Implementation of MediaCodecPlayer stage 1

media/base/android/media_codec_player.h

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_H_
 #define MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_H_
 
 #include "base/android/scoped_java_ref.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "base/threading/thread.h"
+#include "base/time/default_tick_clock.h"
 #include "media/base/android/demuxer_android.h"
 #include "media/base/android/media_player_android.h"
+#include "media/base/demuxer_stream.h"
 #include "media/base/media_export.h"
+#include "media/base/time_delta_interpolator.h"
 #include "ui/gl/android/scoped_java_surface.h"
 
 namespace media {
 
 class BrowserCdm;
+class MediaCodecAudioDecoder;
+class MediaCodecVideoDecoder;
 
 // Returns the task runner for the media thread
 MEDIA_EXPORT scoped_refptr<base::SingleThreadTaskRunner> GetMediaTaskRunner();
 
 
 // This class implements the media player using Android's MediaCodec.
 // It differs from MediaSourcePlayer in that it removes most
 // processing away from UI thread: it uses a dedicated Media thread
 // to receive the data and to handle commands.
 class MEDIA_EXPORT MediaCodecPlayer : public MediaPlayerAndroid,
                                       public DemuxerAndroidClient {
  public:
+
+  // Typedefs for the notification callbacks
+  typedef base::Callback<
+      void (base::TimeDelta duration, int width, int height, bool success)>
+      MetadataChangedCallback;
+
+  typedef base::Callback<
+      void (base::TimeDelta current_timestamp, base::TimeTicks current_ticks)>
+      TimeUpdateCallback;
+
   // Constructs a player with the given ID and demuxer. |manager| must outlive
   // the lifetime of this object.
   MediaCodecPlayer(int player_id,
-                   MediaPlayerManager* manager,
+                   base::WeakPtr<MediaPlayerManager> manager,
                    const RequestMediaResourcesCB& request_media_resources_cb,
                    scoped_ptr<DemuxerAndroid> demuxer,
                    const GURL& frame_url);
   ~MediaCodecPlayer() override;
 
   // MediaPlayerAndroid implementation.

[wolenetz, 2015/05/19 23:05:23]

Please comment in the CL description the known gaps that are currently not
implemented, such as:
CDM/DRM/EME support?
Seek support?
BrowserSeek support? (or does the AccessUnitQueue make this hack a thing of the
past?)
etc.

[Tima Vaisburd, 2015/05/22 23:37:52]

None of this is implemented in this CL. I deliberately removed some pieces in a
hope to make it easier for review. I can add it back you and Min would rather
like to see them here and not in a subsequent reviews. That is the reason for
the states that are not used but mentioned.

The browser seek, as far as I understand, will be needed. We might need to
recreate the MediaCodec at a random moment, and the first frame after the
recreation has to be the key frame. The olnly alternative I see is to keep the
AUs since the last key frame in the AU queue. Wouldn't it be a potentially
significant data duplication?

   void DeleteOnCorrectThread() override;
   void SetVideoSurface(gfx::ScopedJavaSurface surface) override;
   void Start() override;
   void Pause(bool is_media_related_action) override;
   void SeekTo(base::TimeDelta timestamp) override;
   void Release() override;
   void SetVolume(double volume) override;
   int GetVideoWidth() override;
   int GetVideoHeight() override;
   base::TimeDelta GetCurrentTime() override;
   base::TimeDelta GetDuration() override;
   bool IsPlaying() override;
   bool CanPause() override;
   bool CanSeekForward() override;
   bool CanSeekBackward() override;
   bool IsPlayerReady() override;
   void SetCdm(BrowserCdm* cdm) override;
 
   // DemuxerAndroidClient implementation.
   void OnDemuxerConfigsAvailable(const DemuxerConfigs& params) override;
   void OnDemuxerDataAvailable(const DemuxerData& params) override;
   void OnDemuxerSeekDone(base::TimeDelta actual_browser_seek_time) override;
   void OnDemuxerDurationChanged(base::TimeDelta duration) override;
 
   // Helper methods
   void Initialize();
-  void DestroySelf();
+
+  base::WeakPtr<MediaCodecPlayer> weak_ptr() const { return weak_this_; }
 
  private:
+  // The state machine states.
+  enum PlayerState {
+    STATE_PAUSED,
+    STATE_PREFETCHING,
+    STATE_PLAYING,
+    STATE_STOPPING,
+    STATE_WAITING_FOR_CONFIG,
+    STATE_WAITING_FOR_SURFACE,
+    STATE_WAITING_FOR_SEEK,
+    STATE_ERROR,
+  };
+
+  // Callbacks from decoders
+  void RequestDemuxerData(DemuxerStream::Type stream_type);
+  void OnPrefetchDone();
+  void OnStarvation();
+  void OnStopDone();
+  void OnError();
+  void OnTimeIntervalUpdate(base::TimeDelta now_playing,
+                            base::TimeDelta last_buffered);
+
+  // Operations called from the state machine.
+  void SetState(PlayerState new_state);
+  void SetPendingSurface(gfx::ScopedJavaSurface surface);
+  bool HasPendingSurface();
+  void SetPendingStart(bool need_to_start);
+  bool HasPendingStart();
+  bool HasVideo();
+  bool HasAudio();
+  void SetDemuxerConfigs(const DemuxerConfigs& configs);
+  void StartPrefetchDecoders();
+  void StartPlaybackDecoders();
+  void StopDecoders();
+  void RequestToStopDecoders();
+  void ReleaseDecoderResources();
+
+  // Helper methods.
+  void CreateDecoders();
+  bool AudioFinished();
+  bool VideoFinished();
+
+  static const char* AsString(PlayerState state);
+
+  // Data.
+
   // Object for posting tasks on UI thread.
   scoped_refptr<base::SingleThreadTaskRunner> ui_task_runner_;
 
+  // Major components: demuxer, audio and video decoders.
   scoped_ptr<DemuxerAndroid> demuxer_;
+  scoped_ptr<MediaCodecAudioDecoder> audio_decoder_;
+  scoped_ptr<MediaCodecVideoDecoder> video_decoder_;
+
+  // The state of the state machine.
+  PlayerState state_;
+
+  // Notification callbacks, they call MediaPlayerManager.
+  base::Closure request_resources_cb_;
+  MetadataChangedCallback metadata_changed_cb_;
+  TimeUpdateCallback time_update_cb_;
+  base::Closure completion_cb_;
+
+  // We call the MediaPlayerListener(request and release audio focus)
+  // on UI thread with these callbacks.
+  base::Closure attach_listener_cb_;

[wolenetz, 2015/05/19 23:05:23]

What are the analogous methods in MediaSourcePlayer for these?

[Tima Vaisburd, 2015/05/22 22:48:55]

AttachListener() and DetachListener(), I changed the comment to make it clearer.

+  base::Closure detach_listener_cb_;
+
+  // Error callback might be posted internally
+  base::Closure error_cb_;
+
+  // Total duration reported by demuxer.
+  base::TimeDelta duration_;
+
+  // base::TickClock used by |interpolator_|.
+  base::DefaultTickClock default_tick_clock_;
+
+  // Tracks the most recent media time update and provides interpolated values
+  // as playback progresses.
+  TimeDeltaInterpolator interpolator_;
+
+  // |interpolator_| will be accessed from the UI and decoder threads
+  base::Lock interpolator_lock_;
+
+  // Pendng data to be picked up by the upcoming state.
+  gfx::ScopedJavaSurface pending_surface_;
+  bool pending_start_;
 
   base::WeakPtr<MediaCodecPlayer> weak_this_;
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<MediaCodecPlayer> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaCodecPlayer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_ANDROID_MEDIA_CODEC_PLAYER_H_