Commit c7696652 authored by Sebastian Dröge's avatar Sebastian Dröge
Browse files

Fix stereo playback in Chrome 

See
  https://chromium.googlesource.com/external/webrtc/+/194e3bcc53ffa3e98045934377726cb25d7579d2/webrtc/media/engine/webrtcvoiceengine.cc#302
  https://bugs.chromium.org/p/webrtc/issues/detail?id=8133

Technically it's against the spec to modify the SDP but there's no other
API for this and this seems to be the only possible workaround at this
time.
parent 66defe91

server/static/scripts.js

+13 −2
Original line number Diff line number Diff line
@@ -253,8 +253,19 @@ function onServerMessage(ws, event) { 
        try {

            peer_connection.setRemoteDescription(msg.sdp).then(function() {

                try {

                    peer_connection.createAnswer().then(function(sdp) {

                        peer_connection.setLocalDescription(sdp).then(function() {

                    peer_connection.createAnswer().then(function(desc) {

                        // FIXME: Work around Chrome not handling stereo Opus correctly.

                        // See

                        //   https://chromium.googlesource.com/external/webrtc/+/194e3bcc53ffa3e98045934377726cb25d7579d2/webrtc/media/engine/webrtcvoiceengine.cc#302

                        //   https://bugs.chromium.org/p/webrtc/issues/detail?id=8133

                        //

                        // Technically it's against the spec to modify the SDP

                        // but there's no other API for this and this seems to

                        // be the only possible workaround at this time.

                        if (msg.sdp.sdp.includes('sprop-stereo=1')) {

                            desc.sdp = desc.sdp.replace('a=fmtp:96 ', 'a=fmtp:96 stereo=1;');

                        }

                        peer_connection.setLocalDescription(desc).then(function() {

                            if (websocket != null) {

                                try {

                                    websocket.send(JSON.stringify({'sdp': peer_connection.localDescription }));