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 <vector>
   9
  10 #include "base/cancelable_callback.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "base/synchronization/lock.h"
  15 #include "base/time/clock.h"
  16 #include "base/time/default_tick_clock.h"
  17 #include "base/time/time.h"
  18 #include "media/base/buffering_state.h"
  19 #include "media/base/decryptor.h"
  20 #include "media/base/media_export.h"
  21 #include "media/base/pipeline_status.h"
  22 #include "media/base/renderer.h"
  23
  24 namespace base {
  25 class SingleThreadTaskRunner;
  26 }
  27
  28 namespace media {
  29
  30 class AudioRenderer;
  31 class DemuxerStreamProvider;
  32 class TimeSource;
  33 class VideoRenderer;
  34 class WallClockTimeSource;
  35
  36 class MEDIA_EXPORT RendererImpl : public Renderer {
  37  public:
  38   // Renders audio/video streams using |audio_renderer| and |video_renderer|
  39   // provided. All methods except for GetMediaTime() run on the |task_runner|.
  40   // GetMediaTime() runs on the render main thread because it's part of JS sync
  41   // API.
  42   RendererImpl(const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
  43                scoped_ptr<AudioRenderer> audio_renderer,
  44                scoped_ptr<VideoRenderer> video_renderer);
  45
  46   ~RendererImpl() final;
  47
  48   // Renderer implementation.
  49   void Initialize(DemuxerStreamProvider* demuxer_stream_provider,
  50                   const PipelineStatusCB& init_cb,
  51                   const StatisticsCB& statistics_cb,
  52                   const BufferingStateCB& buffering_state_cb,
  53                   const base::Closure& ended_cb,
  54                   const PipelineStatusCB& error_cb,
  55                   const base::Closure& waiting_for_decryption_key_cb) final;
  56   void SetCdm(CdmContext* cdm_context,
  57               const CdmAttachedCB& cdm_attached_cb) final;
  58   void Flush(const base::Closure& flush_cb) final;
  59   void StartPlayingFrom(base::TimeDelta time) final;
  60   void SetPlaybackRate(double playback_rate) final;
  61   void SetVolume(float volume) final;
  62   base::TimeDelta GetMediaTime() final;
  63   bool HasAudio() final;
  64   bool HasVideo() final;
  65
  66   // Helper functions for testing purposes. Must be called before Initialize().
  67   void DisableUnderflowForTesting();
  68   void EnableClocklessVideoPlaybackForTesting();
  69   void set_time_source_for_testing(TimeSource* time_source) {
  70     time_source_ = time_source;
  71   }
  72   void set_video_underflow_threshold_for_testing(base::TimeDelta threshold) {
  73     video_underflow_threshold_ = threshold;
  74   }
  75
  76  private:
  77   enum State {
  78     STATE_UNINITIALIZED,
  79     STATE_INITIALIZING,
  80     STATE_FLUSHING,
  81     STATE_PLAYING,
  82     STATE_ERROR
  83   };
  84
  85   bool GetWallClockTimes(const std::vector<base::TimeDelta>& media_timestamps,
  86                          std::vector<base::TimeTicks>* wall_clock_times);
  87
  88   // Requests that this object notifies when a decryptor is ready through the
  89   // |decryptor_ready_cb| provided.
  90   // If |decryptor_ready_cb| is null, the existing callback will be fired with
  91   // nullptr immediately and reset.
  92   void SetDecryptorReadyCallback(const DecryptorReadyCB& decryptor_ready_cb);
  93
  94   // Helper functions and callbacks for Initialize().
  95   void InitializeAudioRenderer();
  96   void OnAudioRendererInitializeDone(PipelineStatus status);
  97   void InitializeVideoRenderer();
  98   void OnVideoRendererInitializeDone(PipelineStatus status);
  99
 100   // Helper functions and callbacks for Flush().
 101   void FlushAudioRenderer();
 102   void OnAudioRendererFlushDone();
 103   void FlushVideoRenderer();
 104   void OnVideoRendererFlushDone();
 105
 106   // Callback executed by filters to update statistics.
 107   void OnUpdateStatistics(const PipelineStatistics& stats);
 108
 109   // Collection of callback methods and helpers for tracking changes in
 110   // buffering state and transition from paused/underflow states and playing
 111   // states.
 112   //
 113   // While in the kPlaying state:
 114   //   - A waiting to non-waiting transition indicates preroll has completed
 115   //     and StartPlayback() should be called
 116   //   - A non-waiting to waiting transition indicates underflow has occurred
 117   //     and PausePlayback() should be called
 118   void OnBufferingStateChanged(BufferingState* buffering_state,
 119                                BufferingState new_buffering_state);
 120   bool WaitingForEnoughData() const;
 121   void PausePlayback();
 122   void StartPlayback();
 123
 124   // Callbacks executed when a renderer has ended.
 125   void OnAudioRendererEnded();
 126   void OnVideoRendererEnded();
 127   bool PlaybackHasEnded() const;
 128   void RunEndedCallbackIfNeeded();
 129
 130   // Callback executed when a runtime error happens.
 131   void OnError(PipelineStatus error);
 132
 133   State state_;
 134
 135   // Task runner used to execute pipeline tasks.
 136   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 137
 138   DemuxerStreamProvider* demuxer_stream_provider_;
 139
 140   // Permanent callbacks to notify various renderer states/stats.
 141   StatisticsCB statistics_cb_;
 142   base::Closure ended_cb_;
 143   PipelineStatusCB error_cb_;
 144   BufferingStateCB buffering_state_cb_;
 145   base::Closure waiting_for_decryption_key_cb_;
 146
 147   // Temporary callback used for Initialize() and Flush().
 148   PipelineStatusCB init_cb_;
 149   base::Closure flush_cb_;
 150
 151   scoped_ptr<AudioRenderer> audio_renderer_;
 152   scoped_ptr<VideoRenderer> video_renderer_;
 153
 154   // Renderer-provided time source used to control playback.
 155   TimeSource* time_source_;
 156   scoped_ptr<WallClockTimeSource> wall_clock_time_source_;
 157   bool time_ticking_;
 158   double playback_rate_;
 159
 160   // The time to start playback from after starting/seeking has completed.
 161   base::TimeDelta start_time_;
 162
 163   BufferingState audio_buffering_state_;
 164   BufferingState video_buffering_state_;
 165
 166   // Whether we've received the audio/video ended events.
 167   bool audio_ended_;
 168   bool video_ended_;
 169
 170   CdmContext* cdm_context_;
 171
 172   // Callback registered by filters (decoder or demuxer) to be informed of a
 173   // Decryptor.
 174   // Note: We could have multiple filters registering this callback. One
 175   // callback is okay because:
 176   // 1, We always initialize filters in sequence.
 177   // 2, Filter initialization will not finish until this callback is satisfied.
 178   DecryptorReadyCB decryptor_ready_cb_;
 179
 180   bool underflow_disabled_for_testing_;
 181   bool clockless_video_playback_enabled_for_testing_;
 182
 183   // Used to defer underflow for video when audio is present.
 184   base::CancelableClosure deferred_underflow_cb_;
 185
 186   // The amount of time to wait before declaring underflow if the video renderer
 187   // runs out of data but the audio renderer still has enough.
 188   base::TimeDelta video_underflow_threshold_;
 189
 190   base::WeakPtr<RendererImpl> weak_this_;
 191   base::WeakPtrFactory<RendererImpl> weak_factory_;
 192
 193   DISALLOW_COPY_AND_ASSIGN(RendererImpl);
 194 };
 195
 196 }  // namespace media
 197
 198 #endif  // MEDIA_RENDERERS_RENDERER_IMPL_H_