Fix MSE GC, make it less aggressive, more spec-compliant

media/filters/chunk_demuxer.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/filters/chunk_demuxer.h"
 
 #include <algorithm>
 #include <limits>
 #include <list>
 
@@ skipping 113 matching lines @@
 
   // Aborts the current append sequence and resets the parser.
   void Abort(TimeDelta append_window_start,
              TimeDelta append_window_end,
              TimeDelta* timestamp_offset);
 
   // Calls Remove(|start|, |end|, |duration|) on all
   // ChunkDemuxerStreams managed by this object.
   void Remove(TimeDelta start, TimeDelta end, TimeDelta duration);
 
+  // Attempts to perform garbage collection in SourceBuffers associated with

[wolenetz, 2015/08/12 21:09:57]

This comment seems ChunkDemuxer-focused. Move it to
ChunkDemuxer::EvictCodedFrames in the .h?

[servolk, 2015/08/13 00:31:42]

Will do

[servolk, 2015/08/20 02:45:27]

Done.

+  // this ChunkDemuxer. Returns true if garbage collection was successful.
+  // |media_time| parameter should indicate the current playback position.
+  // If it's a valid time value, the garbage collection algorithm will make sure
+  // to preserve unconsumed data buffers in the range between last read position
+  // and the current playback position.
+  bool EvictCodedFrames(DecodeTimestamp media_time);
+
   // Returns true if currently parsing a media segment, or false otherwise.
   bool parsing_media_segment() const { return parsing_media_segment_; }
 
   // Sets |frame_processor_|'s sequence mode to |sequence_mode|.
   void SetSequenceMode(bool sequence_mode);
 
   // Signals the coded frame processor to update its group start timestamp to be
   // |timestamp_offset| if it is in sequence append mode.
   void SetGroupStartTimestampIfInSequenceMode(base::TimeDelta timestamp_offset);
 
@@ skipping 218 matching lines @@
 
   if (video_)
     video_->Remove(start, end, duration);
 
   for (TextStreamMap::iterator itr = text_stream_map_.begin();
        itr != text_stream_map_.end(); ++itr) {
     itr->second->Remove(start, end, duration);
   }
 }
 
+bool SourceState::EvictCodedFrames(DecodeTimestamp media_time) {
+  bool success = true;
+
+  if (audio_)
+    success = audio_->EvictCodedFrames(media_time) && success;
+
+  if (video_)
+    success = video_->EvictCodedFrames(media_time) && success;
+
+  for (TextStreamMap::iterator itr = text_stream_map_.begin();
+       itr != text_stream_map_.end(); ++itr) {
+    success = itr->second->EvictCodedFrames(media_time) && success;
+  }
+
+  return success;
+}
+
 Ranges<TimeDelta> SourceState::GetBufferedRanges(TimeDelta duration,
                                                  bool ended) const {
   // TODO(acolwell): When we start allowing disabled tracks we'll need to update
   // this code to only add ranges from active tracks.
   RangesList ranges_list;
   if (audio_)
     ranges_list.push_back(audio_->GetBufferedRanges(duration));
 
   if (video_)
     ranges_list.push_back(video_->GetBufferedRanges(duration));
@@ skipping 490 matching lines @@
 
   return true;
 }
 
 void ChunkDemuxerStream::Remove(TimeDelta start, TimeDelta end,
                                 TimeDelta duration) {
   base::AutoLock auto_lock(lock_);
   stream_->Remove(start, end, duration);
 }
 
+bool ChunkDemuxerStream::EvictCodedFrames(DecodeTimestamp media_time) {
+  base::AutoLock auto_lock(lock_);
+  return stream_->GarbageCollectIfNeeded(media_time);
+}
+
 void ChunkDemuxerStream::OnSetDuration(TimeDelta duration) {
   base::AutoLock auto_lock(lock_);
   stream_->OnSetDuration(duration);
 }
 
 Ranges<TimeDelta> ChunkDemuxerStream::GetBufferedRanges(
     TimeDelta duration) const {
   base::AutoLock auto_lock(lock_);
 
   if (type_ == TEXT) {
@@ skipping 422 matching lines @@
 Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges(const std::string& id) const {
   base::AutoLock auto_lock(lock_);
   DCHECK(!id.empty());
 
   SourceStateMap::const_iterator itr = source_state_map_.find(id);
 
   DCHECK(itr != source_state_map_.end());
   return itr->second->GetBufferedRanges(duration_, state_ == ENDED);
 }
 
+bool ChunkDemuxer::EvictCodedFrames(base::TimeDelta currentMediaTime) {
+  DVLOG(1) << __FUNCTION__ << " media_time=" << currentMediaTime.InSecondsF();
+  base::AutoLock auto_lock(lock_);
+
+  // Note: The direct conversion from PTS to DTS is safe here, since we don't
+  // need to know currentTime precisely for GC. GC only needs to know which GOP
+  // currentTime points to.
+  DecodeTimestamp media_time_dts =
+      DecodeTimestamp::FromPresentationTime(currentMediaTime);
+
+  bool success = true;
+  for (SourceStateMap::iterator itr = source_state_map_.begin();
+       itr != source_state_map_.end(); ++itr) {
+    success = itr->second->EvictCodedFrames(media_time_dts) && success;
+  }
+  return success;
+}
+
 void ChunkDemuxer::AppendData(
     const std::string& id,
     const uint8* data,
     size_t length,
     TimeDelta append_window_start,
     TimeDelta append_window_end,
     TimeDelta* timestamp_offset,
     const InitSegmentReceivedCB& init_segment_received_cb) {
   DVLOG(1) << "AppendData(" << id << ", " << length << ")";
 
@@ skipping 500 matching lines @@
 }
 
 void ChunkDemuxer::ShutdownAllStreams() {
   for (SourceStateMap::iterator itr = source_state_map_.begin();
        itr != source_state_map_.end(); ++itr) {
     itr->second->Shutdown();
   }
 }
 
 }  // namespace media