Bug 1191696. Part 1 - Handle the promise returned by DecodedStream::StartPlayback in MDSM. r=roc.

dom/media/DecodedStream.cpp

@@ -4,13 +4,13 @@
  * License, v. 2.0. If a copy of the MPL was not distributed with this
  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
 
-#include "DecodedStream.h"
-#include "MediaStreamGraph.h"
 #include "AudioSegment.h"
-#include "VideoSegment.h"
-#include "MediaQueue.h"
+#include "DecodedStream.h"
 #include "MediaData.h"
+#include "MediaQueue.h"
+#include "MediaStreamGraph.h"
 #include "SharedBuffer.h"
+#include "VideoSegment.h"
 #include "VideoUtils.h"
 
 namespace mozilla {
@@ -244,14 +244,15 @@ DecodedStream::~DecodedStream()
 {
 }
 
-void
+nsRefPtr<GenericPromise>
 DecodedStream::StartPlayback(int64_t aStartTime, const MediaInfo& aInfo)
 {
   ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
-  if (mStartTime.isNothing()) {
-    mStartTime.emplace(aStartTime);
-    mInfo = aInfo;
-  }
+  MOZ_ASSERT(mStartTime.isNothing(), "playback already started.");
+  mStartTime.emplace(aStartTime);
+  mInfo = aInfo;
+  // TODO: fix me in next patches.
+  return nullptr;
 }
 
 void DecodedStream::StopPlayback()
@@ -680,12 +681,17 @@ DecodedStream::AdvanceTracks()
   }
 }
 
-bool
+void
 DecodedStream::SendData()
 {
   ReentrantMonitorAutoEnter mon(GetReentrantMonitor());
   MOZ_ASSERT(mStartTime.isSome(), "Must be called after StartPlayback()");
 
+  // Nothing to do when the stream is finished.
+  if (mData->mHaveSentFinish) {
+    return;
+  }
+
   InitTracks();
   SendAudio(mVolume, mSameOrigin);
   SendVideo(mSameOrigin);
@@ -698,8 +704,6 @@ DecodedStream::SendData()
     mData->mHaveSentFinish = true;
     mData->mStream->Finish();
   }
-
-  return finished;
 }
 
 int64_t

dom/media/DecodedStream.h

@@ -12,6 +12,7 @@
 
 #include "mozilla/CheckedInt.h"
 #include "mozilla/Maybe.h"
+#include "mozilla/MozPromise.h"
 #include "mozilla/nsRefPtr.h"
 #include "mozilla/ReentrantMonitor.h"
 #include "mozilla/UniquePtr.h"
@@ -53,7 +54,11 @@ public:
 
   // Mimic MDSM::StartAudioThread.
   // Must be called before any calls to SendData().
-  void StartPlayback(int64_t aStartTime, const MediaInfo& aInfo);
+  //
+  // Return a promise which will be resolved when the stream is finished
+  // or rejected if any error.
+  nsRefPtr<GenericPromise> StartPlayback(int64_t aStartTime,
+                                         const MediaInfo& aInfo);
   // Mimic MDSM::StopAudioThread.
   void StopPlayback();
 
@@ -71,8 +76,7 @@ public:
   bool IsFinished() const;
   bool HasConsumers() const;
 
-  // Return true if stream is finished.
-  bool SendData();
+  void SendData();
 
 protected:
   virtual ~DecodedStream();

dom/media/MediaDecoderStateMachine.cpp

@@ -376,7 +376,7 @@ void MediaDecoderStateMachine::SendStreamData()
   AssertCurrentThreadInMonitor();
   MOZ_ASSERT(!mAudioSink, "Should've been stopped in RunStateMachine()");
 
-  bool finished = mDecodedStream->SendData();
+  mDecodedStream->SendData();
 
   const auto clockTime = GetClock();
   while (true) {
@@ -392,12 +392,6 @@ void MediaDecoderStateMachine::SendStreamData()
     }
     break;
   }
-
-  // To be consistent with AudioSink, |mAudioCompleted| is not set
-  // until all samples are drained.
-  if (finished && AudioQueue().GetSize() == 0) {
-    mAudioCompleted = true;
-  }
 }
 
 bool MediaDecoderStateMachine::HaveEnoughDecodedAudio(int64_t aAmpleAudioUSecs)
@@ -1079,12 +1073,7 @@ void MediaDecoderStateMachine::MaybeStartPlayback()
   MOZ_ASSERT(IsPlaying());
 
   StartAudioThread();
-
-  // Tell DecodedStream to start playback with specified start time and media
-  // info. This is consistent with how we create AudioSink in StartAudioThread().
-  if (mAudioCaptured) {
-    mDecodedStream->StartPlayback(GetMediaTime(), mInfo);
-  }
+  StartDecodedStream();
 
   DispatchDecodeTasksIfNeeded();
 }
@@ -1792,6 +1781,32 @@ MediaDecoderStateMachine::StartAudioThread()
   }
 }
 
+void
+MediaDecoderStateMachine::StopDecodedStream()
+{
+  MOZ_ASSERT(OnTaskQueue());
+  AssertCurrentThreadInMonitor();
+  mDecodedStream->StopPlayback();
+  mDecodedStreamPromise.DisconnectIfExists();
+}
+
+void
+MediaDecoderStateMachine::StartDecodedStream()
+{
+  MOZ_ASSERT(OnTaskQueue());
+  AssertCurrentThreadInMonitor();
+
+  // Tell DecodedStream to start playback with specified start time and media
+  // info. This is consistent with how we create AudioSink in StartAudioThread().
+  if (mAudioCaptured && !mDecodedStreamPromise.Exists()) {
+    mDecodedStreamPromise.Begin(
+      mDecodedStream->StartPlayback(GetMediaTime(), mInfo)->Then(
+        OwnerThread(), __func__, this,
+        &MediaDecoderStateMachine::OnDecodedStreamFinish,
+        &MediaDecoderStateMachine::OnDecodedStreamError));
+  }
+}
+
 int64_t MediaDecoderStateMachine::AudioDecodedUsecs()
 {
   MOZ_ASSERT(OnTaskQueue());
@@ -2395,7 +2410,7 @@ nsresult MediaDecoderStateMachine::RunStateMachine()
         // Stop audio sink after call to AudioEndTime() above, otherwise it will
         // return an incorrect value due to a null mAudioSink.
         StopAudioThread();
-        mDecodedStream->StopPlayback();
+        StopDecodedStream();
       }
 
       return NS_OK;
@@ -2425,7 +2440,7 @@ MediaDecoderStateMachine::Reset()
   // outside of the decoder monitor while we are clearing the queue and causes
   // crash for no samples to be popped.
   StopAudioThread();
-  mDecodedStream->StopPlayback();
+  StopDecodedStream();
 
   mVideoFrameEndTime = -1;
   mDecodedVideoEndTime = -1;
@@ -3076,6 +3091,32 @@ void MediaDecoderStateMachine::OnAudioSinkError()
   DecodeError();
 }
 
+void
+MediaDecoderStateMachine::OnDecodedStreamFinish()
+{
+  MOZ_ASSERT(OnTaskQueue());
+  ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
+  MOZ_ASSERT(mAudioCaptured, "Audio should be captured.");
+
+  mDecodedStreamPromise.Complete();
+  if (mInfo.HasAudio()) {
+    mAudioCompleted = true;
+  }
+  // To notify PlaybackEnded as soon as possible.
+  ScheduleStateMachine();
+}
+
+void
+MediaDecoderStateMachine::OnDecodedStreamError()
+{
+  MOZ_ASSERT(OnTaskQueue());
+  ReentrantMonitorAutoEnter mon(mDecoder->GetReentrantMonitor());
+  MOZ_ASSERT(mAudioCaptured, "Audio should be captured.");
+
+  mDecodedStreamPromise.Complete();
+  DecodeError();
+}
+
 uint32_t MediaDecoderStateMachine::GetAmpleVideoFrames() const
 {
   MOZ_ASSERT(OnTaskQueue());
@@ -3099,7 +3140,7 @@ void MediaDecoderStateMachine::DispatchAudioCaptured()
       // Start DecodedStream if we are already playing. Otherwise it will be
       // handled in MaybeStartPlayback().
       if (self->IsPlaying()) {
-        self->mDecodedStream->StartPlayback(self->GetMediaTime(), self->mInfo);
+        self->StartDecodedStream();
       }
       self->ScheduleStateMachine();
     }
@@ -3115,7 +3156,8 @@ void MediaDecoderStateMachine::DispatchAudioUncaptured()
     MOZ_ASSERT(self->OnTaskQueue());
     ReentrantMonitorAutoEnter mon(self->mDecoder->GetReentrantMonitor());
     if (self->mAudioCaptured) {
-      // Start again the audio sink
+      self->StopDecodedStream();
+      // Start again the audio sink.
       self->mAudioCaptured = false;
       if (self->IsPlaying()) {
         self->StartAudioThread();

dom/media/MediaDecoderStateMachine.h

@@ -518,6 +518,10 @@ protected:
   // one lock count. Called on the state machine thread.
   void StartAudioThread();
 
+  void StopDecodedStream();
+
+  void StartDecodedStream();
+
   // Notification method invoked when mPlayState changes.
   void PlayStateChanged();
 
@@ -670,6 +674,10 @@ private:
   // Rejected by the AudioSink to signal errors.
   void OnAudioSinkError();
 
+  void OnDecodedStreamFinish();
+
+  void OnDecodedStreamError();
+
   // Return true if the video decoder's decode speed can not catch up the
   // play time.
   bool NeedToSkipToNextKeyframe();
@@ -1284,6 +1292,7 @@ private:
   nsRefPtr<MediaResource> mResource;
 
   MozPromiseRequestHolder<GenericPromise> mAudioSinkPromise;
+  MozPromiseRequestHolder<GenericPromise> mDecodedStreamPromise;
 
   MediaEventListener mAudioQueueListener;
   MediaEventListener mVideoQueueListener;