Media Source dispatches inband text tracks

media/webm/webm_stream_parser.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/webm/webm_stream_parser.h"
 
 #include <string>
 
 #include "base/callback.h"
 #include "base/logging.h"
+#include "base/stl_util.h"
 #include "media/webm/webm_cluster_parser.h"
 #include "media/webm/webm_constants.h"
 #include "media/webm/webm_content_encodings.h"
 #include "media/webm/webm_crypto_helpers.h"
 #include "media/webm/webm_info_parser.h"
 #include "media/webm/webm_tracks_parser.h"
+#include "media/webm/webm_webvtt_parser.h"
 
 namespace media {
 
 WebMStreamParser::WebMStreamParser()
     : state_(kWaitingForInit),
       waiting_for_buffers_(false) {
 }
 
-WebMStreamParser::~WebMStreamParser() {}
+WebMStreamParser::~WebMStreamParser() {
+  STLDeleteValues(&text_track_map_);
+}
 
 void WebMStreamParser::Init(const InitCB& init_cb,
                             const NewConfigCB& config_cb,
                             const NewBuffersCB& audio_cb,
                             const NewBuffersCB& video_cb,
+                            const NewBuffersCB& text_cb,
                             const NeedKeyCB& need_key_cb,
+                            const AddTextTrackCB& add_text_track_cb,
                             const NewMediaSegmentCB& new_segment_cb,
                             const base::Closure& end_of_segment_cb,
                             const LogCB& log_cb) {
   DCHECK_EQ(state_, kWaitingForInit);
   DCHECK(init_cb_.is_null());
   DCHECK(!init_cb.is_null());
   DCHECK(!config_cb.is_null());
   DCHECK(!audio_cb.is_null() || !video_cb.is_null());
+  DCHECK(!text_cb.is_null());
   DCHECK(!need_key_cb.is_null());
   DCHECK(!new_segment_cb.is_null());
   DCHECK(!end_of_segment_cb.is_null());
 
   ChangeState(kParsingHeaders);
   init_cb_ = init_cb;
   config_cb_ = config_cb;
   audio_cb_ = audio_cb;
   video_cb_ = video_cb;
+  text_cb_ = text_cb;
   need_key_cb_ = need_key_cb;
+  add_text_track_cb_ = add_text_track_cb;
   new_segment_cb_ = new_segment_cb;
   end_of_segment_cb_ = end_of_segment_cb;
   log_cb_ = log_cb;
 }
 
 void WebMStreamParser::Flush() {
   DCHECK_NE(state_, kWaitingForInit);
 
   byte_queue_.Reset();
 
@@ skipping 131 matching lines @@
 
   const VideoDecoderConfig& video_config = tracks_parser.video_decoder_config();
   if (video_config.is_encrypted())
     FireNeedKey(tracks_parser.video_encryption_key_id());
 
   if (!config_cb_.Run(audio_config, video_config)) {
     DVLOG(1) << "New config data isn't allowed.";
     return -1;
   }
 
+  typedef std::set<int> TextTracksSet;

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: This typedef should probably be in WebMTracksParser and referenced here.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+  const TextTracksSet& text_tracks = tracks_parser.text_tracks();
+
+  for (TextTracksSet::const_iterator itr = text_tracks.begin();
+       itr != text_tracks.end(); ++itr) {
+    // TODO(matthewjheaney): parse track kind, name, lang from track header

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

I'd like to see a separate CL with the necessary changes for this to land before
this patch. It looks like we already have most of the parsing in place for kind
at least. I just don't want to enable inline text tracks and assume that they
are all subtitles.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+    scoped_ptr<TextTrack> text_cb =

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: s/text_cb/text_track/

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+        add_text_track_cb_.Run(kTextSubtitles, "", "");
+
+    // Assume ownership of pointer
+    TextTrack* const text_cb_ptr = text_cb.release();

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: Just inline please.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+
+    // Cache text track object, for use later when we have text track buffers.
+    // (The text track objects are deallocated in the dtor for this class.)
+    text_track_map_.insert(std::make_pair(*itr, text_cb_ptr));
+  }
+
   cluster_parser_.reset(new WebMClusterParser(
       info_parser.timecode_scale(),
       tracks_parser.audio_track_num(),
       tracks_parser.video_track_num(),
       tracks_parser.text_tracks(),
       tracks_parser.ignored_tracks(),
       tracks_parser.audio_encryption_key_id(),
       tracks_parser.video_encryption_key_id(),
       log_cb_));
 
@@ skipping 50 matching lines @@
     new_segment_cb_.Run(cluster_start_time);
     waiting_for_buffers_ = false;
   }
 
   if (!audio_buffers.empty() && !audio_cb_.Run(audio_buffers))
     return -1;
 
   if (!video_buffers.empty() && !video_cb_.Run(video_buffers))
     return -1;
 
+  WebMClusterParser::TextTrackIterator tt_iter =
+    cluster_parser_->CreateTextTrackIterator();
+
+  int tt_num;

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: s/tt_num/track_id/ or s/tt_num/track_number/

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+  const BufferQueue* tt_buffers;

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: s/tt_buffers/buffers since the tt doesn't really distinguish or clarify
anything.

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+
+  while (tt_iter(&tt_num, &tt_buffers)) {
+    TextTrackMap::iterator cb_iter = text_track_map_.find(tt_num);
+
+    if (cb_iter == text_track_map_.end())
+      continue;
+
+    if (!tt_buffers->empty() && !text_cb_.Run(*tt_buffers))
+      return -1;
+
+    OnTextBuffers(*tt_buffers, cb_iter->second);
+  }
+
   if (cluster_ended)
     end_of_segment_cb_.Run();
 
   return bytes_parsed;
 }
 
 void WebMStreamParser::FireNeedKey(const std::string& key_id) {
   int key_id_size = key_id.size();
   DCHECK_GT(key_id_size, 0);
   scoped_ptr<uint8[]> key_id_array(new uint8[key_id_size]);
   memcpy(key_id_array.get(), key_id.data(), key_id_size);
   need_key_cb_.Run(kWebMEncryptInitDataType, key_id_array.Pass(), key_id_size);
 }
 
+void WebMStreamParser::OnTextBuffers(const StreamParser::BufferQueue& buffers,
+                                     TextTrack* text_cb) {

[acolwell GONE FROM CHROMIUM, 2013/05/10 18:41:39]

nit: when this is moved to ChunkDemuxer s/text_cb/text_track/

[Matthew Heaney (Chromium), 2013/05/11 07:29:13]

Done.

+  for (StreamParser::BufferQueue::const_iterator itr = buffers.begin();
+       itr != buffers.end(); ++itr) {
+    OnTextBuffer(*itr, text_cb);
+  }
+}
+
+void WebMStreamParser::OnTextBuffer(const StreamParserBuffer* buffer,
+                                    TextTrack* text_cb) {
+  const base::TimeDelta start = buffer->GetTimestamp();
+  const base::TimeDelta end = start + buffer->GetDuration();
+
+  std::string id, settings, content;
+
+  WebMWebVTTParser::Parse(buffer->GetData(),
+                          buffer->GetDataSize(),
+                          &id, &settings, &content);
+
+  text_cb->addWebVTTCue(start, end, id, content, settings);
+}
+
 }  // namespace media