FFmpeg: Add APNG recording and looping support

CHANGES

@@ -1,4 +1,6 @@
 0.9.0: (Future)
+Features:
+ - Add APNG recording
 Emulation fixes:
  - ARM: Fix ALU reading PC after shifting
  - ARM: Fix STR storing PC after address calculation
@@ -34,6 +36,7 @@ Other fixes:
  - VFS: Fix handle leak when double-mapping (fixes mgba.io/i/1659)
 Misc:
  - FFmpeg: Add more presets
+ - FFmpeg: Add looping option for GIF/APNG
  - Qt: Renderer can be changed while a game is running
  - Qt: Fix non-SDL build (fixes mgba.io/i/1656)
  - Switch: Make OpenGL scale adjustable while running

src/feature/ffmpeg/ffmpeg-encoder.c

@@ -61,6 +61,7 @@ void FFmpegEncoderInit(struct FFmpegEncoder* encoder) {
 	encoder->iheight = GBA_VIDEO_VERTICAL_PIXELS;
 	encoder->frameskip = 1;
 	encoder->skipResidue = 0;
+	encoder->loop = false;
 	encoder->ipixFormat =
 #ifdef COLOR_16_BIT
 #ifdef COLOR_5_6_5
@@ -228,6 +229,10 @@ void FFmpegEncoderSetDimensions(struct FFmpegEncoder* encoder, int width, int he
 	encoder->height = height > 0 ? height : GBA_VIDEO_VERTICAL_PIXELS;
 }
 
+void FFmpegEncoderSetLooping(struct FFmpegEncoder* encoder, bool loop) {
+	encoder->loop = loop;
+}
+
 bool FFmpegEncoderVerifyContainer(struct FFmpegEncoder* encoder) {
 	AVOutputFormat* oformat = av_guess_format(encoder->containerFormat, 0, 0);
 	AVCodec* acodec = avcodec_find_encoder_by_name(encoder->audioCodec);
@@ -469,6 +474,12 @@ bool FFmpegEncoderOpen(struct FFmpegEncoder* encoder, const char* outfile) {
 #endif
 	}
 
+	if (strcmp(encoder->containerFormat, "gif") == 0) {
+		av_opt_set(encoder->context->priv_data, "loop", encoder->loop ? "0" : "-1", 0);
+	} else if (strcmp(encoder->containerFormat, "apng") == 0) {
+		av_opt_set(encoder->context->priv_data, "plays", encoder->loop ? "0" : "1", 0);
+	}
+
 	AVDictionary* opts = 0;
 	av_dict_set(&opts, "strict", "-2", 0);
 	bool res = avio_open(&encoder->context->pb, outfile, AVIO_FLAG_WRITE) < 0 || avformat_write_header(encoder->context, &opts) < 0;

src/feature/ffmpeg/ffmpeg-encoder.h

@@ -80,6 +80,7 @@ struct FFmpegEncoder {
 	int iheight;
 	int frameskip;
 	int skipResidue;
+	bool loop;
 	int64_t currentVideoFrame;
 	struct SwsContext* scaleContext;
 	struct AVStream* videoStream;
@@ -96,6 +97,7 @@ bool FFmpegEncoderSetAudio(struct FFmpegEncoder*, const char* acodec, unsigned a
 bool FFmpegEncoderSetVideo(struct FFmpegEncoder*, const char* vcodec, unsigned vbr, int frameskip);
 bool FFmpegEncoderSetContainer(struct FFmpegEncoder*, const char* container);
 void FFmpegEncoderSetDimensions(struct FFmpegEncoder*, int width, int height);
+void FFmpegEncoderSetLooping(struct FFmpegEncoder*, bool loop);
 bool FFmpegEncoderVerifyContainer(struct FFmpegEncoder*);
 bool FFmpegEncoderOpen(struct FFmpegEncoder*, const char* outfile);
 void FFmpegEncoderClose(struct FFmpegEncoder*);

src/platform/qt/GIFView.cpp

@@ -28,7 +28,6 @@ GIFView::GIFView(QWidget* parent)
 
 	FFmpegEncoderInit(&m_encoder);
 	FFmpegEncoderSetAudio(&m_encoder, nullptr, 0);
-	FFmpegEncoderSetContainer(&m_encoder, "gif");
 }
 
 GIFView::~GIFView() {
@@ -44,9 +43,16 @@ void GIFView::setController(std::shared_ptr<CoreController> controller) {
 }
 
 void GIFView::startRecording() {
-	FFmpegEncoderSetVideo(&m_encoder, "gif", 0, m_ui.frameskip->value());
+	if (m_ui.fmtApng->isChecked()) {
+		FFmpegEncoderSetContainer(&m_encoder, "apng");
+		FFmpegEncoderSetVideo(&m_encoder, "apng", 0, m_ui.frameskip->value());
+	} else {
+		FFmpegEncoderSetContainer(&m_encoder, "gif");
+		FFmpegEncoderSetVideo(&m_encoder, "gif", 0, m_ui.frameskip->value());
+	}
+	FFmpegEncoderSetLooping(&m_encoder, m_ui.loop->isChecked());
 	if (!FFmpegEncoderOpen(&m_encoder, m_filename.toUtf8().constData())) {
-		LOG(QT, ERROR) << tr("Failed to open output GIF file: %1").arg(m_filename);
+		LOG(QT, ERROR) << tr("Failed to open output GIF or APNG file: %1").arg(m_filename);
 		return;
 	}
 	m_ui.start->setEnabled(false);
@@ -64,7 +70,7 @@ void GIFView::stopRecording() {
 }
 
 void GIFView::selectFile() {
-	QString filename = GBAApp::app()->getSaveFileName(this, tr("Select output file"), tr("Graphics Interchange Format (*.gif)"));
+	QString filename = GBAApp::app()->getSaveFileName(this, tr("Select output file"), tr("Graphics Interchange Format (*.gif);;Animated Portable Network Graphics (*.png *.apng)"));
 	m_ui.filename->setText(filename);
 }
 

src/platform/qt/GIFView.ui

@@ -7,50 +7,42 @@
     <x>0</x>
     <y>0</y>
     <width>392</width>
-    <height>220</height>
+    <height>262</height>
    </rect>
   </property>
   <property name="windowTitle">
-   <string>Record GIF</string>
+   <string>Record GIF/APNG</string>
   </property>
   <layout class="QGridLayout" name="gridLayout_3">
    <property name="sizeConstraint">
     <enum>QLayout::SetFixedSize</enum>
    </property>
-   <item row="1" column="0">
+   <item row="2" column="0">
-    <spacer name="horizontalSpacer_2">
+    <widget class="QRadioButton" name="fmtApng">
-     <property name="orientation">
-      <enum>Qt::Horizontal</enum>
-     </property>
-     <property name="sizeHint" stdset="0">
-      <size>
-       <width>40</width>
-       <height>20</height>
-      </size>
-     </property>
-    </spacer>
-   </item>
-   <item row="1" column="1">
-    <widget class="QLabel" name="label">
      <property name="text">
-      <string>Frameskip</string>
+      <string>APNG</string>
      </property>
+     <attribute name="buttonGroup">
+      <string notr="true">format</string>
+     </attribute>
     </widget>
    </item>
-   <item row="1" column="2">
+   <item row="2" column="2">
     <widget class="QSpinBox" name="frameskip">
+     <property name="sizePolicy">
+      <sizepolicy hsizetype="Fixed" vsizetype="Fixed">
+       <horstretch>0</horstretch>
+       <verstretch>0</verstretch>
+      </sizepolicy>
+     </property>
+     <property name="maximum">
+      <number>9</number>
+     </property>
      <property name="value">
       <number>2</number>
      </property>
     </widget>
    </item>
-   <item row="2" column="0" colspan="3">
-    <widget class="QDialogButtonBox" name="buttonBox">
-     <property name="standardButtons">
-      <set>QDialogButtonBox::Close</set>
-     </property>
-    </widget>
-   </item>
    <item row="0" column="0" colspan="3">
     <layout class="QGridLayout" name="gridLayout">
      <item row="1" column="0">
@@ -123,8 +115,55 @@
      </item>
     </layout>
    </item>
+   <item row="2" column="1">
+    <widget class="QLabel" name="label">
+     <property name="text">
+      <string>Frameskip</string>
+     </property>
+    </widget>
+   </item>
+   <item row="3" column="0" colspan="3">
+    <widget class="QDialogButtonBox" name="buttonBox">
+     <property name="standardButtons">
+      <set>QDialogButtonBox::Close</set>
+     </property>
+    </widget>
+   </item>
+   <item row="1" column="0">
+    <widget class="QRadioButton" name="fmtGif">
+     <property name="text">
+      <string>GIF</string>
+     </property>
+     <property name="checked">
+      <bool>true</bool>
+     </property>
+     <attribute name="buttonGroup">
+      <string notr="true">format</string>
+     </attribute>
+    </widget>
+   </item>
+   <item row="1" column="1" colspan="2">
+    <widget class="QCheckBox" name="loop">
+     <property name="text">
+      <string>Loop</string>
+     </property>
+     <property name="checked">
+      <bool>true</bool>
+     </property>
+    </widget>
+   </item>
   </layout>
  </widget>
+ <tabstops>
+  <tabstop>filename</tabstop>
+  <tabstop>start</tabstop>
+  <tabstop>stop</tabstop>
+  <tabstop>selectFile</tabstop>
+  <tabstop>fmtGif</tabstop>
+  <tabstop>fmtApng</tabstop>
+  <tabstop>loop</tabstop>
+  <tabstop>frameskip</tabstop>
+ </tabstops>
  <resources/>
  <connections>
   <connection>
@@ -144,4 +183,7 @@
    </hints>
   </connection>
  </connections>
+ <buttongroups>
+  <buttongroup name="format"/>
+ </buttongroups>
 </ui>

src/platform/qt/Window.cpp

@@ -1455,7 +1455,7 @@ void Window::setupMenu(QMenuBar* menubar) {
 
 #ifdef USE_FFMPEG
 	addGameAction(tr("Record A/V..."), "recordOutput", this, &Window::openVideoWindow, "av");
-	addGameAction(tr("Record GIF..."), "recordGIF", this, &Window::openGIFWindow, "av");
+	addGameAction(tr("Record GIF/APNG..."), "recordGIF", this, &Window::openGIFWindow, "av");
 #endif
 
 	m_actions.addSeparator("av");