Switch to using media::TimeSource inside media::RendererImpl.

media/filters/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_FILTERS_RENDERER_IMPL_H_
 #define MEDIA_FILTERS_RENDERER_IMPL_H_
 
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/synchronization/lock.h"
 #include "base/time/clock.h"
 #include "base/time/default_tick_clock.h"
 #include "base/time/time.h"
 #include "media/base/buffering_state.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 #include "media/base/renderer.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace media {
 
 class AudioRenderer;
 class Demuxer;
-class TimeDeltaInterpolator;
 class TimeSource;
 class VideoRenderer;
+class WallClockTimeSource;
 
 class MEDIA_EXPORT RendererImpl : public Renderer {
  public:
   // Renders audio/video streams in |demuxer| using |audio_renderer| and
   // |video_renderer| provided. All methods except for GetMediaTime() run on the
   // |task_runner|. GetMediaTime() runs on the render main thread because it's
-  // part of JS sync API. |get_duration_cb| is used to get the duration of the
-  // stream.
+  // part of JS sync API.
   RendererImpl(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
                Demuxer* demuxer,
                scoped_ptr<AudioRenderer> audio_renderer,
                scoped_ptr<VideoRenderer> video_renderer);
 
   virtual ~RendererImpl();
 
   // Renderer implementation.
   virtual void Initialize(const base::Closure& init_cb,
                           const StatisticsCB& statistics_cb,
                           const base::Closure& ended_cb,
                           const PipelineStatusCB& error_cb,
-                          const BufferingStateCB& buffering_state_cb,
-                          const TimeDeltaCB& get_duration_cb) OVERRIDE;
+                          const BufferingStateCB& buffering_state_cb) OVERRIDE;
   virtual void Flush(const base::Closure& flush_cb) OVERRIDE;
   virtual void StartPlayingFrom(base::TimeDelta time) OVERRIDE;
   virtual void SetPlaybackRate(float playback_rate) OVERRIDE;
   virtual void SetVolume(float volume) OVERRIDE;
   virtual base::TimeDelta GetMediaTime() OVERRIDE;
   virtual bool HasAudio() OVERRIDE;
   virtual bool HasVideo() OVERRIDE;
   virtual void SetCdm(MediaKeys* cdm) OVERRIDE;
 
   // Helper functions for testing purposes. Must be called before Initialize().
   void DisableUnderflowForTesting();
-  void SetTimeDeltaInterpolatorForTesting(TimeDeltaInterpolator* interpolator);
+  void EnableClocklessVideoPlaybackForTesting();
 
  private:
   enum State {
     STATE_UNINITIALIZED,
     STATE_INITIALIZING,
     STATE_FLUSHING,
     STATE_PLAYING,
     STATE_ERROR
   };
 
-  base::TimeDelta GetMediaDuration();
+  base::TimeDelta GetApproximateMediaTimeForSyncingVideo();
 
   // Helper functions and callbacks for Initialize().
   void InitializeAudioRenderer();
   void OnAudioRendererInitializeDone(PipelineStatus status);
   void InitializeVideoRenderer();
   void OnVideoRendererInitializeDone(PipelineStatus status);
 
   // Helper functions and callbacks for Flush().
   void FlushAudioRenderer();
   void OnAudioRendererFlushDone();
   void FlushVideoRenderer();
   void OnVideoRendererFlushDone();
 
-  // Callback executed by audio renderer to update clock time.
-  void OnAudioTimeUpdate(base::TimeDelta time, base::TimeDelta max_time);
-
-  // Callback executed by video renderer to update clock time.
-  void OnVideoTimeUpdate(base::TimeDelta max_time);
-
   // Callback executed by filters to update statistics.
   void OnUpdateStatistics(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 OnBufferingStateChanged(BufferingState* buffering_state,
                                BufferingState new_buffering_state);
   bool WaitingForEnoughData() const;
   void PausePlayback();
   void StartPlayback();
 
-  void PauseClockAndStopTicking_Locked();
-  void StartClockIfWaitingForTimeUpdate_Locked();
-
   // Callbacks executed when a renderer has ended.
   void OnAudioRendererEnded();
   void OnVideoRendererEnded();
+  bool PlaybackHasEnded() const;
   void RunEndedCallbackIfNeeded();
 
   // Callback executed when a runtime error happens.
   void OnError(PipelineStatus error);
 
   void FireAllPendingCallbacks();
 
   State state_;
 
   // Task runner used to execute pipeline tasks.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 
   Demuxer* demuxer_;
 
-  // Permanent callback to get the media duration.
-  TimeDeltaCB get_duration_cb_;
-
   // Permanent callbacks to notify various renderer states/stats.
   StatisticsCB statistics_cb_;
   base::Closure ended_cb_;
   PipelineStatusCB error_cb_;
   BufferingStateCB buffering_state_cb_;
 
   // Temporary callback used for Initialize() and Flush().
   base::Closure init_cb_;
   base::Closure flush_cb_;
 
   scoped_ptr<AudioRenderer> audio_renderer_;
   scoped_ptr<VideoRenderer> video_renderer_;
 
   // Renderer-provided time source used to control playback.
   TimeSource* time_source_;
+  scoped_ptr<WallClockTimeSource> wall_clock_time_source_;
+  bool time_ticking_;
 
   // The time to start playback from after starting/seeking has completed.
   base::TimeDelta start_time_;
 
   BufferingState audio_buffering_state_;
   BufferingState video_buffering_state_;
 
   // Whether we've received the audio/video ended events.
   bool audio_ended_;
   bool video_ended_;
 
   bool underflow_disabled_for_testing_;
-
-  // Protects time interpolation related member variables, i.e. |interpolator_|,
-  // |default_tick_clock_| and |interpolation_state_|. This is because
-  // |interpolator_| can be used on different threads (see GetMediaTime()).
-  mutable base::Lock interpolator_lock_;

[xhwang, 2014/09/08 22:56:06]

+1 !

-
-  // Tracks the most recent media time update and provides interpolated values
-  // as playback progresses.
-  scoped_ptr<TimeDeltaInterpolator> interpolator_;
-
-  // base::TickClock used by |interpolator_|.
-  // TODO(xhwang): This can be TimeDeltaInterpolator's implementation detail.
-  base::DefaultTickClock default_tick_clock_;
-
-  enum InterpolationState {
-    // Audio (if present) is not rendering. Time isn't being interpolated.
-    INTERPOLATION_STOPPED,
-
-    // Audio (if present) is rendering. Time isn't being interpolated.
-    INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE,
-
-    // Audio (if present) is rendering. Time is being interpolated.
-    INTERPOLATION_STARTED,
-  };
-
-  InterpolationState interpolation_state_;
+  bool clockless_video_playback_enabled_for_testing_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<RendererImpl> weak_factory_;
   base::WeakPtr<RendererImpl> weak_this_;
 
   DISALLOW_COPY_AND_ASSIGN(RendererImpl);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_RENDERER_IMPL_H_