Support encrypted audio stream in demuxer.

media/webm/webm_tracks_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_tracks_parser.h"
 
 #include "base/logging.h"
 #include "base/string_util.h"
 #include "media/base/buffers.h"
 #include "media/webm/webm_constants.h"
 #include "media/webm/webm_content_encodings.h"
 
 namespace media {
 
 // Values for TrackType element.
 static const int kWebMTrackTypeVideo = 1;
 static const int kWebMTrackTypeAudio = 2;
 
 WebMTracksParser::WebMTracksParser()
     : track_type_(-1),
       track_num_(-1),
       audio_track_num_(-1),
       video_track_num_(-1) {
 }
 
 WebMTracksParser::~WebMTracksParser() {}
 
+const std::string& WebMTracksParser::audio_encryption_key_id() const {
+  if (!audio_content_encodings_client_.get())
+    return EmptyString();
+
+  DCHECK(!audio_content_encodings_client_->content_encodings().empty());
+  return audio_content_encodings_client_->content_encodings()[0]->

[acolwell GONE FROM CHROMIUM, 2012/10/10 16:00:06]

If you only ever use the first encoding, why don't you just store the key_id
string instead of keeping the whole client around? Doing that would greatly
simplify this method since it would become a simple member accessor.

[xhwang, 2012/10/11 00:49:41]

Done.

+      encryption_key_id();
+}
+
 const std::string& WebMTracksParser::video_encryption_key_id() const {
   if (!video_content_encodings_client_.get())
     return EmptyString();
 
   DCHECK(!video_content_encodings_client_->content_encodings().empty());
   return video_content_encodings_client_->content_encodings()[0]->

[acolwell GONE FROM CHROMIUM, 2012/10/10 16:00:06]

ditto

[xhwang, 2012/10/11 00:49:41]

Done.

       encryption_key_id();
 }
 
 int WebMTracksParser::Parse(const uint8* buf, int size) {
   track_type_ =-1;
   track_num_ = -1;
   audio_track_num_ = -1;
   video_track_num_ = -1;
 
   WebMListParser parser(kWebMIdTracks, this);
@@ skipping 97 matching lines @@
 bool WebMTracksParser::OnString(int id, const std::string& str) {
   if (id == kWebMIdCodecID && str != "A_VORBIS" && str != "V_VP8") {
     DVLOG(1) << "Unexpected CodecID " << str;
     return false;
   }
 
   return true;
 }
 
 }  // namespace media