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