Support for two audio codec lists down into WebRtcVoiceEngine.

webrtc/pc/mediasession.cc

Index: webrtc/pc/mediasession.cc
diff --git a/webrtc/pc/mediasession.cc b/webrtc/pc/mediasession.cc
index 328f67593bd434cb214abc74781b9994bbb942bc..39468d9316ba87ac5ed0f8d137c62d4ab1321859 100644
--- a/webrtc/pc/mediasession.cc
+++ b/webrtc/pc/mediasession.cc
@@ -50,6 +50,11 @@ void GetSupportedCryptoSuiteNames(void (*func)(std::vector<int>*),
 
 namespace cricket {
 
+namespace {
+std::vector<AudioCodec> MergeAudioCodecLists(
+    const std::vector<AudioCodec>& send_codecs,
+    const std::vector<AudioCodec>& recv_codecs);
+}
 
 // RTP Profile names
 // http://www.iana.org/assignments/rtp-parameters/rtp-parameters.xml
@@ -1252,13 +1257,15 @@ MediaSessionDescriptionFactory::MediaSessionDescriptionFactory(
     : secure_(SEC_DISABLED),
       add_legacy_(true),
       transport_desc_factory_(transport_desc_factory) {
-  channel_manager->GetSupportedAudioCodecs(&audio_sendrecv_codecs_);
+  channel_manager->GetSupportedAudioSendCodecs(&audio_send_codecs_);
+  channel_manager->GetSupportedAudioReceiveCodecs(&audio_recv_codecs_);
+  channel_manager->GetSupportedAudioSendCodecs(&audio_send_codecs_);
   channel_manager->GetSupportedAudioRtpHeaderExtensions(&audio_rtp_extensions_);
   channel_manager->GetSupportedVideoCodecs(&video_codecs_);
   channel_manager->GetSupportedVideoRtpHeaderExtensions(&video_rtp_extensions_);
   channel_manager->GetSupportedDataCodecs(&data_codecs_);
-  audio_send_codecs_ = audio_sendrecv_codecs_;
-  audio_recv_codecs_ = audio_sendrecv_codecs_;
+  audio_sendrecv_codecs_ =
+      MergeAudioCodecLists(audio_send_codecs_, audio_recv_codecs_);
 }
 
 const AudioCodecs& MediaSessionDescriptionFactory::audio_codecs() const {

[pthatcher1, 2016/05/31 18:26:48]

I don't think this is called by anything except one test in
mediasession_unittest.cc.  A better name for it would be audio_sendrev_codecs().
 Can you rename it that?

[ossu, 2016/06/01 08:34:12]

Good call! Will do that.

@@ -1284,32 +1291,8 @@ void MediaSessionDescriptionFactory::set_audio_codecs(
     const AudioCodecs& send_codecs, const AudioCodecs& recv_codecs) {
   audio_send_codecs_ = send_codecs;
   audio_recv_codecs_ = recv_codecs;
-  audio_sendrecv_codecs_.clear();
-
-  // Intersect the two lists of codecs, preserving the order of the send codecs.
-  // If there's any difference in priorities, chances are encoding is more
-  // expensive than decoding, and high-priority send codecs are likely handled
-  // better (e.g. through hardware encoder support) than low-priority ones.
-  // TODO(ossu): This is O(n^2). However, each list should generally be small
-  // enough for this to not be a problem. They are also nicely local in memory
-  // like this.
-  for (const auto& sc : audio_send_codecs_) {
-    for (const auto& rc : audio_recv_codecs_) {
-      const size_t send_channels = (sc.channels == 0) ? 1 : sc.channels;
-      const size_t recv_channels = (rc.channels == 0) ? 1 : rc.channels;
-      if (sc.clockrate == rc.clockrate &&
-          sc.bitrate == rc.bitrate &&
-          send_channels == recv_channels &&
-          (_stricmp(sc.name.c_str(), rc.name.c_str()) == 0) &&
-          sc.params == rc.params &&
-          sc.feedback_params == rc.feedback_params) {
-        AudioCodec out_codec = sc;
-        out_codec.channels = send_channels;
-        audio_sendrecv_codecs_.push_back(out_codec);
-        break;
-      }
-    }
-  }
+  audio_sendrecv_codecs_ =
+      MergeAudioCodecLists(audio_send_codecs_, audio_recv_codecs_);
 }
 
 SessionDescription* MediaSessionDescriptionFactory::CreateOffer(
@@ -2115,4 +2098,36 @@ const DataContentDescription* GetFirstDataContentDescription(
       GetFirstMediaContentDescription(sdesc, MEDIA_TYPE_DATA));
 }
 
+namespace {
+std::vector<AudioCodec> MergeAudioCodecLists(

[pthatcher1, 2016/05/31 18:26:48]

Can you call this MergeSendRecvCodecs?

[ossu, 2016/06/01 08:34:12]

Sure thing!

+    const std::vector<AudioCodec>& send_codecs,
+    const std::vector<AudioCodec>& recv_codecs) {
+  std::vector<AudioCodec> merged;
+  // Intersect the two lists of codecs, preserving the order of the send codecs.
+  // If there's any difference in priorities, chances are encoding is more
+  // expensive than decoding, and high-priority send codecs are likely handled
+  // better (e.g. through hardware encoder support) than low-priority ones.
+  // TODO(ossu): This is O(n^2). However, each list should generally be small
+  // enough for this to not be a problem. They are also nicely local in memory
+  // like this.
+  for (const auto& sc : send_codecs) {
+    for (const auto& rc : recv_codecs) {
+      const size_t send_channels = (sc.channels == 0) ? 1 : sc.channels;
+      const size_t recv_channels = (rc.channels == 0) ? 1 : rc.channels;
+      if (sc.clockrate == rc.clockrate && sc.bitrate == rc.bitrate &&

[ossu, 2016/05/26 14:18:50]

This got clang-formatted. I'll put it back to one comparison per line, to make
it easier to read.

+          send_channels == recv_channels &&
+          (_stricmp(sc.name.c_str(), rc.name.c_str()) == 0) &&
+          sc.params == rc.params && sc.feedback_params == rc.feedback_params) {
+        AudioCodec out_codec = sc;
+        out_codec.channels = send_channels;
+        merged.push_back(out_codec);
+        break;
+      }
+    }
+  }
+
+  return merged;
+}
+}
+
 }  // namespace cricket