media/renderers/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_RENDERERS_RENDERER_IMPL_H_
   6 #define MEDIA_RENDERERS_RENDERER_IMPL_H_
   7
   8 #include "base/cancelable_callback.h"
   9 #include "base/memory/ref_counted.h"
  10 #include "base/memory/scoped_ptr.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/synchronization/lock.h"
  13 #include "base/time/clock.h"
  14 #include "base/time/default_tick_clock.h"
  15 #include "base/time/time.h"
  16 #include "media/base/buffering_state.h"
  17 #include "media/base/decryptor.h"
  18 #include "media/base/media_export.h"
  19 #include "media/base/pipeline_status.h"
  20 #include "media/base/renderer.h"
  21
  22 namespace base {
  23 class SingleThreadTaskRunner;
  24 }
  25
  26 namespace media {
  27
  28 class AudioRenderer;
  29 class DemuxerStreamProvider;
  30 class TimeSource;
  31 class VideoRenderer;
  32 class WallClockTimeSource;
  33
  34 class MEDIA_EXPORT RendererImpl : public Renderer {
  35  public:
  36   // Renders audio/video streams using |audio_renderer| and |video_renderer|
  37   // provided. All methods except for GetMediaTime() run on the |task_runner|.
  38   // GetMediaTime() runs on the render main thread because it's part of JS sync
  39   // API.
  40   RendererImpl(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  41                scoped_ptr<AudioRenderer> audio_renderer,
  42                scoped_ptr<VideoRenderer> video_renderer);
  43
  44   ~RendererImpl() final;
  45
  46   // Renderer implementation.
  47   void Initialize(DemuxerStreamProvider* demuxer_stream_provider,
  48                   const PipelineStatusCB& init_cb,
  49                   const StatisticsCB& statistics_cb,
  50                   const BufferingStateCB& buffering_state_cb,
  51                   const base::Closure& ended_cb,
  52                   const PipelineStatusCB& error_cb,
  53                   const base::Closure& waiting_for_decryption_key_cb) final;
  54   void SetCdm(CdmContext* cdm_context,
  55               const CdmAttachedCB& cdm_attached_cb) final;
  56   void Flush(const base::Closure& flush_cb) final;
  57   void StartPlayingFrom(base::TimeDelta time) final;
  58   void SetPlaybackRate(double playback_rate) final;
  59   void SetVolume(float volume) final;
  60   base::TimeDelta GetMediaTime() final;
  61   bool HasAudio() final;
  62   bool HasVideo() final;
  63
  64   // Helper functions for testing purposes. Must be called before Initialize().
  65   void DisableUnderflowForTesting();
  66   void EnableClocklessVideoPlaybackForTesting();
  67   void set_time_source_for_testing(TimeSource* time_source) {
  68     time_source_ = time_source;
  69   }
  70   void set_video_underflow_threshold_for_testing(base::TimeDelta threshold) {
  71     video_underflow_threshold_ = threshold;
  72   }
  73
  74  private:
  75   enum State {
  76     STATE_UNINITIALIZED,
  77     STATE_INITIALIZING,
  78     STATE_FLUSHING,
  79     STATE_PLAYING,
  80     STATE_ERROR
  81   };
  82
  83   base::TimeTicks GetWallClockTime(base::TimeDelta time);
  84
  85   // Requests that this object notifies when a decryptor is ready through the
  86   // |decryptor_ready_cb| provided.
  87   // If |decryptor_ready_cb| is null, the existing callback will be fired with
  88   // nullptr immediately and reset.
  89   void SetDecryptorReadyCallback(const DecryptorReadyCB& decryptor_ready_cb);
  90
  91   // Helper functions and callbacks for Initialize().
  92   void InitializeAudioRenderer();
  93   void OnAudioRendererInitializeDone(PipelineStatus status);
  94   void InitializeVideoRenderer();
  95   void OnVideoRendererInitializeDone(PipelineStatus status);
  96
  97   // Helper functions and callbacks for Flush().
  98   void FlushAudioRenderer();
  99   void OnAudioRendererFlushDone();
 100   void FlushVideoRenderer();
 101   void OnVideoRendererFlushDone();
 102
 103   // Callback executed by filters to update statistics.
 104   void OnUpdateStatistics(const PipelineStatistics& stats);
 105
 106   // Collection of callback methods and helpers for tracking changes in
 107   // buffering state and transition from paused/underflow states and playing
 108   // states.
 109   //
 110   // While in the kPlaying state:
 111   //   - A waiting to non-waiting transition indicates preroll has completed
 112   //     and StartPlayback() should be called
 113   //   - A non-waiting to waiting transition indicates underflow has occurred
 114   //     and PausePlayback() should be called
 115   void OnBufferingStateChanged(BufferingState* buffering_state,
 116                                BufferingState new_buffering_state);
 117   bool WaitingForEnoughData() const;
 118   void PausePlayback();
 119   void StartPlayback();
 120
 121   // Callbacks executed when a renderer has ended.
 122   void OnAudioRendererEnded();
 123   void OnVideoRendererEnded();
 124   bool PlaybackHasEnded() const;
 125   void RunEndedCallbackIfNeeded();
 126
 127   // Callback executed when a runtime error happens.
 128   void OnError(PipelineStatus error);
 129
 130   State state_;
 131
 132   // Task runner used to execute pipeline tasks.
 133   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 134
 135   DemuxerStreamProvider* demuxer_stream_provider_;
 136
 137   // Permanent callbacks to notify various renderer states/stats.
 138   StatisticsCB statistics_cb_;
 139   base::Closure ended_cb_;
 140   PipelineStatusCB error_cb_;
 141   BufferingStateCB buffering_state_cb_;
 142   base::Closure waiting_for_decryption_key_cb_;
 143
 144   // Temporary callback used for Initialize() and Flush().
 145   PipelineStatusCB init_cb_;
 146   base::Closure flush_cb_;
 147
 148   scoped_ptr<AudioRenderer> audio_renderer_;
 149   scoped_ptr<VideoRenderer> video_renderer_;
 150
 151   // Renderer-provided time source used to control playback.
 152   TimeSource* time_source_;
 153   scoped_ptr<WallClockTimeSource> wall_clock_time_source_;
 154   bool time_ticking_;
 155   double playback_rate_;
 156
 157   // The time to start playback from after starting/seeking has completed.
 158   base::TimeDelta start_time_;
 159
 160   BufferingState audio_buffering_state_;
 161   BufferingState video_buffering_state_;
 162
 163   // Whether we've received the audio/video ended events.
 164   bool audio_ended_;
 165   bool video_ended_;
 166
 167   CdmContext* cdm_context_;
 168
 169   // Callback registered by filters (decoder or demuxer) to be informed of a
 170   // Decryptor.
 171   // Note: We could have multiple filters registering this callback. One
 172   // callback is okay because:
 173   // 1, We always initialize filters in sequence.
 174   // 2, Filter initialization will not finish until this callback is satisfied.
 175   DecryptorReadyCB decryptor_ready_cb_;
 176
 177   bool underflow_disabled_for_testing_;
 178   bool clockless_video_playback_enabled_for_testing_;
 179
 180   // Used to defer underflow for video when audio is present.
 181   base::CancelableClosure deferred_underflow_cb_;
 182
 183   // The amount of time to wait before declaring underflow if the video renderer
 184   // runs out of data but the audio renderer still has enough.
 185   base::TimeDelta video_underflow_threshold_;
 186
 187   base::WeakPtr<RendererImpl> weak_this_;
 188   base::WeakPtrFactory<RendererImpl> weak_factory_;
 189
 190   DISALLOW_COPY_AND_ASSIGN(RendererImpl);
 191 };
 192
 193 }  // namespace media
 194
 195 #endif  // MEDIA_RENDERERS_RENDERER_IMPL_H_