Have specialized AVCodecContext initialization

A common initialization procedure is too restrictive, and we end up setting up audio configuration for video decoding and vice-versa.

dom/media/platforms/ffmpeg/FFmpegAudioDecoder.cpp

@@ -35,6 +35,22 @@ FFmpegAudioDecoder<LIBAV_VER>::Init()
   return NS_OK;
 }
 
+void
+FFmpegAudioDecoder<LIBAV_VER>::InitCodecContext()
+{
+  MOZ_ASSERT(mCodecContext);
+  // We do not want to set this value to 0 as FFmpeg by default will
+  // use the number of cores, which with our mozlibavutil get_cpu_count
+  // isn't implemented.
+  mCodecContext->thread_count = 1;
+  // FFmpeg takes this as a suggestion for what format to use for audio samples.
+  uint32_t major, minor;
+  FFmpegRuntimeLinker::GetVersion(major, minor);
+  // LibAV 0.8 produces rubbish float interleaved samples, request 16 bits audio.
+  mCodecContext->request_sample_fmt =
+    (major == 53) ? AV_SAMPLE_FMT_S16 : AV_SAMPLE_FMT_FLT;
+}
+
 static AudioDataValue*
 CopyAndPackAudio(AVFrame* aFrame, uint32_t aNumChannels, uint32_t aNumAFrames)
 {

dom/media/platforms/ffmpeg/FFmpegAudioDecoder.h

@@ -28,6 +28,7 @@ public:
   virtual nsresult Init() override;
   virtual nsresult Input(MediaRawData* aSample) override;
   virtual nsresult Drain() override;
+  void InitCodecContext() override;
   static AVCodecID GetCodecId(const nsACString& aMimeType);
 
 private:

dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp

@@ -27,13 +27,8 @@ FFmpegDataDecoder<LIBAV_VER>::FFmpegDataDecoder(FlushableMediaTaskQueue* aTaskQu
   , mFrame(NULL)
   , mExtraData(nullptr)
   , mCodecID(aCodecID)
-  , mCodecParser(nullptr)
 {
   MOZ_COUNT_CTOR(FFmpegDataDecoder);
-  if (mCodecParser) {
-    av_parser_close(mCodecParser);
-    mCodecParser = nullptr;
-  }
 }
 
 FFmpegDataDecoder<LIBAV_VER>::~FFmpegDataDecoder()
@@ -41,27 +36,6 @@ FFmpegDataDecoder<LIBAV_VER>::~FFmpegDataDecoder()
   MOZ_COUNT_DTOR(FFmpegDataDecoder);
 }
 
-/**
- * FFmpeg calls back to this function with a list of pixel formats it supports.
- * We choose a pixel format that we support and return it.
- * For now, we just look for YUV420P as it is the only non-HW accelerated format
- * supported by FFmpeg's H264 decoder.
- */
-static PixelFormat
-ChoosePixelFormat(AVCodecContext* aCodecContext, const PixelFormat* aFormats)
-{
-  FFMPEG_LOG("Choosing FFmpeg pixel format for video decoding.");
-  for (; *aFormats > -1; aFormats++) {
-    if (*aFormats == PIX_FMT_YUV420P || *aFormats == PIX_FMT_YUVJ420P) {
-      FFMPEG_LOG("Requesting pixel format YUV420P.");
-      return PIX_FMT_YUV420P;
-    }
-  }
-
-  NS_WARNING("FFmpeg does not share any supported pixel formats.");
-  return PIX_FMT_NONE;
-}
-
 nsresult
 FFmpegDataDecoder<LIBAV_VER>::Init()
 {
@@ -82,19 +56,7 @@ FFmpegDataDecoder<LIBAV_VER>::Init()
 
   mCodecContext->opaque = this;
 
-  // FFmpeg takes this as a suggestion for what format to use for audio samples.
-  uint32_t major, minor;
-  FFmpegRuntimeLinker::GetVersion(major, minor);
-  // LibAV 0.8 produces rubbish float interleaved samples, request 16 bits audio.
-  mCodecContext->request_sample_fmt = major == 53 ?
-    AV_SAMPLE_FMT_S16 : AV_SAMPLE_FMT_FLT;
-
-  // FFmpeg will call back to this to negotiate a video pixel format.
-  mCodecContext->get_format = ChoosePixelFormat;
-
-  mCodecContext->thread_count = PR_GetNumberOfProcessors();
-  mCodecContext->thread_type = FF_THREAD_SLICE | FF_THREAD_FRAME;
-  mCodecContext->thread_safe_callbacks = false;
+  InitCodecContext();
 
   if (mExtraData) {
     mCodecContext->extradata_size = mExtraData->Length();
@@ -126,11 +88,6 @@ FFmpegDataDecoder<LIBAV_VER>::Init()
     return NS_ERROR_FAILURE;
   }
 
-  mCodecParser = av_parser_init(mCodecID);
-  if (mCodecParser) {
-    mCodecParser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
-  }
-
   FFMPEG_LOG("FFmpeg init successful.");
   return NS_OK;
 }

dom/media/platforms/ffmpeg/FFmpegDataDecoder.h

@@ -38,6 +38,7 @@ public:
   static AVCodec* FindAVCodec(AVCodecID aCodec);
 
 protected:
+  virtual void InitCodecContext() {}
   AVFrame*        PrepareFrame();
 
   FlushableMediaTaskQueue* mTaskQueue;
@@ -45,7 +46,6 @@ protected:
   AVFrame*        mFrame;
   nsRefPtr<MediaByteBuffer> mExtraData;
   AVCodecID mCodecID;
-  AVCodecParserContext* mCodecParser;
 
 private:
   static bool sFFmpegInitDone;

dom/media/platforms/ffmpeg/FFmpegH264Decoder.cpp

@@ -21,6 +21,27 @@ typedef mozilla::layers::PlanarYCbCrImage PlanarYCbCrImage;
 namespace mozilla
 {
 
+/**
+ * FFmpeg calls back to this function with a list of pixel formats it supports.
+ * We choose a pixel format that we support and return it.
+ * For now, we just look for YUV420P as it is the only non-HW accelerated format
+ * supported by FFmpeg's H264 decoder.
+ */
+static PixelFormat
+ChoosePixelFormat(AVCodecContext* aCodecContext, const PixelFormat* aFormats)
+{
+  FFMPEG_LOG("Choosing FFmpeg pixel format for video decoding.");
+  for (; *aFormats > -1; aFormats++) {
+    if (*aFormats == PIX_FMT_YUV420P || *aFormats == PIX_FMT_YUVJ420P) {
+      FFMPEG_LOG("Requesting pixel format YUV420P.");
+      return PIX_FMT_YUV420P;
+    }
+  }
+
+  NS_WARNING("FFmpeg does not share any supported pixel formats.");
+  return PIX_FMT_NONE;
+}
+
 FFmpegH264Decoder<LIBAV_VER>::PtsCorrectionContext::PtsCorrectionContext()
   : mNumFaultyPts(0)
   , mNumFaultyDts(0)
@@ -71,6 +92,7 @@ FFmpegH264Decoder<LIBAV_VER>::FFmpegH264Decoder(
   , mPictureHeight(aConfig.mImage.height)
   , mDisplayWidth(aConfig.mDisplay.width)
   , mDisplayHeight(aConfig.mDisplay.height)
+  , mCodecParser(nullptr)
 {
   MOZ_COUNT_CTOR(FFmpegH264Decoder);
   // Use a new MediaByteBuffer as the object will be modified during initialization.
@@ -84,10 +106,25 @@ FFmpegH264Decoder<LIBAV_VER>::Init()
   nsresult rv = FFmpegDataDecoder::Init();
   NS_ENSURE_SUCCESS(rv, rv);
 
+  return NS_OK;
+}
+
+void
+FFmpegH264Decoder<LIBAV_VER>::InitCodecContext()
+{
   mCodecContext->width = mPictureWidth;
   mCodecContext->height = mPictureHeight;
 
-  return NS_OK;
+  mCodecContext->thread_count = PR_GetNumberOfProcessors();
+  mCodecContext->thread_type = FF_THREAD_SLICE | FF_THREAD_FRAME;
+
+  // FFmpeg will call back to this to negotiate a video pixel format.
+  mCodecContext->get_format = ChoosePixelFormat;
+
+  mCodecParser = av_parser_init(mCodecID);
+  if (mCodecParser) {
+    mCodecParser->flags |= PARSER_FLAG_COMPLETE_FRAMES;
+  }
 }
 
 FFmpegH264Decoder<LIBAV_VER>::DecodeResult
@@ -292,6 +329,10 @@ FFmpegH264Decoder<LIBAV_VER>::Flush()
 FFmpegH264Decoder<LIBAV_VER>::~FFmpegH264Decoder()
 {
   MOZ_COUNT_DTOR(FFmpegH264Decoder);
+  if (mCodecParser) {
+    av_parser_close(mCodecParser);
+    mCodecParser = nullptr;
+  }
 }
 
 AVCodecID

dom/media/platforms/ffmpeg/FFmpegH264Decoder.h

@@ -42,6 +42,7 @@ public:
   virtual nsresult Input(MediaRawData* aSample) override;
   virtual nsresult Drain() override;
   virtual nsresult Flush() override;
+  void InitCodecContext() override;
   static AVCodecID GetCodecId(const nsACString& aMimeType);
 
 private:
@@ -67,6 +68,9 @@ private:
   uint32_t mDisplayWidth;
   uint32_t mDisplayHeight;
 
+  // Parser used for VP8 and VP9 decoding.
+  AVCodecParserContext* mCodecParser;
+
   class PtsCorrectionContext {
   public:
     PtsCorrectionContext();