Implement accurate seeking by decoding audio/video until we reach our desired timestamp.

media/filters/audio_renderer_base.cc

 // Copyright (c) 2010 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/filters/audio_renderer_base.h"
 
 #include <algorithm>
 
 #include "base/callback.h"
 #include "media/base/filter_host.h"
@@ skipping 49 matching lines @@
     delete callback;
   }
 }
 
 void AudioRendererBase::Seek(base::TimeDelta time, FilterCallback* callback) {
   AutoLock auto_lock(lock_);
   DCHECK_EQ(kPaused, state_);
   DCHECK_EQ(0u, pending_reads_) << "Pending reads should have completed";
   state_ = kSeeking;
   seek_callback_.reset(callback);
+  seek_timestamp_ = time;
 
   // Throw away everything and schedule our reads.
   last_fill_buffer_time_ = base::TimeDelta();
   recieved_end_of_stream_ = false;
   rendered_end_of_stream_ = false;
 
   // |algorithm_| will request more reads.
   algorithm_->FlushBuffers();
 }
 
@@ skipping 60 matching lines @@
   DCHECK_GT(pending_reads_, 0u);
   --pending_reads_;
 
   // TODO(scherkus): this happens due to a race, primarily because Stop() is a
   // synchronous call when it should be asynchronous and accept a callback.
   // Refer to http://crbug.com/16059
   if (state_ == kStopped) {
     return;
   }
 
-  // Don't enqueue an end-of-stream buffer because it has no data.
+  // Don't enqueue an end-of-stream buffer because it has no data, otherwise
+  // discard decoded audio data until we reach our desired seek timestamp.
   if (buffer_in->IsEndOfStream()) {
     recieved_end_of_stream_ = true;
+  } else if (state_ == kSeeking && !buffer_in->IsEndOfStream() &&
+             (buffer_in->GetTimestamp() + buffer_in->GetDuration()) <
+                 seek_timestamp_) {
+    ScheduleRead_Locked();
   } else {
     // Note: Calling this may schedule more reads.
     algorithm_->EnqueueBuffer(buffer_in);
   }
 
   // Check for our preroll complete condition.
   if (state_ == kSeeking) {
     DCHECK(seek_callback_.get());
     if (algorithm_->IsQueueFull() || recieved_end_of_stream_) {
       // Transition into paused whether we have data in |algorithm_| or not.
@@ skipping 97 matching lines @@
 
 void AudioRendererBase::SetPlaybackRate(float playback_rate) {
   algorithm_->set_playback_rate(playback_rate);
 }
 
 float AudioRendererBase::GetPlaybackRate() {
   return algorithm_->playback_rate();
 }
 
 }  // namespace media