Fix FS-11873: addStream() adds audio/video tracks in random order

addStream() is a deprecated WebRTC API method, and only works via shimming on some platforms. Internally, it is inconsistent in building an offer SDP in the order which FreeSWITCH expects it, which is audio m-lines first.

This can result in intermittent m-line ordering errors on the client.

Instead addTrack() can be used to force the media tracks to be added to the peer in the order FreeSWITCH expects.

diff --git a/html5/verto/js/src/jquery.FSRTC.js b/html5/verto/js/src/jquery.FSRTC.js
index 3b0ef04290e660b51bd67bb2761333176e279685..1046f7c9e28d5a0363d11e221e29fe19e99f42ea 100644 (file)
--- a/html5/verto/js/src/jquery.FSRTC.js
+++ b/html5/verto/js/src/jquery.FSRTC.js
@@ -767,7 +767,13 @@
         };
 
         // attachStream = MediaStream;
-        if (options.attachStream) peer.addStream(options.attachStream);
+        if (options.attachStream) {
+          // FreeSWITCH currently orders its answer SDP such that audio m-lines
+          // always come first, adding the tracks to the peer in that order
+          // prevents possible m-line ordering validation errors on the client.
+          options.attachStream.getAudioTracks().forEach(function(track) { peer.addTrack(track, options.attachStream) });
+          options.attachStream.getVideoTracks().forEach(function(track) { peer.addTrack(track, options.attachStream) });
+        }
 
         // attachStreams[0] = audio-stream;
         // attachStreams[1] = video-stream;