media: Introduce Renderer interface and RendererImpl.

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"
+#include "media/filters/renderer_impl.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),
+      is_initialized_(false),
       state_(kCreated),
-      audio_ended_(false),
-      video_ended_(false),
+      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) {
+      underflow_disabled_for_testing_(false),
+      test_interpolator_(NULL) {
   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";
   DCHECK(!running_) << "Stop() must complete before destroying object";
   DCHECK(stop_cb_.is_null());
   DCHECK(seek_cb_.is_null());
 
   media_log_->AddEvent(
@@ skipping 81 matching lines @@
   base::AutoLock auto_lock(lock_);
   volume_ = volume;
   if (running_) {
     task_runner_->PostTask(FROM_HERE, base::Bind(
         &Pipeline::VolumeChangedTask, base::Unretained(this), volume));
   }
 }
 
 TimeDelta Pipeline::GetMediaTime() const {
   base::AutoLock auto_lock(lock_);
-  return std::min(interpolator_->GetInterpolatedTime(), duration_);
+  return renderer_ ? std::min(renderer_->GetMediaTime(), duration_)
+                   : TimeDelta();
 }
 
 Ranges<TimeDelta> Pipeline::GetBufferedTimeRanges() const {
   base::AutoLock auto_lock(lock_);
   return buffered_time_ranges_;
 }
 
 TimeDelta Pipeline::GetMediaDuration() const {
   base::AutoLock auto_lock(lock_);
   return duration_;
 }
 
 bool Pipeline::DidLoadingProgress() {
   base::AutoLock auto_lock(lock_);
   bool ret = did_loading_progress_;
   did_loading_progress_ = false;
   return ret;
 }
 
 PipelineStatistics Pipeline::GetStatistics() const {
   base::AutoLock auto_lock(lock_);
   return statistics_;
 }
 
+void Pipeline::DisableUnderflowForTesting() {
+  DCHECK(!renderer_);
+  underflow_disabled_for_testing_ = true;
+}
+
 void Pipeline::SetTimeDeltaInterpolatorForTesting(
     TimeDeltaInterpolator* interpolator) {
-  interpolator_.reset(interpolator);
+  DCHECK(!renderer_);
+  DCHECK(interpolator);
+  test_interpolator_ = interpolator;
 }
 
 void Pipeline::SetErrorForTesting(PipelineStatus status) {
   SetError(status);
 }
 
 void Pipeline::SetState(State next_state) {
   DVLOG(1) << GetStateString(state_) << " -> " << GetStateString(next_state);
 
   state_ = next_state;
   media_log_->AddEvent(media_log_->CreatePipelineStateChangedEvent(next_state));
 }
 
 #define RETURN_STRING(state) case state: return #state;
 
 const char* Pipeline::GetStateString(State state) {
   switch (state) {
     RETURN_STRING(kCreated);
     RETURN_STRING(kInitDemuxer);
-    RETURN_STRING(kInitAudioRenderer);
-    RETURN_STRING(kInitVideoRenderer);
+    RETURN_STRING(kInitRenderer);
     RETURN_STRING(kSeeking);
     RETURN_STRING(kPlaying);
     RETURN_STRING(kStopping);
     RETURN_STRING(kStopped);
   }
   NOTREACHED();
   return "INVALID";
 }
 
 #undef RETURN_STRING
 
 Pipeline::State Pipeline::GetNextState() const {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(stop_cb_.is_null())
       << "State transitions don't happen when stopping";
   DCHECK_EQ(status_, PIPELINE_OK)
       << "State transitions don't happen when there's an error: " << status_;
 
   switch (state_) {
     case kCreated:
       return kInitDemuxer;
 
     case kInitDemuxer:
-      if (demuxer_->GetStream(DemuxerStream::AUDIO))
-        return kInitAudioRenderer;
-      if (demuxer_->GetStream(DemuxerStream::VIDEO))
-        return kInitVideoRenderer;
+      if (demuxer_->GetStream(DemuxerStream::AUDIO) ||
+          demuxer_->GetStream(DemuxerStream::VIDEO)) {
+        return kInitRenderer;
+      }
       return kPlaying;
 
-    case kInitAudioRenderer:
-      if (demuxer_->GetStream(DemuxerStream::VIDEO))
-        return kInitVideoRenderer;
-      return kPlaying;
-
-    case kInitVideoRenderer:
-      return kPlaying;
-
+    case kInitRenderer:
     case kSeeking:
       return kPlaying;
 
     case kPlaying:
     case kStopping:
     case kStopped:
       break;
   }
   NOTREACHED() << "State has no transition: " << state_;
   return state_;
@@ skipping 20 matching lines @@
   DCHECK(IsRunning());
   DCHECK_NE(PIPELINE_OK, error);
   VLOG(1) << "Media pipeline error: " << error;
 
   task_runner_->PostTask(FROM_HERE, base::Bind(
       &Pipeline::ErrorChangedTask, base::Unretained(this), error));
 
   media_log_->AddEvent(media_log_->CreatePipelineErrorEvent(error));
 }
 
-void Pipeline::OnAudioTimeUpdate(TimeDelta time, TimeDelta max_time) {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  DCHECK_LE(time.InMicroseconds(), max_time.InMicroseconds());
-  base::AutoLock auto_lock(lock_);
-
-  if (interpolation_state_ == INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE &&
-      time < interpolator_->GetInterpolatedTime()) {
-    return;
-  }
-
-  if (state_ == kSeeking)
-    return;
-
-  interpolator_->SetBounds(time, max_time);
-  StartClockIfWaitingForTimeUpdate_Locked();
-}
-
-void Pipeline::OnVideoTimeUpdate(TimeDelta max_time) {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  if (audio_renderer_)
-    return;
-
-  if (state_ == kSeeking)
-    return;
-
-  base::AutoLock auto_lock(lock_);
-  DCHECK_NE(interpolation_state_, INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE);
-  interpolator_->SetUpperBound(max_time);
-}
-
 void Pipeline::SetDuration(TimeDelta duration) {
   DCHECK(IsRunning());
   media_log_->AddEvent(
       media_log_->CreateTimeEvent(
           MediaLogEvent::DURATION_SET, "duration", duration));
   UMA_HISTOGRAM_LONG_TIMES("Media.Duration", duration);
 
   base::AutoLock auto_lock(lock_);
   duration_ = duration;
   if (!duration_change_cb_.is_null())
@@ skipping 30 matching lines @@
 
   PipelineStatusCB done_cb = base::Bind(
       &Pipeline::OnStateTransition, base::Unretained(this));
 
   // Switch states, performing any entrance actions for the new state as well.
   SetState(GetNextState());
   switch (state_) {
     case kInitDemuxer:
       return InitializeDemuxer(done_cb);
 
-    case kInitAudioRenderer:
-      return InitializeAudioRenderer(done_cb);
-
-    case kInitVideoRenderer:
-      return InitializeVideoRenderer(done_cb);
+    case kInitRenderer:
+      return InitializeRenderer(done_cb);
 
     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_) {
+      if (!is_initialized_) {
+        if (!renderer_) {
           ErrorChangedTask(PIPELINE_ERROR_COULD_NOT_RENDER);
           return;
         }
 
-        if (audio_renderer_)
-          time_source_ = audio_renderer_->GetTimeSource();
+        is_initialized_ = true;
 
         {
           PipelineMetadata metadata;
-          metadata.has_audio = audio_renderer_;
-          metadata.has_video = video_renderer_;
+          metadata.has_audio = renderer_->HasAudio();
+          metadata.has_video = renderer_->HasVideo();
           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 (time_source_)
-        time_source_->SetMediaTime(start_timestamp_);
-      if (audio_renderer_)
-        audio_renderer_->StartPlaying();
-      if (video_renderer_)
-        video_renderer_->StartPlaying();
+      if (renderer_)
+        renderer_->StartPlayingFrom(start_timestamp_);
       if (text_renderer_)
         text_renderer_->StartPlaying();
 
       PlaybackRateChangedTask(GetPlaybackRate());
       VolumeChangedTask(GetVolume());
       return;
 
     case kStopping:
     case kStopped:
     case kCreated:
     case kSeeking:
       NOTREACHED() << "State has no transition: " << state_;
       return;
   }
 }
 
-// Note that the usage of base::Unretained() with the audio/video renderers
-// in the following DoXXX() functions is considered safe as they are owned by
+// Note that the usage of base::Unretained() with the renderers in the following
+// DoXXX() functions is considered safe as they are owned by
 // |pending_callbacks_| and share the same lifetime.
 //
 // That being said, deleting the renderers while keeping |pending_callbacks_|
 // running on the media thread would result in crashes.
 
-#if DCHECK_IS_ON
-static void VerifyBufferingStates(BufferingState* audio_buffering_state,
-                                  BufferingState* video_buffering_state) {
-  DCHECK_EQ(*audio_buffering_state, BUFFERING_HAVE_NOTHING);
-  DCHECK_EQ(*video_buffering_state, BUFFERING_HAVE_NOTHING);
-}
-#endif
-
-void Pipeline::DoSeek(
-    base::TimeDelta seek_timestamp,
-    const PipelineStatusCB& done_cb) {
+void Pipeline::DoSeek(TimeDelta seek_timestamp,
+                      const PipelineStatusCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!pending_callbacks_.get());
   SerialRunner::Queue bound_fns;
-  {
-    base::AutoLock auto_lock(lock_);
-    PauseClockAndStopTicking_Locked();
-  }
 
   // Pause.
   if (text_renderer_) {
     bound_fns.Push(base::Bind(
         &TextRenderer::Pause, base::Unretained(text_renderer_.get())));
   }
 
   // Flush.
-  if (audio_renderer_) {
+  if (renderer_) {
     bound_fns.Push(base::Bind(
-        &AudioRenderer::Flush, base::Unretained(audio_renderer_.get())));
+        &Renderer::Flush, base::Unretained(renderer_.get())));
   }
 
-  if (video_renderer_) {
-    bound_fns.Push(base::Bind(
-        &VideoRenderer::Flush, base::Unretained(video_renderer_.get())));
-  }
-
-#if DCHECK_IS_ON
-  // Verify renderers reset their buffering states.
-  bound_fns.Push(base::Bind(&VerifyBufferingStates,
-                            &audio_buffering_state_,
-                            &video_buffering_state_));
-#endif
-
   if (text_renderer_) {
     bound_fns.Push(base::Bind(
         &TextRenderer::Flush, base::Unretained(text_renderer_.get())));
   }
 
   // Seek demuxer.
   bound_fns.Push(base::Bind(
       &Demuxer::Seek, base::Unretained(demuxer_), seek_timestamp));
 
   pending_callbacks_ = SerialRunner::Run(bound_fns, done_cb);
 }
 
 void Pipeline::DoStop(const PipelineStatusCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(!pending_callbacks_.get());
 
-  audio_renderer_.reset();
-  video_renderer_.reset();
+  renderer_.reset();
   text_renderer_.reset();
 
   if (demuxer_) {
     demuxer_->Stop(base::Bind(done_cb, PIPELINE_OK));
     return;
   }
 
   task_runner_->PostTask(FROM_HERE, base::Bind(done_cb, PIPELINE_OK));
 }
 
 void Pipeline::OnStopCompleted(PipelineStatus status) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK_EQ(state_, kStopping);
-  DCHECK(!audio_renderer_);
-  DCHECK(!video_renderer_);
+  DCHECK(!renderer_);
   DCHECK(!text_renderer_);
+
   {
     base::AutoLock l(lock_);
     running_ = false;
   }
 
   SetState(kStopped);
   pending_callbacks_.reset();
   filter_collection_.reset();
   demuxer_ = NULL;
 
@@ skipping 10 matching lines @@
     // NOTE: pipeline may be deleted at this point in time as a result of
     // executing |stop_cb_|.
     return;
   }
   if (!error_cb_.is_null()) {
     DCHECK_NE(status_, PIPELINE_OK);
     base::ResetAndReturn(&error_cb_).Run(status_);
   }
 }
 
-void Pipeline::AddBufferedTimeRange(base::TimeDelta start,
-                                    base::TimeDelta end) {
+void Pipeline::AddBufferedTimeRange(TimeDelta start,
+                                    TimeDelta end) {
   DCHECK(IsRunning());
   base::AutoLock auto_lock(lock_);
   buffered_time_ranges_.Add(start, end);
   did_loading_progress_ = true;
 }
 
-void Pipeline::OnAudioRendererEnded() {
-  // Force post to process ended tasks after current execution frame.
-  task_runner_->PostTask(FROM_HERE, base::Bind(
-      &Pipeline::DoAudioRendererEnded, base::Unretained(this)));
-  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::AUDIO_ENDED));
-}
-
-void Pipeline::OnVideoRendererEnded() {
-  // Force post to process ended tasks after current execution frame.
-  task_runner_->PostTask(FROM_HERE, base::Bind(
-      &Pipeline::DoVideoRendererEnded, base::Unretained(this)));
-  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::VIDEO_ENDED));
-}
-
-void Pipeline::OnTextRendererEnded() {
-  // Force post to process ended messages after current execution frame.
-  task_runner_->PostTask(FROM_HERE, base::Bind(
-      &Pipeline::DoTextRendererEnded, base::Unretained(this)));
-  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::TEXT_ENDED));
-}
-
 // Called from any thread.
 void Pipeline::OnUpdateStatistics(const PipelineStatistics& stats) {
   base::AutoLock auto_lock(lock_);
   statistics_.audio_bytes_decoded += stats.audio_bytes_decoded;
   statistics_.video_bytes_decoded += stats.video_bytes_decoded;
   statistics_.video_frames_decoded += stats.video_frames_decoded;
   statistics_.video_frames_dropped += stats.video_frames_dropped;
 }
 
 void Pipeline::StartTask() {
@@ skipping 45 matching lines @@
   DoStop(base::Bind(&Pipeline::OnStopCompleted, base::Unretained(this)));
 }
 
 void Pipeline::PlaybackRateChangedTask(float playback_rate) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   // Playback rate changes are only carried out while playing.
   if (state_ != kPlaying)
     return;
 
-  {
-    base::AutoLock auto_lock(lock_);
-    interpolator_->SetPlaybackRate(playback_rate);
-  }
-
-  if (time_source_)
-    time_source_->SetPlaybackRate(playback_rate_);
+  if (renderer_)
+    renderer_->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_)
-    audio_renderer_->SetVolume(volume);
+  if (renderer_)
+    renderer_->SetVolume(volume);
 }
 
 void Pipeline::SeekTask(TimeDelta time, const PipelineStatusCB& seek_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   DCHECK(stop_cb_.is_null());
 
   // Suppress seeking if we're not fully started.
   if (state_ != kPlaying) {
     DCHECK(state_ == kStopping || state_ == kStopped)
         << "Receive extra seek in unexpected state: " << state_;
 
     // TODO(scherkus): should we run the callback?  I'm tempted to say the API
     // will only execute the first Seek() request.
     DVLOG(1) << "Media pipeline has not started, ignoring seek to "
              << time.InMicroseconds() << " (current state: " << state_ << ")";
     return;
   }
 
   DCHECK(seek_cb_.is_null());
 
   SetState(kSeeking);
   seek_cb_ = seek_cb;
-  audio_ended_ = false;
-  video_ended_ = false;
+  ended_ = false;
   text_ended_ = false;
   start_timestamp_ = time;
 
   DoSeek(time, base::Bind(
       &Pipeline::OnStateTransition, base::Unretained(this)));
 }
 
-void Pipeline::DoAudioRendererEnded() {
+void Pipeline::OnRendererEnded() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::ENDED));
 
   if (state_ != kPlaying)
     return;
 
-  DCHECK(!audio_ended_);
-  audio_ended_ = true;
-
-  // Start clock since there is no more audio to trigger clock updates.
-  {
-    base::AutoLock auto_lock(lock_);
-    interpolator_->SetUpperBound(duration_);
-    StartClockIfWaitingForTimeUpdate_Locked();
-  }
+  DCHECK(!ended_);
+  ended_ = true;
 
   RunEndedCallbackIfNeeded();
 }
 
-void Pipeline::DoVideoRendererEnded() {
+void Pipeline::OnTextRendererEnded() {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  media_log_->AddEvent(media_log_->CreateEvent(MediaLogEvent::TEXT_ENDED));
 
   if (state_ != kPlaying)
     return;
-
-  DCHECK(!video_ended_);
-  video_ended_ = true;
-
-  RunEndedCallbackIfNeeded();
-}
-
-void Pipeline::DoTextRendererEnded() {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  if (state_ != kPlaying)
-    return;
 
   DCHECK(!text_ended_);
   text_ended_ = true;
 
   RunEndedCallbackIfNeeded();
 }
 
 void Pipeline::RunEndedCallbackIfNeeded() {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
-  if (audio_renderer_ && !audio_ended_)
-    return;
-
-  if (video_renderer_ && !video_ended_)
+  if (renderer_ && !ended_)
     return;
 
   if (text_renderer_ && text_renderer_->HasTracks() && !text_ended_)
     return;
 
-  {
-    base::AutoLock auto_lock(lock_);
-    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());
   // TODO(matthewjheaney): fix up text_ended_ when text stream
   // is added (http://crbug.com/321446).
   text_renderer_->AddTextStream(text_stream, config);
 }
 
 void Pipeline::RemoveTextStreamTask(DemuxerStream* text_stream) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   text_renderer_->RemoveTextStream(text_stream);
 }
 
 void Pipeline::InitializeDemuxer(const PipelineStatusCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
 
   demuxer_ = filter_collection_->GetDemuxer();
   demuxer_->Initialize(this, done_cb, text_renderer_);
 }
 
-void Pipeline::InitializeAudioRenderer(const PipelineStatusCB& done_cb) {
+void Pipeline::InitializeRenderer(const PipelineStatusCB& done_cb) {
   DCHECK(task_runner_->BelongsToCurrentThread());
+  DCHECK(demuxer_);
 
-  audio_renderer_ = filter_collection_->GetAudioRenderer();
-  audio_renderer_->Initialize(
-      demuxer_->GetStream(DemuxerStream::AUDIO),
+  renderer_.reset(new RendererImpl(

[scherkus (not reviewing), 2014/07/31 20:22:09]

it looks like we should inject a Renderer into Pipeline and make
FilterCollection a detail of RendererImpl

that'll help make testing easier

do you think it'd be easier to do that in this CL, or in a future CL?

[xhwang, 2014/08/01 00:10:14]

Do you mean to pass the Demuxer and Renderer to Pipeline, and make
FilterCollection an impl detail of RendererImpl? That makes sense. I'll finish
updating the tests first, then see how bit that change will be. If it's too big
I'll probably do it in a separate CL.

But how about the demuxer_? The Pipeline owns the Demuxer and the Renderer now. 

+      demuxer_,
+      filter_collection_.Pass(),
+      task_runner_,
+      base::Bind(&Pipeline::GetMediaDuration, base::Unretained(this))));
+
+  if (test_interpolator_)
+    renderer_->SetTimeDeltaInterpolatorForTesting(test_interpolator_);
+  if (underflow_disabled_for_testing_)
+    renderer_->DisableUnderflowForTesting();
+
+  renderer_->Initialize(
       done_cb,
       base::Bind(&Pipeline::OnUpdateStatistics, base::Unretained(this)),
-      base::Bind(&Pipeline::OnAudioTimeUpdate, base::Unretained(this)),
-      base::Bind(&Pipeline::BufferingStateChanged, base::Unretained(this),
-                 &audio_buffering_state_),
-      base::Bind(&Pipeline::OnAudioRendererEnded, base::Unretained(this)),
-      base::Bind(&Pipeline::SetError, base::Unretained(this)));
+      base::Bind(&Pipeline::OnRendererEnded, base::Unretained(this)),
+      base::Bind(&Pipeline::SetError, base::Unretained(this)),
+      base::Bind(&Pipeline::BufferingStateChanged, base::Unretained(this)));
 }
 
-void Pipeline::InitializeVideoRenderer(const PipelineStatusCB& done_cb) {
+void Pipeline::BufferingStateChanged(BufferingState new_buffering_state) {
+  DVLOG(1) << __FUNCTION__ << "(" << new_buffering_state << ") ";
   DCHECK(task_runner_->BelongsToCurrentThread());
-
-  video_renderer_ = filter_collection_->GetVideoRenderer();
-  video_renderer_->Initialize(
-      demuxer_->GetStream(DemuxerStream::VIDEO),
-      demuxer_->GetLiveness() == Demuxer::LIVENESS_LIVE,
-      done_cb,
-      base::Bind(&Pipeline::OnUpdateStatistics, base::Unretained(this)),
-      base::Bind(&Pipeline::OnVideoTimeUpdate, base::Unretained(this)),
-      base::Bind(&Pipeline::BufferingStateChanged, base::Unretained(this),
-                 &video_buffering_state_),
-      base::Bind(&Pipeline::OnVideoRendererEnded, base::Unretained(this)),
-      base::Bind(&Pipeline::SetError, base::Unretained(this)),
-      base::Bind(&Pipeline::GetMediaTime, base::Unretained(this)),
-      base::Bind(&Pipeline::GetMediaDuration, base::Unretained(this)));
-}
-
-void Pipeline::BufferingStateChanged(BufferingState* buffering_state,
-                                     BufferingState new_buffering_state) {
-  DVLOG(1) << __FUNCTION__ << "(" << *buffering_state << ", "
-           << " " << new_buffering_state << ") "
-           << (buffering_state == &audio_buffering_state_ ? "audio" : "video");
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  bool was_waiting_for_enough_data = WaitingForEnoughData();
-
-  *buffering_state = new_buffering_state;
-
-  // Disable underflow by ignoring updates that renderers have ran out of data
-  // after we have started the clock.
-  if (state_ == kPlaying && underflow_disabled_for_testing_ &&
-      interpolation_state_ != INTERPOLATION_STOPPED) {
-    return;
-  }
-
-  // Renderer underflowed.
-  if (!was_waiting_for_enough_data && WaitingForEnoughData()) {
-    PausePlayback();
-
-    // TODO(scherkus): Fire BUFFERING_HAVE_NOTHING callback to alert clients of
-    // underflow state http://crbug.com/144683
-    return;
-  }
-
-  // Renderer prerolled.
-  if (was_waiting_for_enough_data && !WaitingForEnoughData()) {
-    StartPlayback();
-    buffering_state_cb_.Run(BUFFERING_HAVE_ENOUGH);
-    return;
-  }
-}
-
-bool Pipeline::WaitingForEnoughData() const {
-  DCHECK(task_runner_->BelongsToCurrentThread());
-  if (state_ != kPlaying)
-    return false;
-  if (audio_renderer_ && audio_buffering_state_ != BUFFERING_HAVE_ENOUGH)
-    return true;
-  if (video_renderer_ && video_buffering_state_ != BUFFERING_HAVE_ENOUGH)
-    return true;
-  return false;
-}
-
-void Pipeline::PausePlayback() {
-  DVLOG(1) << __FUNCTION__;
-  DCHECK_EQ(state_, kPlaying);
-  DCHECK(WaitingForEnoughData());
-  DCHECK(task_runner_->BelongsToCurrentThread());
-
-  base::AutoLock auto_lock(lock_);
-  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 (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;
-    time_source_->StartTicking();
-  } else {
-    base::AutoLock auto_lock(lock_);
-    interpolation_state_ = INTERPOLATION_STARTED;
-    interpolator_->SetUpperBound(duration_);
-    interpolator_->StartInterpolating();
-  }
-}
-
-void Pipeline::PauseClockAndStopTicking_Locked() {
-  lock_.AssertAcquired();
-  switch (interpolation_state_) {
-    case INTERPOLATION_STOPPED:
-      return;
-
-    case INTERPOLATION_WAITING_FOR_AUDIO_TIME_UPDATE:
-      time_source_->StopTicking();
-      break;
-
-    case INTERPOLATION_STARTED:
-      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();
+  buffering_state_cb_.Run(new_buffering_state);
 }
 
 }  // namespace media