in release/connect-rtc.js [3736:4098]
RTCPeerConnection.prototype.setRemoteDescription = function(description) {
var pc = this;
// Note: pranswer is not supported.
if (['offer', 'answer'].indexOf(description.type) === -1) {
return Promise.reject(makeError('TypeError',
'Unsupported type "' + description.type + '"'));
}
if (!isActionAllowedInSignalingState('setRemoteDescription',
description.type, pc.signalingState) || pc._isClosed) {
return Promise.reject(makeError('InvalidStateError',
'Can not set remote ' + description.type +
' in state ' + pc.signalingState));
}
var streams = {};
pc.remoteStreams.forEach(function(stream) {
streams[stream.id] = stream;
});
var receiverList = [];
var sections = SDPUtils.splitSections(description.sdp);
var sessionpart = sections.shift();
var isIceLite = SDPUtils.matchPrefix(sessionpart,
'a=ice-lite').length > 0;
var usingBundle = SDPUtils.matchPrefix(sessionpart,
'a=group:BUNDLE ').length > 0;
pc.usingBundle = usingBundle;
var iceOptions = SDPUtils.matchPrefix(sessionpart,
'a=ice-options:')[0];
if (iceOptions) {
pc.canTrickleIceCandidates = iceOptions.substr(14).split(' ')
.indexOf('trickle') >= 0;
} else {
pc.canTrickleIceCandidates = false;
}
sections.forEach(function(mediaSection, sdpMLineIndex) {
var lines = SDPUtils.splitLines(mediaSection);
var kind = SDPUtils.getKind(mediaSection);
// treat bundle-only as not-rejected.
var rejected = SDPUtils.isRejected(mediaSection) &&
SDPUtils.matchPrefix(mediaSection, 'a=bundle-only').length === 0;
var protocol = lines[0].substr(2).split(' ')[2];
var direction = SDPUtils.getDirection(mediaSection, sessionpart);
var remoteMsid = SDPUtils.parseMsid(mediaSection);
var mid = SDPUtils.getMid(mediaSection) || SDPUtils.generateIdentifier();
// Reject datachannels which are not implemented yet.
if (rejected || (kind === 'application' && (protocol === 'DTLS/SCTP' ||
protocol === 'UDP/DTLS/SCTP'))) {
// TODO: this is dangerous in the case where a non-rejected m-line
// becomes rejected.
pc.transceivers[sdpMLineIndex] = {
mid: mid,
kind: kind,
protocol: protocol,
rejected: true
};
return;
}
if (!rejected && pc.transceivers[sdpMLineIndex] &&
pc.transceivers[sdpMLineIndex].rejected) {
// recycle a rejected transceiver.
pc.transceivers[sdpMLineIndex] = pc._createTransceiver(kind, true);
}
var transceiver;
var iceGatherer;
var iceTransport;
var dtlsTransport;
var rtpReceiver;
var sendEncodingParameters;
var recvEncodingParameters;
var localCapabilities;
var track;
// FIXME: ensure the mediaSection has rtcp-mux set.
var remoteCapabilities = SDPUtils.parseRtpParameters(mediaSection);
var remoteIceParameters;
var remoteDtlsParameters;
if (!rejected) {
remoteIceParameters = SDPUtils.getIceParameters(mediaSection,
sessionpart);
remoteDtlsParameters = SDPUtils.getDtlsParameters(mediaSection,
sessionpart);
remoteDtlsParameters.role = 'client';
}
recvEncodingParameters =
SDPUtils.parseRtpEncodingParameters(mediaSection);
var rtcpParameters = SDPUtils.parseRtcpParameters(mediaSection);
var isComplete = SDPUtils.matchPrefix(mediaSection,
'a=end-of-candidates', sessionpart).length > 0;
var cands = SDPUtils.matchPrefix(mediaSection, 'a=candidate:')
.map(function(cand) {
return SDPUtils.parseCandidate(cand);
})
.filter(function(cand) {
return cand.component === 1;
});
// Check if we can use BUNDLE and dispose transports.
if ((description.type === 'offer' || description.type === 'answer') &&
!rejected && usingBundle && sdpMLineIndex > 0 &&
pc.transceivers[sdpMLineIndex]) {
pc._disposeIceAndDtlsTransports(sdpMLineIndex);
pc.transceivers[sdpMLineIndex].iceGatherer =
pc.transceivers[0].iceGatherer;
pc.transceivers[sdpMLineIndex].iceTransport =
pc.transceivers[0].iceTransport;
pc.transceivers[sdpMLineIndex].dtlsTransport =
pc.transceivers[0].dtlsTransport;
if (pc.transceivers[sdpMLineIndex].rtpSender) {
pc.transceivers[sdpMLineIndex].rtpSender.setTransport(
pc.transceivers[0].dtlsTransport);
}
if (pc.transceivers[sdpMLineIndex].rtpReceiver) {
pc.transceivers[sdpMLineIndex].rtpReceiver.setTransport(
pc.transceivers[0].dtlsTransport);
}
}
if (description.type === 'offer' && !rejected) {
transceiver = pc.transceivers[sdpMLineIndex] ||
pc._createTransceiver(kind);
transceiver.mid = mid;
if (!transceiver.iceGatherer) {
transceiver.iceGatherer = pc._createIceGatherer(sdpMLineIndex,
usingBundle);
}
if (cands.length && transceiver.iceTransport.state === 'new') {
if (isComplete && (!usingBundle || sdpMLineIndex === 0)) {
transceiver.iceTransport.setRemoteCandidates(cands);
} else {
cands.forEach(function(candidate) {
maybeAddCandidate(transceiver.iceTransport, candidate);
});
}
}
localCapabilities = window.RTCRtpReceiver.getCapabilities(kind);
// filter RTX until additional stuff needed for RTX is implemented
// in adapter.js
if (edgeVersion < 15019) {
localCapabilities.codecs = localCapabilities.codecs.filter(
function(codec) {
return codec.name !== 'rtx';
});
}
sendEncodingParameters = transceiver.sendEncodingParameters || [{
ssrc: (2 * sdpMLineIndex + 2) * 1001
}];
// TODO: rewrite to use http://w3c.github.io/webrtc-pc/#set-associated-remote-streams
var isNewTrack = false;
if (direction === 'sendrecv' || direction === 'sendonly') {
isNewTrack = !transceiver.rtpReceiver;
rtpReceiver = transceiver.rtpReceiver ||
new window.RTCRtpReceiver(transceiver.dtlsTransport, kind);
if (isNewTrack) {
var stream;
track = rtpReceiver.track;
// FIXME: does not work with Plan B.
if (remoteMsid && remoteMsid.stream === '-') {
// no-op. a stream id of '-' means: no associated stream.
} else if (remoteMsid) {
if (!streams[remoteMsid.stream]) {
streams[remoteMsid.stream] = new window.MediaStream();
Object.defineProperty(streams[remoteMsid.stream], 'id', {
get: function() {
return remoteMsid.stream;
}
});
}
Object.defineProperty(track, 'id', {
get: function() {
return remoteMsid.track;
}
});
stream = streams[remoteMsid.stream];
} else {
if (!streams.default) {
streams.default = new window.MediaStream();
}
stream = streams.default;
}
if (stream) {
addTrackToStreamAndFireEvent(track, stream);
transceiver.associatedRemoteMediaStreams.push(stream);
}
receiverList.push([track, rtpReceiver, stream]);
}
} else if (transceiver.rtpReceiver && transceiver.rtpReceiver.track) {
transceiver.associatedRemoteMediaStreams.forEach(function(s) {
var nativeTrack = s.getTracks().find(function(t) {
return t.id === transceiver.rtpReceiver.track.id;
});
if (nativeTrack) {
removeTrackFromStreamAndFireEvent(nativeTrack, s);
}
});
transceiver.associatedRemoteMediaStreams = [];
}
transceiver.localCapabilities = localCapabilities;
transceiver.remoteCapabilities = remoteCapabilities;
transceiver.rtpReceiver = rtpReceiver;
transceiver.rtcpParameters = rtcpParameters;
transceiver.sendEncodingParameters = sendEncodingParameters;
transceiver.recvEncodingParameters = recvEncodingParameters;
// Start the RTCRtpReceiver now. The RTPSender is started in
// setLocalDescription.
pc._transceive(pc.transceivers[sdpMLineIndex],
false,
isNewTrack);
} else if (description.type === 'answer' && !rejected) {
transceiver = pc.transceivers[sdpMLineIndex];
iceGatherer = transceiver.iceGatherer;
iceTransport = transceiver.iceTransport;
dtlsTransport = transceiver.dtlsTransport;
rtpReceiver = transceiver.rtpReceiver;
sendEncodingParameters = transceiver.sendEncodingParameters;
localCapabilities = transceiver.localCapabilities;
pc.transceivers[sdpMLineIndex].recvEncodingParameters =
recvEncodingParameters;
pc.transceivers[sdpMLineIndex].remoteCapabilities =
remoteCapabilities;
pc.transceivers[sdpMLineIndex].rtcpParameters = rtcpParameters;
if (cands.length && iceTransport.state === 'new') {
if ((isIceLite || isComplete) &&
(!usingBundle || sdpMLineIndex === 0)) {
iceTransport.setRemoteCandidates(cands);
} else {
cands.forEach(function(candidate) {
maybeAddCandidate(transceiver.iceTransport, candidate);
});
}
}
if (!usingBundle || sdpMLineIndex === 0) {
if (iceTransport.state === 'new') {
iceTransport.start(iceGatherer, remoteIceParameters,
'controlling');
}
if (dtlsTransport.state === 'new') {
dtlsTransport.start(remoteDtlsParameters);
}
}
// If the offer contained RTX but the answer did not,
// remove RTX from sendEncodingParameters.
var commonCapabilities = getCommonCapabilities(
transceiver.localCapabilities,
transceiver.remoteCapabilities);
var hasRtx = commonCapabilities.codecs.filter(function(c) {
return c.name.toLowerCase() === 'rtx';
}).length;
if (!hasRtx && transceiver.sendEncodingParameters[0].rtx) {
delete transceiver.sendEncodingParameters[0].rtx;
}
pc._transceive(transceiver,
direction === 'sendrecv' || direction === 'recvonly',
direction === 'sendrecv' || direction === 'sendonly');
// TODO: rewrite to use http://w3c.github.io/webrtc-pc/#set-associated-remote-streams
if (rtpReceiver &&
(direction === 'sendrecv' || direction === 'sendonly')) {
track = rtpReceiver.track;
if (remoteMsid) {
if (!streams[remoteMsid.stream]) {
streams[remoteMsid.stream] = new window.MediaStream();
}
addTrackToStreamAndFireEvent(track, streams[remoteMsid.stream]);
receiverList.push([track, rtpReceiver, streams[remoteMsid.stream]]);
} else {
if (!streams.default) {
streams.default = new window.MediaStream();
}
addTrackToStreamAndFireEvent(track, streams.default);
receiverList.push([track, rtpReceiver, streams.default]);
}
} else {
// FIXME: actually the receiver should be created later.
delete transceiver.rtpReceiver;
}
}
});
if (pc._dtlsRole === undefined) {
pc._dtlsRole = description.type === 'offer' ? 'active' : 'passive';
}
pc._remoteDescription = {
type: description.type,
sdp: description.sdp
};
if (description.type === 'offer') {
pc._updateSignalingState('have-remote-offer');
} else {
pc._updateSignalingState('stable');
}
Object.keys(streams).forEach(function(sid) {
var stream = streams[sid];
if (stream.getTracks().length) {
if (pc.remoteStreams.indexOf(stream) === -1) {
pc.remoteStreams.push(stream);
var event = new Event('addstream');
event.stream = stream;
window.setTimeout(function() {
pc._dispatchEvent('addstream', event);
});
}
receiverList.forEach(function(item) {
var track = item[0];
var receiver = item[1];
if (stream.id !== item[2].id) {
return;
}
fireAddTrack(pc, track, receiver, [stream]);
});
}
});
receiverList.forEach(function(item) {
if (item[2]) {
return;
}
fireAddTrack(pc, item[0], item[1], []);
});
// check whether addIceCandidate({}) was called within four seconds after
// setRemoteDescription.
window.setTimeout(function() {
if (!(pc && pc.transceivers)) {
return;
}
pc.transceivers.forEach(function(transceiver) {
if (transceiver.iceTransport &&
transceiver.iceTransport.state === 'new' &&
transceiver.iceTransport.getRemoteCandidates().length > 0) {
console.warn('Timeout for addRemoteCandidate. Consider sending ' +
'an end-of-candidates notification');
transceiver.iceTransport.addRemoteCandidate({});
}
});
}, 4000);
return Promise.resolve();
};