Change the TimeSource interface to return wallclock time for video.

media/base/video_renderer.h

 // Copyright (c) 2012 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_VIDEO_RENDERER_H_
 #define MEDIA_BASE_VIDEO_RENDERER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 #include "base/time/time.h"
 #include "media/base/buffering_state.h"
 #include "media/base/decryptor.h"
 #include "media/base/media_export.h"
 #include "media/base/pipeline_status.h"
 
 namespace media {
 
 class DemuxerStream;
 class VideoDecoder;
 class VideoFrame;
 
 class MEDIA_EXPORT VideoRenderer {
  public:
   // Used to paint VideoFrame.
   typedef base::Callback<void(const scoped_refptr<VideoFrame>&)> PaintCB;
 
   // Used to query the current time or duration of the media.

[xhwang, 2015/03/23 22:20:13]

"time or duration" is not accurate now...

[DaleCurtis, 2015/03/25 00:31:44]

Done.

-  typedef base::Callback<base::TimeDelta()> TimeDeltaCB;
+  typedef base::Callback<base::TimeTicks(base::TimeDelta)> TimeConverterCB;

[xhwang, 2015/03/23 22:20:13]

nit: s/TimeConverterCB/WallClockTimeCB/ ?

[DaleCurtis, 2015/03/25 00:31:45]

Done.

 
   VideoRenderer();
 
   // Stops all operations and fires all pending callbacks.
   virtual ~VideoRenderer();
 
   // Initializes a VideoRenderer with |stream|, executing |init_cb| upon
   // completion. If initialization fails, only |init_cb| (not |error_cb|) will
   // be called.
   //
   // |set_decryptor_ready_cb| is fired when a Decryptor is needed, i.e. when the
   // |stream| is encrypted.
   //
   // |statistics_cb| is executed periodically with video rendering stats, such
   // as dropped frames.
   //
   // |buffering_state_cb| is executed when video rendering has either run out of
   // data or has enough data to continue playback.
   //
   // |paint_cb| is executed on the video frame timing thread whenever a new
   // frame is available for painting. Can be called from any thread.
   //
   // |ended_cb| is executed when video rendering has reached the end of stream.
   //
   // |error_cb| is executed if an error was encountered after initialization.
   //
-  // |get_time_cb| is used to query the current media playback time.
+  // |time_converter_cb| is used to convert media timestamps into wallclock
+  // timestamps.
   //
   // |waiting_for_decryption_key_cb| is executed whenever the key needed to
   // decrypt the stream is not available.
   virtual void Initialize(
       DemuxerStream* stream,
       const PipelineStatusCB& init_cb,
       const SetDecryptorReadyCB& set_decryptor_ready_cb,
       const StatisticsCB& statistics_cb,
       const BufferingStateCB& buffering_state_cb,
       const PaintCB& paint_cb,
       const base::Closure& ended_cb,
       const PipelineStatusCB& error_cb,
-      const TimeDeltaCB& get_time_cb,
+      const TimeConverterCB& time_converter_cb,
       const base::Closure& waiting_for_decryption_key_cb) = 0;
 
   // Discards any video data and stops reading from |stream|, executing
   // |callback| when completed.
   //
   // Clients should expect |buffering_state_cb| to be called with
   // BUFFERING_HAVE_NOTHING while flushing is in progress.
   virtual void Flush(const base::Closure& callback) = 0;
 
   // Starts playback at |timestamp| by reading from |stream| and decoding and
   // rendering video.
   //
   // Only valid to call after a successful Initialize() or Flush().
   virtual void StartPlayingFrom(base::TimeDelta timestamp) = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(VideoRenderer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_VIDEO_RENDERER_H_