Not for submission. fastSeek prototype.

media/renderers/audio_renderer_impl.cc

Index: media/renderers/audio_renderer_impl.cc
diff --git a/media/renderers/audio_renderer_impl.cc b/media/renderers/audio_renderer_impl.cc
index 3d24cf6508bc8a10518b0d60f94b4658755d7579..4bb660440d54bad4b530ee900a9ad458d2737d34 100644
--- a/media/renderers/audio_renderer_impl.cc
+++ b/media/renderers/audio_renderer_impl.cc
@@ -164,7 +164,21 @@ void AudioRendererImpl::SetMediaTime(base::TimeDelta time) {
 
   base::AutoLock auto_lock(lock_);
   DCHECK(!rendering_);
-  DCHECK_EQ(state_, kFlushed);
+  DCHECK(state_ == kFlushed || state_ == kPlaying);
+
+  start_timestamp_ = time;
+  ended_timestamp_ = kInfiniteDuration;
+  last_render_time_ = stop_rendering_time_ = base::TimeTicks();
+  first_packet_timestamp_ = kNoTimestamp;
+  audio_clock_.reset(new AudioClock(time, audio_parameters_.sample_rate()));
+}
+
+void AudioRendererImpl::SetMediaTime_Locked(base::TimeDelta time) {
+  DVLOG(1) << __func__ << "(" << time << ")";
+  DCHECK(task_runner_->BelongsToCurrentThread());
+
+  DCHECK(!rendering_);
+  DCHECK(state_ == kFlushed || state_ == kPlaying);
 
   start_timestamp_ = time;
   ended_timestamp_ = kInfiniteDuration;
@@ -308,7 +322,7 @@ void AudioRendererImpl::ResetDecoderDone() {
   task_runner_->PostTask(FROM_HERE, base::ResetAndReturn(&flush_cb_));
 }
 
-void AudioRendererImpl::StartPlaying() {
+void AudioRendererImpl::StartPlayingFrom(StreamPosition position) {
   DVLOG(1) << __func__;
   DCHECK(task_runner_->BelongsToCurrentThread());
 
@@ -318,6 +332,8 @@ void AudioRendererImpl::StartPlaying() {
   DCHECK_EQ(buffering_state_, BUFFERING_HAVE_NOTHING);
   DCHECK(!pending_read_) << "Pending read must complete before seeking";
 
+  start_rendering_from_first_frame_ =
+      position.kind == StreamPosition::Kind::KEY_FRAME_PRECEDING_TIME;
   ChangeState_Locked(kPlaying);
   AttemptRead_Locked();
 }
@@ -594,6 +610,12 @@ void AudioRendererImpl::DecodedAudioReady(
       return;
     }
 
+    if (start_rendering_from_first_frame_) {
+      LOG(ERROR) << "First audio timestamp: " << buffer->timestamp();
+      SetMediaTime_Locked(buffer->timestamp());
+      start_rendering_from_first_frame_ = false;
+    }
+
     if (!splicer_->AddInput(buffer)) {
       HandleAbortedReadOrDecodeError(AUDIO_RENDERER_ERROR_SPLICE_FAILED);
       return;