Implement reading of media track info from WebM and MP4 containers

media/formats/webm/webm_tracks_parser.h

 // Copyright 2014 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.
 
 #ifndef MEDIA_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_
 #define MEDIA_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_
 
 #include <stdint.h>
 
 #include <map>
 #include <set>
 #include <string>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time/time.h"
 #include "media/base/audio_decoder_config.h"
 #include "media/base/media_log.h"
+#include "media/base/media_tracks.h"
 #include "media/base/text_track_config.h"
 #include "media/base/video_decoder_config.h"
 #include "media/formats/webm/webm_audio_client.h"
 #include "media/formats/webm/webm_content_encodings_client.h"
 #include "media/formats/webm/webm_parser.h"
 #include "media/formats/webm/webm_video_client.h"
 
 namespace media {
 
 // Parser for WebM Tracks element.
@@ skipping 39 matching lines @@
   const VideoDecoderConfig& video_decoder_config() {
     return video_decoder_config_;
   }
 
   typedef std::map<int, TextTrackConfig> TextTracks;
 
   const TextTracks& text_tracks() const {
     return text_tracks_;
   }
 
+  // Note: Calling media_tracks() method passes the ownership of the MediaTracks
+  // object from WebMTracksParser to the caller (which is typically
+  // WebMStreamParser object). So this method must be called only once, after
+  // track parsing has been completed.
+  scoped_ptr<MediaTracks> media_tracks() {
+    CHECK(media_tracks_.get());
+    return std::move(media_tracks_);
+  }
+
  private:
   // WebMParserClient implementation.
   WebMParserClient* OnListStart(int id) override;
   bool OnListEnd(int id) override;
   bool OnUInt(int id, int64_t val) override;
   bool OnFloat(int id, double val) override;
   bool OnBinary(int id, const uint8_t* data, int size) override;
   bool OnString(int id, const std::string& str) override;
 
   int64_t track_type_;
@@ skipping 17 matching lines @@
   std::string audio_encryption_key_id_;
   std::string video_encryption_key_id_;
   scoped_refptr<MediaLog> media_log_;
 
   WebMAudioClient audio_client_;
   AudioDecoderConfig audio_decoder_config_;
 
   WebMVideoClient video_client_;
   VideoDecoderConfig video_decoder_config_;
 
+  scoped_ptr<MediaTracks> media_tracks_;
+
   DISALLOW_COPY_AND_ASSIGN(WebMTracksParser);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_