimin Adjust red, green, blue and alpha input black point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 0.
-
-rimax gimax bimax aimax Adjust red, green, blue and alpha input white point.
-Allowed ranges for options are [-1.0, 1.0]. Defaults are 1.
-
-Input levels are used to lighten highlights (bright tones), darken shadows
-(dark tones), change the balance of bright and dark tones.
-
-romin gomin bomin aomin Adjust red, green, blue and alpha output black point.
-Allowed ranges for options are [0, 1.0]. Defaults are 0.
-
-romax gomax bomax aomax Adjust red, green, blue and alpha output white point.
-Allowed ranges for options are [0, 1.0]. Defaults are 1.
-
-Output levels allows manual selection of a constrained output level range.
-
-
-
-
30.11.1 Examples# TOC
-
-
- Make video output darker:
-
-
colorlevels=rimin=0.058:gimin=0.058:bimin=0.058
- Increase contrast:
-
-
colorlevels=rimin=0.039:gimin=0.039:bimin=0.039:rimax=0.96:gimax=0.96:bimax=0.96
- Make video output lighter:
-
-
colorlevels=rimax=0.902:gimax=0.902:bimax=0.902
- Increase brightness:
-
-
colorlevels=romin=0.5:gomin=0.5:bomin=0.5
-
-
-
-
30.12 colorchannelmixer# TOC
-
-
Adjust video input frames by re-mixing color channels.
-
-
This filter modifies a color channel by adding the values associated to
-the other channels of the same pixels. For example if the value to
-modify is red, the output value will be:
-
-
red =red *rr + blue *rb + green *rg + alpha *ra
-
-
-
The filter accepts the following options:
-
-
-rr rg rb ra Adjust contribution of input red, green, blue and alpha channels for output red channel.
-Default is 1 for rr , and 0 for rg , rb and ra .
-
-gr gg gb ga Adjust contribution of input red, green, blue and alpha channels for output green channel.
-Default is 1 for gg , and 0 for gr , gb and ga .
-
-br bg bb ba Adjust contribution of input red, green, blue and alpha channels for output blue channel.
-Default is 1 for bb , and 0 for br , bg and ba .
-
-ar ag ab aa Adjust contribution of input red, green, blue and alpha channels for output alpha channel.
-Default is 1 for aa , and 0 for ar , ag and ab .
-
-Allowed ranges for options are [-2.0, 2.0].
-
-
-
-
30.12.1 Examples# TOC
-
-
- Convert source to grayscale:
-
-
colorchannelmixer=.3:.4:.3:0:.3:.4:.3:0:.3:.4:.3
- Simulate sepia tones:
-
-
colorchannelmixer=.393:.769:.189:0:.349:.686:.168:0:.272:.534:.131
-
-
-
-
30.13 colormatrix# TOC
-
-
Convert color matrix.
-
-
The filter accepts the following options:
-
-
-src dst Specify the source and destination color matrix. Both values must be
-specified.
-
-The accepted values are:
-
-‘bt709 ’
-BT.709
-
-‘bt601 ’
-BT.601
-
-‘smpte240m ’
-SMPTE-240M
-
-‘fcc ’
-FCC
-
-
-
-
For example to convert from BT.601 to SMPTE-240M, use the command:
-
-
colormatrix=bt601:smpte240m
-
-
-
-
30.14 copy# TOC
-
-
Copy the input source unchanged to the output. This is mainly useful for
-testing purposes.
-
-
-
30.15 crop# TOC
-
-
Crop the input video to given dimensions.
-
-
It accepts the following parameters:
-
-
-w, out_w The width of the output video. It defaults to iw.
-This expression is evaluated only once during the filter
-configuration.
-
-h, out_h The height of the output video. It defaults to ih.
-This expression is evaluated only once during the filter
-configuration.
-
-x The horizontal position, in the input video, of the left edge of the output
-video. It defaults to (in_w-out_w)/2.
-This expression is evaluated per-frame.
-
-y The vertical position, in the input video, of the top edge of the output video.
-It defaults to (in_h-out_h)/2.
-This expression is evaluated per-frame.
-
-keep_aspect If set to 1 will force the output display aspect ratio
-to be the same of the input, by changing the output sample aspect
-ratio. It defaults to 0.
-
-
-
The out_w , out_h , x , y parameters are
-expressions containing the following constants:
-
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-in_w in_h The input width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (cropped) width and height.
-
-ow oh These are the same as out_w and out_h .
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-n The number of the input frame, starting from 0.
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
The expression for out_w may depend on the value of out_h ,
-and the expression for out_h may depend on out_w , but they
-cannot depend on x and y , as x and y are
-evaluated after out_w and out_h .
-
-
The x and y parameters specify the expressions for the
-position of the top-left corner of the output (non-cropped) area. They
-are evaluated for each frame. If the evaluated value is not valid, it
-is approximated to the nearest valid value.
-
-
The expression for x may depend on y , and the expression
-for y may depend on x .
-
-
-
30.15.1 Examples# TOC
-
-
-
-
-
30.16 cropdetect# TOC
-
-
Auto-detect the crop size.
-
-
It calculates the necessary cropping parameters and prints the
-recommended parameters via the logging system. The detected dimensions
-correspond to the non-black area of the input video.
-
-
It accepts the following parameters:
-
-
-limit Set higher black value threshold, which can be optionally specified
-from nothing (0) to everything (255 for 8bit based formats). An intensity
-value greater to the set value is considered non-black. It defaults to 24.
-You can also specify a value between 0.0 and 1.0 which will be scaled depending
-on the bitdepth of the pixel format.
-
-round The value which the width/height should be divisible by. It defaults to
-16. The offset is automatically adjusted to center the video. Use 2 to
-get only even dimensions (needed for 4:2:2 video). 16 is best when
-encoding to most video codecs.
-
-reset_count, reset Set the counter that determines after how many frames cropdetect will
-reset the previously detected largest video area and start over to
-detect the current optimal crop area. Default value is 0.
-
-This can be useful when channel logos distort the video area. 0
-indicates ’never reset’, and returns the largest area encountered during
-playback.
-
-
-
-
30.17 curves# TOC
-
-
Apply color adjustments using curves.
-
-
This filter is similar to the Adobe Photoshop and GIMP curves tools. Each
-component (red, green and blue) has its values defined by N key points
-tied from each other using a smooth curve. The x-axis represents the pixel
-values from the input frame, and the y-axis the new pixel values to be set for
-the output frame.
-
-
By default, a component curve is defined by the two points (0;0) and
-(1;1) . This creates a straight line where each original pixel value is
-"adjusted" to its own value, which means no change to the image.
-
-
The filter allows you to redefine these two points and add some more. A new
-curve (using a natural cubic spline interpolation) will be define to pass
-smoothly through all these new coordinates. The new defined points needs to be
-strictly increasing over the x-axis, and their x and y values must
-be in the [0;1] interval. If the computed curves happened to go outside
-the vector spaces, the values will be clipped accordingly.
-
-
If there is no key point defined in x=0, the filter will automatically
-insert a (0;0) point. In the same way, if there is no key point defined
-in x=1, the filter will automatically insert a (1;1) point.
-
-
The filter accepts the following options:
-
-
-preset Select one of the available color presets. This option can be used in addition
-to the r , g , b parameters; in this case, the later
-options takes priority on the preset values.
-Available presets are:
-
-‘none ’
-‘color_negative ’
-‘cross_process ’
-‘darker ’
-‘increase_contrast ’
-‘lighter ’
-‘linear_contrast ’
-‘medium_contrast ’
-‘negative ’
-‘strong_contrast ’
-‘vintage ’
-
-Default is none.
-
master, m Set the master key points. These points will define a second pass mapping. It
-is sometimes called a "luminance" or "value" mapping. It can be used with
-r , g , b or all since it acts like a
-post-processing LUT.
-
red, r Set the key points for the red component.
-
green, g Set the key points for the green component.
-
blue, b Set the key points for the blue component.
-
all Set the key points for all components (not including master).
-Can be used in addition to the other key points component
-options. In this case, the unset component(s) will fallback on this
-all setting.
-
psfile Specify a Photoshop curves file (.asv) to import the settings from.
-
-
-
To avoid some filtergraph syntax conflicts, each key points list need to be
-defined using the following syntax: x0/y0 x1/y1 x2/y2 ....
-
-
-
30.17.1 Examples# TOC
-
-
-
-
-
30.18 dctdnoiz# TOC
-
-
Denoise frames using 2D DCT (frequency domain filtering).
-
-
This filter is not designed for real time.
-
-
The filter accepts the following options:
-
-
-sigma, s Set the noise sigma constant.
-
-This sigma defines a hard threshold of 3 * sigma; every DCT
-coefficient (absolute value) below this threshold with be dropped.
-
-If you need a more advanced filtering, see expr .
-
-Default is 0.
-
-overlap Set number overlapping pixels for each block. Since the filter can be slow, you
-may want to reduce this value, at the cost of a less effective filter and the
-risk of various artefacts.
-
-If the overlapping value doesn’t allow to process the whole input width or
-height, a warning will be displayed and according borders won’t be denoised.
-
-Default value is blocksize -1, which is the best possible setting.
-
-expr, e Set the coefficient factor expression.
-
-For each coefficient of a DCT block, this expression will be evaluated as a
-multiplier value for the coefficient.
-
-If this is option is set, the sigma option will be ignored.
-
-The absolute value of the coefficient can be accessed through the c
-variable.
-
-n Set the blocksize using the number of bits. 1<<n defines the
-blocksize , which is the width and height of the processed blocks.
-
-The default value is 3 (8x8) and can be raised to 4 for a
-blocksize of 16x16. Note that changing this setting has huge consequences
-on the speed processing. Also, a larger block size does not necessarily means a
-better de-noising.
-
-
-
-
30.18.1 Examples# TOC
-
-
Apply a denoise with a sigma of 4.5:
-
-
-
The same operation can be achieved using the expression system:
-
-
dctdnoiz=e='gte(c, 4.5*3)'
-
-
-
Violent denoise using a block size of 16x16:
-
-
-
-
30.19 decimate# TOC
-
-
Drop duplicated frames at regular intervals.
-
-
The filter accepts the following options:
-
-
-cycle Set the number of frames from which one will be dropped. Setting this to
-N means one frame in every batch of N frames will be dropped.
-Default is 5.
-
-dupthresh Set the threshold for duplicate detection. If the difference metric for a frame
-is less than or equal to this value, then it is declared as duplicate. Default
-is 1.1
-
-scthresh Set scene change threshold. Default is 15.
-
-blockx blocky Set the size of the x and y-axis blocks used during metric calculations.
-Larger blocks give better noise suppression, but also give worse detection of
-small movements. Must be a power of two. Default is 32.
-
-ppsrc Mark main input as a pre-processed input and activate clean source input
-stream. This allows the input to be pre-processed with various filters to help
-the metrics calculation while keeping the frame selection lossless. When set to
-1, the first stream is for the pre-processed input, and the second
-stream is the clean source from where the kept frames are chosen. Default is
-0.
-
-chroma Set whether or not chroma is considered in the metric calculations. Default is
-1.
-
-
-
-
30.20 dejudder# TOC
-
-
Remove judder produced by partially interlaced telecined content.
-
-
Judder can be introduced, for instance, by pullup filter. If the original
-source was partially telecined content then the output of pullup,dejudder
-will have a variable frame rate. May change the recorded frame rate of the
-container. Aside from that change, this filter will not affect constant frame
-rate video.
-
-
The option available in this filter is:
-
-cycle Specify the length of the window over which the judder repeats.
-
-Accepts any integer greater than 1. Useful values are:
-
-‘4 ’
-If the original was telecined from 24 to 30 fps (Film to NTSC).
-
-‘5 ’
-If the original was telecined from 25 to 30 fps (PAL to NTSC).
-
-‘20 ’
-If a mixture of the two.
-
-
-The default is ‘4 ’.
-
-
-
-
30.21 delogo# TOC
-
-
Suppress a TV station logo by a simple interpolation of the surrounding
-pixels. Just set a rectangle covering the logo and watch it disappear
-(and sometimes something even uglier appear - your mileage may vary).
-
-
It accepts the following parameters:
-
-x y Specify the top left corner coordinates of the logo. They must be
-specified.
-
-w h Specify the width and height of the logo to clear. They must be
-specified.
-
-band, t Specify the thickness of the fuzzy edge of the rectangle (added to
-w and h ). The default value is 4.
-
-show When set to 1, a green rectangle is drawn on the screen to simplify
-finding the right x , y , w , and h parameters.
-The default value is 0.
-
-The rectangle is drawn on the outermost pixels which will be (partly)
-replaced with interpolated values. The values of the next pixels
-immediately outside this rectangle in each direction will be used to
-compute the interpolated pixel values inside the rectangle.
-
-
-
-
-
30.21.1 Examples# TOC
-
-
- Set a rectangle covering the area with top left corner coordinates 0,0
-and size 100x77, and a band of size 10:
-
-
delogo=x=0:y=0:w=100:h=77:band=10
-
-
-
-
30.22 deshake# TOC
-
-
Attempt to fix small changes in horizontal and/or vertical shift. This
-filter helps remove camera shake from hand-holding a camera, bumping a
-tripod, moving on a vehicle, etc.
-
-
The filter accepts the following options:
-
-
-x y w h Specify a rectangular area where to limit the search for motion
-vectors.
-If desired the search for motion vectors can be limited to a
-rectangular area of the frame defined by its top left corner, width
-and height. These parameters have the same meaning as the drawbox
-filter which can be used to visualise the position of the bounding
-box.
-
-This is useful when simultaneous movement of subjects within the frame
-might be confused for camera motion by the motion vector search.
-
-If any or all of x , y , w and h are set to -1
-then the full frame is used. This allows later options to be set
-without specifying the bounding box for the motion vector search.
-
-Default - search the whole frame.
-
-rx ry Specify the maximum extent of movement in x and y directions in the
-range 0-64 pixels. Default 16.
-
-edge Specify how to generate pixels to fill blanks at the edge of the
-frame. Available values are:
-
-‘blank, 0 ’
-Fill zeroes at blank locations
-
‘original, 1 ’
-Original image at blank locations
-
‘clamp, 2 ’
-Extruded edge value at blank locations
-
‘mirror, 3 ’
-Mirrored edge at blank locations
-
-Default value is ‘mirror ’.
-
-blocksize Specify the blocksize to use for motion search. Range 4-128 pixels,
-default 8.
-
-contrast Specify the contrast threshold for blocks. Only blocks with more than
-the specified contrast (difference between darkest and lightest
-pixels) will be considered. Range 1-255, default 125.
-
-search Specify the search strategy. Available values are:
-
-‘exhaustive, 0 ’
-Set exhaustive search
-
‘less, 1 ’
-Set less exhaustive search.
-
-Default value is ‘exhaustive ’.
-
-filename If set then a detailed log of the motion search is written to the
-specified file.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
-
30.23 drawbox# TOC
-
-
Draw a colored box on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the top left corner coordinates of the box. It defaults to 0.
-
-width, w height, h The expressions which specify the width and height of the box; if 0 they are interpreted as
-the input width and height. It defaults to 0.
-
-color, c Specify the color of the box to write. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the box edge color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the box edge. Default value is 3.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y offset coordinates where the box is drawn.
-
-w h The width and height of the drawn box.
-
-t The thickness of the drawn box.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
30.23.1 Examples# TOC
-
-
-
-
-
30.24 drawgrid# TOC
-
-
Draw a grid on the input image.
-
-
It accepts the following parameters:
-
-
-x y The expressions which specify the coordinates of some point of grid intersection (meant to configure offset). Both default to 0.
-
-width, w height, h The expressions which specify the width and height of the grid cell, if 0 they are interpreted as the
-input width and height, respectively, minus thickness, so image gets
-framed. Default to 0.
-
-color, c Specify the color of the grid. For the general syntax of this option,
-check the "Color" section in the ffmpeg-utils manual. If the special
-value invert is used, the grid color is the same as the
-video with inverted luma.
-
-thickness, t The expression which sets the thickness of the grid line. Default value is 1.
-
-See below for the list of accepted constants.
-
-
-
The parameters for x , y , w and h and t are expressions containing the
-following constants:
-
-
-dar The input display aspect ratio, it is the same as (w / h ) * sar .
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_h, ih in_w, iw The input grid cell width and height.
-
-sar The input sample aspect ratio.
-
-x y The x and y coordinates of some point of grid intersection (meant to configure offset).
-
-w h The width and height of the drawn cell.
-
-t The thickness of the drawn cell.
-
-These constants allow the x , y , w , h and t expressions to refer to
-each other, so you may for example specify y=x/dar or h=w/dar.
-
-
-
-
-
30.24.1 Examples# TOC
-
-
- Draw a grid with cell 100x100 pixels, thickness 2 pixels, with color red and an opacity of 50%:
-
-
drawgrid=width=100:height=100:thickness=2:color=red@0.5
- Draw a white 3x3 grid with an opacity of 50%:
-
-
drawgrid=w=iw/3:h=ih/3:t=2:c=white@0.5
-
-
-
-
30.25 drawtext# TOC
-
-
Draw a text string or text from a specified file on top of a video, using the
-libfreetype library.
-
-
To enable compilation of this filter, you need to configure FFmpeg with
---enable-libfreetype.
-To enable default font fallback and the font option you need to
-configure FFmpeg with --enable-libfontconfig.
-To enable the text_shaping option, you need to configure FFmpeg with
---enable-libfribidi.
-
-
-
30.25.1 Syntax# TOC
-
-
It accepts the following parameters:
-
-
-box Used to draw a box around text using the background color.
-The value must be either 1 (enable) or 0 (disable).
-The default value of box is 0.
-
-boxcolor The color to be used for drawing box around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of boxcolor is "white".
-
-borderw Set the width of the border to be drawn around the text using bordercolor .
-The default value of borderw is 0.
-
-bordercolor Set the color to be used for drawing border around text. For the syntax of this
-option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of bordercolor is "black".
-
-expansion Select how the text is expanded. Can be either none,
-strftime (deprecated) or
-normal (default). See the Text expansion section
-below for details.
-
-fix_bounds If true, check and fix text coords to avoid clipping.
-
-fontcolor The color to be used for drawing fonts. For the syntax of this option, check
-the "Color" section in the ffmpeg-utils manual.
-
-The default value of fontcolor is "black".
-
-fontcolor_expr String which is expanded the same way as text to obtain dynamic
-fontcolor value. By default this option has empty value and is not
-processed. When this option is set, it overrides fontcolor option.
-
-font The font family to be used for drawing text. By default Sans.
-
-fontfile The font file to be used for drawing text. The path must be included.
-This parameter is mandatory if the fontconfig support is disabled.
-
-fontsize The font size to be used for drawing text.
-The default value of fontsize is 16.
-
-text_shaping If set to 1, attempt to shape the text (for example, reverse the order of
-right-to-left text and join Arabic characters) before drawing it.
-Otherwise, just draw the text exactly as given.
-By default 1 (if supported).
-
-ft_load_flags The flags to be used for loading the fonts.
-
-The flags map the corresponding flags supported by libfreetype, and are
-a combination of the following values:
-
-default no_scale no_hinting render no_bitmap vertical_layout force_autohint crop_bitmap pedantic ignore_global_advance_width no_recurse ignore_transform monochrome linear_design no_autohint
-
-Default value is "default".
-
-For more information consult the documentation for the FT_LOAD_*
-libfreetype flags.
-
-shadowcolor The color to be used for drawing a shadow behind the drawn text. For the
-syntax of this option, check the "Color" section in the ffmpeg-utils manual.
-
-The default value of shadowcolor is "black".
-
-shadowx shadowy The x and y offsets for the text shadow position with respect to the
-position of the text. They can be either positive or negative
-values. The default value for both is "0".
-
-start_number The starting frame number for the n/frame_num variable. The default value
-is "0".
-
-tabsize The size in number of spaces to use for rendering the tab.
-Default value is 4.
-
-timecode Set the initial timecode representation in "hh:mm:ss[:;.]ff"
-format. It can be used with or without text parameter. timecode_rate
-option must be specified.
-
-timecode_rate, rate, r Set the timecode frame rate (timecode only).
-
-text The text string to be drawn. The text must be a sequence of UTF-8
-encoded characters.
-This parameter is mandatory if no file is specified with the parameter
-textfile .
-
-textfile A text file containing text to be drawn. The text must be a sequence
-of UTF-8 encoded characters.
-
-This parameter is mandatory if no text string is specified with the
-parameter text .
-
-If both text and textfile are specified, an error is thrown.
-
-reload If set to 1, the textfile will be reloaded before each frame.
-Be sure to update it atomically, or it may be read partially, or even fail.
-
-x y The expressions which specify the offsets where text will be drawn
-within the video frame. They are relative to the top/left border of the
-output image.
-
-The default value of x and y is "0".
-
-See below for the list of accepted constants and functions.
-
-
-
The parameters for x and y are expressions containing the
-following constants and functions:
-
-
-dar input display aspect ratio, it is the same as (w / h ) * sar
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-line_h, lh the height of each text line
-
-main_h, h, H the input height
-
-main_w, w, W the input width
-
-max_glyph_a, ascent the maximum distance from the baseline to the highest/upper grid
-coordinate used to place a glyph outline point, for all the rendered
-glyphs.
-It is a positive value, due to the grid’s orientation with the Y axis
-upwards.
-
-max_glyph_d, descent the maximum distance from the baseline to the lowest grid coordinate
-used to place a glyph outline point, for all the rendered glyphs.
-This is a negative value, due to the grid’s orientation, with the Y axis
-upwards.
-
-max_glyph_h maximum glyph height, that is the maximum height for all the glyphs
-contained in the rendered text, it is equivalent to ascent -
-descent .
-
-max_glyph_w maximum glyph width, that is the maximum width for all the glyphs
-contained in the rendered text
-
-n the number of input frame, starting from 0
-
-rand(min, max) return a random number included between min and max
-
-sar The input sample aspect ratio.
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-text_h, th the height of the rendered text
-
-text_w, tw the width of the rendered text
-
-x y the x and y offset coordinates where the text is drawn.
-
-These parameters allow the x and y expressions to refer
-each other, so you can for example specify y=x/dar.
-
-
-
-
30.25.2 Text expansion# TOC
-
-
If expansion is set to strftime,
-the filter recognizes strftime() sequences in the provided text and
-expands them accordingly. Check the documentation of strftime(). This
-feature is deprecated.
-
-
If expansion is set to none, the text is printed verbatim.
-
-
If expansion is set to normal (which is the default),
-the following expansion mechanism is used.
-
-
The backslash character ’\’, followed by any character, always expands to
-the second character.
-
-
Sequence of the form %{...} are expanded. The text between the
-braces is a function name, possibly followed by arguments separated by ’:’.
-If the arguments contain special characters or delimiters (’:’ or ’}’),
-they should be escaped.
-
-
Note that they probably must also be escaped as the value for the
-text option in the filter argument string and as the filter
-argument in the filtergraph description, and possibly also for the shell,
-that makes up to four levels of escaping; using a text file avoids these
-problems.
-
-
The following functions are available:
-
-
-expr, eThe expression evaluation result.
-
-It must take one argument specifying the expression to be evaluated,
-which accepts the same constants and functions as the x and
-y values. Note that not all constants should be used, for
-example the text size is not known when evaluating the expression, so
-the constants text_w and text_h will have an undefined
-value.
-
-expr_int_format, eifEvaluate the expression’s value and output as formatted integer.
-
-The first argument is the expression to be evaluated, just as for the expr function.
-The second argument specifies the output format. Allowed values are ’x’, ’X’, ’d’ and
-’u’. They are treated exactly as in the printf function.
-The third parameter is optional and sets the number of positions taken by the output.
-It can be used to add padding with zeros from the left.
-
-gmtimeThe time at which the filter is running, expressed in UTC.
-It can accept an argument: a strftime() format string.
-
-localtimeThe time at which the filter is running, expressed in the local time zone.
-It can accept an argument: a strftime() format string.
-
-metadataFrame metadata. It must take one argument specifying metadata key.
-
-n, frame_numThe frame number, starting from 0.
-
-pict_typeA 1 character description of the current picture type.
-
-ptsThe timestamp of the current frame.
-It can take up to two arguments.
-
-The first argument is the format of the timestamp; it defaults to flt
-for seconds as a decimal number with microsecond accuracy; hms stands
-for a formatted [-]HH:MM:SS.mmm timestamp with millisecond accuracy.
-
-The second argument is an offset added to the timestamp.
-
-
-
-
-
30.25.3 Examples# TOC
-
-
-
-
For more information about libfreetype, check:
-http://www.freetype.org/ .
-
-
For more information about fontconfig, check:
-http://freedesktop.org/software/fontconfig/fontconfig-user.html .
-
-
For more information about libfribidi, check:
-http://fribidi.org/ .
-
-
-
30.26 edgedetect# TOC
-
-
Detect and draw edges. The filter uses the Canny Edge Detection algorithm.
-
-
The filter accepts the following options:
-
-
-low high Set low and high threshold values used by the Canny thresholding
-algorithm.
-
-The high threshold selects the "strong" edge pixels, which are then
-connected through 8-connectivity with the "weak" edge pixels selected
-by the low threshold.
-
-low and high threshold values must be chosen in the range
-[0,1], and low should be lesser or equal to high .
-
-Default value for low is 20/255, and default value for high
-is 50/255.
-
-mode Define the drawing mode.
-
-
-‘wires ’
-Draw white/gray wires on black background.
-
-‘colormix ’
-Mix the colors to create a paint/cartoon effect.
-
-
-Default value is wires .
-
-
-
-
30.26.1 Examples# TOC
-
-
- Standard edge detection with custom values for the hysteresis thresholding:
-
-
edgedetect=low=0.1:high=0.4
- Painting effect without thresholding:
-
-
edgedetect=mode=colormix:high=0
-
-
-
-
30.27 extractplanes# TOC
-
-
Extract color channel components from input video stream into
-separate grayscale video streams.
-
-
The filter accepts the following option:
-
-
-planes Set plane(s) to extract.
-
-Available values for planes are:
-
-‘y ’
-‘u ’
-‘v ’
-‘a ’
-‘r ’
-‘g ’
-‘b ’
-
-
-Choosing planes not available in the input will result in an error.
-That means you cannot select r, g, b planes
-with y, u, v planes at same time.
-
-
-
-
30.27.1 Examples# TOC
-
-
- Extract luma, u and v color channel component from input video frame
-into 3 grayscale outputs:
-
-
ffmpeg -i video.avi -filter_complex 'extractplanes=y+u+v[y][u][v]' -map '[y]' y.avi -map '[u]' u.avi -map '[v]' v.avi
-
-
-
-
30.28 elbg# TOC
-
-
Apply a posterize effect using the ELBG (Enhanced LBG) algorithm.
-
-
For each input image, the filter will compute the optimal mapping from
-the input to the output given the codebook length, that is the number
-of distinct output colors.
-
-
This filter accepts the following options.
-
-
-codebook_length, l Set codebook length. The value must be a positive integer, and
-represents the number of distinct output colors. Default value is 256.
-
-nb_steps, n Set the maximum number of iterations to apply for computing the optimal
-mapping. The higher the value the better the result and the higher the
-computation time. Default value is 1.
-
-seed, s Set a random seed, must be an integer included between 0 and
-UINT32_MAX. If not specified, or if explicitly set to -1, the filter
-will try to use a good random seed on a best effort basis.
-
-
-
-
30.29 fade# TOC
-
-
Apply a fade-in/out effect to the input video.
-
-
It accepts the following parameters:
-
-
-type, t The effect type can be either "in" for a fade-in, or "out" for a fade-out
-effect.
-Default is in.
-
-start_frame, s Specify the number of the frame to start applying the fade
-effect at. Default is 0.
-
-nb_frames, n The number of frames that the fade effect lasts. At the end of the
-fade-in effect, the output video will have the same intensity as the input video.
-At the end of the fade-out transition, the output video will be filled with the
-selected color .
-Default is 25.
-
-alpha If set to 1, fade only alpha channel, if one exists on the input.
-Default value is 0.
-
-start_time, st Specify the timestamp (in seconds) of the frame to start to apply the fade
-effect. If both start_frame and start_time are specified, the fade will start at
-whichever comes last. Default is 0.
-
-duration, d The number of seconds for which the fade effect has to last. At the end of the
-fade-in effect the output video will have the same intensity as the input video,
-at the end of the fade-out transition the output video will be filled with the
-selected color .
-If both duration and nb_frames are specified, duration is used. Default is 0.
-
-color, c Specify the color of the fade. Default is "black".
-
-
-
-
30.29.1 Examples# TOC
-
-
-
-
-
30.30 field# TOC
-
-
Extract a single field from an interlaced image using stride
-arithmetic to avoid wasting CPU time. The output frames are marked as
-non-interlaced.
-
-
The filter accepts the following options:
-
-
-type Specify whether to extract the top (if the value is 0 or
-top) or the bottom field (if the value is 1 or
-bottom).
-
-
-
-
30.31 fieldmatch# TOC
-
-
Field matching filter for inverse telecine. It is meant to reconstruct the
-progressive frames from a telecined stream. The filter does not drop duplicated
-frames, so to achieve a complete inverse telecine fieldmatch needs to be
-followed by a decimation filter such as decimate in the filtergraph.
-
-
The separation of the field matching and the decimation is notably motivated by
-the possibility of inserting a de-interlacing filter fallback between the two.
-If the source has mixed telecined and real interlaced content,
-fieldmatch will not be able to match fields for the interlaced parts.
-But these remaining combed frames will be marked as interlaced, and thus can be
-de-interlaced by a later filter such as yadif before decimation.
-
-
In addition to the various configuration options, fieldmatch can take an
-optional second stream, activated through the ppsrc option. If
-enabled, the frames reconstruction will be based on the fields and frames from
-this second stream. This allows the first input to be pre-processed in order to
-help the various algorithms of the filter, while keeping the output lossless
-(assuming the fields are matched properly). Typically, a field-aware denoiser,
-or brightness/contrast adjustments can help.
-
-
Note that this filter uses the same algorithms as TIVTC/TFM (AviSynth project)
-and VIVTC/VFM (VapourSynth project). The later is a light clone of TFM from
-which fieldmatch is based on. While the semantic and usage are very
-close, some behaviour and options names can differ.
-
-
The decimate filter currently only works for constant frame rate input.
-Do not use fieldmatch and decimate if your input has mixed
-telecined and progressive content with changing framerate.
-
-
The filter accepts the following options:
-
-
-order Specify the assumed field order of the input stream. Available values are:
-
-
-‘auto ’
-Auto detect parity (use FFmpeg’s internal parity value).
-
‘bff ’
-Assume bottom field first.
-
‘tff ’
-Assume top field first.
-
-
-Note that it is sometimes recommended not to trust the parity announced by the
-stream.
-
-Default value is auto .
-
-mode Set the matching mode or strategy to use. pc mode is the safest in the
-sense that it won’t risk creating jerkiness due to duplicate frames when
-possible, but if there are bad edits or blended fields it will end up
-outputting combed frames when a good match might actually exist. On the other
-hand, pcn_ub mode is the most risky in terms of creating jerkiness,
-but will almost always find a good frame if there is one. The other values are
-all somewhere in between pc and pcn_ub in terms of risking
-jerkiness and creating duplicate frames versus finding good matches in sections
-with bad edits, orphaned fields, blended fields, etc.
-
-More details about p/c/n/u/b are available in p/c/n/u/b meaning section.
-
-Available values are:
-
-
-‘pc ’
-2-way matching (p/c)
-
‘pc_n ’
-2-way matching, and trying 3rd match if still combed (p/c + n)
-
‘pc_u ’
-2-way matching, and trying 3rd match (same order) if still combed (p/c + u)
-
‘pc_n_ub ’
-2-way matching, trying 3rd match if still combed, and trying 4th/5th matches if
-still combed (p/c + n + u/b)
-
‘pcn ’
-3-way matching (p/c/n)
-
‘pcn_ub ’
-3-way matching, and trying 4th/5th matches if all 3 of the original matches are
-detected as combed (p/c/n + u/b)
-
-
-The parenthesis at the end indicate the matches that would be used for that
-mode assuming order =tff (and field on auto or
-top ).
-
-In terms of speed pc mode is by far the fastest and pcn_ub is
-the slowest.
-
-Default value is pc_n .
-
-ppsrc Mark the main input stream as a pre-processed input, and enable the secondary
-input stream as the clean source to pick the fields from. See the filter
-introduction for more details. It is similar to the clip2 feature from
-VFM/TFM.
-
-Default value is 0 (disabled).
-
-field Set the field to match from. It is recommended to set this to the same value as
-order unless you experience matching failures with that setting. In
-certain circumstances changing the field that is used to match from can have a
-large impact on matching performance. Available values are:
-
-
-‘auto ’
-Automatic (same value as order ).
-
‘bottom ’
-Match from the bottom field.
-
‘top ’
-Match from the top field.
-
-
-Default value is auto .
-
-mchroma Set whether or not chroma is included during the match comparisons. In most
-cases it is recommended to leave this enabled. You should set this to 0
-only if your clip has bad chroma problems such as heavy rainbowing or other
-artifacts. Setting this to 0 could also be used to speed things up at
-the cost of some accuracy.
-
-Default value is 1.
-
-y0 y1 These define an exclusion band which excludes the lines between y0 and
-y1 from being included in the field matching decision. An exclusion
-band can be used to ignore subtitles, a logo, or other things that may
-interfere with the matching. y0 sets the starting scan line and
-y1 sets the ending line; all lines in between y0 and
-y1 (including y0 and y1 ) will be ignored. Setting
-y0 and y1 to the same value will disable the feature.
-y0 and y1 defaults to 0.
-
-scthresh Set the scene change detection threshold as a percentage of maximum change on
-the luma plane. Good values are in the [8.0, 14.0] range. Scene change
-detection is only relevant in case combmatch =sc . The range for
-scthresh is [0.0, 100.0].
-
-Default value is 12.0.
-
-combmatch When combatch is not none , fieldmatch will take into
-account the combed scores of matches when deciding what match to use as the
-final match. Available values are:
-
-
-‘none ’
-No final matching based on combed scores.
-
‘sc ’
-Combed scores are only used when a scene change is detected.
-
‘full ’
-Use combed scores all the time.
-
-
-Default is sc .
-
-combdbg Force fieldmatch to calculate the combed metrics for certain matches and
-print them. This setting is known as micout in TFM/VFM vocabulary.
-Available values are:
-
-
-‘none ’
-No forced calculation.
-
‘pcn ’
-Force p/c/n calculations.
-
‘pcnub ’
-Force p/c/n/u/b calculations.
-
-
-Default value is none .
-
-cthresh This is the area combing threshold used for combed frame detection. This
-essentially controls how "strong" or "visible" combing must be to be detected.
-Larger values mean combing must be more visible and smaller values mean combing
-can be less visible or strong and still be detected. Valid settings are from
--1 (every pixel will be detected as combed) to 255 (no pixel will
-be detected as combed). This is basically a pixel difference value. A good
-range is [8, 12].
-
-Default value is 9.
-
-chroma Sets whether or not chroma is considered in the combed frame decision. Only
-disable this if your source has chroma problems (rainbowing, etc.) that are
-causing problems for the combed frame detection with chroma enabled. Actually,
-using chroma =0 is usually more reliable, except for the case
-where there is chroma only combing in the source.
-
-Default value is 0.
-
-blockx blocky Respectively set the x-axis and y-axis size of the window used during combed
-frame detection. This has to do with the size of the area in which
-combpel pixels are required to be detected as combed for a frame to be
-declared combed. See the combpel parameter description for more info.
-Possible values are any number that is a power of 2 starting at 4 and going up
-to 512.
-
-Default value is 16.
-
-combpel The number of combed pixels inside any of the blocky by
-blockx size blocks on the frame for the frame to be detected as
-combed. While cthresh controls how "visible" the combing must be, this
-setting controls "how much" combing there must be in any localized area (a
-window defined by the blockx and blocky settings) on the
-frame. Minimum value is 0 and maximum is blocky x blockx (at
-which point no frames will ever be detected as combed). This setting is known
-as MI in TFM/VFM vocabulary.
-
-Default value is 80.
-
-
-
-
30.31.1 p/c/n/u/b meaning# TOC
-
-
-
30.31.1.1 p/c/n# TOC
-
-
We assume the following telecined stream:
-
-
-
Top fields: 1 2 2 3 4
-Bottom fields: 1 2 3 4 4
-
-
-
The numbers correspond to the progressive frame the fields relate to. Here, the
-first two frames are progressive, the 3rd and 4th are combed, and so on.
-
-
When fieldmatch is configured to run a matching from bottom
-(field =bottom ) this is how this input stream get transformed:
-
-
-
Input stream:
- T 1 2 2 3 4
- B 1 2 3 4 4 <-- matching reference
-
-Matches: c c n n c
-
-Output stream:
- T 1 2 3 4 4
- B 1 2 3 4 4
-
-
-
As a result of the field matching, we can see that some frames get duplicated.
-To perform a complete inverse telecine, you need to rely on a decimation filter
-after this operation. See for instance the decimate filter.
-
-
The same operation now matching from top fields (field =top )
-looks like this:
-
-
-
Input stream:
- T 1 2 2 3 4 <-- matching reference
- B 1 2 3 4 4
-
-Matches: c c p p c
-
-Output stream:
- T 1 2 2 3 4
- B 1 2 2 3 4
-
-
-
In these examples, we can see what p , c and n mean;
-basically, they refer to the frame and field of the opposite parity:
-
-
- p matches the field of the opposite parity in the previous frame
- c matches the field of the opposite parity in the current frame
- n matches the field of the opposite parity in the next frame
-
-
-
-
30.31.1.2 u/b# TOC
-
-
The u and b matching are a bit special in the sense that they match
-from the opposite parity flag. In the following examples, we assume that we are
-currently matching the 2nd frame (Top:2, bottom:2). According to the match, a
-’x’ is placed above and below each matched fields.
-
-
With bottom matching (field =bottom ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 1 2 2 2
- 2 2 2 1 3
-
-
-
With top matching (field =top ):
-
-
Match: c p n b u
-
- x x x x x
- Top 1 2 2 1 2 2 1 2 2 1 2 2 1 2 2
- Bottom 1 2 3 1 2 3 1 2 3 1 2 3 1 2 3
- x x x x x
-
-Output frames:
- 2 2 2 1 2
- 2 1 3 2 2
-
-
-
-
30.31.2 Examples# TOC
-
-
Simple IVTC of a top field first telecined stream:
-
-
fieldmatch=order=tff:combmatch=none, decimate
-
-
-
Advanced IVTC, with fallback on yadif for still combed frames:
-
-
fieldmatch=order=tff:combmatch=full, yadif=deint=interlaced, decimate
-
-
-
-
30.32 fieldorder# TOC
-
-
Transform the field order of the input video.
-
-
It accepts the following parameters:
-
-
-order The output field order. Valid values are tff for top field first or bff
-for bottom field first.
-
-
-
The default value is ‘tff ’.
-
-
The transformation is done by shifting the picture content up or down
-by one line, and filling the remaining line with appropriate picture content.
-This method is consistent with most broadcast field order converters.
-
-
If the input video is not flagged as being interlaced, or it is already
-flagged as being of the required output field order, then this filter does
-not alter the incoming video.
-
-
It is very useful when converting to or from PAL DV material,
-which is bottom field first.
-
-
For example:
-
-
ffmpeg -i in.vob -vf "fieldorder=bff" out.dv
-
-
-
-
30.33 fifo# TOC
-
-
Buffer input images and send them when they are requested.
-
-
It is mainly useful when auto-inserted by the libavfilter
-framework.
-
-
It does not take parameters.
-
-
-
30.34 format# TOC
-
-
Convert the input video to one of the specified pixel formats.
-Libavfilter will try to pick one that is suitable as input to
-the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-"pix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
30.34.1 Examples# TOC
-
-
-
-
-
30.35 fps# TOC
-
-
Convert the video to specified constant frame rate by duplicating or dropping
-frames as necessary.
-
-
It accepts the following parameters:
-
-fps The desired output frame rate. The default is 25.
-
-round Rounding method.
-
-Possible values are:
-
-zero zero round towards 0
-
inf round away from 0
-
down round towards -infinity
-
up round towards +infinity
-
near round to nearest
-
-The default is near.
-
-start_time Assume the first PTS should be the given value, in seconds. This allows for
-padding/trimming at the start of stream. By default, no assumption is made
-about the first frame’s expected PTS, so no padding or trimming is done.
-For example, this could be set to 0 to pad the beginning with duplicates of
-the first frame if a video stream starts after the audio stream or to trim any
-frames with a negative PTS.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-fps [:round ].
-
-
See also the setpts filter.
-
-
-
30.35.1 Examples# TOC
-
-
- A typical usage in order to set the fps to 25:
-
-
- Sets the fps to 24, using abbreviation and rounding method to round to nearest:
-
-
fps=fps=film:round=near
-
-
-
-
30.36 framepack# TOC
-
-
Pack two different video streams into a stereoscopic video, setting proper
-metadata on supported codecs. The two views should have the same size and
-framerate and processing will stop when the shorter video ends. Please note
-that you may conveniently adjust view properties with the scale and
-fps filters.
-
-
It accepts the following parameters:
-
-format The desired packing format. Supported values are:
-
-
-sbs The views are next to each other (default).
-
-tab The views are on top of each other.
-
-lines The views are packed by line.
-
-columns The views are packed by column.
-
-frameseq The views are temporally interleaved.
-
-
-
-
-
-
Some examples:
-
-
-
# Convert left and right views into a frame-sequential video
-ffmpeg -i LEFT -i RIGHT -filter_complex framepack=frameseq OUTPUT
-
-# Convert views into a side-by-side video with the same output resolution as the input
-ffmpeg -i LEFT -i RIGHT -filter_complex [0:v]scale=w=iw/2[left],[1:v]scale=w=iw/2[right],[left][right]framepack=sbs OUTPUT
-
-
-
-
30.37 framestep# TOC
-
-
Select one frame every N-th frame.
-
-
This filter accepts the following option:
-
-step Select frame after every step frames.
-Allowed values are positive integers higher than 0. Default value is 1.
-
-
-
-
30.38 frei0r# TOC
-
-
Apply a frei0r effect to the input video.
-
-
To enable the compilation of this filter, you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the frei0r effect to load. If the environment variable
-FREI0R_PATH is defined, the frei0r effect is searched for in each of the
-directories specified by the colon-separated list in FREIOR_PATH.
-Otherwise, the standard frei0r paths are searched, in this order:
-HOME/.frei0r-1/lib/ , /usr/local/lib/frei0r-1/ ,
-/usr/lib/frei0r-1/ .
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r effect.
-
-
-
-
A frei0r effect parameter can be a boolean (its value is either
-"y" or "n"), a double, a color (specified as
-R /G /B , where R , G , and B are floating point
-numbers between 0.0 and 1.0, inclusive) or by a color description specified in the "Color"
-section in the ffmpeg-utils manual), a position (specified as X /Y , where
-X and Y are floating point numbers) and/or a string.
-
-
The number and types of parameters depend on the loaded effect. If an
-effect parameter is not specified, the default value is set.
-
-
-
30.38.1 Examples# TOC
-
-
- Apply the distort0r effect, setting the first two double parameters:
-
-
frei0r=filter_name=distort0r:filter_params=0.5|0.01
- Apply the colordistance effect, taking a color as the first parameter:
-
-
frei0r=colordistance:0.2/0.3/0.4
-frei0r=colordistance:violet
-frei0r=colordistance:0x112233
- Apply the perspective effect, specifying the top left and top right image
-positions:
-
-
frei0r=perspective:0.2/0.2|0.8/0.2
-
-
-
For more information, see
-http://frei0r.dyne.org
-
-
-
30.39 fspp# TOC
-
-
Apply fast and simple postprocessing. It is a faster version of spp .
-
-
It splits (I)DCT into horizontal/vertical passes. Unlike the simple post-
-processing filter, one of them is performed once per block, not per pixel.
-This allows for much higher speed.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 4-5. Default value is 4.
-
-qp Force a constant quantization parameter. It accepts an integer in range 0-63.
-If not set, the filter will use the QP from the video stream (if available).
-
-strength Set filter strength. It accepts an integer in range -15 to 32. Lower values mean
-more details but also more artifacts, while higher values make the image smoother
-but also blurrier. Default value is 0 − PSNR optimal.
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
-
30.40 geq# TOC
-
-
The filter accepts the following options:
-
-
-lum_expr, lum Set the luminance expression.
-
cb_expr, cb Set the chrominance blue expression.
-
cr_expr, cr Set the chrominance red expression.
-
alpha_expr, a Set the alpha expression.
-
red_expr, r Set the red expression.
-
green_expr, g Set the green expression.
-
blue_expr, b Set the blue expression.
-
-
-
The colorspace is selected according to the specified options. If one
-of the lum_expr , cb_expr , or cr_expr
-options is specified, the filter will automatically select a YCbCr
-colorspace. If one of the red_expr , green_expr , or
-blue_expr options is specified, it will select an RGB
-colorspace.
-
-
If one of the chrominance expression is not defined, it falls back on the other
-one. If no alpha expression is specified it will evaluate to opaque value.
-If none of chrominance expressions are specified, they will evaluate
-to the luminance expression.
-
-
The expressions can use the following variables and functions:
-
-
-N The sequential number of the filtered frame, starting from 0.
-
-X Y The coordinates of the current sample.
-
-W H The width and height of the image.
-
-SW SH Width and height scale depending on the currently filtered plane. It is the
-ratio between the corresponding luma plane number of pixels and the current
-plane ones. E.g. for YUV4:2:0 the values are 1,1 for the luma plane, and
-0.5,0.5 for chroma planes.
-
-T Time of the current frame, expressed in seconds.
-
-p(x, y) Return the value of the pixel at location (x ,y ) of the current
-plane.
-
-lum(x, y) Return the value of the pixel at location (x ,y ) of the luminance
-plane.
-
-cb(x, y) Return the value of the pixel at location (x ,y ) of the
-blue-difference chroma plane. Return 0 if there is no such plane.
-
-cr(x, y) Return the value of the pixel at location (x ,y ) of the
-red-difference chroma plane. Return 0 if there is no such plane.
-
-r(x, y) g(x, y) b(x, y) Return the value of the pixel at location (x ,y ) of the
-red/green/blue component. Return 0 if there is no such component.
-
-alpha(x, y) Return the value of the pixel at location (x ,y ) of the alpha
-plane. Return 0 if there is no such plane.
-
-
-
For functions, if x and y are outside the area, the value will be
-automatically clipped to the closer edge.
-
-
-
30.40.1 Examples# TOC
-
-
- Flip the image horizontally:
-
-
- Generate a bidimensional sine wave, with angle PI/3 and a
-wavelength of 100 pixels:
-
-
geq=128 + 100*sin(2*(PI/100)*(cos(PI/3)*(X-50*T) + sin(PI/3)*Y)):128:128
- Generate a fancy enigmatic moving light:
-
-
nullsrc=s=256x256,geq=random(1)/hypot(X-cos(N*0.07)*W/2-W/2\,Y-sin(N*0.09)*H/2-H/2)^2*1000000*sin(N*0.02):128:128
- Generate a quick emboss effect:
-
-
format=gray,geq=lum_expr='(p(X,Y)+(256-p(X-4,Y-4)))/2'
- Modify RGB components depending on pixel position:
-
-
geq=r='X/W*r(X,Y)':g='(1-X/W)*g(X,Y)':b='(H-Y)/H*b(X,Y)'
- Create a radial gradient that is the same size as the input (also see
-the vignette filter):
-
-
geq=lum=255*gauss((X/W-0.5)*3)*gauss((Y/H-0.5)*3)/gauss(0)/gauss(0),format=gray
- Create a linear gradient to use as a mask for another filter, then
-compose with overlay . In this example the video will gradually
-become more blurry from the top to the bottom of the y-axis as defined
-by the linear gradient:
-
-
ffmpeg -i input.mp4 -filter_complex "geq=lum=255*(Y/H),format=gray[grad];[0:v]boxblur=4[blur];[blur][grad]alphamerge[alpha];[0:v][alpha]overlay" output.mp4
-
-
-
-
30.41 gradfun# TOC
-
-
Fix the banding artifacts that are sometimes introduced into nearly flat
-regions by truncation to 8bit color depth.
-Interpolate the gradients that should go where the bands are, and
-dither them.
-
-
It is designed for playback only. Do not use it prior to
-lossy compression, because compression tends to lose the dither and
-bring back the bands.
-
-
It accepts the following parameters:
-
-
-strength The maximum amount by which the filter will change any one pixel. This is also
-the threshold for detecting nearly flat regions. Acceptable values range from
-.51 to 64; the default value is 1.2. Out-of-range values will be clipped to the
-valid range.
-
-radius The neighborhood to fit the gradient to. A larger radius makes for smoother
-gradients, but also prevents the filter from modifying the pixels near detailed
-regions. Acceptable values are 8-32; the default value is 16. Out-of-range
-values will be clipped to the valid range.
-
-
-
-
Alternatively, the options can be specified as a flat string:
-strength [:radius ]
-
-
-
30.41.1 Examples# TOC
-
-
- Apply the filter with a 3.5 strength and radius of 8:
-
-
- Specify radius, omitting the strength (which will fall-back to the default
-value):
-
-
-
-
-
-
30.42 haldclut# TOC
-
-
Apply a Hald CLUT to a video stream.
-
-
First input is the video stream to process, and second one is the Hald CLUT.
-The Hald CLUT input can be a simple picture or a complete video stream.
-
-
The filter accepts the following options:
-
-
-shortest Force termination when the shortest input terminates. Default is 0.
-
repeatlast Continue applying the last CLUT after the end of the stream. A value of
-0 disable the filter after the last frame of the CLUT is reached.
-Default is 1.
-
-
-
haldclut also has the same interpolation options as lut3d (both
-filters share the same internals).
-
-
More information about the Hald CLUT can be found on Eskil Steenberg’s website
-(Hald CLUT author) at http://www.quelsolaar.com/technology/clut.html .
-
-
-
30.42.1 Workflow examples# TOC
-
-
-
30.42.1.1 Hald CLUT video stream# TOC
-
-
Generate an identity Hald CLUT stream altered with various effects:
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "hue=H=2*PI*t:s=sin(2*PI*t)+1, curves=cross_process" -t 10 -c:v ffv1 clut.nut
-
-
-
Note: make sure you use a lossless codec.
-
-
Then use it with haldclut to apply it on some random stream:
-
-
ffmpeg -f lavfi -i mandelbrot -i clut.nut -filter_complex '[0][1] haldclut' -t 20 mandelclut.mkv
-
-
-
The Hald CLUT will be applied to the 10 first seconds (duration of
-clut.nut ), then the latest picture of that CLUT stream will be applied
-to the remaining frames of the mandelbrot stream.
-
-
-
30.42.1.2 Hald CLUT with preview# TOC
-
-
A Hald CLUT is supposed to be a squared image of Level*Level*Level by
-Level*Level*Level pixels. For a given Hald CLUT, FFmpeg will select the
-biggest possible square starting at the top left of the picture. The remaining
-padding pixels (bottom or right) will be ignored. This area can be used to add
-a preview of the Hald CLUT.
-
-
Typically, the following generated Hald CLUT will be supported by the
-haldclut filter:
-
-
-
ffmpeg -f lavfi -i haldclutsrc =8 -vf "
- pad=iw+320 [padded_clut];
- smptebars=s=320x256, split [a][b];
- [padded_clut][a] overlay=W-320:h, curves=color_negative [main];
- [main][b] overlay=W-320" -frames:v 1 clut.png
-
-
-
It contains the original and a preview of the effect of the CLUT: SMPTE color
-bars are displayed on the right-top, and below the same color bars processed by
-the color changes.
-
-
Then, the effect of this Hald CLUT can be visualized with:
-
-
ffplay input.mkv -vf "movie=clut.png, [in] haldclut"
-
-
-
-
30.43 hflip# TOC
-
-
Flip the input video horizontally.
-
-
For example, to horizontally flip the input video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "hflip" out.avi
-
-
-
-
30.44 histeq# TOC
-
This filter applies a global color histogram equalization on a
-per-frame basis.
-
-
It can be used to correct video that has a compressed range of pixel
-intensities. The filter redistributes the pixel intensities to
-equalize their distribution across the intensity range. It may be
-viewed as an "automatically adjusting contrast filter". This filter is
-useful only for correcting degraded or poorly captured source
-video.
-
-
The filter accepts the following options:
-
-
-strength Determine the amount of equalization to be applied. As the strength
-is reduced, the distribution of pixel intensities more-and-more
-approaches that of the input frame. The value must be a float number
-in the range [0,1] and defaults to 0.200.
-
-intensity Set the maximum intensity that can generated and scale the output
-values appropriately. The strength should be set as desired and then
-the intensity can be limited if needed to avoid washing-out. The value
-must be a float number in the range [0,1] and defaults to 0.210.
-
-antibanding Set the antibanding level. If enabled the filter will randomly vary
-the luminance of output pixels by a small amount to avoid banding of
-the histogram. Possible values are none, weak or
-strong. It defaults to none.
-
-
-
-
30.45 histogram# TOC
-
-
Compute and draw a color distribution histogram for the input video.
-
-
The computed histogram is a representation of the color component
-distribution in an image.
-
-
The filter accepts the following options:
-
-
-mode Set histogram mode.
-
-It accepts the following values:
-
-‘levels ’
-Standard histogram that displays the color components distribution in an
-image. Displays color graph for each color component. Shows distribution of
-the Y, U, V, A or R, G, B components, depending on input format, in the
-current frame. Below each graph a color component scale meter is shown.
-
-‘color ’
-Displays chroma values (U/V color placement) in a two dimensional
-graph (which is called a vectorscope). The brighter a pixel in the
-vectorscope, the more pixels of the input frame correspond to that pixel
-(i.e., more pixels have this chroma value). The V component is displayed on
-the horizontal (X) axis, with the leftmost side being V = 0 and the rightmost
-side being V = 255. The U component is displayed on the vertical (Y) axis,
-with the top representing U = 0 and the bottom representing U = 255.
-
-The position of a white pixel in the graph corresponds to the chroma value of
-a pixel of the input clip. The graph can therefore be used to read the hue
-(color flavor) and the saturation (the dominance of the hue in the color). As
-the hue of a color changes, it moves around the square. At the center of the
-square the saturation is zero, which means that the corresponding pixel has no
-color. If the amount of a specific color is increased (while leaving the other
-colors unchanged) the saturation increases, and the indicator moves towards
-the edge of the square.
-
-‘color2 ’
-Chroma values in vectorscope, similar as color but actual chroma values
-are displayed.
-
-‘waveform ’
-Per row/column color component graph. In row mode, the graph on the left side
-represents color component value 0 and the right side represents value = 255.
-In column mode, the top side represents color component value = 0 and bottom
-side represents value = 255.
-
-Default value is levels.
-
-level_height Set height of level in levels. Default value is 200.
-Allowed range is [50, 2048].
-
-scale_height Set height of color scale in levels. Default value is 12.
-Allowed range is [0, 40].
-
-step Set step for waveform mode. Smaller values are useful to find out how
-many values of the same luminance are distributed across input rows/columns.
-Default value is 10. Allowed range is [1, 255].
-
-waveform_mode Set mode for waveform. Can be either row, or column.
-Default is row.
-
-waveform_mirror Set mirroring mode for waveform. 0 means unmirrored, 1
-means mirrored. In mirrored mode, higher values will be represented on the left
-side for row mode and at the top for column mode. Default is
-0 (unmirrored).
-
-display_mode Set display mode for waveform and levels.
-It accepts the following values:
-
-‘parade ’
-Display separate graph for the color components side by side in
-row waveform mode or one below the other in column waveform mode
-for waveform histogram mode. For levels histogram mode,
-per color component graphs are placed below each other.
-
-Using this display mode in waveform histogram mode makes it easy to
-spot color casts in the highlights and shadows of an image, by comparing the
-contours of the top and the bottom graphs of each waveform. Since whites,
-grays, and blacks are characterized by exactly equal amounts of red, green,
-and blue, neutral areas of the picture should display three waveforms of
-roughly equal width/height. If not, the correction is easy to perform by
-making level adjustments the three waveforms.
-
-‘overlay ’
-Presents information identical to that in the parade, except
-that the graphs representing color components are superimposed directly
-over one another.
-
-This display mode in waveform histogram mode makes it easier to spot
-relative differences or similarities in overlapping areas of the color
-components that are supposed to be identical, such as neutral whites, grays,
-or blacks.
-
-Default is parade.
-
-levels_mode Set mode for levels. Can be either linear, or logarithmic.
-Default is linear.
-
-
-
-
30.45.1 Examples# TOC
-
-
- Calculate and draw histogram:
-
-
ffplay -i input -vf histogram
-
-
-
-
30.46 hqdn3d# TOC
-
-
This is a high precision/quality 3d denoise filter. It aims to reduce
-image noise, producing smooth images and making still images really
-still. It should enhance compressibility.
-
-
It accepts the following optional parameters:
-
-
-luma_spatial A non-negative floating point number which specifies spatial luma strength.
-It defaults to 4.0.
-
-chroma_spatial A non-negative floating point number which specifies spatial chroma strength.
-It defaults to 3.0*luma_spatial /4.0.
-
-luma_tmp A floating point number which specifies luma temporal strength. It defaults to
-6.0*luma_spatial /4.0.
-
-chroma_tmp A floating point number which specifies chroma temporal strength. It defaults to
-luma_tmp *chroma_spatial /luma_spatial .
-
-
-
-
30.47 hqx# TOC
-
-
Apply a high-quality magnification filter designed for pixel art. This filter
-was originally created by Maxim Stepin.
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for hq2x, 3 for
-hq3x and 4 for hq4x.
-Default is 3.
-
-
-
-
30.48 hue# TOC
-
-
Modify the hue and/or the saturation of the input.
-
-
It accepts the following parameters:
-
-
-h Specify the hue angle as a number of degrees. It accepts an expression,
-and defaults to "0".
-
-s Specify the saturation in the [-10,10] range. It accepts an expression and
-defaults to "1".
-
-H Specify the hue angle as a number of radians. It accepts an
-expression, and defaults to "0".
-
-b Specify the brightness in the [-10,10] range. It accepts an expression and
-defaults to "0".
-
-
-
h and H are mutually exclusive, and can’t be
-specified at the same time.
-
-
The b , h , H and s option values are
-expressions containing the following constants:
-
-
-n frame count of the input frame starting from 0
-
-pts presentation timestamp of the input frame expressed in time base units
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t timestamp expressed in seconds, NAN if the input timestamp is unknown
-
-tb time base of the input video
-
-
-
-
30.48.1 Examples# TOC
-
-
-
-
-
30.48.2 Commands# TOC
-
-
This filter supports the following commands:
-
-b s h H Modify the hue and/or the saturation and/or brightness of the input video.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.49 idet# TOC
-
-
Detect video interlacing type.
-
-
This filter tries to detect if the input frames as interlaced, progressive,
-top or bottom field first. It will also try and detect fields that are
-repeated between adjacent frames (a sign of telecine).
-
-
Single frame detection considers only immediately adjacent frames when classifying each frame.
-Multiple frame detection incorporates the classification history of previous frames.
-
-
The filter will log these metadata values:
-
-
-single.current_frame Detected type of current frame using single-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-single.tff Cumulative number of frames detected as top field first using single-frame detection.
-
-multiple.tff Cumulative number of frames detected as top field first using multiple-frame detection.
-
-single.bff Cumulative number of frames detected as bottom field first using single-frame detection.
-
-multiple.current_frame Detected type of current frame using multiple-frame detection. One of:
-“tff” (top field first), “bff” (bottom field first),
-“progressive”, or “undetermined”
-
-multiple.bff Cumulative number of frames detected as bottom field first using multiple-frame detection.
-
-single.progressive Cumulative number of frames detected as progressive using single-frame detection.
-
-multiple.progressive Cumulative number of frames detected as progressive using multiple-frame detection.
-
-single.undetermined Cumulative number of frames that could not be classified using single-frame detection.
-
-multiple.undetermined Cumulative number of frames that could not be classified using multiple-frame detection.
-
-repeated.current_frame Which field in the current frame is repeated from the last. One of “neither”, “top”, or “bottom”.
-
-repeated.neither Cumulative number of frames with no repeated field.
-
-repeated.top Cumulative number of frames with the top field repeated from the previous frame’s top field.
-
-repeated.bottom Cumulative number of frames with the bottom field repeated from the previous frame’s bottom field.
-
-
-
The filter accepts the following options:
-
-
-intl_thres Set interlacing threshold.
-
prog_thres Set progressive threshold.
-
repeat_thres Threshold for repeated field detection.
-
half_life Number of frames after which a given frame’s contribution to the
-statistics is halved (i.e., it contributes only 0.5 to it’s
-classification). The default of 0 means that all frames seen are given
-full weight of 1.0 forever.
-
analyze_interlaced_flag When this is not 0 then idet will use the specified number of frames to determine
-if the interlaced flag is accurate, it will not count undetermined frames.
-If the flag is found to be accurate it will be used without any further
-computations, if it is found to be inaccuarte it will be cleared without any
-further computations. This allows inserting the idet filter as a low computational
-method to clean up the interlaced flag
-
-
-
-
30.50 il# TOC
-
-
Deinterleave or interleave fields.
-
-
This filter allows one to process interlaced images fields without
-deinterlacing them. Deinterleaving splits the input frame into 2
-fields (so called half pictures). Odd lines are moved to the top
-half of the output image, even lines to the bottom half.
-You can process (filter) them independently and then re-interleave them.
-
-
The filter accepts the following options:
-
-
-luma_mode, l chroma_mode, c alpha_mode, a Available values for luma_mode , chroma_mode and
-alpha_mode are:
-
-
-‘none ’
-Do nothing.
-
-‘deinterleave, d ’
-Deinterleave fields, placing one above the other.
-
-‘interleave, i ’
-Interleave fields. Reverse the effect of deinterleaving.
-
-Default value is none.
-
-luma_swap, ls chroma_swap, cs alpha_swap, as Swap luma/chroma/alpha fields. Exchange even & odd lines. Default value is 0.
-
-
-
-
30.51 interlace# TOC
-
-
Simple interlacing filter from progressive contents. This interleaves upper (or
-lower) lines from odd frames with lower (or upper) lines from even frames,
-halving the frame rate and preserving image height.
-
-
-
Original Original New Frame
- Frame 'j' Frame 'j+1' (tff)
- ========== =========== ==================
- Line 0 --------------------> Frame 'j' Line 0
- Line 1 Line 1 ----> Frame 'j+1' Line 1
- Line 2 ---------------------> Frame 'j' Line 2
- Line 3 Line 3 ----> Frame 'j+1' Line 3
- ... ... ...
-New Frame + 1 will be generated by Frame 'j+2' and Frame 'j+3' and so on
-
-
-
It accepts the following optional parameters:
-
-
-scan This determines whether the interlaced frame is taken from the even
-(tff - default) or odd (bff) lines of the progressive frame.
-
-lowpass Enable (default) or disable the vertical lowpass filter to avoid twitter
-interlacing and reduce moire patterns.
-
-
-
-
30.52 kerndeint# TOC
-
-
Deinterlace input video by applying Donald Graft’s adaptive kernel
-deinterling. Work on interlaced parts of a video to produce
-progressive frames.
-
-
The description of the accepted parameters follows.
-
-
-thresh Set the threshold which affects the filter’s tolerance when
-determining if a pixel line must be processed. It must be an integer
-in the range [0,255] and defaults to 10. A value of 0 will result in
-applying the process on every pixels.
-
-map Paint pixels exceeding the threshold value to white if set to 1.
-Default is 0.
-
-order Set the fields order. Swap fields if set to 1, leave fields alone if
-0. Default is 0.
-
-sharp Enable additional sharpening if set to 1. Default is 0.
-
-twoway Enable twoway sharpening if set to 1. Default is 0.
-
-
-
-
30.52.1 Examples# TOC
-
-
- Apply default values:
-
-
kerndeint=thresh=10:map=0:order=0:sharp=0:twoway=0
- Enable additional sharpening:
-
-
- Paint processed pixels in white:
-
-
-
-
-
30.53 lenscorrection# TOC
-
-
Correct radial lens distortion
-
-
This filter can be used to correct for radial distortion as can result from the use
-of wide angle lenses, and thereby re-rectify the image. To find the right parameters
-one can use tools available for example as part of opencv or simply trial-and-error.
-To use opencv use the calibration sample (under samples/cpp) from the opencv sources
-and extract the k1 and k2 coefficients from the resulting matrix.
-
-
Note that effectively the same filter is available in the open-source tools Krita and
-Digikam from the KDE project.
-
-
In contrast to the vignette filter, which can also be used to compensate lens errors,
-this filter corrects the distortion of the image, whereas vignette corrects the
-brightness distribution, so you may want to use both filters together in certain
-cases, though you will have to take care of ordering, i.e. whether vignetting should
-be applied before or after lens correction.
-
-
-
30.53.1 Options# TOC
-
-
The filter accepts the following options:
-
-
-cx Relative x-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-width.
-
cy Relative y-coordinate of the focal point of the image, and thereby the center of the
-distortion. This value has a range [0,1] and is expressed as fractions of the image
-height.
-
k1 Coefficient of the quadratic correction term. 0.5 means no correction.
-
k2 Coefficient of the double quadratic correction term. 0.5 means no correction.
-
-
-
The formula that generates the correction is:
-
-
r_src = r_tgt * (1 + k1 * (r_tgt / r_0 )^2 + k2 * (r_tgt / r_0 )^4)
-
-
where r_0 is halve of the image diagonal and r_src and r_tgt are the
-distances from the focal point in the source and target images, respectively.
-
-
-
30.54 lut3d# TOC
-
-
Apply a 3D LUT to an input video.
-
-
The filter accepts the following options:
-
-
-file Set the 3D LUT file name.
-
-Currently supported formats:
-
-‘3dl ’
-AfterEffects
-
‘cube ’
-Iridas
-
‘dat ’
-DaVinci
-
‘m3d ’
-Pandora
-
-interp Select interpolation mode.
-
-Available values are:
-
-
-‘nearest ’
-Use values from the nearest defined point.
-
‘trilinear ’
-Interpolate values using the 8 points defining a cube.
-
‘tetrahedral ’
-Interpolate values using a tetrahedron.
-
-
-
-
-
30.55 lut, lutrgb, lutyuv# TOC
-
-
Compute a look-up table for binding each pixel component input value
-to an output value, and apply it to the input video.
-
-
lutyuv applies a lookup table to a YUV input video, lutrgb
-to an RGB input video.
-
-
These filters accept the following parameters:
-
-c0 set first pixel component expression
-
c1 set second pixel component expression
-
c2 set third pixel component expression
-
c3 set fourth pixel component expression, corresponds to the alpha component
-
-r set red component expression
-
g set green component expression
-
b set blue component expression
-
a alpha component expression
-
-y set Y/luminance component expression
-
u set U/Cb component expression
-
v set V/Cr component expression
-
-
-
Each of them specifies the expression to use for computing the lookup table for
-the corresponding pixel component values.
-
-
The exact component associated to each of the c* options depends on the
-format in input.
-
-
The lut filter requires either YUV or RGB pixel formats in input,
-lutrgb requires RGB pixel formats in input, and lutyuv requires YUV.
-
-
The expressions can contain the following constants and functions:
-
-
-w h The input width and height.
-
-val The input value for the pixel component.
-
-clipval The input value, clipped to the minval -maxval range.
-
-maxval The maximum value for the pixel component.
-
-minval The minimum value for the pixel component.
-
-negval The negated value for the pixel component value, clipped to the
-minval -maxval range; it corresponds to the expression
-"maxval-clipval+minval".
-
-clip(val) The computed value in val , clipped to the
-minval -maxval range.
-
-gammaval(gamma) The computed gamma correction value of the pixel component value,
-clipped to the minval -maxval range. It corresponds to the
-expression
-"pow((clipval-minval)/(maxval-minval)\,gamma )*(maxval-minval)+minval"
-
-
-
-
All expressions default to "val".
-
-
-
30.55.1 Examples# TOC
-
-
-
-
-
30.56 mergeplanes# TOC
-
-
Merge color channel components from several video streams.
-
-
The filter accepts up to 4 input streams, and merge selected input
-planes to the output video.
-
-
This filter accepts the following options:
-
-mapping Set input to output plane mapping. Default is 0.
-
-The mappings is specified as a bitmap. It should be specified as a
-hexadecimal number in the form 0xAa[Bb[Cc[Dd]]]. ’Aa’ describes the
-mapping for the first plane of the output stream. ’A’ sets the number of
-the input stream to use (from 0 to 3), and ’a’ the plane number of the
-corresponding input to use (from 0 to 3). The rest of the mappings is
-similar, ’Bb’ describes the mapping for the output stream second
-plane, ’Cc’ describes the mapping for the output stream third plane and
-’Dd’ describes the mapping for the output stream fourth plane.
-
-format Set output pixel format. Default is yuva444p.
-
-
-
-
30.56.1 Examples# TOC
-
-
- Merge three gray video streams of same width and height into single video stream:
-
-
[a0][a1][a2]mergeplanes=0x001020:yuv444p
- Merge 1st yuv444p stream and 2nd gray video stream into yuva444p video stream:
-
-
[a0][a1]mergeplanes=0x00010210:yuva444p
- Swap Y and A plane in yuva444p stream:
-
-
format=yuva444p,mergeplanes=0x03010200:yuva444p
- Swap U and V plane in yuv420p stream:
-
-
format=yuv420p,mergeplanes=0x000201:yuv420p
- Cast a rgb24 clip to yuv444p:
-
-
format=rgb24,mergeplanes=0x000102:yuv444p
-
-
-
-
30.57 mcdeint# TOC
-
-
Apply motion-compensation deinterlacing.
-
-
It needs one field per frame as input and must thus be used together
-with yadif=1/3 or equivalent.
-
-
This filter accepts the following options:
-
-mode Set the deinterlacing mode.
-
-It accepts one of the following values:
-
-‘fast ’
-‘medium ’
-‘slow ’
-use iterative motion estimation
-
‘extra_slow ’
-like ‘slow ’, but use multiple reference frames.
-
-Default value is ‘fast ’.
-
-parity Set the picture field parity assumed for the input video. It must be
-one of the following values:
-
-
-‘0, tff ’
-assume top field first
-
‘1, bff ’
-assume bottom field first
-
-
-Default value is ‘bff ’.
-
-qp Set per-block quantization parameter (QP) used by the internal
-encoder.
-
-Higher values should result in a smoother motion vector field but less
-optimal individual vectors. Default value is 1.
-
-
-
-
30.58 mp# TOC
-
-
Apply an MPlayer filter to the input video.
-
-
This filter provides a wrapper around some of the filters of
-MPlayer/MEncoder.
-
-
This wrapper is considered experimental. Some of the wrapped filters
-may not work properly and we may drop support for them, as they will
-be implemented natively into FFmpeg. Thus you should avoid
-depending on them when writing portable scripts.
-
-
The filter accepts the parameters:
-filter_name [:=]filter_params
-
-
filter_name is the name of a supported MPlayer filter,
-filter_params is a string containing the parameters accepted by
-the named filter.
-
-
The list of the currently supported filters follows:
-
-eq2 eq ilpack softpulldown
-
-
The parameter syntax and behavior for the listed filters are the same
-of the corresponding MPlayer filters. For detailed instructions check
-the "VIDEO FILTERS" section in the MPlayer manual.
-
-
-
30.58.1 Examples# TOC
-
-
- Adjust gamma, brightness, contrast:
-
-
-
-
See also mplayer(1), http://www.mplayerhq.hu/ .
-
-
-
30.59 mpdecimate# TOC
-
-
Drop frames that do not differ greatly from the previous frame in
-order to reduce frame rate.
-
-
The main use of this filter is for very-low-bitrate encoding
-(e.g. streaming over dialup modem), but it could in theory be used for
-fixing movies that were inverse-telecined incorrectly.
-
-
A description of the accepted options follows.
-
-
-max Set the maximum number of consecutive frames which can be dropped (if
-positive), or the minimum interval between dropped frames (if
-negative). If the value is 0, the frame is dropped unregarding the
-number of previous sequentially dropped frames.
-
-Default value is 0.
-
-hi lo frac Set the dropping threshold values.
-
-Values for hi and lo are for 8x8 pixel blocks and
-represent actual pixel value differences, so a threshold of 64
-corresponds to 1 unit of difference for each pixel, or the same spread
-out differently over the block.
-
-A frame is a candidate for dropping if no 8x8 blocks differ by more
-than a threshold of hi , and if no more than frac blocks (1
-meaning the whole image) differ by more than a threshold of lo .
-
-Default value for hi is 64*12, default value for lo is
-64*5, and default value for frac is 0.33.
-
-
-
-
-
30.60 negate# TOC
-
-
Negate input video.
-
-
It accepts an integer in input; if non-zero it negates the
-alpha component (if available). The default value in input is 0.
-
-
-
30.61 noformat# TOC
-
-
Force libavfilter not to use any of the specified pixel formats for the
-input to the next filter.
-
-
It accepts the following parameters:
-
-pix_fmts A ’|’-separated list of pixel format names, such as
-apix_fmts=yuv420p|monow|rgb24".
-
-
-
-
-
30.61.1 Examples# TOC
-
-
- Force libavfilter to use a format different from yuv420p for the
-input to the vflip filter:
-
-
noformat=pix_fmts=yuv420p,vflip
- Convert the input video to any of the formats not contained in the list:
-
-
noformat=yuv420p|yuv444p|yuv410p
-
-
-
-
30.62 noise# TOC
-
-
Add noise on video input frame.
-
-
The filter accepts the following options:
-
-
-all_seed c0_seed c1_seed c2_seed c3_seed Set noise seed for specific pixel component or all pixel components in case
-of all_seed . Default value is 123457.
-
-all_strength, alls c0_strength, c0s c1_strength, c1s c2_strength, c2s c3_strength, c3s Set noise strength for specific pixel component or all pixel components in case
-all_strength . Default value is 0. Allowed range is [0, 100].
-
-all_flags, allf c0_flags, c0f c1_flags, c1f c2_flags, c2f c3_flags, c3f Set pixel component flags or set flags for all components if all_flags .
-Available values for component flags are:
-
-‘a ’
-averaged temporal noise (smoother)
-
‘p ’
-mix random noise with a (semi)regular pattern
-
‘t ’
-temporal noise (noise pattern changes between frames)
-
‘u ’
-uniform noise (gaussian otherwise)
-
-
-
-
-
30.62.1 Examples# TOC
-
-
Add temporal and uniform noise to input video:
-
-
noise=alls=20:allf=t+u
-
-
-
-
30.63 null# TOC
-
-
Pass the video source unchanged to the output.
-
-
-
30.64 ocv# TOC
-
-
Apply a video transform using libopencv.
-
-
To enable this filter, install the libopencv library and headers and
-configure FFmpeg with --enable-libopencv.
-
-
It accepts the following parameters:
-
-
-filter_name The name of the libopencv filter to apply.
-
-filter_params The parameters to pass to the libopencv filter. If not specified, the default
-values are assumed.
-
-
-
-
Refer to the official libopencv documentation for more precise
-information:
-http://docs.opencv.org/master/modules/imgproc/doc/filtering.html
-
-
Several libopencv filters are supported; see the following subsections.
-
-
-
30.64.1 dilate# TOC
-
-
Dilate an image by using a specific structuring element.
-It corresponds to the libopencv function cvDilate.
-
-
It accepts the parameters: struct_el |nb_iterations .
-
-
struct_el represents a structuring element, and has the syntax:
-cols xrows +anchor_x xanchor_y /shape
-
-
cols and rows represent the number of columns and rows of
-the structuring element, anchor_x and anchor_y the anchor
-point, and shape the shape for the structuring element. shape
-must be "rect", "cross", "ellipse", or "custom".
-
-
If the value for shape is "custom", it must be followed by a
-string of the form "=filename ". The file with name
-filename is assumed to represent a binary image, with each
-printable character corresponding to a bright pixel. When a custom
-shape is used, cols and rows are ignored, the number
-or columns and rows of the read file are assumed instead.
-
-
The default value for struct_el is "3x3+0x0/rect".
-
-
nb_iterations specifies the number of times the transform is
-applied to the image, and defaults to 1.
-
-
Some examples:
-
-
# Use the default values
-ocv=dilate
-
-# Dilate using a structuring element with a 5x5 cross, iterating two times
-ocv=filter_name=dilate:filter_params=5x5+2x2/cross|2
-
-# Read the shape from the file diamond.shape, iterating two times.
-# The file diamond.shape may contain a pattern of characters like this
-# *
-# ***
-# *****
-# ***
-# *
-# The specified columns and rows are ignored
-# but the anchor point coordinates are not
-ocv=dilate:0x0+2x2/custom=diamond.shape|2
-
-
-
-
30.64.2 erode# TOC
-
-
Erode an image by using a specific structuring element.
-It corresponds to the libopencv function cvErode.
-
-
It accepts the parameters: struct_el :nb_iterations ,
-with the same syntax and semantics as the dilate filter.
-
-
-
30.64.3 smooth# TOC
-
-
Smooth the input video.
-
-
The filter takes the following parameters:
-type |param1 |param2 |param3 |param4 .
-
-
type is the type of smooth filter to apply, and must be one of
-the following values: "blur", "blur_no_scale", "median", "gaussian",
-or "bilateral". The default value is "gaussian".
-
-
The meaning of param1 , param2 , param3 , and param4
-depend on the smooth type. param1 and
-param2 accept integer positive values or 0. param3 and
-param4 accept floating point values.
-
-
The default value for param1 is 3. The default value for the
-other parameters is 0.
-
-
These parameters correspond to the parameters assigned to the
-libopencv function cvSmooth.
-
-
-
30.65 overlay# TOC
-
-
Overlay one video on top of another.
-
-
It takes two inputs and has one output. The first input is the "main"
-video on which the second input is overlaid.
-
-
It accepts the following parameters:
-
-
A description of the accepted options follows.
-
-
-x y Set the expression for the x and y coordinates of the overlaid video
-on the main video. Default value is "0" for both expressions. In case
-the expression is invalid, it is set to a huge value (meaning that the
-overlay will not be displayed within the output visible area).
-
-eof_action The action to take when EOF is encountered on the secondary input; it accepts
-one of the following values:
-
-
-repeat Repeat the last frame (the default).
-
endall End both streams.
-
pass Pass the main input through.
-
-
-eval Set when the expressions for x , and y are evaluated.
-
-It accepts the following values:
-
-‘init ’
-only evaluate expressions once during the filter initialization or
-when a command is processed
-
-‘frame ’
-evaluate expressions for each incoming frame
-
-
-Default value is ‘frame ’.
-
-shortest If set to 1, force the output to terminate when the shortest input
-terminates. Default value is 0.
-
-format Set the format for the output video.
-
-It accepts the following values:
-
-‘yuv420 ’
-force YUV420 output
-
-‘yuv422 ’
-force YUV422 output
-
-‘yuv444 ’
-force YUV444 output
-
-‘rgb ’
-force RGB output
-
-
-Default value is ‘yuv420 ’.
-
-rgb (deprecated) If set to 1, force the filter to accept inputs in the RGB
-color space. Default value is 0. This option is deprecated, use
-format instead.
-
-repeatlast If set to 1, force the filter to draw the last overlay frame over the
-main input until the end of the stream. A value of 0 disables this
-behavior. Default value is 1.
-
-
-
The x , and y expressions can contain the following
-parameters.
-
-
-main_w, W main_h, H The main input width and height.
-
-overlay_w, w overlay_h, h The overlay input width and height.
-
-x y The computed values for x and y . They are evaluated for
-each new frame.
-
-hsub vsub horizontal and vertical chroma subsample values of the output
-format. For example for the pixel format "yuv422p" hsub is 2 and
-vsub is 1.
-
-n the number of input frame, starting from 0
-
-pos the position in the file of the input frame, NAN if unknown
-
-t The timestamp, expressed in seconds. It’s NAN if the input timestamp is unknown.
-
-
-
-
Note that the n , pos , t variables are available only
-when evaluation is done per frame , and will evaluate to NAN
-when eval is set to ‘init ’.
-
-
Be aware that frames are taken from each input video in timestamp
-order, hence, if their initial timestamps differ, it is a good idea
-to pass the two inputs through a setpts=PTS-STARTPTS filter to
-have them begin in the same zero timestamp, as the example for
-the movie filter does.
-
-
You can chain together more overlays but you should test the
-efficiency of such approach.
-
-
-
30.65.1 Commands# TOC
-
-
This filter supports the following commands:
-
-x y Modify the x and y of the overlay input.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.65.2 Examples# TOC
-
-
-
-
-
30.66 owdenoise# TOC
-
-
Apply Overcomplete Wavelet denoiser.
-
-
The filter accepts the following options:
-
-
-depth Set depth.
-
-Larger depth values will denoise lower frequency components more, but
-slow down filtering.
-
-Must be an int in the range 8-16, default is 8.
-
-luma_strength, ls Set luma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-chroma_strength, cs Set chroma strength.
-
-Must be a double value in the range 0-1000, default is 1.0.
-
-
-
-
30.67 pad# TOC
-
-
Add paddings to the input image, and place the original input at the
-provided x , y coordinates.
-
-
It accepts the following parameters:
-
-
-width, w height, h Specify an expression for the size of the output image with the
-paddings added. If the value for width or height is 0, the
-corresponding input size is used for the output.
-
-The width expression can reference the value set by the
-height expression, and vice versa.
-
-The default value of width and height is 0.
-
-x y Specify the offsets to place the input image at within the padded area,
-with respect to the top/left border of the output image.
-
-The x expression can reference the value set by the y
-expression, and vice versa.
-
-The default value of x and y is 0.
-
-color Specify the color of the padded area. For the syntax of this option,
-check the "Color" section in the ffmpeg-utils manual.
-
-The default value of color is "black".
-
-
-
The value for the width , height , x , and y
-options are expressions containing the following constants:
-
-
-in_w in_h The input video width and height.
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output width and height (the size of the padded area), as
-specified by the width and height expressions.
-
-ow oh These are the same as out_w and out_h .
-
-x y The x and y offsets as specified by the x and y
-expressions, or NAN if not yet specified.
-
-a same as iw / ih
-
-sar input sample aspect ratio
-
-dar input display aspect ratio, it is the same as (iw / ih ) * sar
-
-hsub vsub The horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.67.1 Examples# TOC
-
-
-
-
-
30.68 perspective# TOC
-
-
Correct perspective of video not recorded perpendicular to the screen.
-
-
A description of the accepted parameters follows.
-
-
-x0 y0 x1 y1 x2 y2 x3 y3 Set coordinates expression for top left, top right, bottom left and bottom right corners.
-Default values are 0:0:W:0:0:H:W:H with which perspective will remain unchanged.
-If the sense option is set to source, then the specified points will be sent
-to the corners of the destination. If the sense option is set to destination,
-then the corners of the source will be sent to the specified coordinates.
-
-The expressions can use the following variables:
-
-
-W H the width and height of video frame.
-
-
-interpolation Set interpolation for perspective correction.
-
-It accepts the following values:
-
-‘linear ’
-‘cubic ’
-
-
-Default value is ‘linear ’.
-
-sense Set interpretation of coordinate options.
-
-It accepts the following values:
-
-‘0, source ’
-
-Send point in the source specified by the given coordinates to
-the corners of the destination.
-
-
-‘1, destination ’
-
-Send the corners of the source to the point in the destination specified
-by the given coordinates.
-
-Default value is ‘source ’.
-
-
-
-
-
-
30.69 phase# TOC
-
-
Delay interlaced video by one field time so that the field order changes.
-
-
The intended use is to fix PAL movies that have been captured with the
-opposite field order to the film-to-video transfer.
-
-
A description of the accepted parameters follows.
-
-
-mode Set phase mode.
-
-It accepts the following values:
-
-‘t ’
-Capture field order top-first, transfer bottom-first.
-Filter will delay the bottom field.
-
-‘b ’
-Capture field order bottom-first, transfer top-first.
-Filter will delay the top field.
-
-‘p ’
-Capture and transfer with the same field order. This mode only exists
-for the documentation of the other options to refer to, but if you
-actually select it, the filter will faithfully do nothing.
-
-‘a ’
-Capture field order determined automatically by field flags, transfer
-opposite.
-Filter selects among ‘t ’ and ‘b ’ modes on a frame by frame
-basis using field flags. If no field information is available,
-then this works just like ‘u ’.
-
-‘u ’
-Capture unknown or varying, transfer opposite.
-Filter selects among ‘t ’ and ‘b ’ on a frame by frame basis by
-analyzing the images and selecting the alternative that produces best
-match between the fields.
-
-‘T ’
-Capture top-first, transfer unknown or varying.
-Filter selects among ‘t ’ and ‘p ’ using image analysis.
-
-‘B ’
-Capture bottom-first, transfer unknown or varying.
-Filter selects among ‘b ’ and ‘p ’ using image analysis.
-
-‘A ’
-Capture determined by field flags, transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using field flags and
-image analysis. If no field information is available, then this works just
-like ‘U ’. This is the default mode.
-
-‘U ’
-Both capture and transfer unknown or varying.
-Filter selects among ‘t ’, ‘b ’ and ‘p ’ using image analysis only.
-
-
-
-
-
30.70 pixdesctest# TOC
-
-
Pixel format descriptor test filter, mainly useful for internal
-testing. The output video should be equal to the input video.
-
-
For example:
-
-
format=monow, pixdesctest
-
-
-
can be used to test the monowhite pixel format descriptor definition.
-
-
-
30.71 pp# TOC
-
-
Enable the specified chain of postprocessing subfilters using libpostproc. This
-library should be automatically selected with a GPL build (--enable-gpl).
-Subfilters must be separated by ’/’ and can be disabled by prepending a ’-’.
-Each subfilter and some options have a short and a long name that can be used
-interchangeably, i.e. dr/dering are the same.
-
-
The filters accept the following options:
-
-
-subfilters Set postprocessing subfilters string.
-
-
-
All subfilters share common options to determine their scope:
-
-
-a/autoq Honor the quality commands for this subfilter.
-
-c/chrom Do chrominance filtering, too (default).
-
-y/nochrom Do luminance filtering only (no chrominance).
-
-n/noluma Do chrominance filtering only (no luminance).
-
-
-
These options can be appended after the subfilter name, separated by a ’|’.
-
-
Available subfilters are:
-
-
-hb/hdeblock[|difference[|flatness]] Horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-vb/vdeblock[|difference[|flatness]] Vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-ha/hadeblock[|difference[|flatness]] Accurate horizontal deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-va/vadeblock[|difference[|flatness]] Accurate vertical deblocking filter
-
-difference Difference factor where higher values mean more deblocking (default: 32).
-
flatness Flatness threshold where lower values mean more deblocking (default: 39).
-
-
-
-
The horizontal and vertical deblocking filters share the difference and
-flatness values so you cannot set different horizontal and vertical
-thresholds.
-
-
-h1/x1hdeblock Experimental horizontal deblocking filter
-
-v1/x1vdeblock Experimental vertical deblocking filter
-
-dr/dering Deringing filter
-
-tn/tmpnoise[|threshold1[|threshold2[|threshold3]]], temporal noise reducer
-threshold1 larger -> stronger filtering
-
threshold2 larger -> stronger filtering
-
threshold3 larger -> stronger filtering
-
-
-al/autolevels[:f/fullyrange], automatic brightness / contrast correction
-f/fullyrange Stretch luminance to 0-255.
-
-
-lb/linblenddeint Linear blend deinterlacing filter that deinterlaces the given block by
-filtering all lines with a (1 2 1) filter.
-
-li/linipoldeint Linear interpolating deinterlacing filter that deinterlaces the given block by
-linearly interpolating every second line.
-
-ci/cubicipoldeint Cubic interpolating deinterlacing filter deinterlaces the given block by
-cubically interpolating every second line.
-
-md/mediandeint Median deinterlacing filter that deinterlaces the given block by applying a
-median filter to every second line.
-
-fd/ffmpegdeint FFmpeg deinterlacing filter that deinterlaces the given block by filtering every
-second line with a (-1 4 2 4 -1) filter.
-
-l5/lowpass5 Vertically applied FIR lowpass deinterlacing filter that deinterlaces the given
-block by filtering all lines with a (-1 2 6 2 -1) filter.
-
-fq/forceQuant[|quantizer] Overrides the quantizer table from the input with the constant quantizer you
-specify.
-
-quantizer Quantizer to use
-
-
-de/default Default pp filter combination (hb|a,vb|a,dr|a)
-
-fa/fast Fast pp filter combination (h1|a,v1|a,dr|a)
-
-ac High quality pp filter combination (ha|a|128|7,va|a,dr|a)
-
-
-
-
30.71.1 Examples# TOC
-
-
- Apply horizontal and vertical deblocking, deringing and automatic
-brightness/contrast:
-
-
- Apply default filters without brightness/contrast correction:
-
-
- Apply default filters and temporal denoiser:
-
-
pp=default/tmpnoise|1|2|3
- Apply deblocking on luminance only, and switch vertical deblocking on or off
-automatically depending on available CPU time:
-
-
-
-
-
30.72 pp7# TOC
-
Apply Postprocessing filter 7. It is variant of the spp filter,
-similar to spp = 6 with 7 point DCT, where only the center sample is
-used after IDCT.
-
-
The filter accepts the following options:
-
-
-qp Force a constant quantization parameter. It accepts an integer in range
-0 to 63. If not set, the filter will use the QP from the video stream
-(if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding.
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
‘medium ’
-Set medium thresholding (good results, default).
-
-
-
-
-
30.73 psnr# TOC
-
-
Obtain the average, maximum and minimum PSNR (Peak Signal to Noise
-Ratio) between two input videos.
-
-
This filter takes in input two input videos, the first input is
-considered the "main" source and is passed unchanged to the
-output. The second input is used as a "reference" video for computing
-the PSNR.
-
-
Both video inputs must have the same resolution and pixel format for
-this filter to work correctly. Also it assumes that both inputs
-have the same number of frames, which are compared one by one.
-
-
The obtained average PSNR is printed through the logging system.
-
-
The filter stores the accumulated MSE (mean squared error) of each
-frame, and at the end of the processing it is averaged across all frames
-equally, and the following formula is applied to obtain the PSNR:
-
-
-
PSNR = 10*log10(MAX^2/MSE)
-
-
-
Where MAX is the average of the maximum values of each component of the
-image.
-
-
The description of the accepted parameters follows.
-
-
-stats_file, f If specified the filter will use the named file to save the PSNR of
-each individual frame.
-
-
-
The file printed if stats_file is selected, contains a sequence of
-key/value pairs of the form key :value for each compared
-couple of frames.
-
-
A description of each shown parameter follows:
-
-
-n sequential number of the input frame, starting from 1
-
-mse_avg Mean Square Error pixel-by-pixel average difference of the compared
-frames, averaged over all the image components.
-
-mse_y, mse_u, mse_v, mse_r, mse_g, mse_g, mse_a Mean Square Error pixel-by-pixel average difference of the compared
-frames for the component specified by the suffix.
-
-psnr_y, psnr_u, psnr_v, psnr_r, psnr_g, psnr_b, psnr_a Peak Signal to Noise ratio of the compared frames for the component
-specified by the suffix.
-
-
-
For example:
-
-
movie=ref_movie.mpg, setpts=PTS-STARTPTS [main];
-[main][ref] psnr="stats_file=stats.log" [out]
-
-
-
On this example the input file being processed is compared with the
-reference file ref_movie.mpg . The PSNR of each individual frame
-is stored in stats.log .
-
-
-
30.74 pullup# TOC
-
-
Pulldown reversal (inverse telecine) filter, capable of handling mixed
-hard-telecine, 24000/1001 fps progressive, and 30000/1001 fps progressive
-content.
-
-
The pullup filter is designed to take advantage of future context in making
-its decisions. This filter is stateless in the sense that it does not lock
-onto a pattern to follow, but it instead looks forward to the following
-fields in order to identify matches and rebuild progressive frames.
-
-
To produce content with an even framerate, insert the fps filter after
-pullup, use fps=24000/1001 if the input frame rate is 29.97fps,
-fps=24 for 30fps and the (rare) telecined 25fps input.
-
-
The filter accepts the following options:
-
-
-jl jr jt jb These options set the amount of "junk" to ignore at the left, right, top, and
-bottom of the image, respectively. Left and right are in units of 8 pixels,
-while top and bottom are in units of 2 lines.
-The default is 8 pixels on each side.
-
-sb Set the strict breaks. Setting this option to 1 will reduce the chances of
-filter generating an occasional mismatched frame, but it may also cause an
-excessive number of frames to be dropped during high motion sequences.
-Conversely, setting it to -1 will make filter match fields more easily.
-This may help processing of video where there is slight blurring between
-the fields, but may also cause there to be interlaced frames in the output.
-Default value is 0.
-
-mp Set the metric plane to use. It accepts the following values:
-
-‘l ’
-Use luma plane.
-
-‘u ’
-Use chroma blue plane.
-
-‘v ’
-Use chroma red plane.
-
-
-This option may be set to use chroma plane instead of the default luma plane
-for doing filter’s computations. This may improve accuracy on very clean
-source material, but more likely will decrease accuracy, especially if there
-is chroma noise (rainbow effect) or any grayscale video.
-The main purpose of setting mp to a chroma plane is to reduce CPU
-load and make pullup usable in realtime on slow machines.
-
-
-
For best results (without duplicated frames in the output file) it is
-necessary to change the output frame rate. For example, to inverse
-telecine NTSC input:
-
-
ffmpeg -i input -vf pullup -r 24000/1001 ...
-
-
-
-
30.75 qp# TOC
-
-
Change video quantization parameters (QP).
-
-
The filter accepts the following option:
-
-
-qp Set expression for quantization parameter.
-
-
-
The expression is evaluated through the eval API and can contain, among others,
-the following constants:
-
-
-known 1 if index is not 129, 0 otherwise.
-
-qp Sequentional index starting from -129 to 128.
-
-
-
-
30.75.1 Examples# TOC
-
-
- Some equation like:
-
-
-
-
-
30.76 removelogo# TOC
-
-
Suppress a TV station logo, using an image file to determine which
-pixels comprise the logo. It works by filling in the pixels that
-comprise the logo with neighboring pixels.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filter bitmap file, which can be any image format supported by
-libavformat. The width and height of the image file must match those of the
-video stream being processed.
-
-
-
Pixels in the provided bitmap image with a value of zero are not
-considered part of the logo, non-zero pixels are considered part of
-the logo. If you use white (255) for the logo and black (0) for the
-rest, you will be safe. For making the filter bitmap, it is
-recommended to take a screen capture of a black frame with the logo
-visible, and then using a threshold filter followed by the erode
-filter once or twice.
-
-
If needed, little splotches can be fixed manually. Remember that if
-logo pixels are not covered, the filter quality will be much
-reduced. Marking too many pixels as part of the logo does not hurt as
-much, but it will increase the amount of blurring needed to cover over
-the image and will destroy more information than necessary, and extra
-pixels will slow things down on a large logo.
-
-
-
30.77 rotate# TOC
-
-
Rotate video by an arbitrary angle expressed in radians.
-
-
The filter accepts the following options:
-
-
A description of the optional parameters follows.
-
-angle, a Set an expression for the angle by which to rotate the input video
-clockwise, expressed as a number of radians. A negative value will
-result in a counter-clockwise rotation. By default it is set to "0".
-
-This expression is evaluated for each frame.
-
-out_w, ow Set the output width expression, default value is "iw".
-This expression is evaluated just once during configuration.
-
-out_h, oh Set the output height expression, default value is "ih".
-This expression is evaluated just once during configuration.
-
-bilinear Enable bilinear interpolation if set to 1, a value of 0 disables
-it. Default value is 1.
-
-fillcolor, c Set the color used to fill the output area not covered by the rotated
-image. For the general syntax of this option, check the "Color" section in the
-ffmpeg-utils manual. If the special value "none" is selected then no
-background is printed (useful for example if the background is never shown).
-
-Default value is "black".
-
-
-
The expressions for the angle and the output size can contain the
-following constants and functions:
-
-
-n sequential number of the input frame, starting from 0. It is always NAN
-before the first frame is filtered.
-
-t time in seconds of the input frame, it is set to 0 when the filter is
-configured. It is always NAN before the first frame is filtered.
-
-hsub vsub horizontal and vertical chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-in_w, iw in_h, ih the input video width and height
-
-out_w, ow out_h, oh the output width and height, that is the size of the padded area as
-specified by the width and height expressions
-
-rotw(a) roth(a) the minimal width/height required for completely containing the input
-video rotated by a radians.
-
-These are only available when computing the out_w and
-out_h expressions.
-
-
-
-
30.77.1 Examples# TOC
-
-
- Rotate the input by PI/6 radians clockwise:
-
-
- Rotate the input by PI/6 radians counter-clockwise:
-
-
- Rotate the input by 45 degrees clockwise:
-
-
- Apply a constant rotation with period T, starting from an angle of PI/3:
-
-
- Make the input video rotation oscillating with a period of T
-seconds and an amplitude of A radians:
-
-
rotate=A*sin(2*PI/T*t)
- Rotate the video, output size is chosen so that the whole rotating
-input video is always completely contained in the output:
-
-
rotate='2*PI*t:ow=hypot(iw,ih):oh=ow'
- Rotate the video, reduce the output size so that no background is ever
-shown:
-
-
rotate=2*PI*t:ow='min(iw,ih)/sqrt(2)':oh=ow:c=none
-
-
-
-
30.77.2 Commands# TOC
-
-
The filter supports the following commands:
-
-
-a, angle Set the angle expression.
-The command accepts the same syntax of the corresponding option.
-
-If the specified expression is not valid, it is kept at its current
-value.
-
-
-
-
30.78 sab# TOC
-
-
Apply Shape Adaptive Blur.
-
-
The filter accepts the following options:
-
-
-luma_radius, lr Set luma blur filter strength, must be a value in range 0.1-4.0, default
-value is 1.0. A greater value will result in a more blurred image, and
-in slower processing.
-
-luma_pre_filter_radius, lpfr Set luma pre-filter radius, must be a value in the 0.1-2.0 range, default
-value is 1.0.
-
-luma_strength, ls Set luma maximum difference between pixels to still be considered, must
-be a value in the 0.1-100.0 range, default value is 1.0.
-
-chroma_radius, cr Set chroma blur filter strength, must be a value in range 0.1-4.0. A
-greater value will result in a more blurred image, and in slower
-processing.
-
-chroma_pre_filter_radius, cpfr Set chroma pre-filter radius, must be a value in the 0.1-2.0 range.
-
-chroma_strength, cs Set chroma maximum difference between pixels to still be considered,
-must be a value in the 0.1-100.0 range.
-
-
-
Each chroma option value, if not explicitly specified, is set to the
-corresponding luma option value.
-
-
-
30.79 scale# TOC
-
-
Scale (resize) the input video, using the libswscale library.
-
-
The scale filter forces the output display aspect ratio to be the same
-of the input, by changing the output sample aspect ratio.
-
-
If the input image format is different from the format requested by
-the next filter, the scale filter will convert the input to the
-requested format.
-
-
-
30.79.1 Options# TOC
-
The filter accepts the following options, or any of the options
-supported by the libswscale scaler.
-
-
See (ffmpeg-scaler)the ffmpeg-scaler manual for
-the complete list of scaler options.
-
-
-width, w height, h Set the output video dimension expression. Default value is the input
-dimension.
-
-If the value is 0, the input width is used for the output.
-
-If one of the values is -1, the scale filter will use a value that
-maintains the aspect ratio of the input image, calculated from the
-other specified dimension. If both of them are -1, the input size is
-used
-
-If one of the values is -n with n > 1, the scale filter will also use a value
-that maintains the aspect ratio of the input image, calculated from the other
-specified dimension. After that it will, however, make sure that the calculated
-dimension is divisible by n and adjust the value if necessary.
-
-See below for the list of accepted constants for use in the dimension
-expression.
-
-interl Set the interlacing mode. It accepts the following values:
-
-
-‘1 ’
-Force interlaced aware scaling.
-
-‘0 ’
-Do not apply interlaced scaling.
-
-‘-1 ’
-Select interlaced aware scaling depending on whether the source frames
-are flagged as interlaced or not.
-
-
-Default value is ‘0 ’.
-
-flags Set libswscale scaling flags. See
-(ffmpeg-scaler)the ffmpeg-scaler manual for the
-complete list of values. If not explicitly specified the filter applies
-the default flags.
-
-size, s Set the video size. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-in_color_matrix out_color_matrix Set in/output YCbCr color space type.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder.
-
-If not specified, the color space type depends on the pixel format.
-
-Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘bt709 ’
-Format conforming to International Telecommunication Union (ITU)
-Recommendation BT.709.
-
-‘fcc ’
-Set color space conforming to the United States Federal Communications
-Commission (FCC) Code of Federal Regulations (CFR) Title 47 (2003) 73.682 (a).
-
-‘bt601 ’
-Set color space conforming to:
-
-
- ITU Radiocommunication Sector (ITU-R) Recommendation BT.601
-
- ITU-R Rec. BT.470-6 (1998) Systems B, B1, and G
-
- Society of Motion Picture and Television Engineers (SMPTE) ST 170:2004
-
-
-
-‘smpte240m ’
-Set color space conforming to SMPTE ST 240:1999.
-
-
-in_range out_range Set in/output YCbCr sample range.
-
-This allows the autodetected value to be overridden as well as allows forcing
-a specific value used for the output and encoder. If not specified, the
-range depends on the pixel format. Possible values:
-
-
-‘auto ’
-Choose automatically.
-
-‘jpeg/full/pc ’
-Set full range (0-255 in case of 8-bit luma).
-
-‘mpeg/tv ’
-Set "MPEG" range (16-235 in case of 8-bit luma).
-
-
-force_original_aspect_ratio Enable decreasing or increasing output video width or height if necessary to
-keep the original aspect ratio. Possible values:
-
-
-‘disable ’
-Scale the video as specified and disable this feature.
-
-‘decrease ’
-The output video dimensions will automatically be decreased if needed.
-
-‘increase ’
-The output video dimensions will automatically be increased if needed.
-
-
-
-One useful instance of this option is that when you know a specific device’s
-maximum allowed resolution, you can use this to limit the output video to
-that, while retaining the aspect ratio. For example, device A allows
-1280x720 playback, and your video is 1920x800. Using this option (set it to
-decrease) and specifying 1280x720 to the command line makes the output
-1280x533.
-
-Please note that this is a different thing than specifying -1 for w
-or h , you still need to specify the output resolution for this option
-to work.
-
-
-
-
The values of the w and h options are expressions
-containing the following constants:
-
-
-in_w in_h The input width and height
-
-iw ih These are the same as in_w and in_h .
-
-out_w out_h The output (scaled) width and height
-
-ow oh These are the same as out_w and out_h
-
-a The same as iw / ih
-
-sar input sample aspect ratio
-
-dar The input display aspect ratio. Calculated from (iw / ih) * sar.
-
-hsub vsub horizontal and vertical input chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-ohsub ovsub horizontal and vertical output chroma subsample values. For example for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.79.2 Examples# TOC
-
-
-
-
-
30.80 separatefields# TOC
-
-
The separatefields takes a frame-based video input and splits
-each frame into its components fields, producing a new half height clip
-with twice the frame rate and twice the frame count.
-
-
This filter use field-dominance information in frame to decide which
-of each pair of fields to place first in the output.
-If it gets it wrong use setfield filter before separatefields filter.
-
-
-
30.81 setdar, setsar# TOC
-
-
The setdar filter sets the Display Aspect Ratio for the filter
-output video.
-
-
This is done by changing the specified Sample (aka Pixel) Aspect
-Ratio, according to the following equation:
-
-
DAR = HORIZONTAL_RESOLUTION / VERTICAL_RESOLUTION * SAR
-
-
-
Keep in mind that the setdar filter does not modify the pixel
-dimensions of the video frame. Also, the display aspect ratio set by
-this filter may be changed by later filters in the filterchain,
-e.g. in case of scaling or if another "setdar" or a "setsar" filter is
-applied.
-
-
The setsar filter sets the Sample (aka Pixel) Aspect Ratio for
-the filter output video.
-
-
Note that as a consequence of the application of this filter, the
-output display aspect ratio will change according to the equation
-above.
-
-
Keep in mind that the sample aspect ratio set by the setsar
-filter may be changed by later filters in the filterchain, e.g. if
-another "setsar" or a "setdar" filter is applied.
-
-
It accepts the following parameters:
-
-
-r, ratio, dar (setdar only), sar (setsar only) Set the aspect ratio used by the filter.
-
-The parameter can be a floating point number string, an expression, or
-a string of the form num :den , where num and
-den are the numerator and denominator of the aspect ratio. If
-the parameter is not specified, it is assumed the value "0".
-In case the form "num :den " is used, the : character
-should be escaped.
-
-max Set the maximum integer value to use for expressing numerator and
-denominator when reducing the expressed aspect ratio to a rational.
-Default value is 100.
-
-
-
-
The parameter sar is an expression containing
-the following constants:
-
-
-E, PI, PHI These are approximated values for the mathematical constants e
-(Euler’s number), pi (Greek pi), and phi (the golden ratio).
-
-w, h The input width and height.
-
-a These are the same as w / h .
-
-sar The input sample aspect ratio.
-
-dar The input display aspect ratio. It is the same as
-(w / h ) * sar .
-
-hsub, vsub Horizontal and vertical chroma subsample values. For example, for the
-pixel format "yuv422p" hsub is 2 and vsub is 1.
-
-
-
-
30.81.1 Examples# TOC
-
-
- To change the display aspect ratio to 16:9, specify one of the following:
-
-
setdar=dar=1.77777
-setdar=dar=16/9
-setdar=dar=1.77777
- To change the sample aspect ratio to 10:11, specify:
-
-
- To set a display aspect ratio of 16:9, and specify a maximum integer value of
-1000 in the aspect ratio reduction, use the command:
-
-
setdar=ratio=16/9:max=1000
-
-
-
-
30.82 setfield# TOC
-
-
Force field for the output video frame.
-
-
The setfield filter marks the interlace type field for the
-output frames. It does not change the input frame, but only sets the
-corresponding property, which affects how the frame is treated by
-following filters (e.g. fieldorder or yadif).
-
-
The filter accepts the following options:
-
-
-mode Available values are:
-
-
-‘auto ’
-Keep the same field property.
-
-‘bff ’
-Mark the frame as bottom-field-first.
-
-‘tff ’
-Mark the frame as top-field-first.
-
-‘prog ’
-Mark the frame as progressive.
-
-
-
-
-
30.83 showinfo# TOC
-
-
Show a line containing various information for each input video frame.
-The input video is not modified.
-
-
The shown line contains a sequence of key/value pairs of the form
-key :value .
-
-
The following values are shown in the output:
-
-
-n The (sequential) number of the input frame, starting from 0.
-
-pts The Presentation TimeStamp of the input frame, expressed as a number of
-time base units. The time base unit depends on the filter input pad.
-
-pts_time The Presentation TimeStamp of the input frame, expressed as a number of
-seconds.
-
-pos The position of the frame in the input stream, or -1 if this information is
-unavailable and/or meaningless (for example in case of synthetic video).
-
-fmt The pixel format name.
-
-sar The sample aspect ratio of the input frame, expressed in the form
-num /den .
-
-s The size of the input frame. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual.
-
-i The type of interlaced mode ("P" for "progressive", "T" for top field first, "B"
-for bottom field first).
-
-iskey This is 1 if the frame is a key frame, 0 otherwise.
-
-type The picture type of the input frame ("I" for an I-frame, "P" for a
-P-frame, "B" for a B-frame, or "?" for an unknown type).
-Also refer to the documentation of the AVPictureType enum and of
-the av_get_picture_type_char function defined in
-libavutil/avutil.h .
-
-checksum The Adler-32 checksum (printed in hexadecimal) of all the planes of the input frame.
-
-plane_checksum The Adler-32 checksum (printed in hexadecimal) of each plane of the input frame,
-expressed in the form "[c0 c1 c2 c3 ]".
-
-
-
-
30.84 shuffleplanes# TOC
-
-
Reorder and/or duplicate video planes.
-
-
It accepts the following parameters:
-
-
-map0 The index of the input plane to be used as the first output plane.
-
-map1 The index of the input plane to be used as the second output plane.
-
-map2 The index of the input plane to be used as the third output plane.
-
-map3 The index of the input plane to be used as the fourth output plane.
-
-
-
-
The first plane has the index 0. The default is to keep the input unchanged.
-
-
Swap the second and third planes of the input:
-
-
ffmpeg -i INPUT -vf shuffleplanes=0:2:1:3 OUTPUT
-
-
-
-
30.85 signalstats# TOC
-
Evaluate various visual metrics that assist in determining issues associated
-with the digitization of analog video media.
-
-
By default the filter will log these metadata values:
-
-
-YMIN Display the minimal Y value contained within the input frame. Expressed in
-range of [0-255].
-
-YLOW Display the Y value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-YAVG Display the average Y value within the input frame. Expressed in range of
-[0-255].
-
-YHIGH Display the Y value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-YMAX Display the maximum Y value contained within the input frame. Expressed in
-range of [0-255].
-
-UMIN Display the minimal U value contained within the input frame. Expressed in
-range of [0-255].
-
-ULOW Display the U value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-UAVG Display the average U value within the input frame. Expressed in range of
-[0-255].
-
-UHIGH Display the U value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-UMAX Display the maximum U value contained within the input frame. Expressed in
-range of [0-255].
-
-VMIN Display the minimal V value contained within the input frame. Expressed in
-range of [0-255].
-
-VLOW Display the V value at the 10% percentile within the input frame. Expressed in
-range of [0-255].
-
-VAVG Display the average V value within the input frame. Expressed in range of
-[0-255].
-
-VHIGH Display the V value at the 90% percentile within the input frame. Expressed in
-range of [0-255].
-
-VMAX Display the maximum V value contained within the input frame. Expressed in
-range of [0-255].
-
-SATMIN Display the minimal saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-SATLOW Display the saturation value at the 10% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATAVG Display the average saturation value within the input frame. Expressed in range
-of [0-~181.02].
-
-SATHIGH Display the saturation value at the 90% percentile within the input frame.
-Expressed in range of [0-~181.02].
-
-SATMAX Display the maximum saturation value contained within the input frame.
-Expressed in range of [0-~181.02].
-
-HUEMED Display the median value for hue within the input frame. Expressed in range of
-[0-360].
-
-HUEAVG Display the average value for hue within the input frame. Expressed in range of
-[0-360].
-
-YDIF Display the average of sample value difference between all values of the Y
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-UDIF Display the average of sample value difference between all values of the U
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-VDIF Display the average of sample value difference between all values of the V
-plane in the current frame and corresponding values of the previous input frame.
-Expressed in range of [0-255].
-
-
-
The filter accepts the following options:
-
-
-stat out
-stat specify an additional form of image analysis.
-out output video with the specified type of pixel highlighted.
-
-Both options accept the following values:
-
-
-‘tout ’
-Identify temporal outliers pixels. A temporal outlier is a pixel
-unlike the neighboring pixels of the same field. Examples of temporal outliers
-include the results of video dropouts, head clogs, or tape tracking issues.
-
-‘vrep ’
-Identify vertical line repetition . Vertical line repetition includes
-similar rows of pixels within a frame. In born-digital video vertical line
-repetition is common, but this pattern is uncommon in video digitized from an
-analog source. When it occurs in video that results from the digitization of an
-analog source it can indicate concealment from a dropout compensator.
-
-‘brng ’
-Identify pixels that fall outside of legal broadcast range.
-
-
-
-color, c Set the highlight color for the out option. The default color is
-yellow.
-
-
-
-
30.85.1 Examples# TOC
-
-
-
-
-
30.86 smartblur# TOC
-
-
Blur the input video without impacting the outlines.
-
-
It accepts the following options:
-
-
-luma_radius, lr Set the luma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-luma_strength, ls Set the luma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-luma_threshold, lt Set the luma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-chroma_radius, cr Set the chroma radius. The option value must be a float number in
-the range [0.1,5.0] that specifies the variance of the gaussian filter
-used to blur the image (slower if larger). Default value is 1.0.
-
-chroma_strength, cs Set the chroma strength. The option value must be a float number
-in the range [-1.0,1.0] that configures the blurring. A value included
-in [0.0,1.0] will blur the image whereas a value included in
-[-1.0,0.0] will sharpen the image. Default value is 1.0.
-
-chroma_threshold, ct Set the chroma threshold used as a coefficient to determine
-whether a pixel should be blurred or not. The option value must be an
-integer in the range [-30,30]. A value of 0 will filter all the image,
-a value included in [0,30] will filter flat areas and a value included
-in [-30,0] will filter edges. Default value is 0.
-
-
-
If a chroma option is not explicitly set, the corresponding luma value
-is set.
-
-
-
30.87 stereo3d# TOC
-
-
Convert between different stereoscopic image formats.
-
-
The filters accept the following options:
-
-
-in Set stereoscopic image format of input.
-
-Available values for input image formats are:
-
-‘sbsl ’
-side by side parallel (left eye left, right eye right)
-
-‘sbsr ’
-side by side crosseye (right eye left, left eye right)
-
-‘sbs2l ’
-side by side parallel with half width resolution
-(left eye left, right eye right)
-
-‘sbs2r ’
-side by side crosseye with half width resolution
-(right eye left, left eye right)
-
-‘abl ’
-above-below (left eye above, right eye below)
-
-‘abr ’
-above-below (right eye above, left eye below)
-
-‘ab2l ’
-above-below with half height resolution
-(left eye above, right eye below)
-
-‘ab2r ’
-above-below with half height resolution
-(right eye above, left eye below)
-
-‘al ’
-alternating frames (left eye first, right eye second)
-
-‘ar ’
-alternating frames (right eye first, left eye second)
-
-Default value is ‘sbsl ’.
-
-
-out Set stereoscopic image format of output.
-
-Available values for output image formats are all the input formats as well as:
-
-‘arbg ’
-anaglyph red/blue gray
-(red filter on left eye, blue filter on right eye)
-
-‘argg ’
-anaglyph red/green gray
-(red filter on left eye, green filter on right eye)
-
-‘arcg ’
-anaglyph red/cyan gray
-(red filter on left eye, cyan filter on right eye)
-
-‘arch ’
-anaglyph red/cyan half colored
-(red filter on left eye, cyan filter on right eye)
-
-‘arcc ’
-anaglyph red/cyan color
-(red filter on left eye, cyan filter on right eye)
-
-‘arcd ’
-anaglyph red/cyan color optimized with the least squares projection of dubois
-(red filter on left eye, cyan filter on right eye)
-
-‘agmg ’
-anaglyph green/magenta gray
-(green filter on left eye, magenta filter on right eye)
-
-‘agmh ’
-anaglyph green/magenta half colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmc ’
-anaglyph green/magenta colored
-(green filter on left eye, magenta filter on right eye)
-
-‘agmd ’
-anaglyph green/magenta color optimized with the least squares projection of dubois
-(green filter on left eye, magenta filter on right eye)
-
-‘aybg ’
-anaglyph yellow/blue gray
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybh ’
-anaglyph yellow/blue half colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybc ’
-anaglyph yellow/blue colored
-(yellow filter on left eye, blue filter on right eye)
-
-‘aybd ’
-anaglyph yellow/blue color optimized with the least squares projection of dubois
-(yellow filter on left eye, blue filter on right eye)
-
-‘irl ’
-interleaved rows (left eye has top row, right eye starts on next row)
-
-‘irr ’
-interleaved rows (right eye has top row, left eye starts on next row)
-
-‘ml ’
-mono output (left eye only)
-
-‘mr ’
-mono output (right eye only)
-
-
-Default value is ‘arcd ’.
-
-
-
-
30.87.1 Examples# TOC
-
-
- Convert input video from side by side parallel to anaglyph yellow/blue dubois:
-
-
- Convert input video from above bellow (left eye above, right eye below) to side by side crosseye.
-
-
-
-
-
30.88 spp# TOC
-
-
Apply a simple postprocessing filter that compresses and decompresses the image
-at several (or - in the case of quality level 6 - all) shifts
-and average the results.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-6. If set to 0, the filter will have no
-effect. A value of 6 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-mode Set thresholding mode. Available modes are:
-
-
-‘hard ’
-Set hard thresholding (default).
-
‘soft ’
-Set soft thresholding (better de-ringing effect, but likely blurrier).
-
-
-use_bframe_qp Enable the use of the QP from the B-Frames if set to 1. Using this
-option may cause flicker since the B-Frames have often larger QP. Default is
-0 (not enabled).
-
-
-
-
30.89 subtitles# TOC
-
-
Draw subtitles on top of input video using the libass library.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libass. This filter also requires a build with libavcodec and
-libavformat to convert the passed subtitles file to ASS (Advanced Substation
-Alpha) subtitles format.
-
-
The filter accepts the following options:
-
-
-filename, f Set the filename of the subtitle file to read. It must be specified.
-
-original_size Specify the size of the original video, the video for which the ASS file
-was composed. For the syntax of this option, check the "Video size" section in
-the ffmpeg-utils manual. Due to a misdesign in ASS aspect ratio arithmetic,
-this is necessary to correctly scale the fonts if the aspect ratio has been
-changed.
-
-charenc Set subtitles input character encoding. subtitles filter only. Only
-useful if not UTF-8.
-
-stream_index, si Set subtitles stream index. subtitles filter only.
-
-
-
If the first key is not specified, it is assumed that the first value
-specifies the filename .
-
-
For example, to render the file sub.srt on top of the input
-video, use the command:
-
-
-
which is equivalent to:
-
-
subtitles=filename=sub.srt
-
-
-
To render the default subtitles stream from file video.mkv , use:
-
-
-
To render the second subtitles stream from that file, use:
-
-
subtitles=video.mkv:si=1
-
-
-
-
30.90 super2xsai# TOC
-
-
Scale the input by 2x and smooth using the Super2xSaI (Scale and
-Interpolate) pixel art scaling algorithm.
-
-
Useful for enlarging pixel art images without reducing sharpness.
-
-
-
30.91 swapuv# TOC
-
Swap U & V plane.
-
-
-
30.92 telecine# TOC
-
-
Apply telecine process to the video.
-
-
This filter accepts the following options:
-
-
-first_field
-‘top, t ’
-top field first
-
‘bottom, b ’
-bottom field first
-The default value is top.
-
-
-pattern A string of numbers representing the pulldown pattern you wish to apply.
-The default value is 23.
-
-
-
-
Some typical patterns:
-
-NTSC output (30i):
-27.5p: 32222
-24p: 23 (classic)
-24p: 2332 (preferred)
-20p: 33
-18p: 334
-16p: 3444
-
-PAL output (25i):
-27.5p: 12222
-24p: 222222222223 ("Euro pulldown")
-16.67p: 33
-16p: 33333334
-
-
-
-
30.93 thumbnail# TOC
-
Select the most representative frame in a given sequence of consecutive frames.
-
-
The filter accepts the following options:
-
-
-n Set the frames batch size to analyze; in a set of n frames, the filter
-will pick one of them, and then handle the next batch of n frames until
-the end. Default is 100.
-
-
-
Since the filter keeps track of the whole frames sequence, a bigger n
-value will result in a higher memory usage, so a high value is not recommended.
-
-
-
30.93.1 Examples# TOC
-
-
- Extract one picture each 50 frames:
-
-
- Complete example of a thumbnail creation with ffmpeg:
-
-
ffmpeg -i in.avi -vf thumbnail,scale=300:200 -frames:v 1 out.png
-
-
-
-
30.94 tile# TOC
-
-
Tile several successive frames together.
-
-
The filter accepts the following options:
-
-
-layout Set the grid size (i.e. the number of lines and columns). For the syntax of
-this option, check the "Video size" section in the ffmpeg-utils manual.
-
-nb_frames Set the maximum number of frames to render in the given area. It must be less
-than or equal to w xh . The default value is 0, meaning all
-the area will be used.
-
-margin Set the outer border margin in pixels.
-
-padding Set the inner border thickness (i.e. the number of pixels between frames). For
-more advanced padding options (such as having different values for the edges),
-refer to the pad video filter.
-
-color Specify the color of the unused area. For the syntax of this option, check the
-"Color" section in the ffmpeg-utils manual. The default value of color
-is "black".
-
-
-
-
30.94.1 Examples# TOC
-
-
-
-
-
30.95 tinterlace# TOC
-
-
Perform various types of temporal field interlacing.
-
-
Frames are counted starting from 1, so the first input frame is
-considered odd.
-
-
The filter accepts the following options:
-
-
-mode Specify the mode of the interlacing. This option can also be specified
-as a value alone. See below for a list of values for this option.
-
-Available values are:
-
-
-‘merge, 0 ’
-Move odd frames into the upper field, even into the lower field,
-generating a double height frame at half frame rate.
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘drop_odd, 1 ’
-Only output even frames, odd frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
- 22222 44444
- 22222 44444
- 22222 44444
- 22222 44444
- ‘drop_even, 2 ’
-Only output odd frames, even frames are dropped, generating a frame with
-unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 33333
-11111 33333
-11111 33333
-11111 33333
- ‘pad, 3 ’
-Expand each frame to full height, but pad alternate lines with black,
-generating a frame with double height at the same input frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-11111 22222 33333 44444
-
-Output:
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
-11111 ..... 33333 .....
-..... 22222 ..... 44444
- ‘interleave_top, 4 ’
-Interleave the upper field from odd frames with the lower field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-
-Output:
-11111 33333
-22222 44444
-11111 33333
-22222 44444
- ‘interleave_bottom, 5 ’
-Interleave the lower field from odd frames with the upper field from
-even frames, generating a frame with unchanged height at half frame rate.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-11111 22222<- 33333 44444<-
-11111<- 22222 33333<- 44444
-
-Output:
-22222 44444
-11111 33333
-22222 44444
-11111 33333
- ‘interlacex2, 6 ’
-Double frame rate with unchanged height. Frames are inserted each
-containing the second temporal field from the previous input frame and
-the first temporal field from the next input frame. This mode relies on
-the top_field_first flag. Useful for interlaced video displays with no
-field synchronisation.
-
-
-
------> time
-Input:
-Frame 1 Frame 2 Frame 3 Frame 4
-
-11111 22222 33333 44444
- 11111 22222 33333 44444
-11111 22222 33333 44444
- 11111 22222 33333 44444
-
-Output:
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-11111 22222 22222 33333 33333 44444 44444
- 11111 11111 22222 22222 33333 33333 44444
-
-
-Numeric values are deprecated but are accepted for backward
-compatibility reasons.
-
-Default mode is merge.
-
-flags Specify flags influencing the filter process.
-
-Available value for flags is:
-
-
-low_pass_filter, vlfp Enable vertical low-pass filtering in the filter.
-Vertical low-pass filtering is required when creating an interlaced
-destination from a progressive source which contains high-frequency
-vertical detail. Filtering will reduce interlace ’twitter’ and Moire
-patterning.
-
-Vertical low-pass filtering can only be enabled for mode
-interleave_top and interleave_bottom .
-
-
-
-
-
-
30.96 transpose# TOC
-
-
Transpose rows with columns in the input video and optionally flip it.
-
-
It accepts the following parameters:
-
-
-dir Specify the transposition direction.
-
-Can assume the following values:
-
-‘0, 4, cclock_flip ’
-Rotate by 90 degrees counterclockwise and vertically flip (default), that is:
-
-
L.R L.l
-. . -> . .
-l.r R.r
- ‘1, 5, clock ’
-Rotate by 90 degrees clockwise, that is:
-
-
L.R l.L
-. . -> . .
-l.r r.R
- ‘2, 6, cclock ’
-Rotate by 90 degrees counterclockwise, that is:
-
-
L.R R.r
-. . -> . .
-l.r L.l
- ‘3, 7, clock_flip ’
-Rotate by 90 degrees clockwise and vertically flip, that is:
-
-
L.R r.R
-. . -> . .
-l.r l.L
-
-
-For values between 4-7, the transposition is only done if the input
-video geometry is portrait and not landscape. These values are
-deprecated, the passthrough option should be used instead.
-
-Numerical values are deprecated, and should be dropped in favor of
-symbolic constants.
-
-passthrough Do not apply the transposition if the input geometry matches the one
-specified by the specified value. It accepts the following values:
-
-‘none ’
-Always apply transposition.
-
‘portrait ’
-Preserve portrait geometry (when height >= width ).
-
‘landscape ’
-Preserve landscape geometry (when width >= height ).
-
-
-Default value is none.
-
-
-
For example to rotate by 90 degrees clockwise and preserve portrait
-layout:
-
-
transpose=dir=1:passthrough=portrait
-
-
-
The command above can also be specified as:
-
-
-
-
30.97 trim# TOC
-
Trim the input so that the output contains one continuous subpart of the input.
-
-
It accepts the following parameters:
-
-start Specify the time of the start of the kept section, i.e. the frame with the
-timestamp start will be the first frame in the output.
-
-end Specify the time of the first frame that will be dropped, i.e. the frame
-immediately preceding the one with the timestamp end will be the last
-frame in the output.
-
-start_pts This is the same as start , except this option sets the start timestamp
-in timebase units instead of seconds.
-
-end_pts This is the same as end , except this option sets the end timestamp
-in timebase units instead of seconds.
-
-duration The maximum duration of the output in seconds.
-
-start_frame The number of the first frame that should be passed to the output.
-
-end_frame The number of the first frame that should be dropped.
-
-
-
start , end , and duration are expressed as time
-duration specifications; see
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-
Note that the first two sets of the start/end options and the duration
-option look at the frame timestamp, while the _frame variants simply count the
-frames that pass through the filter. Also note that this filter does not modify
-the timestamps. If you wish for the output timestamps to start at zero, insert a
-setpts filter after the trim filter.
-
-
If multiple start or end options are set, this filter tries to be greedy and
-keep all the frames that match at least one of the specified constraints. To keep
-only the part that matches all the constraints at once, chain multiple trim
-filters.
-
-
The defaults are such that all the input is kept. So it is possible to set e.g.
-just the end values to keep everything before the specified time.
-
-
Examples:
-
- Drop everything except the second minute of input:
-
-
ffmpeg -i INPUT -vf trim=60:120
- Keep only the first second:
-
-
ffmpeg -i INPUT -vf trim=duration=1
-
-
-
-
-
30.98 unsharp# TOC
-
-
Sharpen or blur the input video.
-
-
It accepts the following parameters:
-
-
-luma_msize_x, lx Set the luma matrix horizontal size. It must be an odd integer between
-3 and 63. The default value is 5.
-
-luma_msize_y, ly Set the luma matrix vertical size. It must be an odd integer between 3
-and 63. The default value is 5.
-
-luma_amount, la Set the luma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 1.0.
-
-chroma_msize_x, cx Set the chroma matrix horizontal size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_msize_y, cy Set the chroma matrix vertical size. It must be an odd integer
-between 3 and 63. The default value is 5.
-
-chroma_amount, ca Set the chroma effect strength. It must be a floating point number, reasonable
-values lay between -1.5 and 1.5.
-
-Negative values will blur the input video, while positive values will
-sharpen it, a value of zero will disable the effect.
-
-Default value is 0.0.
-
-opencl If set to 1, specify using OpenCL capabilities, only available if
-FFmpeg was configured with --enable-opencl. Default value is 0.
-
-
-
-
All parameters are optional and default to the equivalent of the
-string ’5:5:1.0:5:5:0.0’.
-
-
-
30.98.1 Examples# TOC
-
-
- Apply strong luma sharpen effect:
-
-
unsharp=luma_msize_x=7:luma_msize_y=7:luma_amount=2.5
- Apply a strong blur of both luma and chroma parameters:
-
-
-
-
-
30.99 uspp# TOC
-
-
Apply ultra slow/simple postprocessing filter that compresses and decompresses
-the image at several (or - in the case of quality level 8 - all)
-shifts and average the results.
-
-
The way this differs from the behavior of spp is that uspp actually encodes &
-decodes each case with libavcodec Snow, whereas spp uses a simplified intra only 8x8
-DCT similar to MJPEG.
-
-
The filter accepts the following options:
-
-
-quality Set quality. This option defines the number of levels for averaging. It accepts
-an integer in the range 0-8. If set to 0, the filter will have no
-effect. A value of 8 means the higher quality. For each increment of
-that value the speed drops by a factor of approximately 2. Default value is
-3.
-
-qp Force a constant quantization parameter. If not set, the filter will use the QP
-from the video stream (if available).
-
-
-
-
30.100 vidstabdetect# TOC
-
-
Analyze video stabilization/deshaking. Perform pass 1 of 2, see
-vidstabtransform for pass 2.
-
-
This filter generates a file with relative translation and rotation
-transform information about subsequent frames, which is then used by
-the vidstabtransform filter.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
This filter accepts the following options:
-
-
-result Set the path to the file used to write the transforms information.
-Default value is transforms.trf .
-
-shakiness Set how shaky the video is and how quick the camera is. It accepts an
-integer in the range 1-10, a value of 1 means little shakiness, a
-value of 10 means strong shakiness. Default value is 5.
-
-accuracy Set the accuracy of the detection process. It must be a value in the
-range 1-15. A value of 1 means low accuracy, a value of 15 means high
-accuracy. Default value is 15.
-
-stepsize Set stepsize of the search process. The region around minimum is
-scanned with 1 pixel resolution. Default value is 6.
-
-mincontrast Set minimum contrast. Below this value a local measurement field is
-discarded. Must be a floating point value in the range 0-1. Default
-value is 0.3.
-
-tripod Set reference frame number for tripod mode.
-
-If enabled, the motion of the frames is compared to a reference frame
-in the filtered stream, identified by the specified number. The idea
-is to compensate all movements in a more-or-less static scene and keep
-the camera view absolutely still.
-
-If set to 0, it is disabled. The frames are counted starting from 1.
-
-show Show fields and transforms in the resulting frames. It accepts an
-integer in the range 0-2. Default value is 0, which disables any
-visualization.
-
-
-
-
30.100.1 Examples# TOC
-
-
- Use default values:
-
-
- Analyze strongly shaky movie and put the results in file
-mytransforms.trf :
-
-
vidstabdetect=shakiness=10:accuracy=15:result="mytransforms.trf"
- Visualize the result of internal transformations in the resulting
-video:
-
-
- Analyze a video with medium shakiness using ffmpeg:
-
-
ffmpeg -i input -vf vidstabdetect=shakiness=5:show=1 dummy.avi
-
-
-
-
30.101 vidstabtransform# TOC
-
-
Video stabilization/deshaking: pass 2 of 2,
-see vidstabdetect for pass 1.
-
-
Read a file with transform information for each frame and
-apply/compensate them. Together with the vidstabdetect
-filter this can be used to deshake videos. See also
-http://public.hronopik.de/vid.stab . It is important to also use
-the unsharp filter, see below.
-
-
To enable compilation of this filter you need to configure FFmpeg with
---enable-libvidstab.
-
-
-
30.101.1 Options# TOC
-
-
-input Set path to the file used to read the transforms. Default value is
-transforms.trf .
-
-smoothing Set the number of frames (value*2 + 1) used for lowpass filtering the
-camera movements. Default value is 10.
-
-For example a number of 10 means that 21 frames are used (10 in the
-past and 10 in the future) to smoothen the motion in the video. A
-larger value leads to a smoother video, but limits the acceleration of
-the camera (pan/tilt movements). 0 is a special case where a static
-camera is simulated.
-
-optalgo Set the camera path optimization algorithm.
-
-Accepted values are:
-
-‘gauss ’
-gaussian kernel low-pass filter on camera motion (default)
-
‘avg ’
-averaging on transformations
-
-
-maxshift Set maximal number of pixels to translate frames. Default value is -1,
-meaning no limit.
-
-maxangle Set maximal angle in radians (degree*PI/180) to rotate frames. Default
-value is -1, meaning no limit.
-
-crop Specify how to deal with borders that may be visible due to movement
-compensation.
-
-Available values are:
-
-‘keep ’
-keep image information from previous frame (default)
-
‘black ’
-fill the border black
-
-
-invert Invert transforms if set to 1. Default value is 0.
-
-relative Consider transforms as relative to previous frame if set to 1,
-absolute if set to 0. Default value is 0.
-
-zoom Set percentage to zoom. A positive value will result in a zoom-in
-effect, a negative value in a zoom-out effect. Default value is 0 (no
-zoom).
-
-optzoom Set optimal zooming to avoid borders.
-
-Accepted values are:
-
-‘0 ’
-disabled
-
‘1 ’
-optimal static zoom value is determined (only very strong movements
-will lead to visible borders) (default)
-
‘2 ’
-optimal adaptive zoom value is determined (no borders will be
-visible), see zoomspeed
-
-
-Note that the value given at zoom is added to the one calculated here.
-
-zoomspeed Set percent to zoom maximally each frame (enabled when
-optzoom is set to 2). Range is from 0 to 5, default value is
-0.25.
-
-interpol Specify type of interpolation.
-
-Available values are:
-
-‘no ’
-no interpolation
-
‘linear ’
-linear only horizontal
-
‘bilinear ’
-linear in both directions (default)
-
‘bicubic ’
-cubic in both directions (slow)
-
-
-tripod Enable virtual tripod mode if set to 1, which is equivalent to
-relative=0:smoothing=0. Default value is 0.
-
-Use also tripod option of vidstabdetect .
-
-debug Increase log verbosity if set to 1. Also the detected global motions
-are written to the temporary file global_motions.trf . Default
-value is 0.
-
-
-
-
30.101.2 Examples# TOC
-
-
-
-
-
30.102 vflip# TOC
-
-
Flip the input video vertically.
-
-
For example, to vertically flip a video with ffmpeg:
-
-
ffmpeg -i in.avi -vf "vflip" out.avi
-
-
-
-
30.103 vignette# TOC
-
-
Make or reverse a natural vignetting effect.
-
-
The filter accepts the following options:
-
-
-angle, a Set lens angle expression as a number of radians.
-
-The value is clipped in the [0,PI/2] range.
-
-Default value: "PI/5"
-
-x0 y0 Set center coordinates expressions. Respectively "w/2" and "h/2"
-by default.
-
-mode Set forward/backward mode.
-
-Available modes are:
-
-‘forward ’
-The larger the distance from the central point, the darker the image becomes.
-
-‘backward ’
-The larger the distance from the central point, the brighter the image becomes.
-This can be used to reverse a vignette effect, though there is no automatic
-detection to extract the lens angle and other settings (yet). It can
-also be used to create a burning effect.
-
-
-Default value is ‘forward ’.
-
-eval Set evaluation mode for the expressions (angle , x0 , y0 ).
-
-It accepts the following values:
-
-‘init ’
-Evaluate expressions only once during the filter initialization.
-
-‘frame ’
-Evaluate expressions for each incoming frame. This is way slower than the
-‘init ’ mode since it requires all the scalers to be re-computed, but it
-allows advanced dynamic expressions.
-
-
-Default value is ‘init ’.
-
-dither Set dithering to reduce the circular banding effects. Default is 1
-(enabled).
-
-aspect Set vignette aspect. This setting allows one to adjust the shape of the vignette.
-Setting this value to the SAR of the input will make a rectangular vignetting
-following the dimensions of the video.
-
-Default is 1/1.
-
-
-
-
30.103.1 Expressions# TOC
-
-
The alpha , x0 and y0 expressions can contain the
-following parameters.
-
-
-w h input width and height
-
-n the number of input frame, starting from 0
-
-pts the PTS (Presentation TimeStamp) time of the filtered video frame, expressed in
-TB units, NAN if undefined
-
-r frame rate of the input video, NAN if the input frame rate is unknown
-
-t the PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in seconds, NAN if undefined
-
-tb time base of the input video
-
-
-
-
-
30.103.2 Examples# TOC
-
-
- Apply simple strong vignetting effect:
-
-
- Make a flickering vignetting:
-
-
vignette='PI/4+random(1)*PI/50':eval=frame
-
-
-
-
30.104 w3fdif# TOC
-
-
Deinterlace the input video ("w3fdif" stands for "Weston 3 Field
-Deinterlacing Filter").
-
-
Based on the process described by Martin Weston for BBC R&D, and
-implemented based on the de-interlace algorithm written by Jim
-Easterbrook for BBC R&D, the Weston 3 field deinterlacing filter
-uses filter coefficients calculated by BBC R&D.
-
-
There are two sets of filter coefficients, so called "simple":
-and "complex". Which set of filter coefficients is used can
-be set by passing an optional parameter:
-
-
-filter Set the interlacing filter coefficients. Accepts one of the following values:
-
-
-‘simple ’
-Simple filter coefficient set.
-
‘complex ’
-More-complex filter coefficient set.
-
-Default value is ‘complex ’.
-
-deint Specify which frames to deinterlace. Accept one of the following values:
-
-
-‘all ’
-Deinterlace all frames,
-
‘interlaced ’
-Only deinterlace frames marked as interlaced.
-
-
-Default value is ‘all ’.
-
-
-
-
30.105 xbr# TOC
-
Apply the xBR high-quality magnification filter which is designed for pixel
-art. It follows a set of edge-detection rules, see
-http://www.libretro.com/forums/viewtopic.php?f=6&t=134 .
-
-
It accepts the following option:
-
-
-n Set the scaling dimension: 2 for 2xBR, 3 for
-3xBR and 4 for 4xBR.
-Default is 3.
-
-
-
-
30.106 yadif# TOC
-
-
Deinterlace the input video ("yadif" means "yet another deinterlacing
-filter").
-
-
It accepts the following parameters:
-
-
-
-mode The interlacing mode to adopt. It accepts one of the following values:
-
-
-0, send_frame Output one frame for each frame.
-
1, send_field Output one frame for each field.
-
2, send_frame_nospatial Like send_frame, but it skips the spatial interlacing check.
-
3, send_field_nospatial Like send_field, but it skips the spatial interlacing check.
-
-
-The default value is send_frame.
-
-parity The picture field parity assumed for the input interlaced video. It accepts one
-of the following values:
-
-
-0, tff Assume the top field is first.
-
1, bff Assume the bottom field is first.
-
-1, auto Enable automatic detection of field parity.
-
-
-The default value is auto.
-If the interlacing is unknown or the decoder does not export this information,
-top field first will be assumed.
-
-deint Specify which frames to deinterlace. Accept one of the following
-values:
-
-
-0, all Deinterlace all frames.
-
1, interlaced Only deinterlace frames marked as interlaced.
-
-
-The default value is all.
-
-
-
-
30.107 zoompan# TOC
-
-
Apply Zoom & Pan effect.
-
-
This filter accepts the following options:
-
-
-zoom, z Set the zoom expression. Default is 1.
-
-x y Set the x and y expression. Default is 0.
-
-d Set the duration expression in number of frames.
-This sets for how many number of frames effect will last for
-single input image.
-
-s Set the output image size, default is ’hd720’.
-
-
-
Each expression can contain the following constants:
-
-
-in_w, iw Input width.
-
-in_h, ih Input height.
-
-out_w, ow Output width.
-
-out_h, oh Output height.
-
-in Input frame count.
-
-on Output frame count.
-
-x y Last calculated ’x’ and ’y’ position from ’x’ and ’y’ expression
-for current input frame.
-
-px py ’x’ and ’y’ of last output frame of previous input frame or 0 when there was
-not yet such frame (first input frame).
-
-zoom Last calculated zoom from ’z’ expression for current input frame.
-
-pzoom Last calculated zoom of last output frame of previous input frame.
-
-duration Number of output frames for current input frame. Calculated from ’d’ expression
-for each input frame.
-
-pduration number of output frames created for previous input frame
-
-a Rational number: input width / input height
-
-sar sample aspect ratio
-
-dar display aspect ratio
-
-
-
-
-
30.107.1 Examples# TOC
-
-
- Zoom-in up to 1.5 and pan at same time to some spot near center of picture:
-
-
zoompan=z='min(zoom+0.0015,1.5)':d=700:x='if(gte(zoom,1.5),x,x+1/a)':y='if(gte(zoom,1.5),y,y+1)':s=640x360
-
-
-
-
-
31 Video Sources# TOC
-
-
Below is a description of the currently available video sources.
-
-
-
31.1 buffer# TOC
-
-
Buffer video frames, and make them available to the filter chain.
-
-
This source is mainly intended for a programmatic use, in particular
-through the interface defined in libavfilter/vsrc_buffer.h .
-
-
It accepts the following parameters:
-
-
-video_size Specify the size (width and height) of the buffered video frames. For the
-syntax of this option, check the "Video size" section in the ffmpeg-utils
-manual.
-
-width The input video width.
-
-height The input video height.
-
-pix_fmt A string representing the pixel format of the buffered video frames.
-It may be a number corresponding to a pixel format, or a pixel format
-name.
-
-time_base Specify the timebase assumed by the timestamps of the buffered frames.
-
-frame_rate Specify the frame rate expected for the video stream.
-
-pixel_aspect, sar The sample (pixel) aspect ratio of the input video.
-
-sws_param Specify the optional parameters to be used for the scale filter which
-is automatically inserted when an input change is detected in the
-input size or format.
-
-
-
For example:
-
-
buffer=width=320:height=240:pix_fmt=yuv410p:time_base=1/24:sar=1
-
-
-
will instruct the source to accept video frames with size 320x240 and
-with format "yuv410p", assuming 1/24 as the timestamps timebase and
-square pixels (1:1 sample aspect ratio).
-Since the pixel format with name "yuv410p" corresponds to the number 6
-(check the enum AVPixelFormat definition in libavutil/pixfmt.h ),
-this example corresponds to:
-
-
buffer=size=320x240:pixfmt=6:time_base=1/24:pixel_aspect=1/1
-
-
-
Alternatively, the options can be specified as a flat string, but this
-syntax is deprecated:
-
-
width :height :pix_fmt :time_base.num :time_base.den :pixel_aspect.num :pixel_aspect.den [:sws_param ]
-
-
-
31.2 cellauto# TOC
-
-
Create a pattern generated by an elementary cellular automaton.
-
-
The initial state of the cellular automaton can be defined through the
-filename , and pattern options. If such options are
-not specified an initial state is created randomly.
-
-
At each new frame a new row in the video is filled with the result of
-the cellular automaton next generation. The behavior when the whole
-frame is filled is defined by the scroll option.
-
-
This source accepts the following options:
-
-
-filename, f Read the initial cellular automaton state, i.e. the starting row, from
-the specified file.
-In the file, each non-whitespace character is considered an alive
-cell, a newline will terminate the row, and further characters in the
-file will be ignored.
-
-pattern, p Read the initial cellular automaton state, i.e. the starting row, from
-the specified string.
-
-Each non-whitespace character in the string is considered an alive
-cell, a newline will terminate the row, and further characters in the
-string will be ignored.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial cellular automaton row. It
-is a floating point number value ranging from 0 to 1, defaults to
-1/PHI.
-
-This option is ignored when a file or a pattern is specified.
-
-random_seed, seed Set the seed for filling randomly the initial row, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the cellular automaton rule, it is a number ranging from 0 to 255.
-Default value is 110.
-
-size, s Set the size of the output video. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual.
-
-If filename or pattern is specified, the size is set
-by default to the width of the specified initial state row, and the
-height is set to width * PHI.
-
-If size is set, it must contain the width of the specified
-pattern string, and the specified pattern will be centered in the
-larger row.
-
-If a filename or a pattern string is not specified, the size value
-defaults to "320x518" (used for a randomly generated initial state).
-
-scroll If set to 1, scroll the output upward when all the rows in the output
-have been already filled. If set to 0, the new generated row will be
-written over the top row just after the bottom row is filled.
-Defaults to 1.
-
-start_full, full If set to 1, completely fill the output with generated rows before
-outputting the first frame.
-This is the default behavior, for disabling set the value to 0.
-
-stitch If set to 1, stitch the left and right row edges together.
-This is the default behavior, for disabling set the value to 0.
-
-
-
-
31.2.1 Examples# TOC
-
-
- Read the initial state from pattern , and specify an output of
-size 200x400.
-
-
cellauto=f=pattern:s=200x400
- Generate a random initial row with a width of 200 cells, with a fill
-ratio of 2/3:
-
-
cellauto=ratio=2/3:s=200x200
- Create a pattern generated by rule 18 starting by a single alive cell
-centered on an initial row with width 100:
-
-
cellauto=p=@:s=100x400:full=0:rule=18
- Specify a more elaborated initial pattern:
-
-
cellauto=p='@@ @ @@':s=100x400:full=0:rule=18
-
-
-
-
31.3 mandelbrot# TOC
-
-
Generate a Mandelbrot set fractal, and progressively zoom towards the
-point specified with start_x and start_y .
-
-
This source accepts the following options:
-
-
-end_pts Set the terminal pts value. Default value is 400.
-
-end_scale Set the terminal scale value.
-Must be a floating point value. Default value is 0.3.
-
-inner Set the inner coloring mode, that is the algorithm used to draw the
-Mandelbrot fractal internal region.
-
-It shall assume one of the following values:
-
-black Set black mode.
-
convergence Show time until convergence.
-
mincol Set color based on point closest to the origin of the iterations.
-
period Set period mode.
-
-
-Default value is mincol .
-
-bailout Set the bailout value. Default value is 10.0.
-
-maxiter Set the maximum of iterations performed by the rendering
-algorithm. Default value is 7189.
-
-outer Set outer coloring mode.
-It shall assume one of following values:
-
-iteration_count Set iteration cound mode.
-
normalized_iteration_count set normalized iteration count mode.
-
-Default value is normalized_iteration_count .
-
-rate, r Set frame rate, expressed as number of frames per second. Default
-value is "25".
-
-size, s Set frame size. For the syntax of this option, check the "Video
-size" section in the ffmpeg-utils manual. Default value is "640x480".
-
-start_scale Set the initial scale value. Default value is 3.0.
-
-start_x Set the initial x position. Must be a floating point value between
--100 and 100. Default value is -0.743643887037158704752191506114774.
-
-start_y Set the initial y position. Must be a floating point value between
--100 and 100. Default value is -0.131825904205311970493132056385139.
-
-
-
-
31.4 mptestsrc# TOC
-
-
Generate various test patterns, as generated by the MPlayer test filter.
-
-
The size of the generated video is fixed, and is 256x256.
-This source is useful in particular for testing encoding features.
-
-
This source accepts the following options:
-
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-test, t
-Set the number or the name of the test to perform. Supported tests are:
-
-dc_luma dc_chroma freq_luma freq_chroma amp_luma amp_chroma cbp mv ring1 ring2 all
-
-Default value is "all", which will cycle through the list of all tests.
-
-
-
-
Some examples:
-
-
-
will generate a "dc_luma" test pattern.
-
-
-
31.5 frei0r_src# TOC
-
-
Provide a frei0r source.
-
-
To enable compilation of this filter you need to install the frei0r
-header and configure FFmpeg with --enable-frei0r.
-
-
This source accepts the following parameters:
-
-
-size The size of the video to generate. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-framerate The framerate of the generated video. It may be a string of the form
-num /den or a frame rate abbreviation.
-
-filter_name The name to the frei0r source to load. For more information regarding frei0r and
-how to set the parameters, read the frei0r section in the video filters
-documentation.
-
-filter_params A ’|’-separated list of parameters to pass to the frei0r source.
-
-
-
-
For example, to generate a frei0r partik0l source with size 200x200
-and frame rate 10 which is overlaid on the overlay filter main input:
-
-
frei0r_src=size=200x200:framerate=10:filter_name=partik0l:filter_params=1234 [overlay]; [in][overlay] overlay
-
-
-
-
31.6 life# TOC
-
-
Generate a life pattern.
-
-
This source is based on a generalization of John Conway’s life game.
-
-
The sourced input represents a life grid, each pixel represents a cell
-which can be in one of two possible states, alive or dead. Every cell
-interacts with its eight neighbours, which are the cells that are
-horizontally, vertically, or diagonally adjacent.
-
-
At each interaction the grid evolves according to the adopted rule,
-which specifies the number of neighbor alive cells which will make a
-cell stay alive or born. The rule option allows one to specify
-the rule to adopt.
-
-
This source accepts the following options:
-
-
-filename, f Set the file from which to read the initial grid state. In the file,
-each non-whitespace character is considered an alive cell, and newline
-is used to delimit the end of each row.
-
-If this option is not specified, the initial grid is generated
-randomly.
-
-rate, r Set the video rate, that is the number of frames generated per second.
-Default is 25.
-
-random_fill_ratio, ratio Set the random fill ratio for the initial random grid. It is a
-floating point number value ranging from 0 to 1, defaults to 1/PHI.
-It is ignored when a file is specified.
-
-random_seed, seed Set the seed for filling the initial random grid, must be an integer
-included between 0 and UINT32_MAX. If not specified, or if explicitly
-set to -1, the filter will try to use a good random seed on a best
-effort basis.
-
-rule Set the life rule.
-
-A rule can be specified with a code of the kind "SNS /BNB ",
-where NS and NB are sequences of numbers in the range 0-8,
-NS specifies the number of alive neighbor cells which make a
-live cell stay alive, and NB the number of alive neighbor cells
-which make a dead cell to become alive (i.e. to "born").
-"s" and "b" can be used in place of "S" and "B", respectively.
-
-Alternatively a rule can be specified by an 18-bits integer. The 9
-high order bits are used to encode the next cell state if it is alive
-for each number of neighbor alive cells, the low order bits specify
-the rule for "borning" new cells. Higher order bits encode for an
-higher number of neighbor cells.
-For example the number 6153 = (12<<9)+9 specifies a stay alive
-rule of 12 and a born rule of 9, which corresponds to "S23/B03".
-
-Default value is "S23/B3", which is the original Conway’s game of life
-rule, and will keep a cell alive if it has 2 or 3 neighbor alive
-cells, and will born a new cell if there are three alive cells around
-a dead cell.
-
-size, s Set the size of the output video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual.
-
-If filename is specified, the size is set by default to the
-same size of the input file. If size is set, it must contain
-the size specified in the input file, and the initial grid defined in
-that file is centered in the larger resulting area.
-
-If a filename is not specified, the size value defaults to "320x240"
-(used for a randomly generated initial grid).
-
-stitch If set to 1, stitch the left and right grid edges together, and the
-top and bottom edges also. Defaults to 1.
-
-mold Set cell mold speed. If set, a dead cell will go from death_color to
-mold_color with a step of mold . mold can have a
-value from 0 to 255.
-
-life_color Set the color of living (or new born) cells.
-
-death_color Set the color of dead cells. If mold is set, this is the first color
-used to represent a dead cell.
-
-mold_color Set mold color, for definitely dead and moldy cells.
-
-For the syntax of these 3 color options, check the "Color" section in the
-ffmpeg-utils manual.
-
-
-
-
31.6.1 Examples# TOC
-
-
- Read a grid from pattern , and center it on a grid of size
-300x300 pixels:
-
-
life=f=pattern:s=300x300
- Generate a random grid of size 200x200, with a fill ratio of 2/3:
-
-
life=ratio=2/3:s=200x200
- Specify a custom rule for evolving a randomly generated grid:
-
-
- Full example with slow death effect (mold) using ffplay:
-
-
ffplay -f lavfi life=s=300x200:mold=10:r=60:ratio=0.1:death_color=#C83232:life_color=#00ff00,scale=1200:800:flags=16
-
-
-
-
31.7 color, haldclutsrc, nullsrc, rgbtestsrc, smptebars, smptehdbars, testsrc# TOC
-
-
The color source provides an uniformly colored input.
-
-
The haldclutsrc source provides an identity Hald CLUT. See also
-haldclut filter.
-
-
The nullsrc source returns unprocessed video frames. It is
-mainly useful to be employed in analysis / debugging tools, or as the
-source for filters which ignore the input data.
-
-
The rgbtestsrc source generates an RGB test pattern useful for
-detecting RGB vs BGR issues. You should see a red, green and blue
-stripe from top to bottom.
-
-
The smptebars source generates a color bars pattern, based on
-the SMPTE Engineering Guideline EG 1-1990.
-
-
The smptehdbars source generates a color bars pattern, based on
-the SMPTE RP 219-2002.
-
-
The testsrc source generates a test video pattern, showing a
-color pattern, a scrolling gradient and a timestamp. This is mainly
-intended for testing purposes.
-
-
The sources accept the following parameters:
-
-
-color, c Specify the color of the source, only available in the color
-source. For the syntax of this option, check the "Color" section in the
-ffmpeg-utils manual.
-
-level Specify the level of the Hald CLUT, only available in the haldclutsrc
-source. A level of N generates a picture of N*N*N by N*N*N
-pixels to be used as identity matrix for 3D lookup tables. Each component is
-coded on a 1/(N*N) scale.
-
-size, s Specify the size of the sourced video. For the syntax of this option, check the
-"Video size" section in the ffmpeg-utils manual. The default value is
-"320x240".
-
-This option is not available with the haldclutsrc filter.
-
-rate, r Specify the frame rate of the sourced video, as the number of frames
-generated per second. It has to be a string in the format
-frame_rate_num /frame_rate_den , an integer number, a floating point
-number or a valid video frame rate abbreviation. The default value is
-"25".
-
-sar Set the sample aspect ratio of the sourced video.
-
-duration, d Set the duration of the sourced video. See
-(ffmpeg-utils)the Time duration section in the ffmpeg-utils(1) manual
-for the accepted syntax.
-
-If not specified, or the expressed duration is negative, the video is
-supposed to be generated forever.
-
-decimals, n Set the number of decimals to show in the timestamp, only available in the
-testsrc source.
-
-The displayed timestamp value will correspond to the original
-timestamp value multiplied by the power of 10 of the specified
-value. Default value is 0.
-
-
-
For example the following:
-
-
testsrc=duration=5.3:size=qcif:rate=10
-
-
-
will generate a video with a duration of 5.3 seconds, with size
-176x144 and a frame rate of 10 frames per second.
-
-
The following graph description will generate a red source
-with an opacity of 0.2, with size "qcif" and a frame rate of 10
-frames per second.
-
-
color=c=red@0.2:s=qcif:r=10
-
-
-
If the input content is to be ignored, nullsrc can be used. The
-following command generates noise in the luminance plane by employing
-the geq filter:
-
-
nullsrc=s=256x256, geq=random(1)*255:128:128
-
-
-
-
31.7.1 Commands# TOC
-
-
The color source supports the following commands:
-
-
-c, color Set the color of the created image. Accepts the same syntax of the
-corresponding color option.
-
-
-
-
-
32 Video Sinks# TOC
-
-
Below is a description of the currently available video sinks.
-
-
-
32.1 buffersink# TOC
-
-
Buffer video frames, and make them available to the end of the filter
-graph.
-
-
This sink is mainly intended for programmatic use, in particular
-through the interface defined in libavfilter/buffersink.h
-or the options system.
-
-
It accepts a pointer to an AVBufferSinkContext structure, which
-defines the incoming buffers’ formats, to be passed as the opaque
-parameter to avfilter_init_filter for initialization.
-
-
-
32.2 nullsink# TOC
-
-
Null video sink: do absolutely nothing with the input video. It is
-mainly useful as a template and for use in analysis / debugging
-tools.
-
-
-
-
33 Multimedia Filters# TOC
-
-
Below is a description of the currently available multimedia filters.
-
-
-
33.1 avectorscope# TOC
-
-
Convert input audio to a video output, representing the audio vector
-scope.
-
-
The filter is used to measure the difference between channels of stereo
-audio stream. A monoaural signal, consisting of identical left and right
-signal, results in straight vertical line. Any stereo separation is visible
-as a deviation from this line, creating a Lissajous figure.
-If the straight (or deviation from it) but horizontal line appears this
-indicates that the left and right channels are out of phase.
-
-
The filter accepts the following options:
-
-
-mode, m Set the vectorscope mode.
-
-Available values are:
-
-‘lissajous ’
-Lissajous rotated by 45 degrees.
-
-‘lissajous_xy ’
-Same as above but not rotated.
-
-
-Default value is ‘lissajous ’.
-
-size, s Set the video size for the output. For the syntax of this option, check the "Video size"
-section in the ffmpeg-utils manual. Default value is 400x400.
-
-rate, r Set the output frame rate. Default value is 25.
-
-rc gc bc Specify the red, green and blue contrast. Default values are 40, 160 and 80.
-Allowed range is [0, 255].
-
-rf gf bf Specify the red, green and blue fade. Default values are 15, 10 and 5.
-Allowed range is [0, 255].
-
-zoom Set the zoom factor. Default value is 1. Allowed range is [1, 10].
-
-
-
-
33.1.1 Examples# TOC
-
-
- Complete example using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] avectorscope=zoom=1.3:rc=2:gc=200:bc=10:rf=1:gf=8:bf=7 [out0]'
-
-
-
-
33.2 concat# TOC
-
-
Concatenate audio and video streams, joining them together one after the
-other.
-
-
The filter works on segments of synchronized video and audio streams. All
-segments must have the same number of streams of each type, and that will
-also be the number of streams at output.
-
-
The filter accepts the following options:
-
-
-n Set the number of segments. Default is 2.
-
-v Set the number of output video streams, that is also the number of video
-streams in each segment. Default is 1.
-
-a Set the number of output audio streams, that is also the number of audio
-streams in each segment. Default is 0.
-
-unsafe Activate unsafe mode: do not fail if segments have a different format.
-
-
-
-
The filter has v +a outputs: first v video outputs, then
-a audio outputs.
-
-
There are n x(v +a ) inputs: first the inputs for the first
-segment, in the same order as the outputs, then the inputs for the second
-segment, etc.
-
-
Related streams do not always have exactly the same duration, for various
-reasons including codec frame size or sloppy authoring. For that reason,
-related synchronized streams (e.g. a video and its audio track) should be
-concatenated at once. The concat filter will use the duration of the longest
-stream in each segment (except the last one), and if necessary pad shorter
-audio streams with silence.
-
-
For this filter to work correctly, all segments must start at timestamp 0.
-
-
All corresponding streams must have the same parameters in all segments; the
-filtering system will automatically select a common pixel format for video
-streams, and a common sample format, sample rate and channel layout for
-audio streams, but other settings, such as resolution, must be converted
-explicitly by the user.
-
-
Different frame rates are acceptable but will result in variable frame rate
-at output; be sure to configure the output file to handle it.
-
-
-
33.2.1 Examples# TOC
-
-
-
-
-
33.3 ebur128# TOC
-
-
EBU R128 scanner filter. This filter takes an audio stream as input and outputs
-it unchanged. By default, it logs a message at a frequency of 10Hz with the
-Momentary loudness (identified by M), Short-term loudness (S),
-Integrated loudness (I) and Loudness Range (LRA).
-
-
The filter also has a video output (see the video option) with a real
-time graph to observe the loudness evolution. The graphic contains the logged
-message mentioned above, so it is not printed anymore when this option is set,
-unless the verbose logging is set. The main graphing area contains the
-short-term loudness (3 seconds of analysis), and the gauge on the right is for
-the momentary loudness (400 milliseconds).
-
-
More information about the Loudness Recommendation EBU R128 on
-http://tech.ebu.ch/loudness .
-
-
The filter accepts the following options:
-
-
-video Activate the video output. The audio stream is passed unchanged whether this
-option is set or no. The video stream will be the first output stream if
-activated. Default is 0.
-
-size Set the video size. This option is for video only. For the syntax of this
-option, check the "Video size" section in the ffmpeg-utils manual. Default
-and minimum resolution is 640x480.
-
-meter Set the EBU scale meter. Default is 9. Common values are 9 and
-18, respectively for EBU scale meter +9 and EBU scale meter +18. Any
-other integer value between this range is allowed.
-
-metadata Set metadata injection. If set to 1, the audio input will be segmented
-into 100ms output frames, each of them containing various loudness information
-in metadata. All the metadata keys are prefixed with lavfi.r128..
-
-Default is 0.
-
-framelog Force the frame logging level.
-
-Available values are:
-
-‘info ’
-information logging level
-
‘verbose ’
-verbose logging level
-
-
-By default, the logging level is set to info . If the video or
-the metadata options are set, it switches to verbose .
-
-peak Set peak mode(s).
-
-Available modes can be cumulated (the option is a flag type). Possible
-values are:
-
-‘none ’
-Disable any peak mode (default).
-
‘sample ’
-Enable sample-peak mode.
-
-Simple peak mode looking for the higher sample value. It logs a message
-for sample-peak (identified by SPK).
-
‘true ’
-Enable true-peak mode.
-
-If enabled, the peak lookup is done on an over-sampled version of the input
-stream for better peak accuracy. It logs a message for true-peak.
-(identified by TPK) and true-peak per frame (identified by FTPK).
-This mode requires a build with libswresample.
-
-
-
-
-
-
33.3.1 Examples# TOC
-
-
- Real-time graph using ffplay, with a EBU scale meter +18:
-
-
ffplay -f lavfi -i "amovie=input.mp3,ebur128=video=1:meter=18 [out0][out1]"
- Run an analysis with ffmpeg:
-
-
ffmpeg -nostats -i input.mp3 -filter_complex ebur128 -f null -
-
-
-
-
33.4 interleave, ainterleave# TOC
-
-
Temporally interleave frames from several inputs.
-
-
interleave works with video inputs, ainterleave with audio.
-
-
These filters read frames from several inputs and send the oldest
-queued frame to the output.
-
-
Input streams must have a well defined, monotonically increasing frame
-timestamp values.
-
-
In order to submit one frame to output, these filters need to enqueue
-at least one frame for each input, so they cannot work in case one
-input is not yet terminated and will not receive incoming frames.
-
-
For example consider the case when one input is a select filter
-which always drop input frames. The interleave filter will keep
-reading from that input, but it will never be able to send new frames
-to output until the input will send an end-of-stream signal.
-
-
Also, depending on inputs synchronization, the filters will drop
-frames in case one input receives more frames than the other ones, and
-the queue is already filled.
-
-
These filters accept the following options:
-
-
-nb_inputs, n Set the number of different inputs, it is 2 by default.
-
-
-
-
33.4.1 Examples# TOC
-
-
- Interleave frames belonging to different streams using ffmpeg:
-
-
ffmpeg -i bambi.avi -i pr0n.mkv -filter_complex "[0:v][1:v] interleave" out.avi
- Add flickering blur effect:
-
-
select='if(gt(random(0), 0.2), 1, 2)':n=2 [tmp], boxblur=2:2, [tmp] interleave
-
-
-
-
33.5 perms, aperms# TOC
-
-
Set read/write permissions for the output frames.
-
-
These filters are mainly aimed at developers to test direct path in the
-following filter in the filtergraph.
-
-
The filters accept the following options:
-
-
-mode Select the permissions mode.
-
-It accepts the following values:
-
-‘none ’
-Do nothing. This is the default.
-
‘ro ’
-Set all the output frames read-only.
-
‘rw ’
-Set all the output frames directly writable.
-
‘toggle ’
-Make the frame read-only if writable, and writable if read-only.
-
‘random ’
-Set each output frame read-only or writable randomly.
-
-
-seed Set the seed for the random mode, must be an integer included between
-0 and UINT32_MAX. If not specified, or if explicitly set to
--1, the filter will try to use a good random seed on a best effort
-basis.
-
-
-
Note: in case of auto-inserted filter between the permission filter and the
-following one, the permission might not be received as expected in that
-following filter. Inserting a format or aformat filter before the
-perms/aperms filter can avoid this problem.
-
-
-
33.6 select, aselect# TOC
-
-
Select frames to pass in output.
-
-
This filter accepts the following options:
-
-
-expr, e Set expression, which is evaluated for each input frame.
-
-If the expression is evaluated to zero, the frame is discarded.
-
-If the evaluation result is negative or NaN, the frame is sent to the
-first output; otherwise it is sent to the output with index
-ceil(val)-1, assuming that the input index starts from 0.
-
-For example a value of 1.2 corresponds to the output with index
-ceil(1.2)-1 = 2-1 = 1, that is the second output.
-
-outputs, n Set the number of outputs. The output to which to send the selected
-frame is based on the result of the evaluation. Default value is 1.
-
-
-
The expression can contain the following constants:
-
-
-n The (sequential) number of the filtered frame, starting from 0.
-
-selected_n The (sequential) number of the selected frame, starting from 0.
-
-prev_selected_n The sequential number of the last selected frame. It’s NAN if undefined.
-
-TB The timebase of the input timestamps.
-
-pts The PTS (Presentation TimeStamp) of the filtered video frame,
-expressed in TB units. It’s NAN if undefined.
-
-t The PTS of the filtered video frame,
-expressed in seconds. It’s NAN if undefined.
-
-prev_pts The PTS of the previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_pts The PTS of the last previously filtered video frame. It’s NAN if undefined.
-
-prev_selected_t The PTS of the last previously selected video frame. It’s NAN if undefined.
-
-start_pts The PTS of the first video frame in the video. It’s NAN if undefined.
-
-start_t The time of the first video frame in the video. It’s NAN if undefined.
-
-pict_type (video only) The type of the filtered frame. It can assume one of the following
-values:
-
-I P B S SI SP BI
-
-interlace_type (video only) The frame interlace type. It can assume one of the following values:
-
-PROGRESSIVE The frame is progressive (not interlaced).
-
TOPFIRST The frame is top-field-first.
-
BOTTOMFIRST The frame is bottom-field-first.
-
-
-consumed_sample_n (audio only) the number of selected samples before the current frame
-
-samples_n (audio only) the number of samples in the current frame
-
-sample_rate (audio only) the input sample rate
-
-key This is 1 if the filtered frame is a key-frame, 0 otherwise.
-
-pos the position in the file of the filtered frame, -1 if the information
-is not available (e.g. for synthetic video)
-
-scene (video only) value between 0 and 1 to indicate a new scene; a low value reflects a low
-probability for the current frame to introduce a new scene, while a higher
-value means the current frame is more likely to be one (see the example below)
-
-
-
-
The default value of the select expression is "1".
-
-
-
33.6.1 Examples# TOC
-
-
-
-
-
33.7 sendcmd, asendcmd# TOC
-
-
Send commands to filters in the filtergraph.
-
-
These filters read commands to be sent to other filters in the
-filtergraph.
-
-
sendcmd must be inserted between two video filters,
-asendcmd must be inserted between two audio filters, but apart
-from that they act the same way.
-
-
The specification of commands can be provided in the filter arguments
-with the commands option, or in a file specified by the
-filename option.
-
-
These filters accept the following options:
-
-commands, c Set the commands to be read and sent to the other filters.
-
filename, f Set the filename of the commands to be read and sent to the other
-filters.
-
-
-
-
33.7.1 Commands syntax# TOC
-
-
A commands description consists of a sequence of interval
-specifications, comprising a list of commands to be executed when a
-particular event related to that interval occurs. The occurring event
-is typically the current frame time entering or leaving a given time
-interval.
-
-
An interval is specified by the following syntax:
-
-
-
The time interval is specified by the START and END times.
-END is optional and defaults to the maximum time.
-
-
The current frame time is considered within the specified interval if
-it is included in the interval [START , END ), that is when
-the time is greater or equal to START and is lesser than
-END .
-
-
COMMANDS consists of a sequence of one or more command
-specifications, separated by ",", relating to that interval. The
-syntax of a command specification is given by:
-
-
[FLAGS ] TARGET COMMAND ARG
-
-
-
FLAGS is optional and specifies the type of events relating to
-the time interval which enable sending the specified command, and must
-be a non-null sequence of identifier flags separated by "+" or "|" and
-enclosed between "[" and "]".
-
-
The following flags are recognized:
-
-enter The command is sent when the current frame timestamp enters the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was not in the given interval, and the
-current is.
-
-leave The command is sent when the current frame timestamp leaves the
-specified interval. In other words, the command is sent when the
-previous frame timestamp was in the given interval, and the
-current is not.
-
-
-
If FLAGS is not specified, a default value of [enter] is
-assumed.
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional list of argument for
-the given COMMAND .
-
-
Between one interval specification and another, whitespaces, or
-sequences of characters starting with # until the end of line,
-are ignored and can be used to annotate comments.
-
-
A simplified BNF description of the commands specification syntax
-follows:
-
-
COMMAND_FLAG ::= "enter" | "leave"
-COMMAND_FLAGS ::= COMMAND_FLAG [(+|"|")COMMAND_FLAG ]
-COMMAND ::= ["[" COMMAND_FLAGS "]"] TARGET COMMAND [ARG ]
-COMMANDS ::= COMMAND [,COMMANDS ]
-INTERVAL ::= START [-END ] COMMANDS
-INTERVALS ::= INTERVAL [;INTERVALS ]
-
-
-
-
33.7.2 Examples# TOC
-
-
-
-
-
33.8 setpts, asetpts# TOC
-
-
Change the PTS (presentation timestamp) of the input frames.
-
-
setpts works on video frames, asetpts on audio frames.
-
-
This filter accepts the following options:
-
-
-expr The expression which is evaluated for each frame to construct its timestamp.
-
-
-
-
The expression is evaluated through the eval API and can contain the following
-constants:
-
-
-FRAME_RATE frame rate, only defined for constant frame-rate video
-
-PTS The presentation timestamp in input
-
-N The count of the input frame for video or the number of consumed samples,
-not including the current frame for audio, starting from 0.
-
-NB_CONSUMED_SAMPLES The number of consumed samples, not including the current frame (only
-audio)
-
-NB_SAMPLES, S The number of samples in the current frame (only audio)
-
-SAMPLE_RATE, SR The audio sample rate.
-
-STARTPTS The PTS of the first frame.
-
-STARTT the time in seconds of the first frame
-
-INTERLACED State whether the current frame is interlaced.
-
-T the time in seconds of the current frame
-
-POS original position in the file of the frame, or undefined if undefined
-for the current frame
-
-PREV_INPTS The previous input PTS.
-
-PREV_INT previous input time in seconds
-
-PREV_OUTPTS The previous output PTS.
-
-PREV_OUTT previous output time in seconds
-
-RTCTIME The wallclock (RTC) time in microseconds. This is deprecated, use time(0)
-instead.
-
-RTCSTART The wallclock (RTC) time at the start of the movie in microseconds.
-
-TB The timebase of the input timestamps.
-
-
-
-
-
33.8.1 Examples# TOC
-
-
- Start counting PTS from zero
-
-
- Apply fast motion effect:
-
-
- Apply slow motion effect:
-
-
- Set fixed rate of 25 frames per second:
-
-
- Set fixed rate 25 fps with some jitter:
-
-
setpts='1/(25*TB) * (N + 0.05 * sin(N*2*PI/25))'
- Apply an offset of 10 seconds to the input PTS:
-
-
- Generate timestamps from a "live source" and rebase onto the current timebase:
-
-
setpts='(RTCTIME - RTCSTART) / (TB * 1000000)'
- Generate timestamps by counting samples:
-
-
-
-
-
-
33.9 settb, asettb# TOC
-
-
Set the timebase to use for the output frames timestamps.
-It is mainly useful for testing timebase configuration.
-
-
It accepts the following parameters:
-
-
-expr, tb The expression which is evaluated into the output timebase.
-
-
-
-
The value for tb is an arithmetic expression representing a
-rational. The expression can contain the constants "AVTB" (the default
-timebase), "intb" (the input timebase) and "sr" (the sample rate,
-audio only). Default value is "intb".
-
-
-
33.9.1 Examples# TOC
-
-
- Set the timebase to 1/25:
-
-
- Set the timebase to 1/10:
-
-
- Set the timebase to 1001/1000:
-
-
- Set the timebase to 2*intb:
-
-
- Set the default timebase value:
-
-
-
-
-
33.10 showcqt# TOC
-
Convert input audio to a video output representing
-frequency spectrum logarithmically (using constant Q transform with
-Brown-Puckette algorithm), with musical tone scale, from E0 to D#10 (10 octaves).
-
-
The filter accepts the following options:
-
-
-volume Specify transform volume (multiplier) expression. The expression can contain
-variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-a_weighting(f) A-weighting of equal loudness
-
b_weighting(f) B-weighting of equal loudness
-
c_weighting(f) C-weighting of equal loudness
-
-Default value is 16.
-
-tlength Specify transform length expression. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-Default value is 384/f*tc/(384/f+tc).
-
-timeclamp Specify the transform timeclamp. At low frequency, there is trade-off between
-accuracy in time domain and frequency domain. If timeclamp is lower,
-event in time domain is represented more accurately (such as fast bass drum),
-otherwise event in frequency domain is represented more accurately
-(such as bass guitar). Acceptable value is [0.1, 1.0]. Default value is 0.17.
-
-coeffclamp Specify the transform coeffclamp. If coeffclamp is lower, transform is
-more accurate, otherwise transform is faster. Acceptable value is [0.1, 10.0].
-Default value is 1.0.
-
-gamma Specify gamma. Lower gamma makes the spectrum more contrast, higher gamma
-makes the spectrum having more range. Acceptable value is [1.0, 7.0].
-Default value is 3.0.
-
-fontfile Specify font file for use with freetype. If not specified, use embedded font.
-
-fontcolor Specify font color expression. This is arithmetic expression that should return
-integer value 0xRRGGBB. The expression can contain variables:
-
-frequency, freq, f the frequency where transform is evaluated
-
timeclamp, tc value of timeclamp option
-
-and functions:
-
-midi(f) midi number of frequency f, some midi numbers: E0(16), C1(24), C2(36), A4(69)
-
r(x), g(x), b(x) red, green, and blue value of intensity x
-
-Default value is st(0, (midi(f)-59.5)/12);
-st(1, if(between(ld(0),0,1), 0.5-0.5*cos(2*PI*ld(0)), 0));
-r(1-ld(1)) + b(ld(1))
-
-fullhd If set to 1 (the default), the video size is 1920x1080 (full HD),
-if set to 0, the video size is 960x540. Use this option to make CPU usage lower.
-
-fps Specify video fps. Default value is 25.
-
-count Specify number of transform per frame, so there are fps*count transforms
-per second. Note that audio data rate must be divisible by fps*count.
-Default value is 6.
-
-
-
-
-
33.10.1 Examples# TOC
-
-
- Playing audio while showing the spectrum:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt [out0]'
- Same as above, but with frame rate 30 fps:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fps=30:count=5 [out0]'
- Playing at 960x540 and lower CPU usage:
-
-
ffplay -f lavfi 'amovie=a.mp3, asplit [a][out1]; [a] showcqt=fullhd=0:count=3 [out0]'
- A1 and its harmonics: A1, A2, (near)E3, A3:
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt [out0]'
- Same as above, but with more accuracy in frequency domain (and slower):
-
-
ffplay -f lavfi 'aevalsrc=0.1*sin(2*PI*55*t)+0.1*sin(4*PI*55*t)+0.1*sin(6*PI*55*t)+0.1*sin(8*PI*55*t),
- asplit[a][out1]; [a] showcqt=timeclamp=0.5 [out0]'
- B-weighting of equal loudness
-
-
volume=16*b_weighting(f)
- Lower Q factor
-
-
tlength=100/f*tc/(100/f+tc)
- Custom fontcolor, C-note is colored green, others are colored blue
-
-
fontcolor='if(mod(floor(midi(f)+0.5),12), 0x0000FF, g(1))'
-
-
-
-
33.11 showspectrum# TOC
-
-
Convert input audio to a video output, representing the audio frequency
-spectrum.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value is
-640x512.
-
-slide Specify how the spectrum should slide along the window.
-
-It accepts the following values:
-
-‘replace ’
-the samples start again on the left when they reach the right
-
‘scroll ’
-the samples scroll from right to left
-
‘fullframe ’
-frames are only produced when the samples reach the right
-
-
-Default value is replace.
-
-mode Specify display mode.
-
-It accepts the following values:
-
-‘combined ’
-all channels are displayed in the same row
-
‘separate ’
-all channels are displayed in separate rows
-
-
-Default value is ‘combined ’.
-
-color Specify display color mode.
-
-It accepts the following values:
-
-‘channel ’
-each channel is displayed in a separate color
-
‘intensity ’
-each channel is is displayed using the same color scheme
-
-
-Default value is ‘channel ’.
-
-scale Specify scale used for calculating intensity color values.
-
-It accepts the following values:
-
-‘lin ’
-linear
-
‘sqrt ’
-square root, default
-
‘cbrt ’
-cubic root
-
‘log ’
-logarithmic
-
-
-Default value is ‘sqrt ’.
-
-saturation Set saturation modifier for displayed colors. Negative values provide
-alternative color scheme. 0 is no saturation at all.
-Saturation must be in [-10.0, 10.0] range.
-Default value is 1.
-
-win_func Set window function.
-
-It accepts the following values:
-
-‘none ’
-No samples pre-processing (do not expect this to be faster)
-
‘hann ’
-Hann window
-
‘hamming ’
-Hamming window
-
‘blackman ’
-Blackman window
-
-
-Default value is hann.
-
-
-
The usage is very similar to the showwaves filter; see the examples in that
-section.
-
-
-
33.11.1 Examples# TOC
-
-
- Large window with logarithmic color scaling:
-
-
showspectrum=s=1280x480:scale=log
- Complete example for a colored and sliding spectrum per channel using ffplay:
-
-
ffplay -f lavfi 'amovie=input.mp3, asplit [a][out1];
- [a] showspectrum=mode=separate:color=intensity:slide=1:scale=cbrt [out0]'
-
-
-
-
33.12 showwaves# TOC
-
-
Convert input audio to a video output, representing the samples waves.
-
-
The filter accepts the following options:
-
-
-size, s Specify the video size for the output. For the syntax of this option, check
-the "Video size" section in the ffmpeg-utils manual. Default value
-is "600x240".
-
-mode Set display mode.
-
-Available values are:
-
-‘point ’
-Draw a point for each sample.
-
-‘line ’
-Draw a vertical line for each sample.
-
-‘p2p ’
-Draw a point for each sample and a line between them.
-
-‘cline ’
-Draw a centered vertical line for each sample.
-
-
-Default value is point.
-
-n Set the number of samples which are printed on the same column. A
-larger value will decrease the frame rate. Must be a positive
-integer. This option can be set only if the value for rate
-is not explicitly specified.
-
-rate, r Set the (approximate) output frame rate. This is done by setting the
-option n . Default value is "25".
-
-split_channels Set if channels should be drawn separately or overlap. Default value is 0.
-
-
-
-
-
33.12.1 Examples# TOC
-
-
- Output the input file audio and the corresponding video representation
-at the same time:
-
-
amovie=a.mp3,asplit[out0],showwaves[out1]
- Create a synthetic signal and show it with showwaves, forcing a
-frame rate of 30 frames per second:
-
-
aevalsrc=sin(1*2*PI*t)*sin(880*2*PI*t):cos(2*PI*200*t),asplit[out0],showwaves=r=30[out1]
-
-
-
-
33.13 split, asplit# TOC
-
-
Split input into several identical outputs.
-
-
asplit works with audio input, split with video.
-
-
The filter accepts a single parameter which specifies the number of outputs. If
-unspecified, it defaults to 2.
-
-
-
33.13.1 Examples# TOC
-
-
- Create two separate outputs from the same input:
-
-
[in] split [out0][out1]
- To create 3 or more outputs, you need to specify the number of
-outputs, like in:
-
-
[in] asplit=3 [out0][out1][out2]
- Create two separate outputs from the same input, one cropped and
-one padded:
-
-
[in] split [splitout1][splitout2];
-[splitout1] crop=100:100:0:0 [cropout];
-[splitout2] pad=200:200:100:100 [padout];
- Create 5 copies of the input audio with ffmpeg:
-
-
ffmpeg -i INPUT -filter_complex asplit=5 OUTPUT
-
-
-
-
33.14 zmq, azmq# TOC
-
-
Receive commands sent through a libzmq client, and forward them to
-filters in the filtergraph.
-
-
zmq and azmq work as a pass-through filters. zmq
-must be inserted between two video filters, azmq between two
-audio filters.
-
-
To enable these filters you need to install the libzmq library and
-headers and configure FFmpeg with --enable-libzmq.
-
-
For more information about libzmq see:
-http://www.zeromq.org/
-
-
The zmq and azmq filters work as a libzmq server, which
-receives messages sent through a network interface defined by the
-bind_address option.
-
-
The received message must be in the form:
-
-
-
TARGET specifies the target of the command, usually the name of
-the filter class or a specific filter instance name.
-
-
COMMAND specifies the name of the command for the target filter.
-
-
ARG is optional and specifies the optional argument list for the
-given COMMAND .
-
-
Upon reception, the message is processed and the corresponding command
-is injected into the filtergraph. Depending on the result, the filter
-will send a reply to the client, adopting the format:
-
-
ERROR_CODE ERROR_REASON
-MESSAGE
-
-
-
MESSAGE is optional.
-
-
-
33.14.1 Examples# TOC
-
-
Look at tools/zmqsend for an example of a zmq client which can
-be used to send commands processed by these filters.
-
-
Consider the following filtergraph generated by ffplay
-
-
ffplay -dumpgraph 1 -f lavfi "
-color=s=100x100:c=red [l];
-color=s=100x100:c=blue [r];
-nullsrc=s=200x100, zmq [bg];
-[bg][l] overlay [bg+l];
-[bg+l][r] overlay=x=100 "
-
-
-
To change the color of the left side of the video, the following
-command can be used:
-
-
echo Parsed_color_0 c yellow | tools/zmqsend
-
-
-
To change the right side:
-
-
echo Parsed_color_1 c pink | tools/zmqsend
-
-
-
-
-
34 Multimedia Sources# TOC
-
-
Below is a description of the currently available multimedia sources.
-
-
-
34.1 amovie# TOC
-
-
This is the same as movie source, except it selects an audio
-stream by default.
-
-
-
34.2 movie# TOC
-
-
Read audio and/or video stream(s) from a movie container.
-
-
It accepts the following parameters:
-
-
-filename The name of the resource to read (not necessarily a file; it can also be a
-device or a stream accessed through some protocol).
-
-format_name, f Specifies the format assumed for the movie to read, and can be either
-the name of a container or an input device. If not specified, the
-format is guessed from movie_name or by probing.
-
-seek_point, sp Specifies the seek point in seconds. The frames will be output
-starting from this seek point. The parameter is evaluated with
-av_strtod, so the numerical value may be suffixed by an IS
-postfix. The default value is "0".
-
-streams, s Specifies the streams to read. Several streams can be specified,
-separated by "+". The source will then have as many outputs, in the
-same order. The syntax is explained in the “Stream specifiers”
-section in the ffmpeg manual. Two special names, "dv" and "da" specify
-respectively the default (best suited) video and audio stream. Default
-is "dv", or "da" if the filter is called as "amovie".
-
-stream_index, si Specifies the index of the video stream to read. If the value is -1,
-the most suitable video stream will be automatically selected. The default
-value is "-1". Deprecated. If the filter is called "amovie", it will select
-audio instead of video.
-
-loop Specifies how many times to read the stream in sequence.
-If the value is less than 1, the stream will be read again and again.
-Default value is "1".
-
-Note that when the movie is looped the source timestamps are not
-changed, so it will generate non monotonically increasing timestamps.
-
-
-
It allows overlaying a second video on top of the main input of
-a filtergraph, as shown in this graph:
-
-
input -----------> deltapts0 --> overlay --> output
- ^
- |
-movie --> scale--> deltapts1 -------+
-
-
-
34.2.1 Examples# TOC
-
-
- Skip 3.2 seconds from the start of the AVI file in.avi, and overlay it
-on top of the input labelled "in":
-
-
movie=in.avi:seek_point=3.2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read from a video4linux2 device, and overlay it on top of the input
-labelled "in":
-
-
movie=/dev/video0:f=video4linux2, scale=180:-1, setpts=PTS-STARTPTS [over];
-[in] setpts=PTS-STARTPTS [main];
-[main][over] overlay=16:16 [out]
- Read the first video stream and the audio stream with id 0x81 from
-dvd.vob; the video is connected to the pad named "video" and the audio is
-connected to the pad named "audio":
-
-
movie=dvd.vob:s=v:0+#0x81 [video] [audio]
-
-
-
-
-
35 See Also# TOC
-
-
ffprobe ,
-ffmpeg , ffplay , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
36 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- ffprobe Documentation
-
-
-
- ffprobe Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Synopsis# TOC
-
-
ffprobe [options ] [input_file ]
-
-
-
2 Description# TOC
-
-
ffprobe gathers information from multimedia streams and prints it in
-human- and machine-readable fashion.
-
-
For example it can be used to check the format of the container used
-by a multimedia stream and the format and type of each media stream
-contained in it.
-
-
If a filename is specified in input, ffprobe will try to open and
-probe the file content. If the file cannot be opened or recognized as
-a multimedia file, a positive exit code is returned.
-
-
ffprobe may be employed both as a standalone application or in
-combination with a textual filter, which may perform more
-sophisticated processing, e.g. statistical processing or plotting.
-
-
Options are used to list some of the formats supported by ffprobe or
-for specifying which information to display, and for setting how
-ffprobe will show it.
-
-
ffprobe output is designed to be easily parsable by a textual filter,
-and consists of one or more sections of a form defined by the selected
-writer, which is specified by the print_format option.
-
-
Sections may contain other nested sections, and are identified by a
-name (which may be shared by other sections), and an unique
-name. See the output of sections .
-
-
Metadata tags stored in the container or in the streams are recognized
-and printed in the corresponding "FORMAT", "STREAM" or "PROGRAM_STREAM"
-section.
-
-
-
-
3 Options# TOC
-
-
All the numerical options, if not specified otherwise, accept a string
-representing a number as input, which may be followed by one of the SI
-unit prefixes, for example: ’K’, ’M’, or ’G’.
-
-
If ’i’ is appended to the SI unit prefix, the complete prefix will be
-interpreted as a unit prefix for binary multiples, which are based on
-powers of 1024 instead of powers of 1000. Appending ’B’ to the SI unit
-prefix multiplies the value by 8. This allows using, for example:
-’KB’, ’MiB’, ’G’ and ’B’ as number suffixes.
-
-
Options which do not take arguments are boolean options, and set the
-corresponding value to true. They can be set to false by prefixing
-the option name with "no". For example using "-nofoo"
-will set the boolean option with name "foo" to false.
-
-
-
3.1 Stream specifiers# TOC
-
Some options are applied per-stream, e.g. bitrate or codec. Stream specifiers
-are used to precisely specify which stream(s) a given option belongs to.
-
-
A stream specifier is a string generally appended to the option name and
-separated from it by a colon. E.g. -codec:a:1 ac3 contains the
-a:1 stream specifier, which matches the second audio stream. Therefore, it
-would select the ac3 codec for the second audio stream.
-
-
A stream specifier can match several streams, so that the option is applied to all
-of them. E.g. the stream specifier in -b:a 128k matches all audio
-streams.
-
-
An empty stream specifier matches all streams. For example, -codec copy
-or -codec: copy would copy all the streams without reencoding.
-
-
Possible forms of stream specifiers are:
-
-stream_index Matches the stream with this index. E.g. -threads:1 4 would set the
-thread count for the second stream to 4.
-
stream_type [:stream_index ]stream_type is one of following: ’v’ for video, ’a’ for audio, ’s’ for subtitle,
-’d’ for data, and ’t’ for attachments. If stream_index is given, then it matches
-stream number stream_index of this type. Otherwise, it matches all
-streams of this type.
-
p:program_id [:stream_index ] If stream_index is given, then it matches the stream with number stream_index
-in the program with the id program_id . Otherwise, it matches all streams in the
-program.
-
#stream_id or i:stream_id Match the stream by stream id (e.g. PID in MPEG-TS container).
-
m:key [:value ] Matches streams with the metadata tag key having the specified value. If
-value is not given, matches streams that contain the given tag with any
-value.
-
-Note that in ffmpeg, matching by metadata will only work properly for
-input files.
-
-
-
-
3.2 Generic options# TOC
-
-
These options are shared amongst the ff* tools.
-
-
--L Show license.
-
--h, -?, -help, --help [arg ] Show help. An optional parameter may be specified to print help about a specific
-item. If no argument is specified, only basic (non advanced) tool
-options are shown.
-
-Possible values of arg are:
-
-long Print advanced tool options in addition to the basic tool options.
-
-full Print complete list of options, including shared and private options
-for encoders, decoders, demuxers, muxers, filters, etc.
-
-decoder=decoder_name Print detailed information about the decoder named decoder_name . Use the
--decoders option to get a list of all decoders.
-
-encoder=encoder_name Print detailed information about the encoder named encoder_name . Use the
--encoders option to get a list of all encoders.
-
-demuxer=demuxer_name Print detailed information about the demuxer named demuxer_name . Use the
--formats option to get a list of all demuxers and muxers.
-
-muxer=muxer_name Print detailed information about the muxer named muxer_name . Use the
--formats option to get a list of all muxers and demuxers.
-
-filter=filter_name Print detailed information about the filter name filter_name . Use the
--filters option to get a list of all filters.
-
-
--version Show version.
-
--formats Show available formats (including devices).
-
--devices Show available devices.
-
--codecs Show all codecs known to libavcodec.
-
-Note that the term ’codec’ is used throughout this documentation as a shortcut
-for what is more correctly called a media bitstream format.
-
--decoders Show available decoders.
-
--encoders Show all available encoders.
-
--bsfs Show available bitstream filters.
-
--protocols Show available protocols.
-
--filters Show available libavfilter filters.
-
--pix_fmts Show available pixel formats.
-
--sample_fmts Show available sample formats.
-
--layouts Show channel names and standard channel layouts.
-
--colors Show recognized color names.
-
--sources device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sources of the intput device.
-Some devices may provide system-dependent source names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sources pulse,server=192.168.0.4
- -sinks device [,opt1 =val1 [,opt2 =val2 ]...] Show autodetected sinks of the output device.
-Some devices may provide system-dependent sink names that cannot be autodetected.
-The returned list cannot be assumed to be always complete.
-
-
ffmpeg -sinks pulse,server=192.168.0.4
- -loglevel [repeat+]loglevel | -v [repeat+]loglevel Set the logging level used by the library.
-Adding "repeat+" indicates that repeated log output should not be compressed
-to the first line and the "Last message repeated n times" line will be
-omitted. "repeat" can also be used alone.
-If "repeat" is used alone, and with no prior loglevel set, the default
-loglevel will be used. If multiple loglevel parameters are given, using
-’repeat’ will not change the loglevel.
-loglevel is a string or a number containing one of the following values:
-
-‘quiet, -8 ’
-Show nothing at all; be silent.
-
‘panic, 0 ’
-Only show fatal errors which could lead the process to crash, such as
-and assert failure. This is not currently used for anything.
-
‘fatal, 8 ’
-Only show fatal errors. These are errors after which the process absolutely
-cannot continue after.
-
‘error, 16 ’
-Show all errors, including ones which can be recovered from.
-
‘warning, 24 ’
-Show all warnings and errors. Any message related to possibly
-incorrect or unexpected events will be shown.
-
‘info, 32 ’
-Show informative messages during processing. This is in addition to
-warnings and errors. This is the default value.
-
‘verbose, 40 ’
-Same as info, except more verbose.
-
‘debug, 48 ’
-Show everything, including debugging information.
-
-
-By default the program logs to stderr, if coloring is supported by the
-terminal, colors are used to mark errors and warnings. Log coloring
-can be disabled setting the environment variable
-AV_LOG_FORCE_NOCOLOR or NO_COLOR, or can be forced setting
-the environment variable AV_LOG_FORCE_COLOR.
-The use of the environment variable NO_COLOR is deprecated and
-will be dropped in a following FFmpeg version.
-
--report Dump full command line and console output to a file named
-program -YYYYMMDD -HHMMSS .log-loglevel verbose.
-
-Setting the environment variable FFREPORT to any value has the
-same effect. If the value is a ’:’-separated key=value sequence, these
-options will affect the report; option values must be escaped if they
-contain special characters or the options delimiter ’:’ (see the
-“Quoting and escaping” section in the ffmpeg-utils manual).
-
-The following options are recognized:
-
-file set the file name to use for the report; %p is expanded to the name
-of the program, %t is expanded to a timestamp, %% is expanded
-to a plain %
-
level set the log verbosity level using a numerical value (see -loglevel).
-
-
-For example, to output a report to a file named ffreport.log
-using a log level of 32 (alias for log level info):
-
-
-
FFREPORT=file=ffreport.log:level=32 ffmpeg -i input output
- Errors in parsing the environment variable are not fatal, and will not
-appear in the report.
-
--hide_banner Suppress printing banner.
-
-All FFmpeg tools will normally show a copyright notice, build options
-and library versions. This option can be used to suppress printing
-this information.
-
--cpuflags flags (global ) Allows setting and clearing cpu flags. This option is intended
-for testing. Do not use it unless you know what you’re doing.
-
-
ffmpeg -cpuflags -sse+mmx ...
-ffmpeg -cpuflags mmx ...
-ffmpeg -cpuflags 0 ...
- Possible flags for this option are:
-
-‘x86 ’
-
-‘mmx ’
-‘mmxext ’
-‘sse ’
-‘sse2 ’
-‘sse2slow ’
-‘sse3 ’
-‘sse3slow ’
-‘ssse3 ’
-‘atom ’
-‘sse4.1 ’
-‘sse4.2 ’
-‘avx ’
-‘xop ’
-‘fma4 ’
-‘3dnow ’
-‘3dnowext ’
-‘cmov ’
-
-‘ARM ’
-
-‘armv5te ’
-‘armv6 ’
-‘armv6t2 ’
-‘vfp ’
-‘vfpv3 ’
-‘neon ’
-
-‘PowerPC ’
-
-‘altivec ’
-
-‘Specific Processors ’
-
-‘pentium2 ’
-‘pentium3 ’
-‘pentium4 ’
-‘k6 ’
-‘k62 ’
-‘athlon ’
-‘athlonxp ’
-‘k8 ’
-
-
-
--opencl_bench Benchmark all available OpenCL devices and show the results. This option
-is only available when FFmpeg has been compiled with --enable-opencl.
-
--opencl_options options (global ) Set OpenCL environment options. This option is only available when
-FFmpeg has been compiled with --enable-opencl.
-
-options must be a list of key =value option pairs
-separated by ’:’. See the “OpenCL Options” section in the
-ffmpeg-utils manual for the list of supported options.
-
-
-
-
3.3 AVOptions# TOC
-
-
These options are provided directly by the libavformat, libavdevice and
-libavcodec libraries. To see the list of available AVOptions, use the
--help option. They are separated into two categories:
-
-generic These options can be set for any container, codec or device. Generic options
-are listed under AVFormatContext options for containers/devices and under
-AVCodecContext options for codecs.
-
private These options are specific to the given container, device or codec. Private
-options are listed under their corresponding containers/devices/codecs.
-
-
-
For example to write an ID3v2.3 header instead of a default ID3v2.4 to
-an MP3 file, use the id3v2_version private option of the MP3
-muxer:
-
-
ffmpeg -i input.flac -id3v2_version 3 out.mp3
-
-
-
All codec AVOptions are per-stream, and thus a stream specifier
-should be attached to them.
-
-
Note: the -nooption syntax cannot be used for boolean
-AVOptions, use -option 0 /-option 1 .
-
-
Note: the old undocumented way of specifying per-stream AVOptions by
-prepending v/a/s to the options name is now obsolete and will be
-removed soon.
-
-
-
3.4 Main options# TOC
-
-
--f format Force format to use.
-
--unit Show the unit of the displayed values.
-
--prefix Use SI prefixes for the displayed values.
-Unless the "-byte_binary_prefix" option is used all the prefixes
-are decimal.
-
--byte_binary_prefix Force the use of binary prefixes for byte values.
-
--sexagesimal Use sexagesimal format HH:MM:SS.MICROSECONDS for time values.
-
--pretty Prettify the format of the displayed values, it corresponds to the
-options "-unit -prefix -byte_binary_prefix -sexagesimal".
-
--of, -print_format writer_name [=writer_options ] Set the output printing format.
-
-writer_name specifies the name of the writer, and
-writer_options specifies the options to be passed to the writer.
-
-For example for printing the output in JSON format, specify:
-
-
-For more details on the available output printing formats, see the
-Writers section below.
-
--sections Print sections structure and section information, and exit. The output
-is not meant to be parsed by a machine.
-
--select_streams stream_specifier Select only the streams specified by stream_specifier . This
-option affects only the options related to streams
-(e.g. show_streams, show_packets, etc.).
-
-For example to show only audio streams, you can use the command:
-
-
ffprobe -show_streams -select_streams a INPUT
- To show only video packets belonging to the video stream with index 1:
-
-
ffprobe -show_packets -select_streams v:1 INPUT
- -show_data Show payload data, as a hexadecimal and ASCII dump. Coupled with
--show_packets , it will dump the packets’ data. Coupled with
--show_streams , it will dump the codec extradata.
-
-The dump is printed as the "data" field. It may contain newlines.
-
--show_data_hash algorithm Show a hash of payload data, for packets with -show_packets and for
-codec extradata with -show_streams .
-
--show_error Show information about the error found when trying to probe the input.
-
-The error information is printed within a section with name "ERROR".
-
--show_format Show information about the container format of the input multimedia
-stream.
-
-All the container format information is printed within a section with
-name "FORMAT".
-
--show_format_entry name Like -show_format , but only prints the specified entry of the
-container format information, rather than all. This option may be given more
-than once, then all specified entries will be shown.
-
-This option is deprecated, use show_entries instead.
-
--show_entries section_entries Set list of entries to show.
-
-Entries are specified according to the following
-syntax. section_entries contains a list of section entries
-separated by :. Each section entry is composed by a section
-name (or unique name), optionally followed by a list of entries local
-to that section, separated by ,.
-
-If section name is specified but is followed by no =, all
-entries are printed to output, together with all the contained
-sections. Otherwise only the entries specified in the local section
-entries list are printed. In particular, if = is specified but
-the list of local entries is empty, then no entries will be shown for
-that section.
-
-Note that the order of specification of the local section entries is
-not honored in the output, and the usual display order will be
-retained.
-
-The formal syntax is given by:
-
-
LOCAL_SECTION_ENTRIES ::= SECTION_ENTRY_NAME [,LOCAL_SECTION_ENTRIES ]
-SECTION_ENTRY ::= SECTION_NAME [=[LOCAL_SECTION_ENTRIES ]]
-SECTION_ENTRIES ::= SECTION_ENTRY [:SECTION_ENTRIES ]
-For example, to show only the index and type of each stream, and the PTS
-time, duration time, and stream index of the packets, you can specify
-the argument:
-
-
packet=pts_time,duration_time,stream_index : stream=index,codec_type
- To show all the entries in the section "format", but only the codec
-type in the section "stream", specify the argument:
-
-
format : stream=codec_type
- To show all the tags in the stream and format sections:
-
-
stream_tags : format_tags
- To show only the title tag (if available) in the stream
-sections:
-
-
--show_packets Show information about each packet contained in the input multimedia
-stream.
-
-The information for each single packet is printed within a dedicated
-section with name "PACKET".
-
--show_frames Show information about each frame and subtitle contained in the input
-multimedia stream.
-
-The information for each single frame is printed within a dedicated
-section with name "FRAME" or "SUBTITLE".
-
--show_streams Show information about each media stream contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "STREAM".
-
--show_programs Show information about programs and their streams contained in the input
-multimedia stream.
-
-Each media stream information is printed within a dedicated section
-with name "PROGRAM_STREAM".
-
--show_chapters Show information about chapters stored in the format.
-
-Each chapter is printed within a dedicated section with name "CHAPTER".
-
--count_frames Count the number of frames per stream and report it in the
-corresponding stream section.
-
--count_packets Count the number of packets per stream and report it in the
-corresponding stream section.
-
--read_intervals read_intervals
-Read only the specified intervals. read_intervals must be a
-sequence of interval specifications separated by ",".
-ffprobe will seek to the interval starting point, and will
-continue reading from that.
-
-Each interval is specified by two optional parts, separated by "%".
-
-The first part specifies the interval start position. It is
-interpreted as an abolute position, or as a relative offset from the
-current position if it is preceded by the "+" character. If this first
-part is not specified, no seeking will be performed when reading this
-interval.
-
-The second part specifies the interval end position. It is interpreted
-as an absolute position, or as a relative offset from the current
-position if it is preceded by the "+" character. If the offset
-specification starts with "#", it is interpreted as the number of
-packets to read (not including the flushing packets) from the interval
-start. If no second part is specified, the program will read until the
-end of the input.
-
-Note that seeking is not accurate, thus the actual interval start
-point may be different from the specified position. Also, when an
-interval duration is specified, the absolute end time will be computed
-by adding the duration to the interval start point found by seeking
-the file, rather than to the specified start value.
-
-The formal syntax is given by:
-
-
INTERVAL ::= [START |+START_OFFSET ][%[END |+END_OFFSET ]]
-INTERVALS ::= INTERVAL [,INTERVALS ]
-A few examples follow.
-
- Seek to time 10, read packets until 20 seconds after the found seek
-point, then seek to position 01:30 (1 minute and thirty
-seconds) and read packets until position 01:45.
-
-
- Read only 42 packets after seeking to position 01:23:
-
-
- Read only the first 20 seconds from the start:
-
-
- Read from the start until position 02:30:
-
-
-
-
--show_private_data, -private Show private data, that is data depending on the format of the
-particular shown element.
-This option is enabled by default, but you may need to disable it
-for specific uses, for example when creating XSD-compliant XML output.
-
--show_program_version Show information related to program version.
-
-Version information is printed within a section with name
-"PROGRAM_VERSION".
-
--show_library_versions Show information related to library versions.
-
-Version information for each library is printed within a section with
-name "LIBRARY_VERSION".
-
--show_versions Show information related to program and library versions. This is the
-equivalent of setting both -show_program_version and
--show_library_versions options.
-
--show_pixel_formats Show information about all pixel formats supported by FFmpeg.
-
-Pixel format information for each format is printed within a section
-with name "PIXEL_FORMAT".
-
--bitexact Force bitexact output, useful to produce output which is not dependent
-on the specific build.
-
--i input_file Read input_file .
-
-
-
-
-
4 Writers# TOC
-
-
A writer defines the output format adopted by ffprobe, and will be
-used for printing all the parts of the output.
-
-
A writer may accept one or more arguments, which specify the options
-to adopt. The options are specified as a list of key =value
-pairs, separated by ":".
-
-
All writers support the following options:
-
-
-string_validation, sv Set string validation mode.
-
-The following values are accepted.
-
-‘fail ’
-The writer will fail immediately in case an invalid string (UTF-8)
-sequence or code point is found in the input. This is especially
-useful to validate input metadata.
-
-‘ignore ’
-Any validation error will be ignored. This will result in possibly
-broken output, especially with the json or xml writer.
-
-‘replace ’
-The writer will substitute invalid UTF-8 sequences or code points with
-the string specified with the string_validation_replacement .
-
-
-Default value is ‘replace ’.
-
-string_validation_replacement, svr Set replacement string to use in case string_validation is
-set to ‘replace ’.
-
-In case the option is not specified, the writer will assume the empty
-string, that is it will remove the invalid sequences from the input
-strings.
-
-
-
A description of the currently available writers follows.
-
-
-
4.1 default# TOC
-
Default format.
-
-
Print each section in the form:
-
-
[SECTION]
-key1=val1
-...
-keyN=valN
-[/SECTION]
-
-
-
Metadata tags are printed as a line in the corresponding FORMAT, STREAM or
-PROGRAM_STREAM section, and are prefixed by the string "TAG:".
-
-
A description of the accepted options follows.
-
-
-nokey, nk If set to 1 specify not to print the key of each field. Default value
-is 0.
-
-noprint_wrappers, nw If set to 1 specify not to print the section header and footer.
-Default value is 0.
-
-
-
-
4.2 compact, csv# TOC
-
Compact and CSV format.
-
-
The csv writer is equivalent to compact, but supports
-different defaults.
-
-
Each section is printed on a single line.
-If no option is specifid, the output has the form:
-
-
section|key1=val1| ... |keyN=valN
-
-
-
Metadata tags are printed in the corresponding "format" or "stream"
-section. A metadata tag key, if printed, is prefixed by the string
-"tag:".
-
-
The description of the accepted options follows.
-
-
-item_sep, s Specify the character to use for separating fields in the output line.
-It must be a single printable character, it is "|" by default ("," for
-the csv writer).
-
-nokey, nk If set to 1 specify not to print the key of each field. Its default
-value is 0 (1 for the csv writer).
-
-escape, e Set the escape mode to use, default to "c" ("csv" for the csv
-writer).
-
-It can assume one of the following values:
-
-c Perform C-like escaping. Strings containing a newline (’\n’), carriage
-return (’\r’), a tab (’\t’), a form feed (’\f’), the escaping
-character (’\’) or the item separator character SEP are escaped using C-like fashioned
-escaping, so that a newline is converted to the sequence "\n", a
-carriage return to "\r", ’\’ to "\\" and the separator SEP is
-converted to "\SEP ".
-
-csv Perform CSV-like escaping, as described in RFC4180. Strings
-containing a newline (’\n’), a carriage return (’\r’), a double quote
-(’"’), or SEP are enclosed in double-quotes.
-
-none Perform no escaping.
-
-
-print_section, p Print the section name at the begin of each line if the value is
-1, disable it with value set to 0. Default value is
-1.
-
-
-
-
-
4.3 flat# TOC
-
Flat format.
-
-
A free-form output where each line contains an explicit key=value, such as
-"streams.stream.3.tags.foo=bar". The output is shell escaped, so it can be
-directly embedded in sh scripts as long as the separator character is an
-alphanumeric character or an underscore (see sep_char option).
-
-
The description of the accepted options follows.
-
-
-sep_char, s Separator character used to separate the chapter, the section name, IDs and
-potential tags in the printed field key.
-
-Default value is ’.’.
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
-
INI format output.
-
-
Print output in an INI based format.
-
-
The following conventions are adopted:
-
-
- all key and values are UTF-8
- ’.’ is the subgroup separator
- newline, ’\t’, ’\f’, ’\b’ and the following characters are escaped
- ’\’ is the escape character
- ’#’ is the comment indicator
- ’=’ is the key/value separator
- ’:’ is not used but usually parsed as key/value separator
-
-
-
This writer accepts options as a list of key =value pairs,
-separated by ":".
-
-
The description of the accepted options follows.
-
-
-hierarchical, h Specify if the section name specification should be hierarchical. If
-set to 1, and if there is more than one section in the current
-chapter, the section name will be prefixed by the name of the
-chapter. A value of 0 will disable this behavior.
-
-Default value is 1.
-
-
-
-
4.5 json# TOC
-
JSON based format.
-
-
Each section is printed using JSON notation.
-
-
The description of the accepted options follows.
-
-
-compact, c If set to 1 enable compact output, that is each section will be
-printed on a single line. Default value is 0.
-
-
-
For more information about JSON, see http://www.json.org/ .
-
-
-
-
XML based format.
-
-
The XML output is described in the XML schema description file
-ffprobe.xsd installed in the FFmpeg datadir.
-
-
An updated version of the schema can be retrieved at the url
-http://www.ffmpeg.org/schema/ffprobe.xsd , which redirects to the
-latest schema committed into the FFmpeg development source code tree.
-
-
Note that the output issued will be compliant to the
-ffprobe.xsd schema only when no special global output options
-(unit , prefix , byte_binary_prefix ,
-sexagesimal etc.) are specified.
-
-
The description of the accepted options follows.
-
-
-fully_qualified, q If set to 1 specify if the output should be fully qualified. Default
-value is 0.
-This is required for generating an XML file which can be validated
-through an XSD file.
-
-xsd_compliant, x If set to 1 perform more checks for ensuring that the output is XSD
-compliant. Default value is 0.
-This option automatically sets fully_qualified to 1.
-
-
-
For more information about the XML format, see
-http://www.w3.org/XML/ .
-
-
-
5 Timecode# TOC
-
-
ffprobe supports Timecode extraction:
-
-
- MPEG1/2 timecode is extracted from the GOP, and is available in the video
-stream details (-show_streams , see timecode ).
-
- MOV timecode is extracted from tmcd track, so is available in the tmcd
-stream metadata (-show_streams , see TAG:timecode ).
-
- DV, GXF and AVI timecodes are available in format metadata
-(-show_format , see TAG:timecode ).
-
-
-
-
-
-
6 See Also# TOC
-
-
ffprobe-all ,
-ffmpeg , ffplay , ffserver ,
-ffmpeg-utils ,
-ffmpeg-scaler ,
-ffmpeg-resampler ,
-ffmpeg-codecs ,
-ffmpeg-bitstream-filters ,
-ffmpeg-formats ,
-ffmpeg-devices ,
-ffmpeg-protocols ,
-ffmpeg-filters
-
-
-
-
7 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- General Documentation
-
-
-
- General Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 External libraries# TOC
-
-
FFmpeg can be hooked up with a number of external libraries to add support
-for more formats. None of them are used by default, their use has to be
-explicitly requested by passing the appropriate flags to
-./configure.
-
-
-
1.1 OpenJPEG# TOC
-
-
FFmpeg can use the OpenJPEG libraries for encoding/decoding J2K videos. Go to
-http://www.openjpeg.org/ to get the libraries and follow the installation
-instructions. To enable using OpenJPEG in FFmpeg, pass --enable-libopenjpeg to
-./configure .
-
-
-
-
1.2 OpenCORE, VisualOn, and Fraunhofer libraries# TOC
-
-
Spun off Google Android sources, OpenCore, VisualOn and Fraunhofer
-libraries provide encoders for a number of audio codecs.
-
-
-
OpenCORE and VisualOn libraries are under the Apache License 2.0
-(see http://www.apache.org/licenses/LICENSE-2.0 for details), which is
-incompatible to the LGPL version 2.1 and GPL version 2. You have to
-upgrade FFmpeg’s license to LGPL version 3 (or if you have enabled
-GPL components, GPL version 3) by passing --enable-version3 to configure in
-order to use it.
-
-
The Fraunhofer AAC library is licensed under a license incompatible to the GPL
-and is not known to be compatible to the LGPL. Therefore, you have to pass
---enable-nonfree to configure to use it.
-
-
-
1.2.1 OpenCORE AMR# TOC
-
-
FFmpeg can make use of the OpenCORE libraries for AMR-NB
-decoding/encoding and AMR-WB decoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the libraries.
-Then pass --enable-libopencore-amrnb and/or
---enable-libopencore-amrwb to configure to enable them.
-
-
-
1.2.2 VisualOn AAC encoder library# TOC
-
-
FFmpeg can make use of the VisualOn AACenc library for AAC encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libvo-aacenc to configure to enable it.
-
-
-
1.2.3 VisualOn AMR-WB encoder library# TOC
-
-
FFmpeg can make use of the VisualOn AMR-WBenc library for AMR-WB encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libvo-amrwbenc to configure to enable it.
-
-
-
1.2.4 Fraunhofer AAC library# TOC
-
-
FFmpeg can make use of the Fraunhofer AAC library for AAC encoding.
-
-
Go to http://sourceforge.net/projects/opencore-amr/ and follow the
-instructions for installing the library.
-Then pass --enable-libfdk-aac to configure to enable it.
-
-
-
1.3 LAME# TOC
-
-
FFmpeg can make use of the LAME library for MP3 encoding.
-
-
Go to http://lame.sourceforge.net/ and follow the
-instructions for installing the library.
-Then pass --enable-libmp3lame to configure to enable it.
-
-
-
1.4 TwoLAME# TOC
-
-
FFmpeg can make use of the TwoLAME library for MP2 encoding.
-
-
Go to http://www.twolame.org/ and follow the
-instructions for installing the library.
-Then pass --enable-libtwolame to configure to enable it.
-
-
-
1.5 libvpx# TOC
-
-
FFmpeg can make use of the libvpx library for VP8/VP9 encoding.
-
-
Go to http://www.webmproject.org/ and follow the instructions for
-installing the library. Then pass --enable-libvpx to configure to
-enable it.
-
-
-
1.6 libwavpack# TOC
-
-
FFmpeg can make use of the libwavpack library for WavPack encoding.
-
-
Go to http://www.wavpack.com/ and follow the instructions for
-installing the library. Then pass --enable-libwavpack to configure to
-enable it.
-
-
-
1.7 OpenH264# TOC
-
-
FFmpeg can make use of the OpenH264 library for H.264 encoding.
-
-
Go to http://www.openh264.org/ and follow the instructions for
-installing the library. Then pass --enable-libopenh264 to configure to
-enable it.
-
-
-
1.8 x264# TOC
-
-
FFmpeg can make use of the x264 library for H.264 encoding.
-
-
Go to http://www.videolan.org/developers/x264.html and follow the
-instructions for installing the library. Then pass --enable-libx264 to
-configure to enable it.
-
-
-
-
1.9 x265# TOC
-
-
FFmpeg can make use of the x265 library for HEVC encoding.
-
-
Go to http://x265.org/developers.html and follow the instructions
-for installing the library. Then pass --enable-libx265 to configure
-to enable it.
-
-
-
-
1.10 libilbc# TOC
-
-
iLBC is a narrowband speech codec that has been made freely available
-by Google as part of the WebRTC project. libilbc is a packaging friendly
-copy of the iLBC codec. FFmpeg can make use of the libilbc library for
-iLBC encoding and decoding.
-
-
Go to https://github.com/TimothyGu/libilbc and follow the instructions for
-installing the library. Then pass --enable-libilbc to configure to
-enable it.
-
-
-
1.11 libzvbi# TOC
-
-
libzvbi is a VBI decoding library which can be used by FFmpeg to decode DVB
-teletext pages and DVB teletext subtitles.
-
-
Go to http://sourceforge.net/projects/zapping/ and follow the instructions for
-installing the library. Then pass --enable-libzvbi to configure to
-enable it.
-
-
-
-
1.12 AviSynth# TOC
-
-
FFmpeg can read AviSynth scripts as input. To enable support, pass
---enable-avisynth to configure. The correct headers are
-included in compat/avisynth/, which allows the user to enable support
-without needing to search for these headers themselves.
-
-
For Windows, supported AviSynth variants are
-AviSynth 2.5 or 2.6 for 32-bit builds and
-AviSynth+ 0.1 for 32-bit and 64-bit builds.
-
-
For Linux and OS X, the supported AviSynth variant is
-AvxSynth .
-
-
-
AviSynth and AvxSynth are loaded dynamically. Distributors can build FFmpeg
-with --enable-avisynth, and the binaries will work regardless of the
-end user having AviSynth or AvxSynth installed - they’ll only need to be
-installed to use AviSynth scripts (obviously).
-
-
-
-
2 Supported File Formats, Codecs or Features# TOC
-
-
You can use the -formats and -codecs options to have an exhaustive list.
-
-
-
2.1 File Formats# TOC
-
-
FFmpeg supports the following file formats through the libavformat
-library:
-
-
-Name Encoding Decoding Comments 4xm X 4X Technologies format, used in some games. 8088flex TMV X ACT Voice X contains G.729 audio Adobe Filmstrip X X Audio IFF (AIFF) X X American Laser Games MM X Multimedia format used in games like Mad Dog McCree. 3GPP AMR X X Amazing Studio Packed Animation File X Multimedia format used in game Heart Of Darkness. Apple HTTP Live Streaming X Artworx Data Format X ADP X Audio format used on the Nintendo Gamecube. AFC X Audio format used on the Nintendo Gamecube. ASF X X AST X X Audio format used on the Nintendo Wii. AVI X X AviSynth X AVR X Audio format used on Mac. AVS X Multimedia format used by the Creature Shock game. Beam Software SIFF X Audio and video format used in some games by Beam Software. Bethesda Softworks VID X Used in some games from Bethesda Softworks. Binary text X Bink X Multimedia format used by many games. Bitmap Brothers JV X Used in Z and Z95 games. Brute Force & Ignorance X Used in the game Flash Traffic: City of Angels. BRSTM X Audio format used on the Nintendo Wii. BWF X X CRI ADX X X Audio-only format used in console video games. Discworld II BMV X Interplay C93 X Used in the game Cyberia from Interplay. Delphine Software International CIN X Multimedia format used by Delphine Software games. CD+G X Video format used by CD+G karaoke disks Phantom Cine X Commodore CDXL X Amiga CD video format Core Audio Format X X Apple Core Audio Format CRC testing format X Creative Voice X X Created for the Sound Blaster Pro. CRYO APC X Audio format used in some games by CRYO Interactive Entertainment. D-Cinema audio X X Deluxe Paint Animation X DFA X This format is used in Chronomaster game DSD Stream File (DSF) X DV video X X DXA X This format is used in the non-Windows version of the Feeble Files
- game and different game cutscenes repacked for use with ScummVM. Electronic Arts cdata X Electronic Arts Multimedia X Used in various EA games; files have extensions like WVE and UV2. Ensoniq Paris Audio File X FFM (FFserver live feed) X X Flash (SWF) X X Flash 9 (AVM2) X X Only embedded audio is decoded. FLI/FLC/FLX animation X .fli/.flc files Flash Video (FLV) X X Macromedia Flash video files framecrc testing format X FunCom ISS X Audio format used in various games from FunCom like The Longest Journey. G.723.1 X X G.729 BIT X X G.729 raw X GIF Animation X X GXF X X General eXchange Format SMPTE 360M, used by Thomson Grass Valley
- playout servers. HNM X Only version 4 supported, used in some games from Cryo Interactive iCEDraw File X ICO X X Microsoft Windows ICO id Quake II CIN video X id RoQ X X Used in Quake III, Jedi Knight 2 and other computer games. IEC61937 encapsulation X X IFF X Interchange File Format iLBC X X Interplay MVE X Format used in various Interplay computer games. IV8 X A format generated by IndigoVision 8000 video server. IVF (On2) X X A format used by libvpx IRCAM X X LATM X X LMLM4 X Used by Linux Media Labs MPEG-4 PCI boards LOAS X contains LATM multiplexed AAC audio LRC X X LVF X LXF X VR native stream format, used by Leitch/Harris’ video servers. Magic Lantern Video (MLV) X Matroska X X Matroska audio X FFmpeg metadata X X Metadata in text format. MAXIS XA X Used in Sim City 3000; file extension .xa. MD Studio X Metal Gear Solid: The Twin Snakes X Megalux Frame X Used by Megalux Ultimate Paint Mobotix .mxg X Monkey’s Audio X Motion Pixels MVI X MOV/QuickTime/MP4 X X 3GP, 3GP2, PSP, iPod variants supported MP2 X X MP3 X X MPEG-1 System X X muxed audio and video, VCD format supported MPEG-PS (program stream) X X also known as VOB file, SVCD and DVD format supported MPEG-TS (transport stream) X X also known as DVB Transport Stream MPEG-4 X X MPEG-4 is a variant of QuickTime. Mirillis FIC video X No cursor rendering. MIME multipart JPEG X MSN TCP webcam X Used by MSN Messenger webcam streams. MTV X Musepack X Musepack SV8 X Material eXchange Format (MXF) X X SMPTE 377M, used by D-Cinema, broadcast industry. Material eXchange Format (MXF), D-10 Mapping X X SMPTE 386M, D-10/IMX Mapping. NC camera feed X NC (AVIP NC4600) camera streams NIST SPeech HEader REsources X NTT TwinVQ (VQF) X Nippon Telegraph and Telephone Corporation TwinVQ. Nullsoft Streaming Video X NuppelVideo X NUT X X NUT Open Container Format Ogg X X Playstation Portable PMP X Portable Voice Format X TechnoTrend PVA X Used by TechnoTrend DVB PCI boards. QCP X raw ADTS (AAC) X X raw AC-3 X X raw Chinese AVS video X X raw CRI ADX X X raw Dirac X X raw DNxHD X X raw DTS X X raw DTS-HD X raw E-AC-3 X X raw FLAC X X raw GSM X raw H.261 X X raw H.263 X X raw H.264 X X raw HEVC X X raw Ingenient MJPEG X raw MJPEG X X raw MLP X raw MPEG X raw MPEG-1 X raw MPEG-2 X raw MPEG-4 X X raw NULL X raw video X X raw id RoQ X raw Shorten X raw TAK X raw TrueHD X X raw VC-1 X X raw PCM A-law X X raw PCM mu-law X X raw PCM signed 8 bit X X raw PCM signed 16 bit big-endian X X raw PCM signed 16 bit little-endian X X raw PCM signed 24 bit big-endian X X raw PCM signed 24 bit little-endian X X raw PCM signed 32 bit big-endian X X raw PCM signed 32 bit little-endian X X raw PCM unsigned 8 bit X X raw PCM unsigned 16 bit big-endian X X raw PCM unsigned 16 bit little-endian X X raw PCM unsigned 24 bit big-endian X X raw PCM unsigned 24 bit little-endian X X raw PCM unsigned 32 bit big-endian X X raw PCM unsigned 32 bit little-endian X X raw PCM floating-point 32 bit big-endian X X raw PCM floating-point 32 bit little-endian X X raw PCM floating-point 64 bit big-endian X X raw PCM floating-point 64 bit little-endian X X RDT X REDCODE R3D X File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio. RealMedia X X Redirector X RedSpark X Renderware TeXture Dictionary X RL2 X Audio and video format used in some games by Entertainment Software Partners. RPL/ARMovie X Lego Mindstorms RSO X X RSD X RTMP X X Output is performed by publishing stream to RTMP server RTP X X RTSP X X SAP X X SBG X SDP X Sega FILM/CPK X Used in many Sega Saturn console games. Silicon Graphics Movie X Sierra SOL X .sol files used in Sierra Online games. Sierra VMD X Used in Sierra CD-ROM games. Smacker X Multimedia format used by many games. SMJPEG X X Used in certain Loki game ports. Smush X Multimedia format used in some LucasArts games. Sony OpenMG (OMA) X X Audio format used in Sony Sonic Stage and Sony Vegas. Sony PlayStation STR X Sony Wave64 (W64) X X SoX native format X X SUN AU format X X SUP raw PGS subtitles X Text files X THP X Used on the Nintendo GameCube. Tiertex Limited SEQ X Tiertex .seq files used in the DOS CD-ROM version of the game Flashback. True Audio X VC-1 test bitstream X X Vivo X WAV X X WavPack X X WebM X X Windows Televison (WTV) X X Wing Commander III movie X Multimedia format used in Origin’s Wing Commander III computer game. Westwood Studios audio X Multimedia format used in Westwood Studios games. Westwood Studios VQA X Multimedia format used in Westwood Studios games. XMV X Microsoft video container used in Xbox games. xWMA X Microsoft audio container used by XAudio 2. eXtended BINary text (XBIN) X YUV4MPEG pipe X X Psygnosis YOP X
-
-
X means that encoding (resp. decoding) is supported.
-
-
-
2.2 Image Formats# TOC
-
-
FFmpeg can read and write images for each frame of a video sequence. The
-following image formats are supported:
-
-
-Name Encoding Decoding Comments .Y.U.V X X one raw file per component Alias PIX X X Alias/Wavefront PIX image format animated GIF X X BMP X X Microsoft BMP image BRender PIX X Argonaut BRender 3D engine image format. DPX X X Digital Picture Exchange EXR X OpenEXR JPEG X X Progressive JPEG is not supported. JPEG 2000 X X JPEG-LS X X LJPEG X Lossless JPEG PAM X X PAM is a PNM extension with alpha support. PBM X X Portable BitMap image PCX X X PC Paintbrush PGM X X Portable GrayMap image PGMYUV X X PGM with U and V components in YUV 4:2:0 PIC X Pictor/PC Paint PNG X X PPM X X Portable PixelMap image PTX X V.Flash PTX format SGI X X SGI RGB image format Sun Rasterfile X X Sun RAS image format TIFF X X YUV, JPEG and some extension is not supported yet. Truevision Targa X X Targa (.TGA) image format WebP E X WebP image format, encoding supported through external library libwebp XBM X X X BitMap image format XFace X X X-Face image format XWD X X X Window Dump image format
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.3 Video Codecs# TOC
-
-
-Name Encoding Decoding Comments 4X Movie X Used in certain computer games. 8088flex TMV X A64 multicolor X Creates video suitable to be played on a commodore 64 (multicolor mode). Amazing Studio PAF Video X American Laser Games MM X Used in games like Mad Dog McCree. AMV Video X X Used in Chinese MP3 players. ANSI/ASCII art X Apple Intermediate Codec X Apple MJPEG-B X Apple ProRes X X Apple QuickDraw X fourcc: qdrw Asus v1 X X fourcc: ASV1 Asus v2 X X fourcc: ASV2 ATI VCR1 X fourcc: VCR1 ATI VCR2 X fourcc: VCR2 Auravision Aura X Auravision Aura 2 X Autodesk Animator Flic video X Autodesk RLE X fourcc: AASC Avid 1:1 10-bit RGB Packer X X fourcc: AVrp AVS (Audio Video Standard) video X Video encoding used by the Creature Shock game. AYUV X X Microsoft uncompressed packed 4:4:4:4 Beam Software VB X Bethesda VID video X Used in some games from Bethesda Softworks. Bink Video X Bitmap Brothers JV video X y41p Brooktree uncompressed 4:1:1 12-bit X X Brute Force & Ignorance X Used in the game Flash Traffic: City of Angels. C93 video X Codec used in Cyberia game. CamStudio X fourcc: CSCD CD+G X Video codec for CD+G karaoke disks CDXL X Amiga CD video codec Chinese AVS video E X AVS1-P2, JiZhun profile, encoding through external library libxavs Delphine Software International CIN video X Codec used in Delphine Software International games. Discworld II BMV Video X Canopus Lossless Codec X Cinepak X Cirrus Logic AccuPak X X fourcc: CLJR CPiA Video Format X Creative YUV (CYUV) X DFA X Codec used in Chronomaster game. Dirac E X supported through external library libschroedinger Deluxe Paint Animation X DNxHD X X aka SMPTE VC3 Duck TrueMotion 1.0 X fourcc: DUCK Duck TrueMotion 2.0 X fourcc: TM20 DV (Digital Video) X X Dxtory capture format X Feeble Files/ScummVM DXA X Codec originally used in Feeble Files game. Electronic Arts CMV video X Used in NHL 95 game. Electronic Arts Madcow video X Electronic Arts TGV video X Electronic Arts TGQ video X Electronic Arts TQI video X Escape 124 X Escape 130 X FFmpeg video codec #1 X X lossless codec (fourcc: FFV1) Flash Screen Video v1 X X fourcc: FSV1 Flash Screen Video v2 X X Flash Video (FLV) X X Sorenson H.263 used in Flash Forward Uncompressed X Fraps X Go2Webinar X fourcc: G2M4 H.261 X X H.263 / H.263-1996 X X H.263+ / H.263-1998 / H.263 version 2 X X H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10 E X encoding supported through external library libx264 and OpenH264 HEVC X X encoding supported through the external library libx265 HNM version 4 X HuffYUV X X HuffYUV FFmpeg variant X X IBM Ultimotion X fourcc: ULTI id Cinematic video X Used in Quake II. id RoQ video X X Used in Quake III, Jedi Knight 2, other computer games. IFF ILBM X IFF interleaved bitmap IFF ByteRun1 X IFF run length encoded bitmap Intel H.263 X Intel Indeo 2 X Intel Indeo 3 X Intel Indeo 4 X Intel Indeo 5 X Interplay C93 X Used in the game Cyberia from Interplay. Interplay MVE video X Used in Interplay .MVE files. J2K X X Karl Morton’s video codec X Codec used in Worms games. Kega Game Video (KGV1) X Kega emulator screen capture codec. Lagarith X LCL (LossLess Codec Library) MSZH X LCL (LossLess Codec Library) ZLIB E E LOCO X LucasArts SANM/Smush X Used in LucasArts games / SMUSH animations. lossless MJPEG X X Microsoft ATC Screen X Also known as Microsoft Screen 3. Microsoft Expression Encoder Screen X Also known as Microsoft Titanium Screen 2. Microsoft RLE X Microsoft Screen 1 X Also known as Windows Media Video V7 Screen. Microsoft Screen 2 X Also known as Windows Media Video V9 Screen. Microsoft Video 1 X Mimic X Used in MSN Messenger Webcam streams. Miro VideoXL X fourcc: VIXL MJPEG (Motion JPEG) X X Mobotix MxPEG video X Motion Pixels video X MPEG-1 video X X MPEG-2 video X X MPEG-4 part 2 X X libxvidcore can be used alternatively for encoding. MPEG-4 part 2 Microsoft variant version 1 X MPEG-4 part 2 Microsoft variant version 2 X X MPEG-4 part 2 Microsoft variant version 3 X X Nintendo Gamecube THP video X NuppelVideo/RTjpeg X Video encoding used in NuppelVideo files. On2 VP3 X still experimental On2 VP5 X fourcc: VP50 On2 VP6 X fourcc: VP60,VP61,VP62 On2 VP7 X fourcc: VP70,VP71 VP8 E X fourcc: VP80, encoding supported through external library libvpx VP9 E X encoding supported through external library libvpx Pinnacle TARGA CineWave YUV16 X fourcc: Y216 Prores X fourcc: apch,apcn,apcs,apco Q-team QPEG X fourccs: QPEG, Q1.0, Q1.1 QuickTime 8BPS video X QuickTime Animation (RLE) video X X fourcc: ’rle ’ QuickTime Graphics (SMC) X fourcc: ’smc ’ QuickTime video (RPZA) X fourcc: rpza R10K AJA Kona 10-bit RGB Codec X X R210 Quicktime Uncompressed RGB 10-bit X X Raw Video X X RealVideo 1.0 X X RealVideo 2.0 X X RealVideo 3.0 X still far from ideal RealVideo 4.0 X Renderware TXD (TeXture Dictionary) X Texture dictionaries used by the Renderware Engine. RL2 video X used in some games by Entertainment Software Partners Sierra VMD video X Used in Sierra VMD files. Silicon Graphics Motion Video Compressor 1 (MVC1) X Silicon Graphics Motion Video Compressor 2 (MVC2) X Silicon Graphics RLE 8-bit video X Smacker video X Video encoding used in Smacker. SMPTE VC-1 X Snow X X experimental wavelet codec (fourcc: SNOW) Sony PlayStation MDEC (Motion DECoder) X Sorenson Vector Quantizer 1 X X fourcc: SVQ1 Sorenson Vector Quantizer 3 X fourcc: SVQ3 Sunplus JPEG (SP5X) X fourcc: SP5X TechSmith Screen Capture Codec X fourcc: TSCC TechSmith Screen Capture Codec 2 X fourcc: TSC2 Theora E X encoding supported through external library libtheora Tiertex Limited SEQ video X Codec used in DOS CD-ROM FlashBack game. Ut Video X X v210 QuickTime uncompressed 4:2:2 10-bit X X v308 QuickTime uncompressed 4:4:4 X X v408 QuickTime uncompressed 4:4:4:4 X X v410 QuickTime uncompressed 4:4:4 10-bit X X VBLE Lossless Codec X VMware Screen Codec / VMware Video X Codec used in videos captured by VMware. Westwood Studios VQA (Vector Quantized Animation) video X Windows Media Image X Windows Media Video 7 X X Windows Media Video 8 X X Windows Media Video 9 X not completely working Wing Commander III / Xan X Used in Wing Commander III .MVE files. Wing Commander IV / Xan X Used in Wing Commander IV. Winnov WNV1 X WMV7 X X YAMAHA SMAF X X Psygnosis YOP Video X yuv4 X X libquicktime uncompressed packed 4:2:0 ZeroCodec Lossless Video X ZLIB X X part of LCL, encoder experimental Zip Motion Blocks Video X X Encoder works only in PAL8.
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.4 Audio Codecs# TOC
-
-
-Name Encoding Decoding Comments 8SVX exponential X 8SVX fibonacci X AAC+ E X encoding supported through external library libaacplus AAC E X encoding supported through external library libfaac and libvo-aacenc AC-3 IX IX ADPCM 4X Movie X ADPCM CDROM XA X ADPCM Creative Technology X 16 -> 4, 8 -> 4, 8 -> 3, 8 -> 2 ADPCM Electronic Arts X Used in various EA titles. ADPCM Electronic Arts Maxis CDROM XS X Used in Sim City 3000. ADPCM Electronic Arts R1 X ADPCM Electronic Arts R2 X ADPCM Electronic Arts R3 X ADPCM Electronic Arts XAS X ADPCM G.722 X X ADPCM G.726 X X ADPCM IMA AMV X Used in AMV files ADPCM IMA Electronic Arts EACS X ADPCM IMA Electronic Arts SEAD X ADPCM IMA Funcom X ADPCM IMA QuickTime X X ADPCM IMA Loki SDL MJPEG X ADPCM IMA WAV X X ADPCM IMA Westwood X ADPCM ISS IMA X Used in FunCom games. ADPCM IMA Dialogic X ADPCM IMA Duck DK3 X Used in some Sega Saturn console games. ADPCM IMA Duck DK4 X Used in some Sega Saturn console games. ADPCM IMA Radical X ADPCM Microsoft X X ADPCM MS IMA X X ADPCM Nintendo Gamecube AFC X ADPCM Nintendo Gamecube DTK X ADPCM Nintendo Gamecube THP X ADPCM QT IMA X X ADPCM SEGA CRI ADX X X Used in Sega Dreamcast games. ADPCM Shockwave Flash X X ADPCM Sound Blaster Pro 2-bit X ADPCM Sound Blaster Pro 2.6-bit X ADPCM Sound Blaster Pro 4-bit X ADPCM VIMA Used in LucasArts SMUSH animations. ADPCM Westwood Studios IMA X Used in Westwood Studios games like Command and Conquer. ADPCM Yamaha X X AMR-NB E X encoding supported through external library libopencore-amrnb AMR-WB E X encoding supported through external library libvo-amrwbenc Amazing Studio PAF Audio X Apple lossless audio X X QuickTime fourcc ’alac’ ATRAC1 X ATRAC3 X ATRAC3+ X Bink Audio X Used in Bink and Smacker files in many games. CELT E decoding supported through external library libcelt Delphine Software International CIN audio X Codec used in Delphine Software International games. Discworld II BMV Audio X COOK X All versions except 5.1 are supported. DCA (DTS Coherent Acoustics) X X DPCM id RoQ X X Used in Quake III, Jedi Knight 2 and other computer games. DPCM Interplay X Used in various Interplay computer games. DPCM Sierra Online X Used in Sierra Online game audio files. DPCM Sol X DPCM Xan X Used in Origin’s Wing Commander IV AVI files. DSD (Direct Stream Digitial), least significant bit first X DSD (Direct Stream Digitial), most significant bit first X DSD (Direct Stream Digitial), least significant bit first, planar X DSD (Direct Stream Digitial), most significant bit first, planar X DSP Group TrueSpeech X DV audio X Enhanced AC-3 X X EVRC (Enhanced Variable Rate Codec) X FLAC (Free Lossless Audio Codec) X IX G.723.1 X X G.729 X GSM E X encoding supported through external library libgsm GSM Microsoft variant E X encoding supported through external library libgsm IAC (Indeo Audio Coder) X iLBC (Internet Low Bitrate Codec) E E encoding and decoding supported through external library libilbc IMC (Intel Music Coder) X MACE (Macintosh Audio Compression/Expansion) 3:1 X MACE (Macintosh Audio Compression/Expansion) 6:1 X MLP (Meridian Lossless Packing) X Used in DVD-Audio discs. Monkey’s Audio X MP1 (MPEG audio layer 1) IX MP2 (MPEG audio layer 2) IX IX encoding supported also through external library TwoLAME MP3 (MPEG audio layer 3) E IX encoding supported through external library LAME, ADU MP3 and MP3onMP4 also supported MPEG-4 Audio Lossless Coding (ALS) X Musepack SV7 X Musepack SV8 X Nellymoser Asao X X On2 AVC (Audio for Video Codec) X Opus E E supported through external library libopus PCM A-law X X PCM mu-law X X PCM signed 8-bit planar X X PCM signed 16-bit big-endian planar X X PCM signed 16-bit little-endian planar X X PCM signed 24-bit little-endian planar X X PCM signed 32-bit little-endian planar X X PCM 32-bit floating point big-endian X X PCM 32-bit floating point little-endian X X PCM 64-bit floating point big-endian X X PCM 64-bit floating point little-endian X X PCM D-Cinema audio signed 24-bit X X PCM signed 8-bit X X PCM signed 16-bit big-endian X X PCM signed 16-bit little-endian X X PCM signed 24-bit big-endian X X PCM signed 24-bit little-endian X X PCM signed 32-bit big-endian X X PCM signed 32-bit little-endian X X PCM signed 16/20/24-bit big-endian in MPEG-TS X PCM unsigned 8-bit X X PCM unsigned 16-bit big-endian X X PCM unsigned 16-bit little-endian X X PCM unsigned 24-bit big-endian X X PCM unsigned 24-bit little-endian X X PCM unsigned 32-bit big-endian X X PCM unsigned 32-bit little-endian X X PCM Zork X QCELP / PureVoice X QDesign Music Codec 2 X There are still some distortions. RealAudio 1.0 (14.4K) X X Real 14400 bit/s codec RealAudio 2.0 (28.8K) X Real 28800 bit/s codec RealAudio 3.0 (dnet) IX X Real low bitrate AC-3 codec RealAudio Lossless X RealAudio SIPR / ACELP.NET X Shorten X Sierra VMD audio X Used in Sierra VMD files. Smacker audio X SMPTE 302M AES3 audio X X Sonic X X experimental codec Sonic lossless X X experimental codec Speex E E supported through external library libspeex TAK (Tom’s lossless Audio Kompressor) X True Audio (TTA) X X TrueHD X Used in HD-DVD and Blu-Ray discs. TwinVQ (VQF flavor) X VIMA X Used in LucasArts SMUSH animations. Vorbis E X A native but very primitive encoder exists. Voxware MetaSound X WavPack X X Westwood Audio (SND1) X Windows Media Audio 1 X X Windows Media Audio 2 X X Windows Media Audio Lossless X Windows Media Audio Pro X Windows Media Audio Voice X
-
-
X means that encoding (resp. decoding) is supported.
-
-
E means that support is provided through an external library.
-
-
I means that an integer-only version is available, too (ensures high
-performance on systems without hardware floating point support).
-
-
-
2.5 Subtitle Formats# TOC
-
-
-Name Muxing Demuxing Encoding Decoding 3GPP Timed Text X X AQTitle X X DVB X X X X DVB teletext X E DVD X X X X JACOsub X X X MicroDVD X X X MPL2 X X MPsub (MPlayer) X X PGS X PJS (Phoenix) X X RealText X X SAMI X X Spruce format (STL) X X SSA/ASS X X X X SubRip (SRT) X X X X SubViewer v1 X X SubViewer X X TED Talks captions X X VobSub (IDX+SUB) X X VPlayer X X WebVTT X X X X XSUB X X
-
-
X means that the feature is supported.
-
-
E means that support is provided through an external library.
-
-
-
2.6 Network Protocols# TOC
-
-
-Name Support file X FTP X Gopher X HLS X HTTP X HTTPS X Icecast X MMSH X MMST X pipe X RTMP X RTMPE X RTMPS X RTMPT X RTMPTE X RTMPTS X RTP X SAMBA E SCTP X SFTP E TCP X TLS X UDP X
-
-
X means that the protocol is supported.
-
-
E means that support is provided through an external library.
-
-
-
-
2.7 Input/Output Devices# TOC
-
-
-Name Input Output ALSA X X BKTR X caca X DV1394 X Lavfi virtual device X Linux framebuffer X X JACK X LIBCDIO X LIBDC1394 X OpenAL X OpenGL X OSS X X PulseAudio X X SDL X Video4Linux2 X X VfW capture X X11 grabbing X Win32 grabbing X
-
-
X means that input/output is supported.
-
-
-
2.8 Timecode# TOC
-
-
-Codec/format Read Write AVI X X DV X X GXF X X MOV X X MPEG1/2 X X MXF X X
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Using git to develop FFmpeg
-
-
-
- Using git to develop FFmpeg
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Introduction# TOC
-
-
This document aims in giving some quick references on a set of useful git
-commands. You should always use the extensive and detailed documentation
-provided directly by git:
-
-
-
-
shows you the available subcommands,
-
-
-
git <command> --help
-man git-<command>
-
-
-
shows information about the subcommand <command>.
-
-
Additional information could be found on the
-Git Reference website
-
-
For more information about the Git project, visit the
-
-
Git website
-
-
Consult these resources whenever you have problems, they are quite exhaustive.
-
-
What follows now is a basic introduction to Git and some FFmpeg-specific
-guidelines to ease the contribution to the project
-
-
-
2 Basics Usage# TOC
-
-
-
2.1 Get GIT# TOC
-
-
You can get git from http://git-scm.com/
-Most distribution and operating system provide a package for it.
-
-
-
-
2.2 Cloning the source tree# TOC
-
-
-
git clone git://source.ffmpeg.org/ffmpeg <target>
-
-
-
This will put the FFmpeg sources into the directory <target> .
-
-
-
git clone git@source.ffmpeg.org:ffmpeg <target>
-
-
-
This will put the FFmpeg sources into the directory <target> and let
-you push back your changes to the remote repository.
-
-
Make sure that you do not have Windows line endings in your checkouts,
-otherwise you may experience spurious compilation failures. One way to
-achieve this is to run
-
-
-
git config --global core.autocrlf false
-
-
-
-
-
2.3 Updating the source tree to the latest revision# TOC
-
-
-
-
pulls in the latest changes from the tracked branch. The tracked branch
-can be remote. By default the master branch tracks the branch master in
-the remote origin.
-
-
-
--rebase (see below) is recommended.
-
-
-
2.4 Rebasing your local branches# TOC
-
-
-
-
fetches the changes from the main repository and replays your local commits
-over it. This is required to keep all your local changes at the top of
-FFmpeg’s master tree. The master tree will reject pushes with merge commits.
-
-
-
-
2.5 Adding/removing files/directories# TOC
-
-
-
git add [-A] <filename/dirname>
-git rm [-r] <filename/dirname>
-
-
-
GIT needs to get notified of all changes you make to your working
-directory that makes files appear or disappear.
-Line moves across files are automatically tracked.
-
-
-
-
2.6 Showing modifications# TOC
-
-
-
git diff <filename(s)>
-
-
-
will show all local modifications in your working directory as unified diff.
-
-
-
-
2.7 Inspecting the changelog# TOC
-
-
-
-
You may also use the graphical tools like gitview or gitk or the web
-interface available at http://source.ffmpeg.org/
-
-
-
2.8 Checking source tree status# TOC
-
-
-
-
detects all the changes you made and lists what actions will be taken in case
-of a commit (additions, modifications, deletions, etc.).
-
-
-
-
2.9 Committing# TOC
-
-
-
-
to double check your changes before committing them to avoid trouble later
-on. All experienced developers do this on each and every commit, no matter
-how small.
-Every one of them has been saved from looking like a fool by this many times.
-It’s very easy for stray debug output or cosmetic modifications to slip in,
-please avoid problems through this extra level of scrutiny.
-
-
For cosmetics-only commits you should get (almost) empty output from
-
-
-
git diff -w -b <filename(s)>
-
-
-
Also check the output of
-
-
-
-
to make sure you don’t have untracked files or deletions.
-
-
-
git add [-i|-p|-A] <filenames/dirnames>
-
-
-
Make sure you have told git your name and email address
-
-
-
git config --global user.name "My Name"
-git config --global user.email my@email.invalid
-
-
-
Use –global to set the global configuration for all your git checkouts.
-
-
Git will select the changes to the files for commit. Optionally you can use
-the interactive or the patch mode to select hunk by hunk what should be
-added to the commit.
-
-
-
-
-
Git will commit the selected changes to your current local branch.
-
-
You will be prompted for a log message in an editor, which is either
-set in your personal configuration file through
-
-
-
git config --global core.editor
-
-
-
or set by one of the following environment variables:
-GIT_EDITOR , VISUAL or EDITOR .
-
-
Log messages should be concise but descriptive. Explain why you made a change,
-what you did will be obvious from the changes themselves most of the time.
-Saying just "bug fix" or "10l" is bad. Remember that people of varying skill
-levels look at and educate themselves while reading through your code. Don’t
-include filenames in log messages, Git provides that information.
-
-
Possibly make the commit message have a terse, descriptive first line, an
-empty line and then a full description. The first line will be used to name
-the patch by git format-patch.
-
-
-
2.10 Preparing a patchset# TOC
-
-
-
git format-patch <commit> [-o directory]
-
-
-
will generate a set of patches for each commit between <commit> and
-current HEAD . E.g.
-
-
-
git format-patch origin/master
-
-
-
will generate patches for all commits on current branch which are not
-present in upstream.
-A useful shortcut is also
-
-
-
-
which will generate patches from last n commits.
-By default the patches are created in the current directory.
-
-
-
2.11 Sending patches for review# TOC
-
-
-
git send-email <commit list|directory>
-
-
-
will send the patches created by git format-patch or directly
-generates them. All the email fields can be configured in the global/local
-configuration or overridden by command line.
-Note that this tool must often be installed separately (e.g. git-email
-package on Debian-based distros).
-
-
-
-
2.12 Renaming/moving/copying files or contents of files# TOC
-
-
Git automatically tracks such changes, making those normal commits.
-
-
-
mv/cp path/file otherpath/otherfile
-git add [-A] .
-git commit
-
-
-
-
-
3 Git configuration# TOC
-
-
In order to simplify a few workflows, it is advisable to configure both
-your personal Git installation and your local FFmpeg repository.
-
-
-
3.1 Personal Git installation# TOC
-
-
Add the following to your ~/.gitconfig to help git send-email
-and git format-patch detect renames:
-
-
-
[diff]
- renames = copy
-
-
-
-
3.2 Repository configuration# TOC
-
-
In order to have git send-email automatically send patches
-to the ffmpeg-devel mailing list, add the following stanza
-to /path/to/ffmpeg/repository/.git/config :
-
-
-
[sendemail]
- to = ffmpeg-devel@ffmpeg.org
-
-
-
-
4 FFmpeg specific# TOC
-
-
-
4.1 Reverting broken commits# TOC
-
-
-
-
git reset will uncommit the changes till <commit> rewriting
-the current branch history.
-
-
-
-
allows one to amend the last commit details quickly.
-
-
-
git rebase -i origin/master
-
-
-
will replay local commits over the main repository allowing to edit, merge
-or remove some of them in the process.
-
-
-
git reset, git commit --amend and git rebase
-rewrite history, so you should use them ONLY on your local or topic branches.
-The main repository will reject those changes.
-
-
-
-
git revert will generate a revert commit. This will not make the
-faulty commit disappear from the history.
-
-
-
4.2 Pushing changes to remote trees# TOC
-
-
-
-
Will push the changes to the default remote (origin ).
-Git will prevent you from pushing changes if the local and remote trees are
-out of sync. Refer to and to sync the local tree.
-
-
-
git remote add <name> <url>
-
-
-
Will add additional remote with a name reference, it is useful if you want
-to push your local branch for review on a remote host.
-
-
-
git push <remote> <refspec>
-
-
-
Will push the changes to the <remote> repository.
-Omitting <refspec> makes git push update all the remote
-branches matching the local ones.
-
-
-
4.3 Finding a specific svn revision# TOC
-
-
Since version 1.7.1 git supports :/foo syntax for specifying commits
-based on a regular expression. see man gitrevisions
-
-
-
git show :/'as revision 23456'
-
-
-
will show the svn changeset r23456 . With older git versions searching in
-the git log output is the easiest option (especially if a pager with
-search capabilities is used).
-This commit can be checked out with
-
-
-
git checkout -b svn_23456 :/'as revision 23456'
-
-
-
or for git < 1.7.1 with
-
-
-
git checkout -b svn_23456 $SHA1
-
-
-
where $SHA1 is the commit hash from the git log output.
-
-
-
-
5 pre-push checklist# TOC
-
-
Once you have a set of commits that you feel are ready for pushing,
-work through the following checklist to doublecheck everything is in
-proper order. This list tries to be exhaustive. In case you are just
-pushing a typo in a comment, some of the steps may be unnecessary.
-Apply your common sense, but if in doubt, err on the side of caution.
-
-
First, make sure that the commits and branches you are going to push
-match what you want pushed and that nothing is missing, extraneous or
-wrong. You can see what will be pushed by running the git push command
-with –dry-run first. And then inspecting the commits listed with
-git log -p 1234567..987654. The git status command
-may help in finding local changes that have been forgotten to be added.
-
-
Next let the code pass through a full run of our testsuite.
-
-
- make distclean
- /path/to/ffmpeg/configure
- make check
- if fate fails due to missing samples run make fate-rsync and retry
-
-
-
Make sure all your changes have been checked before pushing them, the
-testsuite only checks against regressions and that only to some extend. It does
-obviously not check newly added features/code to be working unless you have
-added a test for that (which is recommended).
-
-
Also note that every single commit should pass the test suite, not just
-the result of a series of patches.
-
-
Once everything passed, push the changes to your public ffmpeg clone and post a
-merge request to ffmpeg-devel. You can also push them directly but this is not
-recommended.
-
-
-
6 Server Issues# TOC
-
-
Contact the project admins root@ffmpeg.org if you have technical
-problems with the GIT server.
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavcodec Documentation
-
-
-
- Libavcodec Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavcodec library provides a generic encoding/decoding framework
-and contains multiple decoders and encoders for audio, video and
-subtitle streams, and several bitstream filters.
-
-
The shared architecture provides various services ranging from bit
-stream I/O to DSP optimizations, and makes it suitable for
-implementing robust and fast codecs as well as for experimentation.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-codecs , bitstream-filters ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavdevice Documentation
-
-
-
- Libavdevice Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavdevice library provides a generic framework for grabbing from
-and rendering to many common multimedia input/output devices, and
-supports several input and output devices, including Video4Linux2,
-VfW, DShow, and ALSA.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-devices ,
-libavutil , libavcodec , libavformat
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavfilter Documentation
-
-
-
- Libavfilter Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavfilter library provides a generic audio/video filtering
-framework containing several filters, sources and sinks.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-filters ,
-libavutil , libswscale , libswresample ,
-libavcodec , libavformat , libavdevice
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavformat Documentation
-
-
-
- Libavformat Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavformat library provides a generic framework for multiplexing
-and demultiplexing (muxing and demuxing) audio, video and subtitle
-streams. It encompasses multiple muxers and demuxers for multimedia
-container formats.
-
-
It also supports several input and output protocols to access a media
-resource.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-formats , ffmpeg-protocols ,
-libavutil , libavcodec
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libavutil Documentation
-
-
-
- Libavutil Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libavutil library is a utility library to aid portable
-multimedia programming. It contains safe portable string functions,
-random number generators, data structures, additional mathematics
-functions, cryptography and multimedia related functionality (like
-enumerations for pixel and sample formats). It is not a library for
-code needed by both libavcodec and libavformat.
-
-
The goals for this library is to be:
-
-
-Modular It should have few interdependencies and the possibility of disabling individual
-parts during ./configure.
-
-Small Both sources and objects should be small.
-
-Efficient It should have low CPU and memory usage.
-
-Useful It should avoid useless features that almost no one needs.
-
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-utils
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libswresample Documentation
-
-
-
- Libswresample Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libswresample library performs highly optimized audio resampling,
-rematrixing and sample format conversion operations.
-
-
Specifically, this library performs the following conversions:
-
-
- Resampling : is the process of changing the audio rate, for
-example from a high sample rate of 44100Hz to 8000Hz. Audio
-conversion from high to low sample rate is a lossy process. Several
-resampling options and algorithms are available.
-
- Format conversion : is the process of converting the type of
-samples, for example from 16-bit signed samples to unsigned 8-bit or
-float samples. It also handles packing conversion, when passing from
-packed layout (all samples belonging to distinct channels interleaved
-in the same buffer), to planar layout (all samples belonging to the
-same channel stored in a dedicated buffer or "plane").
-
- Rematrixing : is the process of changing the channel layout, for
-example from stereo to mono. When the input channels cannot be mapped
-to the output streams, the process is lossy, since it involves
-different gain factors and mixing.
-
-
-
Various other audio conversions (e.g. stretching and padding) are
-enabled through dedicated options.
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-resampler ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Libswscale Documentation
-
-
-
- Libswscale Documentation
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
-
The libswscale library performs highly optimized image scaling and
-colorspace and pixel format conversion operations.
-
-
Specifically, this library performs the following conversions:
-
-
-
-
-
-
2 See Also# TOC
-
-
ffmpeg , ffplay , ffprobe , ffserver ,
-ffmpeg-scaler ,
-libavutil
-
-
-
-
3 Authors# TOC
-
-
The FFmpeg developers.
-
-
For details about the authorship, see the Git history of the project
-(git://source.ffmpeg.org/ffmpeg), e.g. by typing the command
-git log in the FFmpeg source directory, or browsing the
-online repository at http://source.ffmpeg.org .
-
-
Maintainers for the specific components are listed in the file
-MAINTAINERS in the source code tree.
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- NUT
-
-
-
- NUT
-
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Description# TOC
-
NUT is a low overhead generic container format. It stores audio, video,
-subtitle and user-defined streams in a simple, yet efficient, way.
-
-
It was created by a group of FFmpeg and MPlayer developers in 2003
-and was finalized in 2008.
-
-
The official nut specification is at svn://svn.mplayerhq.hu/nut
-In case of any differences between this text and the official specification,
-the official specification shall prevail.
-
-
-
-
NUT has some variants signaled by using the flags field in its main header.
-
-
-BROADCAST Extend the syncpoint to report the sender wallclock PIPE Omit completely the syncpoint
-
-
-
2.1 BROADCAST# TOC
-
-
The BROADCAST variant provides a secondary time reference to facilitate
-detecting endpoint latency and network delays.
-It assumes all the endpoint clocks are syncronized.
-To be used in real-time scenarios.
-
-
-
2.2 PIPE# TOC
-
-
The PIPE variant assumes NUT is used as non-seekable intermediate container,
-by not using syncpoint removes unneeded overhead and reduces the overall
-memory usage.
-
-
-
3 Container-specific codec tags# TOC
-
-
-
3.1 Generic raw YUVA formats# TOC
-
-
Since many exotic planar YUVA pixel formats are not considered by
-the AVI/QuickTime FourCC lists, the following scheme is adopted for
-representing them.
-
-
The first two bytes can contain the values:
-Y1 = only Y
-Y2 = Y+A
-Y3 = YUV
-Y4 = YUVA
-
-
The third byte represents the width and height chroma subsampling
-values for the UV planes, that is the amount to shift the luma
-width/height right to find the chroma width/height.
-
-
The fourth byte is the number of bits used (8, 16, ...).
-
-
If the order of bytes is inverted, that means that each component has
-to be read big-endian.
-
-
-
3.2 Raw Audio# TOC
-
-
-ALAW A-LAW ULAW MU-LAW P<type><interleaving><bits> little-endian PCM <bits><interleaving><type>P big-endian PCM
-
-
<type> is S for signed integer, U for unsigned integer, F for IEEE float
-<interleaving> is D for default, P is for planar.
-<bits> is 8/16/24/32
-
-
-
PFD[32] would for example be signed 32 bit little-endian IEEE float
-
-
-
-
3.3 Subtitles# TOC
-
-
-UTF8 Raw UTF-8 SSA[0] SubStation Alpha DVDS DVD subtitles DVBS DVB subtitles
-
-
-
3.4 Raw Data# TOC
-
-
-
-
-
3.5 Codecs# TOC
-
-
-3IV1 non-compliant MPEG-4 generated by old 3ivx ASV1 Asus Video ASV2 Asus Video 2 CVID Cinepak CYUV Creative YUV DIVX non-compliant MPEG-4 generated by old DivX DUCK Truemotion 1 FFV1 FFmpeg video 1 FFVH FFmpeg Huffyuv H261 ITU H.261 H262 ITU H.262 H263 ITU H.263 H264 ITU H.264 HFYU Huffyuv I263 Intel H.263 IV31 Indeo 3.1 IV32 Indeo 3.2 IV50 Indeo 5.0 LJPG ITU JPEG (lossless) MJLS ITU JPEG-LS MJPG ITU JPEG MPG4 MS MPEG-4v1 (not ISO MPEG-4) MP42 MS MPEG-4v2 MP43 MS MPEG-4v3 MP4V ISO MPEG-4 Part 2 Video (from old encoders) mpg1 ISO MPEG-1 Video mpg2 ISO MPEG-2 Video MRLE MS RLE MSVC MS Video 1 RT21 Indeo 2.1 RV10 RealVideo 1.0 RV20 RealVideo 2.0 RV30 RealVideo 3.0 RV40 RealVideo 4.0 SNOW FFmpeg Snow SVQ1 Sorenson Video 1 SVQ3 Sorenson Video 3 theo Xiph Theora TM20 Truemotion 2.0 UMP4 non-compliant MPEG-4 generated by UB Video MPEG-4 VCR1 ATI VCR1 VP30 VP 3.0 VP31 VP 3.1 VP50 VP 5.0 VP60 VP 6.0 VP61 VP 6.1 VP62 VP 6.2 VP70 VP 7.0 WMV1 MS WMV7 WMV2 MS WMV8 WMV3 MS WMV9 WV1F non-compliant MPEG-4 generated by ? WVC1 VC-1 XVID non-compliant MPEG-4 generated by old Xvid XVIX non-compliant MPEG-4 generated by old Xvid with interlacing bug
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
- Platform Specific Information
-
-
-
- Platform Specific Information
-
-
-
-
-
-
-
-
Table of Contents
-
-
-
-
-
-
1 Unix-like# TOC
-
-
Some parts of FFmpeg cannot be built with version 2.15 of the GNU
-assembler which is still provided by a few AMD64 distributions. To
-make sure your compiler really uses the required version of gas
-after a binutils upgrade, run:
-
-
-
$(gcc -print-prog-name=as) --version
-
-
-
If not, then you should install a different compiler that has no
-hard-coded path to gas. In the worst case pass --disable-asm
-to configure.
-
-
-
1.1 Advanced linking configuration# TOC
-
-
If you compiled FFmpeg libraries statically and you want to use them to
-build your own shared library, you may need to force PIC support (with
---enable-pic during FFmpeg configure) and add the following option
-to your project LDFLAGS:
-
-
-
-
If your target platform requires position independent binaries, you should
-pass the correct linking flag (e.g. -pie) to --extra-ldexeflags.
-
-
-
-
-
BSD make will not build FFmpeg, you need to install and use GNU Make
-(gmake).
-
-
-
1.3 (Open)Solaris# TOC
-
-
GNU Make is required to build FFmpeg, so you have to invoke (gmake),
-standard Solaris Make will not work. When building with a non-c99 front-end
-(gcc, generic suncc) add either --extra-libs=/usr/lib/values-xpg6.o
-or --extra-libs=/usr/lib/64/values-xpg6.o to the configure options
-since the libc is not c99-compliant by default. The probes performed by
-configure may raise an exception leading to the death of configure itself
-due to a bug in the system shell. Simply invoke a different shell such as
-bash directly to work around this:
-
-
-
-
-
1.4 Darwin (Mac OS X, iPhone)# TOC
-
-
The toolchain provided with Xcode is sufficient to build the basic
-unacelerated code.
-
-
Mac OS X on PowerPC or ARM (iPhone) requires a preprocessor from
-https://github.com/FFmpeg/gas-preprocessor or
-https://github.com/yuvi/gas-preprocessor (currently outdated) to build the optimized
-assembly functions. Put the Perl script somewhere
-in your PATH, FFmpeg’s configure will pick it up automatically.
-
-
Mac OS X on amd64 and x86 requires yasm to build most of the
-optimized assembly functions. Fink ,
-Gentoo Prefix ,
-Homebrew
-or MacPorts can easily provide it.
-
-
-
-
-
-
Using a cross-compiler is preferred for various reasons.
-http://www.delorie.com/howto/djgpp/linux-x-djgpp.html
-
-
-
-
-
-
For information about compiling FFmpeg on OS/2 see
-http://www.edm2.com/index.php/FFmpeg .
-
-
-
-
4 Windows# TOC
-
-
To get help and instructions for building FFmpeg under Windows, check out
-the FFmpeg Windows Help Forum at http://ffmpeg.zeranoe.com/forum/ .
-
-
-
4.1 Native Windows compilation using MinGW or MinGW-w64# TOC
-
-
FFmpeg can be built to run natively on Windows using the MinGW or MinGW-w64
-toolchains. Install the latest versions of MSYS and MinGW or MinGW-w64 from
-http://www.mingw.org/ or http://mingw-w64.sourceforge.net/ .
-You can find detailed installation instructions in the download section and
-the FAQ.
-
-
Notes:
-
-
- Building natively using MSYS can be sped up by disabling implicit rules
-in the Makefile by calling make -r instead of plain make. This
-speed up is close to non-existent for normal one-off builds and is only
-noticeable when running make for a second time (for example during
-make install).
-
- In order to compile FFplay, you must have the MinGW development library
-of SDL and pkg-config installed.
-
- By using ./configure --enable-shared when configuring FFmpeg,
-you can build the FFmpeg libraries (e.g. libavutil, libavcodec,
-libavformat) as DLLs.
-
-
-
-
-
4.2 Microsoft Visual C++ or Intel C++ Compiler for Windows# TOC
-
-
FFmpeg can be built with MSVC 2012 or earlier using a C99-to-C89 conversion utility
-and wrapper, or with MSVC 2013 and ICL natively.
-
-
You will need the following prerequisites:
-
-
-
-
To set up a proper environment in MSYS, you need to run msys.bat from
-the Visual Studio or Intel Compiler command prompt.
-
-
Place yasm.exe somewhere in your PATH. If using MSVC 2012 or
-earlier, place c99wrap.exe and c99conv.exe somewhere in your
-PATH as well.
-
-
Next, make sure any other headers and libs you want to use, such as zlib, are
-located in a spot that the compiler can see. Do so by modifying the LIB
-and INCLUDE environment variables to include the Windows-style
-paths to these directories. Alternatively, you can try and use the
---extra-cflags/--extra-ldflags configure options. If using MSVC
-2012 or earlier, place inttypes.h somewhere the compiler can see too.
-
-
Finally, run:
-
-
-
For MSVC:
-./configure --toolchain=msvc
-
-For ICL:
-./configure --toolchain=icl
-
-make
-make install
-
-
-
If you wish to compile shared libraries, add --enable-shared to your
-configure options. Note that due to the way MSVC and ICL handle DLL imports and
-exports, you cannot compile static and shared libraries at the same time, and
-enabling shared libraries will automatically disable the static ones.
-
-
Notes:
-
-
-
-
-
4.2.1 Linking to FFmpeg with Microsoft Visual C++# TOC
-
-
If you plan to link with MSVC-built static libraries, you will need
-to make sure you have Runtime Library set to
-Multi-threaded (/MT) in your project’s settings.
-
-
You will need to define inline to something MSVC understands:
-
-
#define inline __inline
-
-
-
Also note, that as stated in Microsoft Visual C++ , you will need
-an MSVC-compatible inttypes.h .
-
-
If you plan on using import libraries created by dlltool, you must
-set References to No (/OPT:NOREF) under the linker optimization
-settings, otherwise the resulting binaries will fail during runtime.
-This is not required when using import libraries generated by lib.exe.
-This issue is reported upstream at
-http://sourceware.org/bugzilla/show_bug.cgi?id=12633 .
-
-
To create import libraries that work with the /OPT:REF option
-(which is enabled by default in Release mode), follow these steps:
-
-
- Open the Visual Studio Command Prompt .
-
-Alternatively, in a normal command line prompt, call vcvars32.bat
-which sets up the environment variables for the Visual C++ tools
-(the standard location for this file is something like
-C:\Program Files (x86_\Microsoft Visual Studio 10.0\VC\bin\vcvars32.bat ).
-
- Enter the bin directory where the created LIB and DLL files
-are stored.
-
- Generate new import libraries with lib.exe:
-
-
-
lib /machine:i386 /def:..\lib\foo-version.def /out:foo.lib
- Replace foo-version and foo with the respective library names.
-
-
-
-
-
4.3 Cross compilation for Windows with Linux# TOC
-
-
You must use the MinGW cross compilation tools available at
-http://www.mingw.org/ .
-
-
Then configure FFmpeg with the following options:
-
-
./configure --target-os=mingw32 --cross-prefix=i386-mingw32msvc-
-
-
(you can change the cross-prefix according to the prefix chosen for the
-MinGW tools).
-
-
Then you can easily test FFmpeg with Wine .
-
-
-
4.4 Compilation under Cygwin# TOC
-
-
Please use Cygwin 1.7.x as the obsolete 1.5.x Cygwin versions lack
-llrint() in its C library.
-
-
Install your Cygwin with all the "Base" packages, plus the
-following "Devel" ones:
-
-
binutils, gcc4-core, make, git, mingw-runtime, texinfo
-
-
-
In order to run FATE you will also need the following "Utils" packages:
-
-
-
If you want to build FFmpeg with additional libraries, download Cygwin
-"Devel" packages for Ogg and Vorbis from any Cygwin packages repository:
-
-
libogg-devel, libvorbis-devel
-
-
-
These library packages are only available from
-Cygwin Ports :
-
-
-
yasm, libSDL-devel, libfaac-devel, libaacplus-devel, libgsm-devel, libmp3lame-devel,
-libschroedinger1.0-devel, speex-devel, libtheora-devel, libxvidcore-devel
-
-
-
The recommendation for x264 is to build it from source, as it evolves too
-quickly for Cygwin Ports to be up to date.
-
-
-
4.5 Crosscompilation for Windows under Cygwin# TOC
-
-
With Cygwin you can create Windows binaries that do not need the cygwin1.dll.
-
-
Just install your Cygwin as explained before, plus these additional
-"Devel" packages:
-
-
gcc-mingw-core, mingw-runtime, mingw-zlib
-
-
-
and add some special flags to your configure invocation.
-
-
For a static build run
-
-
./configure --target-os=mingw32 --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-
-
-
and for a build with shared libraries
-
-
./configure --target-os=mingw32 --enable-shared --disable-static --extra-cflags=-mno-cygwin --extra-libs=-mno-cygwin
-
-
-
-
5 Plan 9# TOC
-
-
The native Plan 9 compiler
-does not implement all the C99 features needed by FFmpeg so the gcc
-port must be used. Furthermore, a few items missing from the C
-library and shell environment need to be fixed.
-
-
- GNU awk, grep, make, and sed
-
-Working packages of these tools can be found at
-ports2plan9 .
-They can be installed with 9front’s pkg
-utility by setting pkgpath to
-http://ports2plan9.googlecode.com/files/.
-
- Missing/broken head and printf commands
-
-Replacements adequate for building FFmpeg can be found in the
-compat/plan9 directory. Place these somewhere they will be
-found by the shell. These are not full implementations of the
-commands and are not suitable for general use.
-
- Missing C99 stdint.h and inttypes.h
-
-Replacement headers are available from
-http://code.google.com/p/plan9front/issues/detail?id=152 .
-
- Missing or non-standard library functions
-
-Some functions in the C library are missing or incomplete. The
-gcc-apelibs-1207 ports2plan9
-includes an updated C library, but installing the full package gives
-unusable executables. Instead, keep the files from gccbin.tgz
-under /386/lib/gnu. From the libc.a archive in the
-gcc-apelibs-1207 package, extract the following object files and
-turn them into a library:
-
-
- strerror.o
- strtoll.o
- snprintf.o
- vsnprintf.o
- vfprintf.o
- _IO_getc.o
- _IO_putc.o
-
-
-Use the --extra-libs option of configure to inform the
-build system of this library.
-
- FPU exceptions enabled by default
-
-Unlike most other systems, Plan 9 enables FPU exceptions by default.
-These must be disabled before calling any FFmpeg functions. While the
-included tools will do this automatically, other users of the
-libraries must do it themselves.
-
-
-
-
-
- This document was generated on January 14, 2015 using makeinfo
-
-
-
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diff --git a/Externals/ffmpeg/shared/presets/libvpx-1080p.ffpreset b/Externals/ffmpeg/shared/presets/libvpx-1080p.ffpreset
deleted file mode 100644
index cf25932100..0000000000
--- a/Externals/ffmpeg/shared/presets/libvpx-1080p.ffpreset
+++ /dev/null
@@ -1,19 +0,0 @@
-vcodec=libvpx
-
-g=120
-lag-in-frames=16
-deadline=good
-cpu-used=0
-vprofile=1
-qmax=51
-qmin=11
-slices=4
-b=2M
-
-#ignored unless using -pass 2
-maxrate=24M
-minrate=100k
-auto-alt-ref=1
-arnr-maxframes=7
-arnr-strength=5
-arnr-type=centered
diff --git a/Externals/ffmpeg/shared/presets/libvpx-1080p50_60.ffpreset b/Externals/ffmpeg/shared/presets/libvpx-1080p50_60.ffpreset
deleted file mode 100644
index 4a88040d34..0000000000
--- a/Externals/ffmpeg/shared/presets/libvpx-1080p50_60.ffpreset
+++ /dev/null
@@ -1,19 +0,0 @@
-vcodec=libvpx
-
-g=120
-lag-in-frames=25
-deadline=good
-cpu-used=0
-vprofile=1
-qmax=51
-qmin=11
-slices=4
-b=2M
-
-#ignored unless using -pass 2
-maxrate=24M
-minrate=100k
-auto-alt-ref=1
-arnr-maxframes=7
-arnr-strength=5
-arnr-type=centered
diff --git a/Externals/ffmpeg/shared/presets/libvpx-360p.ffpreset b/Externals/ffmpeg/shared/presets/libvpx-360p.ffpreset
deleted file mode 100644
index f9729ba2bb..0000000000
--- a/Externals/ffmpeg/shared/presets/libvpx-360p.ffpreset
+++ /dev/null
@@ -1,18 +0,0 @@
-vcodec=libvpx
-
-g=120
-lag-in-frames=16
-deadline=good
-cpu-used=0
-vprofile=0
-qmax=63
-qmin=0
-b=768k
-
-#ignored unless using -pass 2
-maxrate=1.5M
-minrate=40k
-auto-alt-ref=1
-arnr-maxframes=7
-arnr-strength=5
-arnr-type=centered
diff --git a/Externals/ffmpeg/shared/presets/libvpx-720p.ffpreset b/Externals/ffmpeg/shared/presets/libvpx-720p.ffpreset
deleted file mode 100644
index e84cc150cd..0000000000
--- a/Externals/ffmpeg/shared/presets/libvpx-720p.ffpreset
+++ /dev/null
@@ -1,19 +0,0 @@
-vcodec=libvpx
-
-g=120
-lag-in-frames=16
-deadline=good
-cpu-used=0
-vprofile=0
-qmax=51
-qmin=11
-slices=4
-b=2M
-
-#ignored unless using -pass 2
-maxrate=24M
-minrate=100k
-auto-alt-ref=1
-arnr-maxframes=7
-arnr-strength=5
-arnr-type=centered
diff --git a/Externals/ffmpeg/shared/presets/libvpx-720p50_60.ffpreset b/Externals/ffmpeg/shared/presets/libvpx-720p50_60.ffpreset
deleted file mode 100644
index 8fce2bfb5a..0000000000
--- a/Externals/ffmpeg/shared/presets/libvpx-720p50_60.ffpreset
+++ /dev/null
@@ -1,19 +0,0 @@
-vcodec=libvpx
-
-g=120
-lag-in-frames=25
-deadline=good
-cpu-used=0
-vprofile=0
-qmax=51
-qmin=11
-slices=4
-b=2M
-
-#ignored unless using -pass 2
-maxrate=24M
-minrate=100k
-auto-alt-ref=1
-arnr-maxframes=7
-arnr-strength=5
-arnr-type=centered