Initial asymmetric codec support in MediaSessionDescription

webrtc/pc/mediasession.h

Index: webrtc/pc/mediasession.h
diff --git a/webrtc/pc/mediasession.h b/webrtc/pc/mediasession.h
index 39ac26bd8dad104c5b10b0d450caf7cf67e85233..37cb438b4eb00e4332ba72f36c2f55b0fc31cc72 100644
--- a/webrtc/pc/mediasession.h
+++ b/webrtc/pc/mediasession.h
@@ -52,6 +52,8 @@ enum MediaContentDirection {
   MD_SENDRECV
 };
 
+std::string MediaContentDirectionToString(MediaContentDirection direction);
+
 enum CryptoType {
   CT_NONE,
   CT_SDES,
@@ -79,6 +81,30 @@ const int kBufferedModeDisabled = 0;
 // Default RTCP CNAME for unit tests.
 const char kDefaultRtcpCname[] = "DefaultRtcpCname";
 
+struct RtpTransceiverDirection {
+  bool send;
+  bool recv;
+
+  RtpTransceiverDirection(bool send, bool recv) : send(send), recv(recv) {}
+
+  bool operator==(const RtpTransceiverDirection& o) const {
+    return send == o.send && recv == o.recv;
+  }
+
+  bool operator!=(const RtpTransceiverDirection& o) const {
+    return !(*this == o);
+  }
+
+  static RtpTransceiverDirection FromMediaContentDirection(
+      MediaContentDirection md);
+
+  MediaContentDirection ToMediaContentDirection() const;
+};
+
+RtpTransceiverDirection
+NegotiateRtpTransceiverDirection(RtpTransceiverDirection offer,
+                                 RtpTransceiverDirection wants);
+
 struct MediaSessionOptions {
   MediaSessionOptions()
       : recv_audio(true),
@@ -395,8 +421,11 @@ class MediaSessionDescriptionFactory {
   MediaSessionDescriptionFactory(ChannelManager* cmanager,
                                  const TransportDescriptionFactory* factory);
 
-  const AudioCodecs& audio_codecs() const { return audio_codecs_; }
-  void set_audio_codecs(const AudioCodecs& codecs) { audio_codecs_ = codecs; }
+  const AudioCodecs& audio_codecs() const;
+  const AudioCodecs& audio_send_codecs() const;
+  const AudioCodecs& audio_recv_codecs() const;
+  void set_audio_codecs(const AudioCodecs& send_codecs,
+                        const AudioCodecs& recv_codecs);
   void set_audio_rtp_header_extensions(const RtpHeaderExtensions& extensions) {
     audio_rtp_extensions_ = extensions;
   }
@@ -430,7 +459,15 @@ class MediaSessionDescriptionFactory {
         const SessionDescription* current_description) const;
 
  private:
+  const AudioCodecs& GetAudioCodecsForOffer(
+      const RtpTransceiverDirection& direction) const;
+  const AudioCodecs& GetAudioCodecsForAnswer(
+      const RtpTransceiverDirection& offer,
+      const RtpTransceiverDirection& answer) const;
   void GetCodecsToOffer(const SessionDescription* current_description,
+                        const AudioCodecs& supported_audio_codecs,
+                        const VideoCodecs& supported_video_codecs,
+                        const DataCodecs& supported_data_codecs,
                         AudioCodecs* audio_codecs,
                         VideoCodecs* video_codecs,
                         DataCodecs* data_codecs) const;
@@ -502,7 +539,9 @@ class MediaSessionDescriptionFactory {
       StreamParamsVec* current_streams,
       SessionDescription* answer) const;
 
-  AudioCodecs audio_codecs_;
+  AudioCodecs audio_send_codecs_;
+  AudioCodecs audio_recv_codecs_;
+  AudioCodecs audio_sendrecv_codecs_;
   RtpHeaderExtensions audio_rtp_extensions_;
   VideoCodecs video_codecs_;
   RtpHeaderExtensions video_rtp_extensions_;