BizHawk/BizHawk.Client.EmuHawk/AVOut/NutMuxer.cs

708 lines
19 KiB
C#

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.IO;
using System.Numerics;
namespace BizHawk.Client.EmuHawk
{
/// <summary>
/// implements a simple muxer for the NUT media format
/// http://ffmpeg.org/~michael/nut.txt
/// </summary>
public class NutMuxer
{
// this code isn't really any good for general purpose nut creation
#region simple buffer reuser
public class ReusableBufferPool<T>
{
private readonly List<T[]> _available = new List<T[]>();
private readonly ICollection<T[]> _inUse = new HashSet<T[]>();
private readonly int _capacity;
/// <param name="capacity">total number of buffers to keep around</param>
public ReusableBufferPool(int capacity)
{
_capacity = capacity;
}
private T[] GetBufferInternal(int length, bool zerofill, Func<T[], bool> criteria)
{
if (_inUse.Count == _capacity)
{
throw new InvalidOperationException();
}
T[] candidate = _available.FirstOrDefault(criteria);
if (candidate == null)
{
if (_available.Count + _inUse.Count == _capacity)
{
// out of space! should not happen often
Console.WriteLine("Purging");
_available.Clear();
}
candidate = new T[length];
}
else
{
if (zerofill)
{
Array.Clear(candidate, 0, candidate.Length);
}
_available.Remove(candidate);
}
_inUse.Add(candidate);
return candidate;
}
public T[] GetBuffer(int length, bool zerofill = false)
{
return GetBufferInternal(length, zerofill, a => a.Length == length);
}
public T[] GetBufferAtLeast(int length, bool zerofill = false)
{
return GetBufferInternal(length, zerofill, a => a.Length >= length && a.Length / (float)length <= 2.0f);
}
/// <exception cref="ArgumentException"><paramref name="buffer"/> is not in use</exception>
public void ReleaseBuffer(T[] buffer)
{
if (!_inUse.Remove(buffer))
{
throw new ArgumentException();
}
_available.Add(buffer);
}
}
#endregion
#region binary write helpers
/// <summary>
/// variable length value, unsigned
/// </summary>
private static void WriteVarU(ulong v, Stream stream)
{
byte[] b = new byte[10];
int i = 0;
do
{
if (i > 0)
b[i++] = (byte)((v & 127) | 128);
else
b[i++] = (byte)(v & 127);
v /= 128;
} while (v > 0);
for (; i > 0; i--)
{
stream.WriteByte(b[i - 1]);
}
}
/// <summary>
/// variable length value, unsigned
/// </summary>
static void WriteVarU(int v, Stream stream)
{
if (v < 0)
{
throw new ArgumentOutOfRangeException(nameof(v), "unsigned must be non-negative");
}
WriteVarU((ulong)v, stream);
}
/// <summary>
/// variable length value, unsigned
/// </summary>
private static void WriteVarU(long v, Stream stream)
{
if (v < 0)
{
throw new ArgumentOutOfRangeException(nameof(v), "unsigned must be non-negative");
}
WriteVarU((ulong)v, stream);
}
/// <summary>
/// utf-8 string with length prepended
/// </summary>
private static void WriteString(string s, Stream stream)
{
WriteBytes(Encoding.UTF8.GetBytes(s), stream);
}
/// <summary>
/// arbitrary sequence of bytes with length prepended
/// </summary>
static void WriteBytes(byte[] b, Stream stream)
{
WriteVarU(b.Length, stream);
stream.Write(b, 0, b.Length);
}
/// <summary>
/// big endian 64 bit unsigned
/// </summary>
private static void WriteBe64(ulong v, Stream stream)
{
byte[] b = new byte[8];
for (int i = 7; i >= 0; i--)
{
b[i] = (byte)(v & 255);
v >>= 8;
}
stream.Write(b, 0, 8);
}
/// <summary>
/// big endian 32 bit unsigned
/// </summary>
private static void WriteBe32(uint v, Stream stream)
{
byte[] b = new byte[4];
for (int i = 3; i >= 0; i--)
{
b[i] = (byte)(v & 255);
v >>= 8;
}
stream.Write(b, 0, 4);
}
#endregion
#region CRC calculator
private static readonly uint[] CrcTable =
{
0x00000000, 0x04C11DB7, 0x09823B6E, 0x0D4326D9,
0x130476DC, 0x17C56B6B, 0x1A864DB2, 0x1E475005,
0x2608EDB8, 0x22C9F00F, 0x2F8AD6D6, 0x2B4BCB61,
0x350C9B64, 0x31CD86D3, 0x3C8EA00A, 0x384FBDBD,
};
/// <summary>
/// seems to be different than standard CRC32?????
/// </summary>
/// <returns>crc32, nut variant</returns>
private static uint NutCRC32(byte[] buf)
{
uint crc = 0;
foreach (var b in buf)
{
crc ^= (uint)b << 24;
crc = (crc << 4) ^ CrcTable[crc >> 28];
crc = (crc << 4) ^ CrcTable[crc >> 28];
}
return crc;
}
#endregion
/// <summary>
/// writes a single packet out, including CheckSums
/// </summary>
private class NutPacket : Stream
{
public enum StartCode : ulong
{
Main = 0x4e4d7a561f5f04ad,
Stream = 0x4e5311405bf2f9db,
Syncpoint = 0x4e4be4adeeca4569,
Index = 0x4e58dd672f23e64e,
Info = 0x4e49ab68b596ba78
}
private MemoryStream _data;
private readonly StartCode _startCode;
private readonly Stream _underlying;
/// <summary>
/// create a new NutPacket
/// </summary>
/// <param name="startCode">startCode for this packet</param>
/// <param name="underlying">stream to write to</param>
public NutPacket(StartCode startCode, Stream underlying)
{
_data = new MemoryStream();
_startCode = startCode;
_underlying = underlying;
}
public override bool CanRead => false;
public override bool CanSeek => false;
public override bool CanWrite => true;
/// <summary>
/// write data out to underlying stream, including header, footer, checksums
/// this cannot be done more than once!
/// </summary>
public override void Flush()
{
// first, prep header
var header = new MemoryStream();
WriteBe64((ulong)_startCode, header);
WriteVarU(_data.Length + 4, header); // +4 for checksum
if (_data.Length > 4092)
{
WriteBe32(NutCRC32(header.ToArray()), header);
}
var tmp = header.ToArray();
_underlying.Write(tmp, 0, tmp.Length);
tmp = _data.ToArray();
_underlying.Write(tmp, 0, tmp.Length);
WriteBe32(NutCRC32(tmp), _underlying);
_data = null;
}
public override long Length => throw new NotImplementedException();
public override long Position
{
get => throw new NotImplementedException();
set => throw new NotImplementedException();
}
public override int Read(byte[] buffer, int offset, int count)
{
throw new NotImplementedException();
}
public override long Seek(long offset, SeekOrigin origin)
{
throw new NotImplementedException();
}
public override void SetLength(long value)
{
throw new NotImplementedException();
}
public override void Write(byte[] buffer, int offset, int count)
{
_data.Write(buffer, offset, count);
}
}
#region fields
/// <summary>
/// stores basic AV parameters
/// </summary>
private class AVParams
{
public int Width { get; set; }
public int Height { get; set; }
public int Samplerate { get; set; }
public int FpsNum { get; set; }
public int FpsDen { get; set; }
public int Channels { get; set; }
/// <summary>
/// puts fpsNum, fpsDen in lowest terms
/// </summary>
public void Reduce()
{
int gcd = (int)BigInteger.GreatestCommonDivisor(new BigInteger(FpsNum), new BigInteger(FpsDen));
FpsNum /= gcd;
FpsDen /= gcd;
}
}
// stores basic AV parameters
private readonly AVParams _avParams;
// target output for nut stream
private Stream _output;
// PTS of video stream. timebase is 1/framerate, so this is equal to number of frames
private ulong _videoOpts;
// PTS of audio stream. timebase is 1/samplerate, so this is equal to number of samples
private ulong _audioPts;
// has EOR been written on this stream?
private bool _videoDone;
// has EOR been written on this stream?
private bool _audioDone;
// video packets waiting to be written
private readonly Queue<NutFrame> _videoQueue;
// audio packets waiting to be written
private readonly Queue<NutFrame> _audioQueue;
readonly ReusableBufferPool<byte> _bufferPool = new ReusableBufferPool<byte>(12);
#endregion
#region header writers
/// <summary>
/// write out the main header
/// </summary>
private void WriteMainHeader()
{
// note: this file starttag not actually part of main headers
var tmp = Encoding.ASCII.GetBytes("nut/multimedia container\0");
_output.Write(tmp, 0, tmp.Length);
var header = new NutPacket(NutPacket.StartCode.Main, _output);
WriteVarU(3, header); // version
WriteVarU(2, header); // stream_count
WriteVarU(65536, header); // max_distance
WriteVarU(2, header); // time_base_count
// timebase is length of single frame, so reversed num+den is intentional
WriteVarU(_avParams.FpsDen, header); // time_base_num[0]
WriteVarU(_avParams.FpsNum, header); // time_base_den[0]
WriteVarU(1, header); // time_base_num[1]
WriteVarU(_avParams.Samplerate, header); // time_base_den[1]
// frame flag compression is ignored for simplicity
for (int i = 0; i < 255; i++) // not 256 because entry 0x4e is skipped (as it would indicate a startcode)
{
WriteVarU(1 << 12, header); // tmp_flag = FLAG_CODED
WriteVarU(0, header); // tmp_fields
}
// header compression ignored because it's not useful to us
WriteVarU(0, header); // header_count_minus1
// BROADCAST_MODE only useful for realtime transmission clock recovery
WriteVarU(0, header); // main_flags
header.Flush();
}
// write out the 0th stream header (video)
private void WriteVideoHeader()
{
var header = new NutPacket(NutPacket.StartCode.Stream, _output);
WriteVarU(0, header); // stream_id
WriteVarU(0, header); // stream_class = video
WriteString("BGRA", header); // fourcc = "BGRA"
WriteVarU(0, header); // time_base_id = 0
WriteVarU(8, header); // msb_pts_shift
WriteVarU(1, header); // max_pts_distance
WriteVarU(0, header); // decode_delay
WriteVarU(1, header); // stream_flags = FLAG_FIXED_FPS
WriteBytes(new byte[0], header); // codec_specific_data
// stream_class = video
WriteVarU(_avParams.Width, header); // width
WriteVarU(_avParams.Height, header); // height
WriteVarU(1, header); // sample_width
WriteVarU(1, header); // sample_height
WriteVarU(18, header); // colorspace_type = full range rec709 (avisynth's "PC.709")
header.Flush();
}
// write out the 1st stream header (audio)
private void WriteAudioHeader()
{
var header = new NutPacket(NutPacket.StartCode.Stream, _output);
WriteVarU(1, header); // stream_id
WriteVarU(1, header); // stream_class = audio
WriteString("\x01\x00\x00\x00", header); // fourcc = 01 00 00 00
WriteVarU(1, header); // time_base_id = 1
WriteVarU(8, header); // msb_pts_shift
WriteVarU(_avParams.Samplerate, header); // max_pts_distance
WriteVarU(0, header); // decode_delay
WriteVarU(0, header); // stream_flags = none; no FIXED_FPS because we aren't guaranteeing same-size audio chunks
WriteBytes(new byte[0], header); // codec_specific_data
// stream_class = audio
WriteVarU(_avParams.Samplerate, header); // samplerate_num
WriteVarU(1, header); // samplerate_den
WriteVarU(_avParams.Channels, header); // channel_count
header.Flush();
}
#endregion
/// <summary>
/// stores a single frame with syncpoint, in mux-ready form
/// used because reordering of audio and video can be needed for proper interleave
/// </summary>
private class NutFrame
{
/// <summary>
/// data ready to be written to stream/disk
/// </summary>
private readonly byte[] _data;
/// <summary>
/// valid length of the data
/// </summary>
private readonly int _actualLength;
/// <summary>
/// presentation timestamp
/// </summary>
private readonly ulong _pts;
/// <summary>
/// fraction of the specified timebase
/// </summary>
private readonly ulong _ptsNum;
/// <summary>
/// fraction of the specified timebase
/// </summary>
private readonly ulong _ptsDen;
private readonly ReusableBufferPool<byte> _pool;
/// <param name="payload">frame data</param>
/// <param name="payLoadLen">actual length of frame data</param>
/// <param name="pts">presentation timestamp</param>
/// <param name="ptsNum">numerator of timebase</param>
/// <param name="ptsDen">denominator of timebase</param>
/// <param name="ptsIndex">which timestamp base is used, assumed to be also stream number</param>
public NutFrame(byte[] payload, int payLoadLen, ulong pts, ulong ptsNum, ulong ptsDen, int ptsIndex, ReusableBufferPool<byte> pool)
{
_pts = pts;
_ptsNum = ptsNum;
_ptsDen = ptsDen;
_pool = pool;
_data = pool.GetBufferAtLeast(payLoadLen + 2048);
var frame = new MemoryStream(_data);
// create syncpoint
var sync = new NutPacket(NutPacket.StartCode.Syncpoint, frame);
WriteVarU(pts * 2 + (ulong)ptsIndex, sync); // global_key_pts
WriteVarU(1, sync); // back_ptr_div_16, this is wrong
sync.Flush();
var frameHeader = new MemoryStream();
frameHeader.WriteByte(0); // frame_code
// frame_flags = FLAG_CODED, so:
int flags = 0;
flags |= 1 << 0; // FLAG_KEY
if (payLoadLen == 0)
{
flags |= 1 << 1; // FLAG_EOR
}
flags |= 1 << 3; // FLAG_CODED_PTS
flags |= 1 << 4; // FLAG_STREAM_ID
flags |= 1 << 5; // FLAG_SIZE_MSB
flags |= 1 << 6; // FLAG_CHECKSUM
WriteVarU(flags, frameHeader);
WriteVarU(ptsIndex, frameHeader); // stream_id
WriteVarU(pts + 256, frameHeader); // coded_pts = pts + 1 << msb_pts_shift
WriteVarU(payLoadLen, frameHeader); // data_size_msb
var frameHeaderArr = frameHeader.ToArray();
frame.Write(frameHeaderArr, 0, frameHeaderArr.Length);
WriteBe32(NutCRC32(frameHeaderArr), frame); // checksum
frame.Write(payload, 0, payLoadLen);
_actualLength = (int)frame.Position;
}
/// <summary>
/// compare two NutFrames by pts
/// </summary>
public static bool operator <=(NutFrame lhs, NutFrame rhs)
{
BigInteger left = new BigInteger(lhs._pts);
left = left * lhs._ptsNum * rhs._ptsDen;
BigInteger right = new BigInteger(rhs._pts);
right = right * rhs._ptsNum * lhs._ptsDen;
return left <= right;
}
public static bool operator >=(NutFrame lhs, NutFrame rhs)
{
BigInteger left = new BigInteger(lhs._pts);
left = left * lhs._ptsNum * rhs._ptsDen;
BigInteger right = new BigInteger(rhs._pts);
right = right * rhs._ptsNum * lhs._ptsDen;
return left >= right;
}
/// <summary>
/// write out frame, with syncpoint and all headers
/// </summary>
public void WriteData(Stream dest)
{
dest.Write(_data, 0, _actualLength);
_pool.ReleaseBuffer(_data);
}
}
/// <summary>write a video frame to the stream</summary>
/// <param name="data">raw video data; if length 0, write EOR</param>
/// <exception cref="Exception">internal error, possible A/V desync</exception>
/// <exception cref="InvalidOperationException">already written EOR</exception>
public void WriteVideoFrame(int[] video)
{
if (_videoDone)
throw new InvalidOperationException("Can't write data after end of relevance!");
if (_audioQueue.Count > 5)
throw new Exception("A/V Desync?");
int dataLen = video.Length * sizeof(int);
byte[] data = _bufferPool.GetBufferAtLeast(dataLen);
Buffer.BlockCopy(video, 0, data, 0, dataLen);
if (dataLen == 0)
{
_videoDone = true;
}
var f = new NutFrame(data, dataLen, _videoOpts, (ulong) _avParams.FpsDen, (ulong) _avParams.FpsNum, 0, _bufferPool);
_bufferPool.ReleaseBuffer(data);
_videoOpts++;
_videoQueue.Enqueue(f);
while (_audioQueue.Count > 0 && f >= _audioQueue.Peek())
{
_audioQueue.Dequeue().WriteData(_output);
}
}
/// <summary>write an audio frame to the stream</summary>
/// <param name="data">raw audio data; if length 0, write EOR</param>
/// <exception cref="Exception">internal error, possible A/V desync</exception>
/// <exception cref="InvalidOperationException">already written EOR</exception>
public void WriteAudioFrame(short[] samples)
{
if (_audioDone)
{
throw new Exception("Can't write audio after end of relevance!");
}
if (_videoQueue.Count > 5)
{
throw new Exception("A/V Desync?");
}
int dataLen = samples.Length * sizeof(short);
byte[] data = _bufferPool.GetBufferAtLeast(dataLen);
Buffer.BlockCopy(samples, 0, data, 0, dataLen);
if (dataLen == 0)
{
_audioDone = true;
}
var f = new NutFrame(data, dataLen, _audioPts, 1, (ulong)_avParams.Samplerate, 1, _bufferPool);
_bufferPool.ReleaseBuffer(data);
_audioPts += (ulong)samples.Length / (ulong)_avParams.Channels;
_audioQueue.Enqueue(f);
while (_videoQueue.Count > 0 && f >= _videoQueue.Peek())
{
_videoQueue.Dequeue().WriteData(_output);
}
}
/// <summary>
/// create a new NutMuxer
/// </summary>
/// <param name="width">video width</param>
/// <param name="height">video height</param>
/// <param name="fpsNum">fps numerator</param>
/// <param name="fpsDen">fps denominator</param>
/// <param name="samplerate">audio samplerate</param>
/// <param name="channels">audio number of channels</param>
/// <param name="underlying">Stream to write to</param>
public NutMuxer(int width, int height, int fpsNum, int fpsDen, int samplerate, int channels, Stream underlying)
{
_avParams = new AVParams
{
Width = width,
Height = height,
FpsNum = fpsNum,
FpsDen = fpsDen
};
_avParams.Reduce(); // TimeBases in nut MUST be relatively prime
_avParams.Samplerate = samplerate;
_avParams.Channels = channels;
_output = underlying;
_audioPts = 0;
_videoOpts = 0;
_audioQueue = new Queue<NutFrame>();
_videoQueue = new Queue<NutFrame>();
WriteMainHeader();
WriteVideoHeader();
WriteAudioHeader();
_videoDone = false;
_audioDone = false;
}
/// <summary>
/// finish and flush everything
/// closes underlying stream!!
/// </summary>
public void Finish()
{
if (!_videoDone)
{
WriteVideoFrame(new int[0]);
}
if (!_audioDone)
{
WriteAudioFrame(new short[0]);
}
// flush any remaining queued packets
while (_audioQueue.Count > 0 && _videoQueue.Count > 0)
{
if (_audioQueue.Peek() <= _videoQueue.Peek())
{
_audioQueue.Dequeue().WriteData(_output);
}
else
{
_videoQueue.Dequeue().WriteData(_output);
}
}
while (_audioQueue.Count > 0)
{
_audioQueue.Dequeue().WriteData(_output);
}
while (_videoQueue.Count > 0)
{
_videoQueue.Dequeue().WriteData(_output);
}
_output.Close();
_output = null;
}
}
}