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

This fixes a host of seeking, synchronization and layout test issues but does incur a CPU performance hit while seeking.  In the worst case a seek could take quite some time if the content was high resolution H.264 and we attempted to seek to right before a keyframe.

We'll see how people like the new behaviour and back this change out if needed.

BUG=48984
TEST=layout tests, media_unittests

Review URL: http://codereview.chromium.org/3032030

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@53872 0039d316-1c4b-4281-b951-d872f2087c98

5 files changed, 33 insertions, 5 deletions

diff --git a/media/filters/audio_renderer_base.cc b/media/filters/audio_renderer_base.cc
index f3f9294..c0690e8 100644
--- a/media/filters/audio_renderer_base.cc
+++ b/media/filters/audio_renderer_base.cc
@@ -67,6 +67,7 @@ void AudioRendererBase::Seek(base::TimeDelta time, FilterCallback* callback) {
   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();
@@ -147,9 +148,14 @@ void AudioRendererBase::OnFillBufferDone(scoped_refptr<Buffer> buffer_in) {
     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);
diff --git a/media/filters/audio_renderer_base.h b/media/filters/audio_renderer_base.h
index 279d59f..fc9cac6 100644
--- a/media/filters/audio_renderer_base.h
+++ b/media/filters/audio_renderer_base.h
@@ -135,6 +135,8 @@ class AudioRendererBase : public AudioRenderer {
   scoped_ptr<FilterCallback> pause_callback_;
   scoped_ptr<FilterCallback> seek_callback_;
 
+  base::TimeDelta seek_timestamp_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioRendererBase);
 };
 
diff --git a/media/filters/ffmpeg_audio_decoder.cc b/media/filters/ffmpeg_audio_decoder.cc
index 09b0caf..133e7dc 100644
--- a/media/filters/ffmpeg_audio_decoder.cc
+++ b/media/filters/ffmpeg_audio_decoder.cc
@@ -155,6 +155,17 @@ static void ConvertAudioF32ToS32(void* buffer, int buffer_size) {
 }
 
 void FFmpegAudioDecoder::DoDecode(Buffer* input) {
+  // FFmpeg tends to seek Ogg audio streams in the middle of nowhere, giving us
+  // a whole bunch of AV_NOPTS_VALUE packets.  Discard them until we find
+  // something valid.
+  // TODO(hclam): remove this once fixing the issue in FFmpeg.
+  if (input->GetTimestamp() == StreamSample::kInvalidTimestamp &&
+      estimated_next_timestamp_ == StreamSample::kInvalidTimestamp &&
+      !input->IsEndOfStream()) {
+    DecoderBase<AudioDecoder, Buffer>::OnDecodeComplete();
+    return;
+  }
+
   // Due to FFmpeg API changes we no longer have const read-only pointers.
   AVPacket packet;
   av_init_packet(&packet);
diff --git a/media/filters/video_renderer_base.cc b/media/filters/video_renderer_base.cc
index c50dfd4..00cf9dc 100644
--- a/media/filters/video_renderer_base.cc
+++ b/media/filters/video_renderer_base.cc
@@ -151,6 +151,7 @@ void VideoRendererBase::Seek(base::TimeDelta time, FilterCallback* callback) {
   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.
   // TODO(jiesun): this should be guaranteed by pause/flush before seek happen.
@@ -390,10 +391,16 @@ void VideoRendererBase::OnFillBufferDone(scoped_refptr<VideoFrame> frame) {
   DCHECK_GT(pending_reads_, 0u);
   --pending_reads_;
 
-  // Enqueue the frame.
-  frames_queue_ready_.push_back(frame);
-  DCHECK_LE(frames_queue_ready_.size(), kMaxFrames);
-  frame_available_.Signal();
+  // Discard frames until we reach our desired seek timestamp.
+  if (state_ == kSeeking && !frame->IsEndOfStream() &&
+      (frame->GetTimestamp() + frame->GetDuration()) < seek_timestamp_) {
+    frames_queue_done_.push_back(frame);
+    ScheduleRead_Locked();
+  } else {
+    frames_queue_ready_.push_back(frame);
+    DCHECK_LE(frames_queue_ready_.size(), kMaxFrames);
+    frame_available_.Signal();
+  }
 
   // Check for our preroll complete condition.
   if (state_ == kSeeking) {
diff --git a/media/filters/video_renderer_base.h b/media/filters/video_renderer_base.h
index ff5c232..f8176f7 100644
--- a/media/filters/video_renderer_base.h
+++ b/media/filters/video_renderer_base.h
@@ -181,6 +181,8 @@ class VideoRendererBase : public VideoRenderer,
   scoped_ptr<FilterCallback> pause_callback_;
   scoped_ptr<FilterCallback> seek_callback_;
 
+  base::TimeDelta seek_timestamp_;
+
   DISALLOW_COPY_AND_ASSIGN(VideoRendererBase);
 };