Implemented passing media track info from ffmpeg into blink

media/filters/ffmpeg_demuxer.cc

Index: media/filters/ffmpeg_demuxer.cc
diff --git a/media/filters/ffmpeg_demuxer.cc b/media/filters/ffmpeg_demuxer.cc
index 18863e657b80f29ffe75fad5673d3c9474a93b52..81ce1abb12ab9ae258a8ce1720f3fdc2c26fbbc1 100644
--- a/media/filters/ffmpeg_demuxer.cc
+++ b/media/filters/ffmpeg_demuxer.cc
@@ -27,6 +27,7 @@
 #include "media/base/decrypt_config.h"
 #include "media/base/limits.h"
 #include "media/base/media_log.h"
+#include "media/base/media_tracks.h"
 #include "media/base/timestamp_constants.h"
 #include "media/ffmpeg/ffmpeg_common.h"
 #include "media/filters/ffmpeg_aac_bitstream_converter.h"
@@ -741,6 +742,7 @@ FFmpegDemuxer::FFmpegDemuxer(
     const scoped_refptr<base::SingleThreadTaskRunner>& task_runner,
     DataSource* data_source,
     const EncryptedMediaInitDataCB& encrypted_media_init_data_cb,
+    const MediaTracksUpdatedCB& media_tracks_updated_cb,
     const scoped_refptr<MediaLog>& media_log)
     : host_(NULL),
       task_runner_(task_runner),
@@ -756,9 +758,11 @@ FFmpegDemuxer::FFmpegDemuxer(
       text_enabled_(false),
       duration_known_(false),
       encrypted_media_init_data_cb_(encrypted_media_init_data_cb),
+      media_tracks_updated_cb_(media_tracks_updated_cb),
       weak_factory_(this) {
   DCHECK(task_runner_.get());
   DCHECK(data_source_);
+  DCHECK(!media_tracks_updated_cb_.is_null());
 }
 
 FFmpegDemuxer::~FFmpegDemuxer() {}
@@ -1320,6 +1324,32 @@ void FFmpegDemuxer::OnFindStreamInfoDone(const PipelineStatusCB& status_cb,
   media_log_->SetTimeProperty("start_time", start_time_);
   media_log_->SetIntegerProperty("bitrate", bitrate_);
 
+  {
+    scoped_ptr<MediaTracks> media_tracks(new MediaTracks());
+
+    if (audio_stream) {
+      AVDictionaryEntry* lang_tag =
+          av_dict_get(audio_stream->metadata, "language", NULL, 0);
+      std::string track_language = "und";
+      if (lang_tag && lang_tag->value)
+        track_language = lang_tag->value;
+
+      media_tracks->AddAudioTrack(audio_config, "audio", "main", "",
+                                  track_language);
+    }
+    if (video_stream) {
+      AVDictionaryEntry* lang_tag =
+          av_dict_get(video_stream->metadata, "language", NULL, 0);
+      std::string track_language = "und";
+      if (lang_tag && lang_tag->value)
+        track_language = lang_tag->value;
+
+      media_tracks->AddVideoTrack(video_config, "video", "main", "",
+                                  track_language);
+    }
+    media_tracks_updated_cb_.Run(std::move(media_tracks));
+  }
+
   status_cb.Run(PIPELINE_OK);
 }