media/base/android/media_codec_decoder.h

   1 // Copyright 2015 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_BASE_ANDROID_MEDIA_CODEC_DECODER_H_
   6 #define MEDIA_BASE_ANDROID_MEDIA_CODEC_DECODER_H_
   7
   8 #include "base/android/scoped_java_ref.h"
   9 #include "base/callback.h"
  10 #include "base/macros.h"
  11 #include "base/memory/ref_counted.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/single_thread_task_runner.h"
  14 #include "base/synchronization/lock.h"
  15 #include "base/threading/thread.h"
  16 #include "base/time/time.h"
  17 #include "media/base/android/access_unit_queue.h"
  18 #include "media/base/android/demuxer_stream_player_params.h"
  19
  20 namespace media {
  21
  22 class MediaCodecBridge;
  23
  24 // The decoder for MediaCodecPlayer.
  25 // This class accepts the incoming data into AccessUnitQueue and works with
  26 // MediaCodecBridge for decoding and rendering the frames. The MediaCodecPlayer
  27 // has two decoder objects: audio and video.
  28 //
  29 // The decoder works on two threads. The data from demuxer comes on Media
  30 // thread. The commands from MediaCodecPlayer, such as Prefetch, Start,
  31 // RequestToStop also come on the Media thread. The operations with MediaCodec
  32 // buffers and rendering happen on a separate thread called Decoder thread.
  33 // This class creates, starts and stops it as necessary.
  34 //
  35 // Decoder's internal state machine goes through the following states:
  36 //
  37 //  [ Stopped ] <-------------------          (any state except Error)
  38 //       |                         |                   |
  39 //       | Prefetch                |--- internal ------|
  40 //       v                         |   transition      v
  41 //  [ Prefetching ]                |               [ Error ]
  42 //       |                         |
  43 //       | internal transition     |
  44 //       v                         |            Error recovery:
  45 //  [ Prefetched ]                 |
  46 //       |                         |        (any state including Error)
  47 //       | Start                   |                   |
  48 //       v                         |                   | ReleaseDecoderResources
  49 //  [ Running ]                    |                   v
  50 //       |                         |              [ Stopped ]
  51 //       | RequestToStop           |
  52 //       v                         |
  53 //  [ Stopping ] -------------------
  54 //
  55 //
  56 //  [ Stopped ] --------------------
  57 //       ^                         |
  58 //       |       Flush             |
  59 //       ---------------------------
  60
  61 class MediaCodecDecoder {
  62  public:
  63   // The result of MediaCodec configuration, used by MediaCodecPlayer.
  64   enum ConfigStatus {
  65     CONFIG_FAILURE = 0,
  66     CONFIG_OK,
  67     CONFIG_KEY_FRAME_REQUIRED,
  68   };
  69
  70   // The decoder reports current playback time to the MediaCodecPlayer.
  71   // For audio, the parameters designate the beginning and end of a time
  72   // interval. The beginning is the estimated time that is playing right now.
  73   // The end is the playback time of the last buffered data. During normal
  74   // playback the subsequent intervals overlap.
  75   // For video both values are PTS of the corresponding frame, i.e. the interval
  76   // has zero width.
  77   typedef base::Callback<void(base::TimeDelta, base::TimeDelta)>
  78       SetTimeCallback;
  79
  80   // MediaCodecDecoder constructor.
  81   // Parameters:
  82   //   media_task_runner:
  83   //     A task runner for the controlling thread. All public methods should be
  84   //     called on this thread, and callbacks are delivered on this thread.
  85   //     The MediaCodecPlayer uses a dedicated (Media) thread for this.
  86   //   external_request_data_cb:
  87   //     Called periodically as the amount of internally stored data decreases.
  88   //     The receiver should call OnDemuxerDataAvailable() with more data.
  89   //   starvation_cb:
  90   //     Called when starvation is detected. The decoder state does not change.
  91   //     The player is supposed to stop and then prefetch the decoder.
  92   //   stop_done_cb:
  93   //     Called when async stop request is completed.
  94   //   error_cb:
  95   //     Called when a MediaCodec error occurred. If this happens, a player has
  96   //     to either call ReleaseDecoderResources() or destroy the decoder object.
  97   //   decoder_thread_name:
  98   //     The thread name to be passed to decoder thread constructor.
  99   MediaCodecDecoder(
 100       const scoped_refptr<base::SingleThreadTaskRunner>& media_task_runner,
 101       const base::Closure& external_request_data_cb,
 102       const base::Closure& starvation_cb,
 103       const base::Closure& stop_done_cb,
 104       const base::Closure& error_cb,
 105       const char* decoder_thread_name);
 106   virtual ~MediaCodecDecoder();
 107
 108   virtual const char* class_name() const;
 109
 110   // MediaCodecDecoder exists through the whole lifetime of the player
 111   // to support dynamic addition and removal of the streams.
 112   // This method returns true if the current stream (audio or video)
 113   // is currently active.
 114   virtual bool HasStream() const = 0;
 115
 116   // Stores configuration for the use of upcoming Configure()
 117   virtual void SetDemuxerConfigs(const DemuxerConfigs& configs) = 0;
 118
 119   // Stops decoder thread, releases the MediaCodecBridge and other resources.
 120   virtual void ReleaseDecoderResources();
 121
 122   // Flushes the MediaCodec and resets the AccessUnitQueue.
 123   // Decoder thread should not be running.
 124   virtual void Flush();
 125
 126   // Releases MediaCodecBridge.
 127   void ReleaseMediaCodec();
 128
 129   // Returns corresponding conditions.
 130   bool IsPrefetchingOrPlaying() const;
 131   bool IsStopped() const;
 132   bool IsCompleted() const;
 133
 134   base::android::ScopedJavaLocalRef<jobject> GetMediaCrypto();
 135
 136   // Starts prefetching: accumulates enough data in AccessUnitQueue.
 137   // Decoder thread is not running.
 138   void Prefetch(const base::Closure& prefetch_done_cb);
 139
 140   // Configures MediaCodec.
 141   ConfigStatus Configure();
 142
 143   // Starts the decoder thread and resumes the playback.
 144   bool Start(base::TimeDelta current_time);
 145
 146   // Stops the playback process synchronously. This method stops the decoder
 147   // thread synchronously, and then releases all MediaCodec buffers.
 148   void SyncStop();
 149
 150   // Requests to stop the playback and returns.
 151   // Decoder will stop asynchronously after all the dequeued output buffers
 152   // are rendered.
 153   void RequestToStop();
 154
 155   // Notification posted when asynchronous stop is done or playback completed.
 156   void OnLastFrameRendered(bool completed);
 157
 158   // Puts the incoming data into AccessUnitQueue.
 159   void OnDemuxerDataAvailable(const DemuxerData& data);
 160
 161  protected:
 162   // Returns true if the new DemuxerConfigs requires MediaCodec
 163   // reconfiguration.
 164   virtual bool IsCodecReconfigureNeeded(const DemuxerConfigs& curr,
 165                                         const DemuxerConfigs& next) const = 0;
 166
 167   // Does the part of MediaCodecBridge configuration that is specific
 168   // to audio or video.
 169   virtual ConfigStatus ConfigureInternal() = 0;
 170
 171   // Associates PTS with device time so we can calculate delays.
 172   // We use delays for video decoder only.
 173   virtual void SynchronizePTSWithTime(base::TimeDelta current_time) {}
 174
 175   // Processes the change of the output format, varies by stream.
 176   virtual void OnOutputFormatChanged() = 0;
 177
 178   // Renders the decoded frame and releases output buffer, or posts
 179   // a delayed task to do it at a later time,
 180   virtual void Render(int buffer_index,
 181                       size_t size,
 182                       bool render_output,
 183                       base::TimeDelta pts,
 184                       bool eos_encountered) = 0;
 185
 186   // Returns the number of delayed task (we might have them for video).
 187   virtual int NumDelayedRenderTasks() const;
 188
 189   // Releases output buffers that are dequeued and not released yet
 190   // because their rendering is delayed (video).
 191   virtual void ReleaseDelayedBuffers() {}
 192
 193   // Helper methods.
 194
 195   // Notifies the decoder if the frame is the last one.
 196   void CheckLastFrame(bool eos_encountered, bool has_delayed_tasks);
 197
 198   // Protected data.
 199
 200   // Object for posting tasks on Media thread.
 201   scoped_refptr<base::SingleThreadTaskRunner> media_task_runner_;
 202
 203   // Controls Android MediaCodec
 204   scoped_ptr<MediaCodecBridge> media_codec_bridge_;
 205
 206   // We call MediaCodecBridge on this thread for both
 207   // input and output buffers.
 208   base::Thread decoder_thread_;
 209
 210   // The queue of access units.
 211   AccessUnitQueue au_queue_;
 212
 213  private:
 214   enum DecoderState {
 215     kStopped = 0,
 216     kPrefetching,
 217     kPrefetched,
 218     kRunning,
 219     kStopping,
 220     kError,
 221   };
 222
 223   // Helper method that processes an error from MediaCodec.
 224   void OnCodecError();
 225
 226   // Requests data. Ensures there is no more than one request at a time.
 227   void RequestData();
 228
 229   // Prefetching callback that is posted to Media thread
 230   // in the kPrefetching state.
 231   void PrefetchNextChunk();
 232
 233   // The callback to do actual playback. Posted to Decoder thread
 234   // in the kRunning state.
 235   void ProcessNextFrame();
 236
 237   // Helper method for ProcessNextFrame.
 238   // Pushes one input buffer to the MediaCodec if the codec can accept it.
 239   // Returns false if there was MediaCodec error.
 240   bool EnqueueInputBuffer();
 241
 242   // Helper method for ProcessNextFrame.
 243   // Pulls all currently available output frames and renders them.
 244   // Returns false if there was MediaCodec error.
 245   bool DepleteOutputBufferQueue(bool* eos_encountered);
 246
 247   DecoderState GetState() const;
 248   void SetState(DecoderState state);
 249   const char* AsString(DecoderState state);
 250
 251   // Private Data.
 252
 253   // External data request callback that is passed to decoder.
 254   base::Closure external_request_data_cb_;
 255
 256   // These notifications are called on corresponding conditions.
 257   base::Closure prefetch_done_cb_;
 258   base::Closure starvation_cb_;
 259   base::Closure stop_done_cb_;
 260   base::Closure error_cb_;
 261
 262   // Data request callback that is posted by decoder internally.
 263   base::Closure request_data_cb_;
 264
 265   // Callback used to post OnCodecError method.
 266   base::Closure internal_error_cb_;
 267
 268   // Internal state.
 269   DecoderState state_;
 270   mutable base::Lock state_lock_;
 271
 272   // Flag is set when the EOS is enqueued into MediaCodec. Reset by Flush.
 273   bool eos_enqueued_;
 274
 275   // Flag is set when the EOS is received in MediaCodec output. Reset by Flush.
 276   bool completed_;
 277
 278   // Flag to ensure we post last frame notification once.
 279   bool last_frame_posted_;
 280
 281   // Indicates whether the data request is in progress.
 282   bool is_data_request_in_progress_;
 283
 284   // Indicates whether the incoming data should be ignored.
 285   bool is_incoming_data_invalid_;
 286
 287   // NOTE: Weak pointers must be invalidated before all other member variables.
 288   base::WeakPtrFactory<MediaCodecDecoder> weak_factory_;
 289
 290   DISALLOW_COPY_AND_ASSIGN(MediaCodecDecoder);
 291 };
 292
 293 }  // namespace media
 294
 295 #endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_DECODER_H_