media/renderers/video_renderer_impl.h

   1 // Copyright 2013 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_VIDEO_RENDERER_IMPL_H_
   6 #define MEDIA_RENDERERS_VIDEO_RENDERER_IMPL_H_
   7
   8 #include <deque>
   9
  10 #include "base/memory/ref_counted.h"
  11 #include "base/memory/scoped_ptr.h"
  12 #include "base/memory/scoped_vector.h"
  13 #include "base/memory/weak_ptr.h"
  14 #include "base/synchronization/condition_variable.h"
  15 #include "base/synchronization/lock.h"
  16 #include "base/timer/timer.h"
  17 #include "media/base/decryptor.h"
  18 #include "media/base/demuxer_stream.h"
  19 #include "media/base/media_log.h"
  20 #include "media/base/pipeline_status.h"
  21 #include "media/base/video_decoder.h"
  22 #include "media/base/video_frame.h"
  23 #include "media/base/video_renderer.h"
  24 #include "media/base/video_renderer_sink.h"
  25 #include "media/filters/decoder_stream.h"
  26 #include "media/filters/video_renderer_algorithm.h"
  27 #include "media/renderers/gpu_video_accelerator_factories.h"
  28 #include "media/video/gpu_memory_buffer_video_frame_pool.h"
  29
  30 namespace base {
  31 class SingleThreadTaskRunner;
  32 class TickClock;
  33 }
  34
  35 namespace media {
  36
  37 // VideoRendererImpl creates its own thread for the sole purpose of timing frame
  38 // presentation.  It handles reading from the VideoFrameStream and stores the
  39 // results in a queue of decoded frames and executing a callback when a frame is
  40 // ready for rendering.
  41 class MEDIA_EXPORT VideoRendererImpl
  42     : public VideoRenderer,
  43       public NON_EXPORTED_BASE(VideoRendererSink::RenderCallback) {
  44  public:
  45   // |decoders| contains the VideoDecoders to use when initializing.
  46   //
  47   // Implementors should avoid doing any sort of heavy work in this method and
  48   // instead post a task to a common/worker thread to handle rendering.  Slowing
  49   // down the video thread may result in losing synchronization with audio.
  50   //
  51   // Setting |drop_frames_| to true causes the renderer to drop expired frames.
  52   VideoRendererImpl(
  53       const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
  54       const scoped_refptr<base::TaskRunner>& worker_task_runner,
  55       VideoRendererSink* sink,
  56       ScopedVector<VideoDecoder> decoders,
  57       bool drop_frames,
  58       const scoped_refptr<GpuVideoAcceleratorFactories>& gpu_factories,
  59       const scoped_refptr<MediaLog>& media_log);
  60   ~VideoRendererImpl() override;
  61
  62   // VideoRenderer implementation.
  63   void Initialize(DemuxerStream* stream,
  64                   const PipelineStatusCB& init_cb,
  65                   const SetDecryptorReadyCB& set_decryptor_ready_cb,
  66                   const StatisticsCB& statistics_cb,
  67                   const BufferingStateCB& buffering_state_cb,
  68                   const base::Closure& ended_cb,
  69                   const PipelineStatusCB& error_cb,
  70                   const TimeSource::WallClockTimeCB& wall_clock_time_cb,
  71                   const base::Closure& waiting_for_decryption_key_cb) override;
  72   void Flush(const base::Closure& callback) override;
  73   void StartPlayingFrom(base::TimeDelta timestamp) override;
  74   void OnTimeStateChanged(bool time_progressing) override;
  75
  76   void SetTickClockForTesting(scoped_ptr<base::TickClock> tick_clock);
  77   void SetGpuMemoryBufferVideoForTesting(
  78       scoped_ptr<GpuMemoryBufferVideoFramePool> gpu_memory_buffer_pool);
  79
  80   // VideoRendererSink::RenderCallback implementation.
  81   scoped_refptr<VideoFrame> Render(base::TimeTicks deadline_min,
  82                                    base::TimeTicks deadline_max,
  83                                    bool background_rendering) override;
  84   void OnFrameDropped() override;
  85
  86  private:
  87   // Callback for |video_frame_stream_| initialization.
  88   void OnVideoFrameStreamInitialized(bool success);
  89
  90   // Callback for |video_frame_stream_| to deliver decoded video frames and
  91   // report video decoding status. If a frame is available the planes will be
  92   // copied asynchronously and FrameReady will be called once finished copying.
  93   void FrameReadyForCopyingToGpuMemoryBuffers(
  94       VideoFrameStream::Status status,
  95       const scoped_refptr<VideoFrame>& frame);
  96
  97   // Callback for |video_frame_stream_| to deliver decoded video frames and
  98   // report video decoding status.
  99   void FrameReady(uint32_t sequence_token,
 100                   VideoFrameStream::Status status,
 101                   const scoped_refptr<VideoFrame>& frame);
 102
 103   // Helper method for enqueueing a frame to |alogorithm_|.
 104   void AddReadyFrame_Locked(const scoped_refptr<VideoFrame>& frame);
 105
 106   // Helper method that schedules an asynchronous read from the
 107   // |video_frame_stream_| as long as there isn't a pending read and we have
 108   // capacity.
 109   void AttemptRead();
 110   void AttemptRead_Locked();
 111
 112   // Called when VideoFrameStream::Reset() completes.
 113   void OnVideoFrameStreamResetDone();
 114
 115   // Returns true if the renderer has enough data for playback purposes.
 116   // Note that having enough data may be due to reaching end of stream.
 117   bool HaveEnoughData_Locked();
 118   void TransitionToHaveEnough_Locked();
 119   void TransitionToHaveNothing();
 120
 121   // Runs |statistics_cb_| with |frames_decoded_| and |frames_dropped_|, resets
 122   // them to 0.
 123   void UpdateStats_Locked();
 124
 125   // Called after we've painted the first frame.  If |time_progressing_| is
 126   // false it Stop() on |sink_|.
 127   void MaybeStopSinkAfterFirstPaint();
 128
 129   // Returns true if there is no more room for additional buffered frames.
 130   bool HaveReachedBufferingCap();
 131
 132   // Starts or stops |sink_| respectively. Do not call while |lock_| is held.
 133   void StartSink();
 134   void StopSink();
 135
 136   // Fires |ended_cb_| if there are no remaining usable frames and
 137   // |received_end_of_stream_| is true.  Sets |rendered_end_of_stream_| if it
 138   // does so.
 139   //
 140   // When called from the media thread, |time_progressing| should reflect the
 141   // value of |time_progressing_|.  When called from Render() on the sink
 142   // callback thread, the inverse of |render_first_frame_and_stop_| should be
 143   // used as a proxy for |time_progressing_|.
 144   //
 145   // Returns algorithm_->EffectiveFramesQueued().
 146   size_t MaybeFireEndedCallback_Locked(bool time_progressing);
 147
 148   // Helper method for converting a single media timestamp to wall clock time.
 149   base::TimeTicks ConvertMediaTimestamp(base::TimeDelta media_timestamp);
 150
 151   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
 152
 153   // Sink which calls into VideoRendererImpl via Render() for video frames.  Do
 154   // not call any methods on the sink while |lock_| is held or the two threads
 155   // might deadlock. Do not call Start() or Stop() on the sink directly, use
 156   // StartSink() and StopSink() to ensure background rendering is started.  Only
 157   // access these values on |task_runner_|.
 158   VideoRendererSink* const sink_;
 159   bool sink_started_;
 160
 161   // Used for accessing data members.
 162   base::Lock lock_;
 163
 164   // Provides video frames to VideoRendererImpl.
 165   scoped_ptr<VideoFrameStream> video_frame_stream_;
 166
 167   // Pool of GpuMemoryBuffers and resources used to create hardware frames.
 168   scoped_ptr<GpuMemoryBufferVideoFramePool> gpu_memory_buffer_pool_;
 169
 170   scoped_refptr<MediaLog> media_log_;
 171
 172   // Flag indicating low-delay mode.
 173   bool low_delay_;
 174
 175   // Keeps track of whether we received the end of stream buffer and finished
 176   // rendering.
 177   bool received_end_of_stream_;
 178   bool rendered_end_of_stream_;
 179
 180   // Important detail: being in kPlaying doesn't imply that video is being
 181   // rendered. Rather, it means that the renderer is ready to go. The actual
 182   // rendering of video is controlled by time advancing via |get_time_cb_|.
 183   //
 184   //   kUninitialized
 185   //         | Initialize()
 186   //         |
 187   //         V
 188   //    kInitializing
 189   //         | Decoders initialized
 190   //         |
 191   //         V            Decoders reset
 192   //      kFlushed <------------------ kFlushing
 193   //         | StartPlayingFrom()         ^
 194   //         |                            |
 195   //         |                            | Flush()
 196   //         `---------> kPlaying --------'
 197   enum State {
 198     kUninitialized,
 199     kInitializing,
 200     kFlushing,
 201     kFlushed,
 202     kPlaying
 203   };
 204   State state_;
 205
 206   // An integer that represents how many times the video frame stream has been
 207   // reset. This is useful when doing video frame copies asynchronously since we
 208   // want to discard video frames that might be received after the stream has
 209   // been reset.
 210   uint32_t sequence_token_;
 211
 212   // Keep track of the outstanding read on the VideoFrameStream. Flushing can
 213   // only complete once the read has completed.
 214   bool pending_read_;
 215
 216   bool drop_frames_;
 217
 218   BufferingState buffering_state_;
 219
 220   // Playback operation callbacks.
 221   base::Closure flush_cb_;
 222
 223   // Event callbacks.
 224   PipelineStatusCB init_cb_;
 225   StatisticsCB statistics_cb_;
 226   BufferingStateCB buffering_state_cb_;
 227   base::Closure ended_cb_;
 228   PipelineStatusCB error_cb_;
 229   TimeSource::WallClockTimeCB wall_clock_time_cb_;
 230
 231   base::TimeDelta start_timestamp_;
 232
 233   // Keeps track of the number of frames decoded and dropped since the
 234   // last call to |statistics_cb_|. These must be accessed under lock.
 235   int frames_decoded_;
 236   int frames_dropped_;
 237
 238   scoped_ptr<base::TickClock> tick_clock_;
 239
 240   // Algorithm for selecting which frame to render; manages frames and all
 241   // timing related information.
 242   scoped_ptr<VideoRendererAlgorithm> algorithm_;
 243
 244   // Indicates that Render() was called with |background_rendering| set to true,
 245   // so we've entered a background rendering mode where dropped frames are not
 246   // counted.  Must be accessed under |lock_| once |sink_| is started.
 247   bool was_background_rendering_;
 248
 249   // Indicates whether or not media time is currently progressing or not.  Must
 250   // only be accessed from |task_runner_|.
 251   bool time_progressing_;
 252
 253   // Indicates that Render() should only render the first frame and then request
 254   // that the sink be stopped.  |posted_maybe_stop_after_first_paint_| is used
 255   // to avoid repeated task posts.
 256   bool render_first_frame_and_stop_;
 257   bool posted_maybe_stop_after_first_paint_;
 258
 259   // NOTE: Weak pointers must be invalidated before all other member variables.
 260   base::WeakPtrFactory<VideoRendererImpl> weak_factory_;
 261
 262   DISALLOW_COPY_AND_ASSIGN(VideoRendererImpl);
 263 };
 264
 265 }  // namespace media
 266
 267 #endif  // MEDIA_RENDERERS_VIDEO_RENDERER_IMPL_H_