src/media/filters/renderer_impl.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef MEDIA_FILTERS_RENDERER_IMPL_H_
   6 #define MEDIA_FILTERS_RENDERER_IMPL_H_
   7
   8 #include "base/memory/ref_counted.h"
   9 #include "base/memory/scoped_ptr.h"
  10 #include "base/memory/weak_ptr.h"
  11 #include "base/synchronization/lock.h"
  12 #include "base/time/clock.h"
  13 #include "base/time/default_tick_clock.h"
  14 #include "base/time/time.h"
  15 #include "media/base/buffering_state.h"
  16 #include "media/base/media_export.h"
  17 #include "media/base/pipeline_status.h"
  18 #include "media/base/renderer.h"
  19
  20 namespace base {
  21 class SingleThreadTaskRunner;
  22 }
  23
  24 namespace media {
  25
  26 class AudioRenderer;
  27 class DemuxerStreamProvider;
  28 class TimeSource;
  29 class VideoRenderer;
  30 class WallClockTimeSource;
  31
  32 class MEDIA_EXPORT RendererImpl : public Renderer {
  33  public:
  34   // Renders audio/video streams using |audio_renderer| and |video_renderer|
  35   // provided. All methods except for GetMediaTime() run on the |task_runner|.
  36   // GetMediaTime() runs on the render main thread because it's part of JS sync
  37   // API.
  38   RendererImpl(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  39                scoped_ptr<AudioRenderer> audio_renderer,
  40                scoped_ptr<VideoRenderer> video_renderer);
  41
  42   ~RendererImpl() override;
  43
  44   // Renderer implementation.
  45   void Initialize(DemuxerStreamProvider* demuxer_stream_provider,
  46                   const base::Closure& init_cb,
  47                   const StatisticsCB& statistics_cb,
  48                   const base::Closure& ended_cb,
  49                   const PipelineStatusCB& error_cb,
  50                   const BufferingStateCB& buffering_state_cb) override;
  51   void Flush(const base::Closure& flush_cb) override;
  52   void StartPlayingFrom(base::TimeDelta time) override;
  53   void SetPlaybackRate(float playback_rate) override;
  54   void SetVolume(float volume) override;
  55   base::TimeDelta GetMediaTime() override;
  56   bool HasAudio() override;
  57   bool HasVideo() override;
  58   void SetCdm(MediaKeys* cdm) override;
  59
  60   // Helper functions for testing purposes. Must be called before Initialize().
  61   void DisableUnderflowForTesting();
  62   void EnableClocklessVideoPlaybackForTesting();
  63
  64  private:
  65   enum State {
  66     STATE_UNINITIALIZED,
  67     STATE_INITIALIZING,
  68     STATE_FLUSHING,
  69     STATE_PLAYING,
  70     STATE_ERROR
  71   };
  72
  73   base::TimeDelta GetMediaTimeForSyncingVideo();
  74
  75   // Helper functions and callbacks for Initialize().
  76   void InitializeAudioRenderer();
  77   void OnAudioRendererInitializeDone(PipelineStatus status);
  78   void InitializeVideoRenderer();
  79   void OnVideoRendererInitializeDone(PipelineStatus status);
  80
  81   // Helper functions and callbacks for Flush().
  82   void FlushAudioRenderer();
  83   void OnAudioRendererFlushDone();
  84   void FlushVideoRenderer();
  85   void OnVideoRendererFlushDone();
  86
  87   // Callback executed by filters to update statistics.
  88   void OnUpdateStatistics(const PipelineStatistics& stats);
  89
  90   // Collection of callback methods and helpers for tracking changes in
  91   // buffering state and transition from paused/underflow states and playing
  92   // states.
  93   //
  94   // While in the kPlaying state:
  95   //   - A waiting to non-waiting transition indicates preroll has completed
  96   //     and StartPlayback() should be called
  97   //   - A non-waiting to waiting transition indicates underflow has occurred
  98   //     and PausePlayback() should be called
  99   void OnBufferingStateChanged(BufferingState* buffering_state,
 100                                BufferingState new_buffering_state);
 101   bool WaitingForEnoughData() const;
 102   void PausePlayback();
 103   void StartPlayback();
 104
 105   // Callbacks executed when a renderer has ended.
 106   void OnAudioRendererEnded();
 107   void OnVideoRendererEnded();
 108   bool PlaybackHasEnded() const;
 109   void RunEndedCallbackIfNeeded();
 110
 111   // Callback executed when a runtime error happens.
 112   void OnError(PipelineStatus error);
 113
 114   void FireAllPendingCallbacks();
 115
 116   State state_;
 117
 118   // Task runner used to execute pipeline tasks.
 119   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 120
 121   DemuxerStreamProvider* demuxer_stream_provider_;
 122
 123   // Permanent callbacks to notify various renderer states/stats.
 124   StatisticsCB statistics_cb_;
 125   base::Closure ended_cb_;
 126   PipelineStatusCB error_cb_;
 127   BufferingStateCB buffering_state_cb_;
 128
 129   // Temporary callback used for Initialize() and Flush().
 130   base::Closure init_cb_;
 131   base::Closure flush_cb_;
 132
 133   scoped_ptr<AudioRenderer> audio_renderer_;
 134   scoped_ptr<VideoRenderer> video_renderer_;
 135
 136   // Renderer-provided time source used to control playback.
 137   TimeSource* time_source_;
 138   scoped_ptr<WallClockTimeSource> wall_clock_time_source_;
 139   bool time_ticking_;
 140
 141   // The time to start playback from after starting/seeking has completed.
 142   base::TimeDelta start_time_;
 143
 144   BufferingState audio_buffering_state_;
 145   BufferingState video_buffering_state_;
 146
 147   // Whether we've received the audio/video ended events.
 148   bool audio_ended_;
 149   bool video_ended_;
 150
 151   bool underflow_disabled_for_testing_;
 152   bool clockless_video_playback_enabled_for_testing_;
 153
 154   // NOTE: Weak pointers must be invalidated before all other member variables.
 155   base::WeakPtrFactory<RendererImpl> weak_factory_;
 156   base::WeakPtr<RendererImpl> weak_this_;
 157
 158   DISALLOW_COPY_AND_ASSIGN(RendererImpl);
 159 };
 160
 161 }  // namespace media
 162
 163 #endif  // MEDIA_FILTERS_RENDERER_IMPL_H_