media: Introduce Renderer interface and RendererImpl.

media/base/pipeline.h

Index: media/base/pipeline.h
diff --git a/media/base/pipeline.h b/media/base/pipeline.h
index fe5962a4dd2831dc05ed5309270e1667b6ff67cb..fed95a3f2743dde7971c3b4711f34978d91cdc2d 100644
--- a/media/base/pipeline.h
+++ b/media/base/pipeline.h
@@ -5,15 +5,11 @@
 #ifndef MEDIA_BASE_PIPELINE_H_
 #define MEDIA_BASE_PIPELINE_H_
 
-#include <string>
-
 #include "base/gtest_prod_util.h"
 #include "base/memory/weak_ptr.h"
-#include "base/synchronization/condition_variable.h"
 #include "base/synchronization/lock.h"
 #include "base/threading/thread_checker.h"
 #include "base/time/default_tick_clock.h"
-#include "media/base/audio_renderer.h"
 #include "media/base/buffering_state.h"
 #include "media/base/demuxer.h"
 #include "media/base/media_export.h"
@@ -32,11 +28,10 @@ namespace media {
 
 class FilterCollection;
 class MediaLog;
+class Renderer;
 class TextRenderer;
 class TextTrackConfig;
 class TimeDeltaInterpolator;
-class TimeSource;
-class VideoRenderer;
 
 // Metadata describing a pipeline once it has been initialized.
 struct PipelineMetadata {
@@ -178,10 +173,6 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Gets the current pipeline statistics.
   PipelineStatistics GetStatistics() const;
 
-  void set_underflow_disabled_for_testing(bool disabled) {
-    underflow_disabled_for_testing_ = disabled;
-  }
-  void SetTimeDeltaInterpolatorForTesting(TimeDeltaInterpolator* interpolator);
   void SetErrorForTesting(PipelineStatus status);
   bool HasWeakPtrsForTesting() const;
 
@@ -195,8 +186,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   enum State {
     kCreated,
     kInitDemuxer,
-    kInitAudioRenderer,
-    kInitVideoRenderer,
+    kInitRenderer,
     kSeeking,
     kPlaying,
     kStopping,
@@ -229,12 +219,6 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Callback executed by filters to update statistics.
   void OnUpdateStatistics(const PipelineStatistics& stats);
 
-  // Callback executed by audio renderer to update clock time.
-  void OnAudioTimeUpdate(base::TimeDelta time, base::TimeDelta max_time);
-
-  // Callback executed by video renderer to update clock time.
-  void OnVideoTimeUpdate(base::TimeDelta max_time);
-
   // The following "task" methods correspond to the public methods, but these
   // methods are run as the result of posting a task to the Pipeline's
   // task runner.
@@ -257,8 +241,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   void SeekTask(base::TimeDelta time, const PipelineStatusCB& seek_cb);
 
   // Callbacks executed when a renderer has ended.
-  void OnAudioRendererEnded();
-  void OnVideoRendererEnded();
+  void OnRendererEnded();
   void OnTextRendererEnded();
   void RunEndedCallbackIfNeeded();
 
@@ -272,20 +255,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Kicks off initialization for each media object, executing |done_cb| with
   // the result when completed.
   void InitializeDemuxer(const PipelineStatusCB& done_cb);
-  void InitializeAudioRenderer(const PipelineStatusCB& done_cb);
-  void InitializeVideoRenderer(const PipelineStatusCB& done_cb);
-
-  // Kicks off destroying filters. Called by StopTask() and ErrorChangedTask().
-  // When we start to tear down the pipeline, we will consider two cases:
-  // 1. when pipeline has not been initialized, we will transit to stopping
-  // state first.
-  // 2. when pipeline has been initialized, we will first transit to pausing
-  // => flushing => stopping => stopped state.
-  // This will remove the race condition during stop between filters.
-  void TearDownPipeline();
-
-  // Compute the time corresponding to a byte offset.
-  base::TimeDelta TimeForByteOffset_Locked(int64 byte_offset) const;
+  void InitializeRenderer(const PipelineStatusCB& done_cb);
 
   void OnStateTransition(PipelineStatus status);
   void StateTransitionTask(PipelineStatus status);
@@ -299,23 +269,7 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   void DoStop(const PipelineStatusCB& done_cb);
   void OnStopCompleted(PipelineStatus status);
 
-  // Collection of callback methods and helpers for tracking changes in
-  // buffering state and transition from paused/underflow states and playing
-  // states.
-  //
-  // While in the kPlaying state:
-  //   - A waiting to non-waiting transition indicates preroll has completed
-  //     and StartPlayback() should be called
-  //   - A non-waiting to waiting transition indicates underflow has occurred
-  //     and PausePlayback() should be called
-  void BufferingStateChanged(BufferingState* buffering_state,
-                             BufferingState new_buffering_state);
-  bool WaitingForEnoughData() const;
-  void PausePlayback();
-  void StartPlayback();
-
-  void PauseClockAndStopTicking_Locked();
-  void StartClockIfWaitingForTimeUpdate_Locked();
+  void BufferingStateChanged(BufferingState new_buffering_state);
 
   // Task runner used to execute pipeline tasks.
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
@@ -349,26 +303,6 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // Current duration as 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.
-  scoped_ptr<TimeDeltaInterpolator> interpolator_;
-
-  enum InterpolationState {
-    // Audio (if present) is not rendering. Time isn't being interpolated.
-    INTERPOLATION_STOPPED,
-
-    // Audio (if present) is rendering. Time isn't being interpolated.
-    INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE,
-
-    // Audio (if present) is rendering. Time is being interpolated.
-    INTERPOLATION_STARTED,
-  };
-
-  InterpolationState interpolation_state_;
-
   // Status of the pipeline.  Initialized to PIPELINE_OK which indicates that
   // the pipeline is operating correctly. Any other value indicates that the
   // pipeline is stopped or is stopping.  Clients can call the Stop() method to
@@ -378,6 +312,8 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   // The following data members are only accessed by tasks posted to
   // |task_runner_|.
 
+  bool is_initialized_;
+
   // Member that tracks the current state.
   State state_;
 
@@ -385,12 +321,8 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
   base::TimeDelta start_timestamp_;
 
   // Whether we've received the audio/video/text ended events.
-  bool audio_ended_;
-  bool video_ended_;
-  bool text_ended_;
-
-  BufferingState audio_buffering_state_;
-  BufferingState video_buffering_state_;
+  bool renderer_ended_;
+  bool text_renderer_ended_;
 
   // Temporary callback used for Start() and Seek().
   PipelineStatusCB seek_cb_;
@@ -413,19 +345,13 @@ class MEDIA_EXPORT Pipeline : public DemuxerHost {
 
   // Holds the initialized renderers. Used for setting the volume,
   // playback rate, and determining when playback has finished.
-  scoped_ptr<AudioRenderer> audio_renderer_;
-  scoped_ptr<VideoRenderer> video_renderer_;
+  scoped_ptr<Renderer> renderer_;
   scoped_ptr<TextRenderer> text_renderer_;
 
-  // Renderer-provided time source used to control playback.
-  TimeSource* time_source_;
-
   PipelineStatistics statistics_;
 
   scoped_ptr<SerialRunner> pending_callbacks_;
 
-  bool underflow_disabled_for_testing_;
-
   base::ThreadChecker thread_checker_;
 
   // NOTE: Weak pointers must be invalidated before all other member variables.