Make media::AudioRenderer inherit from media::TimeSource.

media/base/pipeline.cc

 // 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.
 
 #include "media/base/pipeline.h"
 
 #include <algorithm>
 
 #include "base/bind.h"
 #include "base/callback.h"
 #include "base/callback_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/location.h"
 #include "base/metrics/histogram.h"
 #include "base/single_thread_task_runner.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_util.h"
 #include "base/synchronization/condition_variable.h"
 #include "media/base/audio_decoder.h"
 #include "media/base/audio_renderer.h"
 #include "media/base/filter_collection.h"
 #include "media/base/media_log.h"
 #include "media/base/text_renderer.h"
 #include "media/base/text_track_config.h"
 #include "media/base/time_delta_interpolator.h"
+#include "media/base/time_source.h"
 #include "media/base/video_decoder.h"
 #include "media/base/video_decoder_config.h"
 #include "media/base/video_renderer.h"
 
 using base::TimeDelta;
 
 namespace media {
 
 Pipeline::Pipeline(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     MediaLog* media_log)
     : task_runner_(task_runner),
       media_log_(media_log),
       running_(false),
       did_loading_progress_(false),
       volume_(1.0f),
       playback_rate_(0.0f),
       interpolator_(new TimeDeltaInterpolator(&default_tick_clock_)),
       interpolation_state_(INTERPOLATION_STOPPED),
       status_(PIPELINE_OK),
       state_(kCreated),
       audio_ended_(false),
       video_ended_(false),
       text_ended_(false),
       audio_buffering_state_(BUFFERING_HAVE_NOTHING),
       video_buffering_state_(BUFFERING_HAVE_NOTHING),
       demuxer_(NULL),
+      time_source_(NULL),
       underflow_disabled_for_testing_(false) {
   media_log_->AddEvent(media_log_->CreatePipelineStateChangedEvent(kCreated));
   media_log_->AddEvent(
       media_log_->CreateEvent(MediaLogEvent::PIPELINE_CREATED));
   interpolator_->SetBounds(base::TimeDelta(), base::TimeDelta());
 }
 
 Pipeline::~Pipeline() {
   DCHECK(thread_checker_.CalledOnValidThread())
       << "Pipeline must be destroyed on same thread that created it";
@@ skipping 309 matching lines @@
     case kPlaying:
       // Finish initial start sequence the first time we enter the playing
       // state.
       if (filter_collection_) {
         filter_collection_.reset();
         if (!audio_renderer_ && !video_renderer_) {
           ErrorChangedTask(PIPELINE_ERROR_COULD_NOT_RENDER);
           return;
         }
 
+        if (audio_renderer_)
+          time_source_ = audio_renderer_->GetTimeSource();
+
         {
           PipelineMetadata metadata;
           metadata.has_audio = audio_renderer_;
           metadata.has_video = video_renderer_;
           metadata.timeline_offset = demuxer_->GetTimelineOffset();
           DemuxerStream* stream = demuxer_->GetStream(DemuxerStream::VIDEO);
           if (stream) {
             metadata.natural_size =
                 stream->video_decoder_config().natural_size();
             metadata.video_rotation = stream->video_rotation();
           }
           metadata_cb_.Run(metadata);
         }
       }
 
       base::ResetAndReturn(&seek_cb_).Run(PIPELINE_OK);
 
       {
         base::AutoLock auto_lock(lock_);
         interpolator_->SetBounds(start_timestamp_, start_timestamp_);
       }
 
-      if (audio_renderer_) {
-        audio_renderer_->SetMediaTime(start_timestamp_);
+      if (time_source_)

[xhwang, 2014/07/22 00:29:28]

Once we use WallClockTimeSource, we should be able to drop this condition check?

[scherkus (not reviewing), 2014/07/22 00:30:59]

correct! all condition checking for time_source_ will go away

+        time_source_->SetMediaTime(start_timestamp_);
+      if (audio_renderer_)
         audio_renderer_->StartPlaying();
-      }
       if (video_renderer_)
         video_renderer_->StartPlaying();
       if (text_renderer_)
         text_renderer_->StartPlaying();
 
       PlaybackRateChangedTask(GetPlaybackRate());
       VolumeChangedTask(GetVolume());
       return;
 
     case kStopping:
@@ skipping 21 matching lines @@
 #endif
 
 void Pipeline::DoSeek(
     base::TimeDelta seek_timestamp,
     const PipelineStatusCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!pending_callbacks_.get());
   SerialRunner::Queue bound_fns;
   {
     base::AutoLock auto_lock(lock_);
-    PauseClockAndStopRendering_Locked();
+    PauseClockAndStopTicking_Locked();
   }
 
   // Pause.
   if (text_renderer_) {
     bound_fns.Push(base::Bind(
         &TextRenderer::Pause, base::Unretained(text_renderer_.get())));
   }
 
   // Flush.
   if (audio_renderer_) {
@@ skipping 181 matching lines @@
 
   // Playback rate changes are only carried out while playing.
   if (state_ != kPlaying)
     return;
 
   {
     base::AutoLock auto_lock(lock_);
     interpolator_->SetPlaybackRate(playback_rate);
   }
 
-  if (audio_renderer_)
-    audio_renderer_->SetPlaybackRate(playback_rate_);
+  if (time_source_)
+    time_source_->SetPlaybackRate(playback_rate_);
 }
 
 void Pipeline::VolumeChangedTask(float volume) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   // Volume changes are only carried out while playing.
   if (state_ != kPlaying)
     return;
 
   if (audio_renderer_)
@@ skipping 79 matching lines @@
     return;
 
   if (video_renderer_ && !video_ended_)
     return;
 
   if (text_renderer_ && text_renderer_->HasTracks() && !text_ended_)
     return;
 
   {
     base::AutoLock auto_lock(lock_);
-    PauseClockAndStopRendering_Locked();
+    PauseClockAndStopTicking_Locked();
     interpolator_->SetBounds(duration_, duration_);
   }
 
   DCHECK_EQ(status_, PIPELINE_OK);
   ended_cb_.Run();
 }
 
 void Pipeline::AddTextStreamTask(DemuxerStream* text_stream,
                                  const TextTrackConfig& config) {
   DCHECK(task_runner_->BelongsToCurrentThread());
@@ skipping 92 matching lines @@
   return false;
 }
 
 void Pipeline::PausePlayback() {
   DVLOG(1) << __FUNCTION__;
   DCHECK_EQ(state_, kPlaying);
   DCHECK(WaitingForEnoughData());
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   base::AutoLock auto_lock(lock_);
-  PauseClockAndStopRendering_Locked();
+  PauseClockAndStopTicking_Locked();
 }
 
 void Pipeline::StartPlayback() {
   DVLOG(1) << __FUNCTION__;
   DCHECK_EQ(state_, kPlaying);
   DCHECK_EQ(interpolation_state_, INTERPOLATION_STOPPED);
   DCHECK(!WaitingForEnoughData());
   DCHECK(task_runner_->BelongsToCurrentThread());
 
-  if (audio_renderer_) {
+  if (time_source_) {
     // We use audio stream to update the clock. So if there is such a
     // stream, we pause the clock until we receive a valid timestamp.
     base::AutoLock auto_lock(lock_);
     interpolation_state_ = INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE;
-    audio_renderer_->StartRendering();
+    time_source_->StartTicking();
   } else {
     base::AutoLock auto_lock(lock_);
     interpolation_state_ = INTERPOLATION_STARTED;
     interpolator_->SetUpperBound(duration_);
     interpolator_->StartInterpolating();
   }
 }
 
-void Pipeline::PauseClockAndStopRendering_Locked() {
+void Pipeline::PauseClockAndStopTicking_Locked() {
   lock_.AssertAcquired();
   switch (interpolation_state_) {
     case INTERPOLATION_STOPPED:
       return;
 
     case INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE:
-      audio_renderer_->StopRendering();
+      time_source_->StopTicking();

[xhwang, 2014/07/22 00:29:28]

This is a bit odd here. Maybe time_source_ should be renamed to
audio_time_source_. But it's probably okay if you unify the
interpolator_/time_source_ code in the next CL.

[scherkus (not reviewing), 2014/07/22 00:30:59]

yeah it'll get cleaned up

       break;
 
     case INTERPOLATION_STARTED:
-      if (audio_renderer_)
-        audio_renderer_->StopRendering();
+      if (time_source_)
+        time_source_->StopTicking();
       interpolator_->StopInterpolating();
       break;
   }
 
   interpolation_state_ = INTERPOLATION_STOPPED;
 }
 
 void Pipeline::StartClockIfWaitingForTimeUpdate_Locked() {
   lock_.AssertAcquired();
   if (interpolation_state_ != INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE)
     return;
 
   interpolation_state_ = INTERPOLATION_STARTED;
   interpolator_->StartInterpolating();
 }
 
 }  // namespace media