Add Opus decode wrapper to media.

webkit/media/filter_helpers.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 "webkit/media/filter_helpers.h"
 
 #include "base/bind.h"
+#include "base/command_line.h"
 #include "media/base/filter_collection.h"
+#include "media/base/media_switches.h"
 #include "media/filters/chunk_demuxer.h"
 #include "media/filters/dummy_demuxer.h"
 #include "media/filters/ffmpeg_audio_decoder.h"
 #include "media/filters/ffmpeg_demuxer.h"
 #include "media/filters/ffmpeg_video_decoder.h"
+#include "media/filters/opus_audio_decoder.h"
 #include "third_party/WebKit/Source/WebKit/chromium/public/platform/WebURL.h"
 #include "webkit/media/crypto/proxy_decryptor.h"
 #include "webkit/media/media_stream_client.h"
 
 namespace webkit_media {
 
 // Constructs and adds the default audio/video decoders to |filter_collection|.
 // Note that decoders in the |filter_collection| are ordered. The first
 // audio/video decoder in the |filter_collection| that supports the input
 // audio/video stream will be selected as the audio/video decoder in the media
 // pipeline. This is done by trying to initialize the decoder with the input
 // stream. Some decoder may only accept certain types of streams.
 static void AddDefaultDecodersToCollection(
     const scoped_refptr<base::MessageLoopProxy>& message_loop,
     media::FilterCollection* filter_collection,
     ProxyDecryptor* proxy_decryptor) {
+
   scoped_refptr<media::FFmpegAudioDecoder> ffmpeg_audio_decoder =
       new media::FFmpegAudioDecoder(message_loop);
   filter_collection->GetAudioDecoders()->push_back(ffmpeg_audio_decoder);
 
+  const CommandLine* cmd_line = CommandLine::ForCurrentProcess();
+  if (cmd_line->HasSwitch(switches::kEnableOpusPlayback)) {
+    scoped_refptr<media::OpusAudioDecoder> opus_audio_decoder =
+        new media::OpusAudioDecoder(message_loop);
+    filter_collection->GetAudioDecoders()->push_back(opus_audio_decoder);
+  }
+
   scoped_refptr<media::FFmpegVideoDecoder> ffmpeg_video_decoder =
       new media::FFmpegVideoDecoder(message_loop, proxy_decryptor);
   filter_collection->GetVideoDecoders()->push_back(ffmpeg_video_decoder);
 }
 
 bool BuildMediaStreamCollection(
     const WebKit::WebURL& url,
     MediaStreamClient* client,
     const scoped_refptr<base::MessageLoopProxy>& message_loop,
     media::FilterCollection* filter_collection) {
@@ skipping 39 matching lines @@
     media::FilterCollection* filter_collection,
     ProxyDecryptor* proxy_decryptor) {
   filter_collection->SetDemuxer(new media::FFmpegDemuxer(
       message_loop, data_source));
 
   AddDefaultDecodersToCollection(message_loop, filter_collection,
                                  proxy_decryptor);
 }
 
 }  // webkit_media