Media Source dispatches inband text 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 <deque>
 #include <limits>
 
@@ skipping 388 matching lines @@
       *buffer = StreamParserBuffer::CreateEOSBuffer();
       return true;
   }
 
   NOTREACHED();
   return false;
 }
 
 ChunkDemuxer::ChunkDemuxer(const base::Closure& open_cb,
                            const NeedKeyCB& need_key_cb,
+                           const TextTrackCB& text_track_cb,
+                           const TextCB& text_cb,
                            const LogCB& log_cb)
     : state_(WAITING_FOR_INIT),
       host_(NULL),
       open_cb_(open_cb),
       need_key_cb_(need_key_cb),
+      text_track_cb_(text_track_cb),
+      text_cb_(text_cb),
       log_cb_(log_cb),
       duration_(kNoTimestamp()),
       user_specified_duration_(-1) {
   DCHECK(!open_cb_.is_null());
   DCHECK(!need_key_cb_.is_null());
 }
 
 void ChunkDemuxer::Initialize(DemuxerHost* host, const PipelineStatusCB& cb) {
   DVLOG(1) << "Init()";
 
@@ skipping 134 matching lines @@
     audio_cb = base::Bind(&ChunkDemuxer::OnAudioBuffers,
                           base::Unretained(this));
   }
 
   if (has_video) {
     source_id_video_ = id;
     video_cb = base::Bind(&ChunkDemuxer::OnVideoBuffers,
                           base::Unretained(this));
   }
 
+  // TODO(matthewjheaney): need a predicate here?
+  StreamParser::NewBuffersCB text_cb;
+  text_cb = base::Bind(&ChunkDemuxer::OnTextBuffers,

[acolwell GONE FROM CHROMIUM, 2013/04/05 16:29:23]

nit: Inline this in the Init() call like the other Binds.

[Matthew Heaney (Chromium), 2013/05/09 03:53:11]

I wasn't sure whether this is OBE or not.  Some of this moved into the
webm_stream_parser.  I had to interpret your outline a bit, so see if this
implementation is what you had in mind.

+                       base::Unretained(this));
+
   stream_parser->Init(
       base::Bind(&ChunkDemuxer::OnStreamParserInitDone, base::Unretained(this)),
       base::Bind(&ChunkDemuxer::OnNewConfigs, base::Unretained(this),
                  has_audio, has_video),
       audio_cb,
       video_cb,
       base::Bind(&ChunkDemuxer::OnNeedKey, base::Unretained(this)),
+      text_track_cb_,
+      text_cb,
       base::Bind(&ChunkDemuxer::OnNewMediaSegment, base::Unretained(this), id),
       base::Bind(&ChunkDemuxer::OnEndOfMediaSegment,
                  base::Unretained(this), id),
       log_cb_);
 
   stream_parser_map_[id] = stream_parser.release();
   SourceInfo info = { base::TimeDelta(), true };
   source_info_map_[id] = info;
 
   return kOk;
 }
 
 void ChunkDemuxer::RemoveId(const std::string& id) {

[acolwell GONE FROM CHROMIUM, 2013/04/05 16:29:23]

You'll need to add code in here to handle the case where the id that is
providing the text tracks gets removed. This should remove the tracks from the
presentation.

   base::AutoLock auto_lock(lock_);
   CHECK(IsValidId(id));
 
   delete stream_parser_map_[id];
   stream_parser_map_.erase(id);
   source_info_map_.erase(id);
 
   if (source_id_audio_ == id) {
     if (audio_)
       audio_->Shutdown();
@@ skipping 470 matching lines @@
 // this method can be removed and need_key_cb_ can be passed directly
 // to the parser.
 bool ChunkDemuxer::OnNeedKey(const std::string& type,
                              scoped_array<uint8> init_data,
                              int init_data_size) {
   lock_.AssertAcquired();
   need_key_cb_.Run(type, init_data.Pass(), init_data_size);
   return true;
 }
 
+bool ChunkDemuxer::OnTextBuffers(const StreamParser::BufferQueue& buffers) {
+  lock_.AssertAcquired();
+  DCHECK_NE(state_, SHUTDOWN);
+
+  StreamParser::BufferQueue::const_iterator it = buffers.begin();
+  const StreamParser::BufferQueue::const_iterator it_end = buffers.end();
+
+  while (it != it_end) {
+    const StreamParser::BufferQueue::value_type& buffer = *it++;

[acolwell GONE FROM CHROMIUM, 2013/04/05 16:29:23]

nit: Please don't use this construct. Use a normal for loop. Doing this makes
the code unnecessarily verbose makes it less clear what is going on here.

[Matthew Heaney (Chromium), 2013/05/09 03:53:11]

Done.

+    const base::TimeDelta time = buffer->GetDecodeTimestamp();

[acolwell GONE FROM CHROMIUM, 2013/04/05 16:29:23]

AdjustBufferTimestamp() needs to be called here like in the other OnXXXBuffers()
methods.

[Matthew Heaney (Chromium), 2013/05/09 03:53:11]

I did have a question about that, since some of this code moved into
webm_stream_parser.cc.  Did I push things too far down?

+    text_cb_.Run(time);
+  }
+
+  return true;
+}
+
 void ChunkDemuxer::OnNewMediaSegment(const std::string& source_id,
                                      TimeDelta timestamp) {
   DCHECK(timestamp != kNoTimestamp());
   DVLOG(2) << "OnNewMediaSegment(" << source_id << ", "
            << timestamp.InSecondsF() << ")";
   lock_.AssertAcquired();
 
   CHECK(IsValidId(source_id));
   source_info_map_[source_id].can_update_offset = false;
   base::TimeDelta start_timestamp =
@@ skipping 65 matching lines @@
 
 Ranges<TimeDelta> ChunkDemuxer::GetBufferedRanges() const {
   if (audio_ && !video_)
     return audio_->GetBufferedRanges(duration_);
   else if (!audio_ && video_)
     return video_->GetBufferedRanges(duration_);
   return ComputeIntersection();
 }
 
 }  // namespace media