Add SDP semantics option to RTCConfiguration
This setting allows the user of PeerConnection to choose whether
to use Plan B (current) or Unified Plan (future) semantics.
Unified Plan semantics are not yet supported.
Bug: chromium:465349
Change-Id: I77a5c376c83f335f734488e11e619582a314bffe
Reviewed-on: https://webrtc-review.googlesource.com/22766
Commit-Queue: Steve Anton <steveanton@webrtc.org>
Reviewed-by: Peter Thatcher <pthatcher@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Reviewed-by: Zhi Huang <zhihuang@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#20806}diff --git a/api/peerconnectioninterface.h b/api/peerconnectioninterface.h
index 60f1635..c95cc7d 100644
--- a/api/peerconnectioninterface.h
+++ b/api/peerconnectioninterface.h
@@ -141,6 +141,10 @@
virtual ~StatsObserver() {}
};
+// For now, kDefault is interpreted as kPlanB.
+// TODO(bugs.webrtc.org/8530): Switch default to kUnifiedPlan.
+enum class SdpSemantics { kDefault, kPlanB, kUnifiedPlan };
+
class PeerConnectionInterface : public rtc::RefCountInterface {
public:
// See http://dev.w3.org/2011/webrtc/editor/webrtc.html#state-definitions .
@@ -476,6 +480,34 @@
// called.
webrtc::TurnCustomizer* turn_customizer = nullptr;
+ // Configure the SDP semantics used by this PeerConnection. Note that the
+ // WebRTC 1.0 specification requires kUnifiedPlan semantics. The
+ // RtpTransceiver API is only available with kUnifiedPlan semantics.
+ //
+ // kPlanB will cause PeerConnection to create offers and answers with at
+ // most one audio and one video m= section with multiple RtpSenders and
+ // RtpReceivers specified as multiple a=ssrc lines within the section. This
+ // will also cause PeerConnection to reject offers/answers with multiple m=
+ // sections of the same media type.
+ //
+ // kUnifiedPlan will cause PeerConnection to create offers and answers with
+ // multiple m= sections where each m= section maps to one RtpSender and one
+ // RtpReceiver (an RtpTransceiver), either both audio or both video. Plan B
+ // style offers or answers will be rejected in calls to SetLocalDescription
+ // or SetRemoteDescription.
+ //
+ // For users who only send at most one audio and one video track, this
+ // choice does not matter and should be left as kDefault.
+ //
+ // For users who wish to send multiple audio/video streams and need to stay
+ // interoperable with legacy WebRTC implementations, specify kPlanB.
+ //
+ // For users who wish to send multiple audio/video streams and/or wish to
+ // use the new RtpTransceiver API, specify kUnifiedPlan.
+ //
+ // TODO(steveanton): Implement support for kUnifiedPlan.
+ SdpSemantics sdp_semantics = SdpSemantics::kDefault;
+
//
// Don't forget to update operator== if adding something.
//