Implement disabling and enabling media tracks

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>
 #include <utility>
@@ skipping 20 matching lines @@
 namespace media {
 
 ChunkDemuxerStream::ChunkDemuxerStream(Type type,
                                        bool splice_frames_enabled,
                                        MediaTrack::Id media_track_id)
     : type_(type),
       liveness_(DemuxerStream::LIVENESS_UNKNOWN),
       media_track_id_(media_track_id),
       state_(UNINITIALIZED),
       splice_frames_enabled_(splice_frames_enabled),
-      partial_append_window_trimming_enabled_(false) {}
+      partial_append_window_trimming_enabled_(false),
+      is_enabled_(true) {}
 
 void ChunkDemuxerStream::StartReturningData() {
   DVLOG(1) << "ChunkDemuxerStream::StartReturningData()";
   base::AutoLock auto_lock(lock_);
   DCHECK(read_cb_.is_null());
   ChangeState_Locked(RETURNING_DATA_FOR_READS);
 }
 
 void ChunkDemuxerStream::AbortReads() {
   DVLOG(1) << "ChunkDemuxerStream::AbortReads()";
@@ skipping 185 matching lines @@
   stream_->UnmarkEndOfStream();
 }
 
 // DemuxerStream methods.
 void ChunkDemuxerStream::Read(const ReadCB& read_cb) {
   base::AutoLock auto_lock(lock_);
   DCHECK_NE(state_, UNINITIALIZED);
   DCHECK(read_cb_.is_null());
 
   read_cb_ = BindToCurrentLoop(read_cb);
+
+  if (!is_enabled_) {
+    DVLOG(1) << "Read from disabled stream, returning EOS";
+    base::ResetAndReturn(&read_cb_).Run(kOk,
+                                        StreamParserBuffer::CreateEOSBuffer());
+    return;
+  }
+
   CompletePendingReadIfPossible_Locked();
 }
 
 DemuxerStream::Type ChunkDemuxerStream::type() const { return type_; }
 
 DemuxerStream::Liveness ChunkDemuxerStream::liveness() const {
   base::AutoLock auto_lock(lock_);
   return liveness_;
 }
 
 AudioDecoderConfig ChunkDemuxerStream::audio_decoder_config() {
   CHECK_EQ(type_, AUDIO);
   base::AutoLock auto_lock(lock_);
   return stream_->GetCurrentAudioDecoderConfig();
 }
 
 VideoDecoderConfig ChunkDemuxerStream::video_decoder_config() {
   CHECK_EQ(type_, VIDEO);
   base::AutoLock auto_lock(lock_);
   return stream_->GetCurrentVideoDecoderConfig();
 }
 
 bool ChunkDemuxerStream::SupportsConfigChanges() { return true; }
 
 VideoRotation ChunkDemuxerStream::video_rotation() {
   return VIDEO_ROTATION_0;
 }
 
+bool ChunkDemuxerStream::enabled() const {
+  base::AutoLock auto_lock(lock_);
+  return is_enabled_;
+}
+
+void ChunkDemuxerStream::set_enabled(bool enabled, base::TimeDelta timestamp) {
+  base::AutoLock auto_lock(lock_);
+
+  if (enabled == is_enabled_)
+    return;
+
+  is_enabled_ = enabled;
+  if (enabled) {
+    DCHECK(stream_);
+    stream_->Seek(timestamp);
+    if (!stream_restarted_cb_.is_null())
+      stream_restarted_cb_.Run(this, timestamp);
+  } else if (!read_cb_.is_null()) {
+    DVLOG(1) << "Read from disabled stream, returning EOS";
+    base::ResetAndReturn(&read_cb_).Run(kOk,
+                                        StreamParserBuffer::CreateEOSBuffer());
+  }
+}
+
+void ChunkDemuxerStream::SetStreamRestartedCB(const StreamRestartedCB& cb) {
+  DCHECK(!cb.is_null());
+  stream_restarted_cb_ = cb;
+}
+
 TextTrackConfig ChunkDemuxerStream::text_track_config() {
   CHECK_EQ(type_, TEXT);
   base::AutoLock auto_lock(lock_);
   return stream_->GetCurrentTextTrackConfig();
 }
 
 void ChunkDemuxerStream::SetStreamMemoryLimit(size_t memory_limit) {
   stream_->set_memory_limit(memory_limit);
 }
 
@@ skipping 301 matching lines @@
 Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges(const std::string& id) const {
   base::AutoLock auto_lock(lock_);
   DCHECK(!id.empty());
 
   MediaSourceStateMap::const_iterator itr = source_state_map_.find(id);
 
   DCHECK(itr != source_state_map_.end());
   return itr->second->GetBufferedRanges(duration_, state_ == ENDED);
 }
 
+void ChunkDemuxer::OnEnabledAudioTracksChanged(
+    const std::vector<MediaTrack::Id>& track_ids,
+    base::TimeDelta currTime) {
+  // Note: We intentionally don't lock here, since we are not accessing any

[chcunningham, 2016/06/24 23:32:55]

You are locking though ;)

[servolk, 2016/06/25 00:36:33]

But only while accessing |track_id_to_demux_stream_map_|. I agree we can do that
only when DCHECK_IS_ON.

+  // members directly.
+  DemuxerStream* audio_stream = GetStream(DemuxerStream::AUDIO);
+  bool enabled = false;
+  CHECK(audio_stream);
+  if (track_ids.size() > 0) {

[chcunningham, 2016/06/24 23:32:55]

IIUC size should never exceed 1 as currently implemented. DCHECK?

[servolk, 2016/06/25 00:36:33]

Done.

+    base::AutoLock auto_lock(lock_);

[chcunningham, 2016/06/24 23:32:55]

Seems you're not settled on this part. I wonder if you could put the lock and
the dcheck inside an ifdef for when DCHECKING is enabled. I forget the specific
define... something like DCHECK_ON 

[servolk, 2016/06/25 00:36:33]

Done.

+    // DCHECK(track_id_to_demux_stream_map_[track_ids[0]] == audio_stream);
+    enabled = true;
+  }
+  audio_stream->set_enabled(enabled, currTime);
+}
+
+void ChunkDemuxer::OnSelectedVideoTrackChanged(
+    const std::vector<MediaTrack::Id>& track_ids,
+    base::TimeDelta currTime) {
+  // Note: We intentionally don't lock here, since we are not accessing any

[chcunningham, 2016/06/24 23:32:55]

This method has the same unsettled state around the locking. Maybe take the same
approach here as I suggest above?

[servolk, 2016/06/25 00:36:33]

Done.

+  // members directly.
+  DemuxerStream* video_stream = GetStream(DemuxerStream::VIDEO);
+  bool enabled = false;
+  CHECK(video_stream);
+  if (track_ids.size() > 0) {
+    base::AutoLock auto_lock(lock_);
+    // DCHECK(track_id_to_demux_stream_map_[track_ids[0]] == video_stream);
+    enabled = true;
+  }
+  video_stream->set_enabled(enabled, currTime);
+}
+
 bool ChunkDemuxer::EvictCodedFrames(const std::string& id,
                                     base::TimeDelta currentMediaTime,
                                     size_t newDataSize) {
   DVLOG(1) << __FUNCTION__ << "(" << id << ")"
            << " media_time=" << currentMediaTime.InSecondsF()
            << " newDataSize=" << newDataSize;
   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
@@ skipping 555 matching lines @@
 }
 
 void ChunkDemuxer::ShutdownAllStreams() {
   for (MediaSourceStateMap::iterator itr = source_state_map_.begin();
        itr != source_state_map_.end(); ++itr) {
     itr->second->Shutdown();
   }
 }
 
 }  // namespace media