Bug 1128380: Make AmpleVideoFrames calculation dynamic. r=cpearce

dom/media/MediaDecoderReader.h

@@ -262,6 +262,10 @@ public:
   // the newer async model.
   virtual bool IsAsync() const { return false; }
 
+  // Returns true if this decoder reader uses hardware accelerated video
+  // decoding.
+  virtual bool VideoIsHardwareAccelerated() const { return false; }
+
 protected:
   virtual ~MediaDecoderReader();
 

dom/media/MediaDecoderStateMachine.cpp

@@ -220,7 +220,6 @@ MediaDecoderStateMachine::MediaDecoderStateMachine(MediaDecoder* aDecoder,
   mVolume(1.0),
   mPlaybackRate(1.0),
   mPreservesPitch(true),
-  mAmpleVideoFrames(MIN_VIDEO_QUEUE_SIZE),
   mLowAudioThresholdUsecs(detail::LOW_AUDIO_USECS),
   mAmpleAudioThresholdUsecs(detail::AMPLE_AUDIO_USECS),
   mQuickBufferingLowDataThresholdUsecs(detail::QUICK_BUFFERING_LOW_DATA_USECS),
@@ -581,7 +580,7 @@ bool MediaDecoderStateMachine::HaveEnoughDecodedVideo()
 {
   AssertCurrentThreadInMonitor();
 
-  if (static_cast<uint32_t>(VideoQueue().GetSize()) < mAmpleVideoFrames * mPlaybackRate) {
+  if (static_cast<uint32_t>(VideoQueue().GetSize()) < GetAmpleVideoFrames() * mPlaybackRate) {
     return false;
   }
 
@@ -2239,13 +2238,10 @@ nsresult MediaDecoderStateMachine::DecodeMetadata()
   mInfo = info;
 
   if (HasVideo()) {
-    mAmpleVideoFrames = (mReader->IsAsync() && mInfo.mVideo.mIsHardwareAccelerated)
-      ? std::max<uint32_t>(sVideoQueueHWAccelSize, MIN_VIDEO_QUEUE_SIZE)
-      : std::max<uint32_t>(sVideoQueueDefaultSize, MIN_VIDEO_QUEUE_SIZE);
     DECODER_LOG("Video decode isAsync=%d HWAccel=%d videoQueueSize=%d",
                 mReader->IsAsync(),
-                mInfo.mVideo.mIsHardwareAccelerated,
+                mReader->VideoIsHardwareAccelerated(),
-                mAmpleVideoFrames);
+                GetAmpleVideoFrames());
   }
 
   mDecoder->StartProgressUpdates();
@@ -3672,6 +3668,14 @@ void MediaDecoderStateMachine::OnAudioSinkError()
   DecodeError();
 }
 
+uint32_t MediaDecoderStateMachine::GetAmpleVideoFrames() const
+{
+  AssertCurrentThreadInMonitor();
+  return (mReader->IsAsync() && mReader->VideoIsHardwareAccelerated())
+    ? std::max<uint32_t>(sVideoQueueHWAccelSize, MIN_VIDEO_QUEUE_SIZE)
+    : std::max<uint32_t>(sVideoQueueDefaultSize, MIN_VIDEO_QUEUE_SIZE);
+}
+
 } // namespace mozilla
 
 // avoid redefined macro in unified build

dom/media/MediaDecoderStateMachine.h

@@ -904,10 +904,11 @@ protected:
   uint32_t mBufferingWait;
   int64_t  mLowDataThresholdUsecs;
 
-  // If we've got more than mAmpleVideoFrames decoded video frames waiting in
+  // If we've got more than this number of decoded video frames waiting in
   // the video queue, we will not decode any more video frames until some have
   // been consumed by the play state machine thread.
-  uint32_t mAmpleVideoFrames;
+  // Must hold monitor.
+  uint32_t GetAmpleVideoFrames() const;
 
   // Low audio threshold. If we've decoded less than this much audio we
   // consider our audio decode "behind", and we may skip video decoding
@@ -946,7 +947,11 @@ protected:
     MOZ_ASSERT(result <= mAmpleAudioThresholdUsecs, "Prerolling will never finish");
     return result;
   }
-  uint32_t VideoPrerollFrames() const { return mScheduler->IsRealTime() ? 0 : mAmpleVideoFrames / 2; }
+
+  uint32_t VideoPrerollFrames() const
+  {
+    return mScheduler->IsRealTime() ? 0 : GetAmpleVideoFrames() / 2;
+  }
 
   bool DonePrerollingAudio()
   {

dom/media/MediaInfo.h

@@ -46,7 +46,6 @@ private:
     mDisplay = nsIntSize(aWidth, aHeight);
     mStereoMode = StereoMode::MONO;
     mHasVideo = aHasVideo;
-    mIsHardwareAccelerated = false;
 
     // TODO: TrackInfo should be initialized by its specific codec decoder.
     // This following call should be removed once we have that implemented.
@@ -76,8 +75,6 @@ public:
   bool mHasVideo;
 
   TrackInfo mTrackInfo;
-
-  bool mIsHardwareAccelerated;
 };
 
 class AudioInfo {

dom/media/fmp4/MP4Reader.cpp

@@ -497,7 +497,6 @@ MP4Reader::ReadMetadata(MediaInfo* aInfo,
     NS_ENSURE_TRUE(mVideo.mDecoder != nullptr, NS_ERROR_FAILURE);
     nsresult rv = mVideo.mDecoder->Init();
     NS_ENSURE_SUCCESS(rv, rv);
-    mInfo.mVideo.mIsHardwareAccelerated = mVideo.mDecoder->IsHardwareAccelerated();
 
     // Collect telemetry from h264 AVCC SPS.
     if (!mFoundSPSForTelemetry) {
@@ -1100,4 +1099,10 @@ MP4Reader::SetSharedDecoderManager(SharedDecoderManager* aManager)
 #endif
 }
 
+bool
+MP4Reader::VideoIsHardwareAccelerated() const
+{
+  return mVideo.mDecoder && mVideo.mDecoder->IsHardwareAccelerated();
+}
+
 } // namespace mozilla

dom/media/fmp4/MP4Reader.h

@@ -82,6 +82,8 @@ public:
 
   virtual bool IsAsync() const MOZ_OVERRIDE { return true; }
 
+  virtual bool VideoIsHardwareAccelerated() const MOZ_OVERRIDE;
+
 private:
 
   bool InitDemuxer();

dom/media/mediasource/MediaSourceReader.h

@@ -142,10 +142,16 @@ public:
 #endif
 
   virtual bool IsAsync() const MOZ_OVERRIDE {
+    ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
     return (!GetAudioReader() || GetAudioReader()->IsAsync()) &&
            (!GetVideoReader() || GetVideoReader()->IsAsync());
   }
 
+  virtual bool VideoIsHardwareAccelerated() const MOZ_OVERRIDE {
+    ReentrantMonitorAutoEnter decoderMon(mDecoder->GetReentrantMonitor());
+    return GetVideoReader() && GetVideoReader()->VideoIsHardwareAccelerated();
+  }
+
   // Returns true if aReader is a currently active audio or video
   bool IsActiveReader(MediaDecoderReader* aReader);