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| 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_FILTERS_VIDEO_RENDERER_IMPL_H_ | |
| 6 #define MEDIA_FILTERS_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/threading/platform_thread.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/filters/decoder_stream.h" | |
| 25 | |
| 26 namespace base { | |
| 27 class SingleThreadTaskRunner; | |
| 28 } | |
| 29 | |
| 30 namespace media { | |
| 31 | |
| 32 // VideoRendererImpl creates its own thread for the sole purpose of timing frame | |
| 33 // presentation. It handles reading from the VideoFrameStream and stores the | |
| 34 // results in a queue of decoded frames and executing a callback when a frame is | |
| 35 // ready for rendering. | |
| 36 class MEDIA_EXPORT VideoRendererImpl | |
| 37 : public VideoRenderer, | |
| 38 public base::PlatformThread::Delegate { | |
| 39 public: | |
| 40 // |decoders| contains the VideoDecoders to use when initializing. | |
| 41 // | |
| 42 // Implementors should avoid doing any sort of heavy work in this method and | |
| 43 // instead post a task to a common/worker thread to handle rendering. Slowing | |
| 44 // down the video thread may result in losing synchronization with audio. | |
| 45 // | |
| 46 // Setting |drop_frames_| to true causes the renderer to drop expired frames. | |
| 47 VideoRendererImpl( | |
| 48 const scoped_refptr<base::SingleThreadTaskRunner>& task_runner, | |
| 49 ScopedVector<VideoDecoder> decoders, | |
| 50 bool drop_frames, | |
| 51 const scoped_refptr<MediaLog>& media_log); | |
| 52 ~VideoRendererImpl() override; | |
| 53 | |
| 54 // VideoRenderer implementation. | |
| 55 void Initialize(DemuxerStream* stream, | |
| 56 const PipelineStatusCB& init_cb, | |
| 57 const SetDecryptorReadyCB& set_decryptor_ready_cb, | |
| 58 const StatisticsCB& statistics_cb, | |
| 59 const BufferingStateCB& buffering_state_cb, | |
| 60 const PaintCB& paint_cb, | |
| 61 const base::Closure& ended_cb, | |
| 62 const PipelineStatusCB& error_cb, | |
| 63 const TimeDeltaCB& get_time_cb) override; | |
| 64 void Flush(const base::Closure& callback) override; | |
| 65 void StartPlayingFrom(base::TimeDelta timestamp) override; | |
| 66 | |
| 67 // PlatformThread::Delegate implementation. | |
| 68 void ThreadMain() override; | |
| 69 | |
| 70 private: | |
| 71 // Creates a dedicated |thread_| for video rendering. | |
| 72 void CreateVideoThread(); | |
| 73 | |
| 74 // Callback for |video_frame_stream_| initialization. | |
| 75 void OnVideoFrameStreamInitialized(bool success); | |
| 76 | |
| 77 // Callback for |video_frame_stream_| to deliver decoded video frames and | |
| 78 // report video decoding status. | |
| 79 void FrameReady(VideoFrameStream::Status status, | |
| 80 const scoped_refptr<VideoFrame>& frame); | |
| 81 | |
| 82 // Helper method for adding a frame to |ready_frames_|. | |
| 83 void AddReadyFrame_Locked(const scoped_refptr<VideoFrame>& frame); | |
| 84 | |
| 85 // Helper method that schedules an asynchronous read from the | |
| 86 // |video_frame_stream_| as long as there isn't a pending read and we have | |
| 87 // capacity. | |
| 88 void AttemptRead(); | |
| 89 void AttemptRead_Locked(); | |
| 90 | |
| 91 // Called when VideoFrameStream::Reset() completes. | |
| 92 void OnVideoFrameStreamResetDone(); | |
| 93 | |
| 94 // Runs |paint_cb_| with the next frame from |ready_frames_|. | |
| 95 // | |
| 96 // A read is scheduled to replace the frame. | |
| 97 void PaintNextReadyFrame_Locked(); | |
| 98 | |
| 99 // Drops the next frame from |ready_frames_| and runs |statistics_cb_|. | |
| 100 // | |
| 101 // A read is scheduled to replace the frame. | |
| 102 void DropNextReadyFrame_Locked(); | |
| 103 | |
| 104 // Returns true if the renderer has enough data for playback purposes. | |
| 105 // Note that having enough data may be due to reaching end of stream. | |
| 106 bool HaveEnoughData_Locked(); | |
| 107 void TransitionToHaveEnough_Locked(); | |
| 108 | |
| 109 // Runs |statistics_cb_| with |frames_decoded_| and |frames_dropped_|, resets | |
| 110 // them to 0, and then waits on |frame_available_| for up to the | |
| 111 // |wait_duration|. | |
| 112 void UpdateStatsAndWait_Locked(base::TimeDelta wait_duration); | |
| 113 | |
| 114 scoped_refptr<base::SingleThreadTaskRunner> task_runner_; | |
| 115 | |
| 116 // Used for accessing data members. | |
| 117 base::Lock lock_; | |
| 118 | |
| 119 // Provides video frames to VideoRendererImpl. | |
| 120 scoped_ptr<VideoFrameStream> video_frame_stream_; | |
| 121 | |
| 122 // Flag indicating low-delay mode. | |
| 123 bool low_delay_; | |
| 124 | |
| 125 // Queue of incoming frames yet to be painted. | |
| 126 typedef std::deque<scoped_refptr<VideoFrame> > VideoFrameQueue; | |
| 127 VideoFrameQueue ready_frames_; | |
| 128 | |
| 129 // Keeps track of whether we received the end of stream buffer and finished | |
| 130 // rendering. | |
| 131 bool received_end_of_stream_; | |
| 132 bool rendered_end_of_stream_; | |
| 133 | |
| 134 // Used to signal |thread_| as frames are added to |frames_|. Rule of thumb: | |
| 135 // always check |state_| to see if it was set to STOPPED after waking up! | |
| 136 base::ConditionVariable frame_available_; | |
| 137 | |
| 138 // Important detail: being in kPlaying doesn't imply that video is being | |
| 139 // rendered. Rather, it means that the renderer is ready to go. The actual | |
| 140 // rendering of video is controlled by time advancing via |get_time_cb_|. | |
| 141 // | |
| 142 // kUninitialized | |
| 143 // | Initialize() | |
| 144 // | | |
| 145 // V | |
| 146 // kInitializing | |
| 147 // | Decoders initialized | |
| 148 // | | |
| 149 // V Decoders reset | |
| 150 // kFlushed <------------------ kFlushing | |
| 151 // | StartPlayingFrom() ^ | |
| 152 // | | | |
| 153 // | | Flush() | |
| 154 // `---------> kPlaying --------' | |
| 155 enum State { | |
| 156 kUninitialized, | |
| 157 kInitializing, | |
| 158 kFlushing, | |
| 159 kFlushed, | |
| 160 kPlaying | |
| 161 }; | |
| 162 State state_; | |
| 163 | |
| 164 // Video thread handle. | |
| 165 base::PlatformThreadHandle thread_; | |
| 166 | |
| 167 // Keep track of the outstanding read on the VideoFrameStream. Flushing can | |
| 168 // only complete once the read has completed. | |
| 169 bool pending_read_; | |
| 170 | |
| 171 bool drop_frames_; | |
| 172 | |
| 173 BufferingState buffering_state_; | |
| 174 | |
| 175 // Playback operation callbacks. | |
| 176 base::Closure flush_cb_; | |
| 177 | |
| 178 // Event callbacks. | |
| 179 PipelineStatusCB init_cb_; | |
| 180 StatisticsCB statistics_cb_; | |
| 181 BufferingStateCB buffering_state_cb_; | |
| 182 base::Closure ended_cb_; | |
| 183 PipelineStatusCB error_cb_; | |
| 184 TimeDeltaCB get_time_cb_; | |
| 185 | |
| 186 base::TimeDelta start_timestamp_; | |
| 187 | |
| 188 // Embedder callback for notifying a new frame is available for painting. | |
| 189 PaintCB paint_cb_; | |
| 190 | |
| 191 // The timestamp of the last frame removed from the |ready_frames_| queue, | |
| 192 // either for calling |paint_cb_| or for dropping. Set to kNoTimestamp() | |
| 193 // during flushing. | |
| 194 base::TimeDelta last_timestamp_; | |
| 195 | |
| 196 // The timestamp of the last successfully painted frame. Set to kNoTimestamp() | |
| 197 // during flushing. | |
| 198 base::TimeDelta last_painted_timestamp_; | |
| 199 | |
| 200 // Keeps track of the number of frames decoded and dropped since the | |
| 201 // last call to |statistics_cb_|. These must be accessed under lock. | |
| 202 int frames_decoded_; | |
| 203 int frames_dropped_; | |
| 204 | |
| 205 bool is_shutting_down_; | |
| 206 | |
| 207 // NOTE: Weak pointers must be invalidated before all other member variables. | |
| 208 base::WeakPtrFactory<VideoRendererImpl> weak_factory_; | |
| 209 | |
| 210 DISALLOW_COPY_AND_ASSIGN(VideoRendererImpl); | |
| 211 }; | |
| 212 | |
| 213 } // namespace media | |
| 214 | |
| 215 #endif // MEDIA_FILTERS_VIDEO_RENDERER_IMPL_H_ | |
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