Refactor MSE implementation on Android to simplify the logic and improve the performance

content/renderer/media/android/media_source_delegate.cc

Index: content/renderer/media/android/media_source_delegate.cc
diff --git a/content/renderer/media/android/media_source_delegate.cc b/content/renderer/media/android/media_source_delegate.cc
index 324ee80b47a1b2f74b8072c73b02e4833d602846..4ea5c365b5eb156952b4d38959e79fbd1ae3e02d 100644
--- a/content/renderer/media/android/media_source_delegate.cc
+++ b/content/renderer/media/android/media_source_delegate.cc
@@ -390,17 +390,13 @@ void MediaSourceDelegate::OnBufferReady(
       break;
 
     case DemuxerStream::kConfigChanged:
-      // In case of kConfigChanged, need to read decoder_config once
-      // for the next reads.
-      // TODO(kjyoun): Investigate if we need to use this new config. See
-      // http://crbug.com/255783
-      if (is_audio) {
-        audio_stream_->audio_decoder_config();
-      } else {
+      if (!is_audio) {
         gfx::Size size = video_stream_->video_decoder_config().coded_size();

[wolenetz, 2014/04/25 23:13:13]

nit: Do we need to report coded_size() here? Or is natural_size() (from
demuxer_configs[0].video_size) sufficient, allowing us to just query the video
config at most once here (by moving the two new lines below to before this
clause, and using the retrieved DemuxerConfigs' video_size here)?

[qinmin, 2014/04/26 01:30:11]

Done. we should simply using natural_size.
On 2014/04/25 23:13:13, wolenetz wrote:

         DVLOG(1) << "Video config is changed: " << size.width() << "x"
                  << size.height();
       }
+      data->demuxer_configs.resize(1);
+      GetDeumuxerConfigFromStream(&data->demuxer_configs[0], is_audio);

[wolenetz, 2014/04/25 23:13:13]

nit: ditto (spelling), here and below.

[qinmin, 2014/04/26 01:30:11]

Done.

       data->access_units[index].status = status;
       data->access_units.resize(index + 1);
       break;
@@ -641,13 +637,6 @@ void MediaSourceDelegate::DeleteSelf() {
   delete this;
 }
 
-void MediaSourceDelegate::OnMediaConfigRequest() {
-  DCHECK(media_loop_->BelongsToCurrentThread());
-  DVLOG(1) << __FUNCTION__ << " : " << demuxer_client_id_;
-  if (CanNotifyDemuxerReady())
-    NotifyDemuxerReady();
-}
-
 bool MediaSourceDelegate::CanNotifyDemuxerReady() {
   DCHECK(media_loop_->BelongsToCurrentThread());
   return is_demuxer_ready_;
@@ -659,24 +648,8 @@ void MediaSourceDelegate::NotifyDemuxerReady() {
   DCHECK(CanNotifyDemuxerReady());
 
   scoped_ptr<DemuxerConfigs> configs(new DemuxerConfigs());
-  if (audio_stream_) {
-    media::AudioDecoderConfig config = audio_stream_->audio_decoder_config();
-    configs->audio_codec = config.codec();
-    configs->audio_channels =
-        media::ChannelLayoutToChannelCount(config.channel_layout());
-    configs->audio_sampling_rate = config.samples_per_second();
-    configs->is_audio_encrypted = config.is_encrypted();
-    configs->audio_extra_data = std::vector<uint8>(
-        config.extra_data(), config.extra_data() + config.extra_data_size());
-  }
-  if (video_stream_) {
-    media::VideoDecoderConfig config = video_stream_->video_decoder_config();
-    configs->video_codec = config.codec();
-    configs->video_size = config.natural_size();
-    configs->is_video_encrypted = config.is_encrypted();
-    configs->video_extra_data = std::vector<uint8>(
-        config.extra_data(), config.extra_data() + config.extra_data_size());
-  }
+  GetDeumuxerConfigFromStream(configs.get(), true);
+  GetDeumuxerConfigFromStream(configs.get(), false);
   configs->duration = GetDuration();
 
   if (demuxer_client_)
@@ -762,4 +735,28 @@ base::TimeDelta MediaSourceDelegate::FindBufferedBrowserSeekTime_Locked(
   return seek_time;
 }
 
+void MediaSourceDelegate::GetDeumuxerConfigFromStream(
+    media::DemuxerConfigs* configs, bool is_audio) {
+  DCHECK(media_loop_->BelongsToCurrentThread());
+  if (is_audio && audio_stream_) {
+    media::AudioDecoderConfig config = audio_stream_->audio_decoder_config();
+    configs->audio_codec = config.codec();
+    configs->audio_channels =
+        media::ChannelLayoutToChannelCount(config.channel_layout());
+    configs->audio_sampling_rate = config.samples_per_second();
+    configs->is_audio_encrypted = config.is_encrypted();
+    configs->audio_extra_data = std::vector<uint8>(
+        config.extra_data(), config.extra_data() + config.extra_data_size());
+    return;
+  }
+  if (!is_audio && video_stream_) {
+    media::VideoDecoderConfig config = video_stream_->video_decoder_config();
+    configs->video_codec = config.codec();
+    configs->video_size = config.natural_size();
+    configs->is_video_encrypted = config.is_encrypted();
+    configs->video_extra_data = std::vector<uint8>(
+        config.extra_data(), config.extra_data() + config.extra_data_size());
+  }
+}
+
 }  // namespace content