Implement disabling and enabling media tracks

media/renderers/renderer_impl.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_RENDERERS_RENDERER_IMPL_H_
 #define MEDIA_RENDERERS_RENDERER_IMPL_H_
 
 #include <memory>
 #include <vector>
 
@@ skipping 44 matching lines @@
   void SetCdm(CdmContext* cdm_context,
               const CdmAttachedCB& cdm_attached_cb) final;
   void Flush(const base::Closure& flush_cb) final;
   void StartPlayingFrom(base::TimeDelta time) final;
   void SetPlaybackRate(double playback_rate) final;
   void SetVolume(float volume) final;
   base::TimeDelta GetMediaTime() final;
   bool HasAudio() final;
   bool HasVideo() final;
 
+  void RestartStreamPlayback(DemuxerStream* stream, base::TimeDelta time);
+
   // Helper functions for testing purposes. Must be called before Initialize().
   void DisableUnderflowForTesting();
   void EnableClocklessVideoPlaybackForTesting();
   void set_time_source_for_testing(TimeSource* time_source) {
     time_source_ = time_source;
   }
   void set_video_underflow_threshold_for_testing(base::TimeDelta threshold) {
     video_underflow_threshold_ = threshold;
   }
 
@@ skipping 21 matching lines @@
   void OnAudioRendererInitializeDone(PipelineStatus status);
   void InitializeVideoRenderer();
   void OnVideoRendererInitializeDone(PipelineStatus status);
 
   // Helper functions and callbacks for Flush().
   void FlushAudioRenderer();
   void OnAudioRendererFlushDone();
   void FlushVideoRenderer();
   void OnVideoRendererFlushDone();
 
+  void RestartAudioRenderer(base::TimeDelta time);
+  void RestartVideoRenderer(base::TimeDelta time);
+
   // Callback executed by filters to update statistics.
   void OnStatisticsUpdate(const PipelineStatistics& stats);
 
   // Collection of callback methods and helpers for tracking changes in
   // buffering state and transition from paused/underflow states and playing
   // states.
   //
   // While in the kPlaying state:
   //   - A waiting to non-waiting transition indicates preroll has completed
   //     and StartPlayback() should be called
   //   - A non-waiting to waiting transition indicates underflow has occurred
   //     and PausePlayback() should be called
   void OnBufferingStateChange(DemuxerStream::Type type,
                               BufferingState new_buffering_state);
+  // Handles the buffering notifications that we might get while an audio or a
+  // video stream is being restarted. In those cases we don't want to report
+  // underflows immediately and instead give decoders a chance to catch up with
+  // currently playing stream. Returns true if the buffering nofication has been
+  // handled and no further processing is necessary, returns false to indicate
+  // that we should fall back to the regular OnBufferingStateChange logic.
+  bool HandleRestartedStreamBufferingChanges(
+      DemuxerStream::Type type,
+      BufferingState new_buffering_state);
   bool WaitingForEnoughData() const;
   void PausePlayback();
   void StartPlayback();
 
   // Callbacks executed when a renderer has ended.
   void OnRendererEnded(DemuxerStream::Type type);
   bool PlaybackHasEnded() const;
   void RunEndedCallbackIfNeeded();
 
   // Callback executed when a runtime error happens.
@@ skipping 35 matching lines @@
   bool audio_ended_;
   bool video_ended_;
 
   CdmContext* cdm_context_;
   CdmAttachedCB pending_cdm_attached_cb_;
 
   bool underflow_disabled_for_testing_;
   bool clockless_video_playback_enabled_for_testing_;
 
   // Used to defer underflow for video when audio is present.
-  base::CancelableClosure deferred_underflow_cb_;
+  base::CancelableClosure deferred_video_underflow_cb_;
+
+  // Used to defer underflow for audio when restarting audio playback.
+  base::CancelableClosure deferred_audio_restart_underflow_cb_;
 
   // The amount of time to wait before declaring underflow if the video renderer
   // runs out of data but the audio renderer still has enough.
   base::TimeDelta video_underflow_threshold_;
 
+  bool restarting_audio_ = false;
+  bool restarting_video_ = false;
+
   base::WeakPtr<RendererImpl> weak_this_;
   base::WeakPtrFactory<RendererImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_RENDERERS_RENDERER_IMPL_H_