rtcmulticonnection-v3
Version:
RTCMultiConnection is a WebRTC JavaScript wrapper library runs top over RTCPeerConnection API to support all possible peer-to-peer features.
280 lines (222 loc) • 9.5 kB
JavaScript
// CodecsHandler.js
var CodecsHandler = (function() {
var isMobileDevice = !!navigator.userAgent.match(/Android|iPhone|iPad|iPod|BlackBerry|IEMobile/i);
if (typeof cordova !== 'undefined') {
isMobileDevice = true;
}
if (navigator && navigator.userAgent && navigator.userAgent.indexOf('Crosswalk') !== -1) {
isMobileDevice = true;
}
// "removeVPX" and "removeNonG722" methods are taken from github/mozilla/webrtc-landing
function removeVPX(sdp) {
if (!sdp || typeof sdp !== 'string') {
throw 'Invalid arguments.';
}
// this method is NOT reliable
sdp = sdp.replace('a=rtpmap:100 VP8/90000\r\n', '');
sdp = sdp.replace('a=rtpmap:101 VP9/90000\r\n', '');
sdp = sdp.replace(/m=video ([0-9]+) RTP\/SAVPF ([0-9 ]*) 100/g, 'm=video $1 RTP\/SAVPF $2');
sdp = sdp.replace(/m=video ([0-9]+) RTP\/SAVPF ([0-9 ]*) 101/g, 'm=video $1 RTP\/SAVPF $2');
sdp = sdp.replace(/m=video ([0-9]+) RTP\/SAVPF 100([0-9 ]*)/g, 'm=video $1 RTP\/SAVPF$2');
sdp = sdp.replace(/m=video ([0-9]+) RTP\/SAVPF 101([0-9 ]*)/g, 'm=video $1 RTP\/SAVPF$2');
sdp = sdp.replace('a=rtcp-fb:120 nack\r\n', '');
sdp = sdp.replace('a=rtcp-fb:120 nack pli\r\n', '');
sdp = sdp.replace('a=rtcp-fb:120 ccm fir\r\n', '');
sdp = sdp.replace('a=rtcp-fb:101 nack\r\n', '');
sdp = sdp.replace('a=rtcp-fb:101 nack pli\r\n', '');
sdp = sdp.replace('a=rtcp-fb:101 ccm fir\r\n', '');
return sdp;
}
function disableNACK(sdp) {
if (!sdp || typeof sdp !== 'string') {
throw 'Invalid arguments.';
}
sdp = sdp.replace('a=rtcp-fb:126 nack\r\n', '');
sdp = sdp.replace('a=rtcp-fb:126 nack pli\r\n', 'a=rtcp-fb:126 pli\r\n');
sdp = sdp.replace('a=rtcp-fb:97 nack\r\n', '');
sdp = sdp.replace('a=rtcp-fb:97 nack pli\r\n', 'a=rtcp-fb:97 pli\r\n');
return sdp;
}
function prioritize(codecMimeType, peer) {
if (!peer || !peer.getSenders || !peer.getSenders().length) {
return;
}
if (!codecMimeType || typeof codecMimeType !== 'string') {
throw 'Invalid arguments.';
}
peer.getSenders().forEach(function(sender) {
var params = sender.getParameters();
for (var i = 0; i < params.codecs.length; i++) {
if (params.codecs[i].mimeType == codecMimeType) {
params.codecs.unshift(params.codecs.splice(i, 1));
break;
}
}
sender.setParameters(params);
});
}
function removeNonG722(sdp) {
return sdp.replace(/m=audio ([0-9]+) RTP\/SAVPF ([0-9 ]*)/g, 'm=audio $1 RTP\/SAVPF 9');
}
function setBAS(sdp, bandwidth, isScreen) {
if (!bandwidth) {
return sdp;
}
if (typeof isFirefox !== 'undefined' && isFirefox) {
return sdp;
}
if (isMobileDevice) {
return sdp;
}
if (isScreen) {
if (!bandwidth.screen) {
console.warn('It seems that you are not using bandwidth for screen. Screen sharing is expected to fail.');
} else if (bandwidth.screen < 300) {
console.warn('It seems that you are using wrong bandwidth value for screen. Screen sharing is expected to fail.');
}
}
// if screen; must use at least 300kbs
if (bandwidth.screen && isScreen) {
sdp = sdp.replace(/b=AS([^\r\n]+\r\n)/g, '');
sdp = sdp.replace(/a=mid:video\r\n/g, 'a=mid:video\r\nb=AS:' + bandwidth.screen + '\r\n');
}
// remove existing bandwidth lines
if (bandwidth.audio || bandwidth.video || bandwidth.data) {
sdp = sdp.replace(/b=AS([^\r\n]+\r\n)/g, '');
}
if (bandwidth.audio) {
sdp = sdp.replace(/a=mid:audio\r\n/g, 'a=mid:audio\r\nb=AS:' + bandwidth.audio + '\r\n');
}
if (bandwidth.video) {
sdp = sdp.replace(/a=mid:video\r\n/g, 'a=mid:video\r\nb=AS:' + (isScreen ? bandwidth.screen : bandwidth.video) + '\r\n');
}
return sdp;
}
// Find the line in sdpLines that starts with |prefix|, and, if specified,
// contains |substr| (case-insensitive search).
function findLine(sdpLines, prefix, substr) {
return findLineInRange(sdpLines, 0, -1, prefix, substr);
}
// Find the line in sdpLines[startLine...endLine - 1] that starts with |prefix|
// and, if specified, contains |substr| (case-insensitive search).
function findLineInRange(sdpLines, startLine, endLine, prefix, substr) {
var realEndLine = endLine !== -1 ? endLine : sdpLines.length;
for (var i = startLine; i < realEndLine; ++i) {
if (sdpLines[i].indexOf(prefix) === 0) {
if (!substr ||
sdpLines[i].toLowerCase().indexOf(substr.toLowerCase()) !== -1) {
return i;
}
}
}
return null;
}
// Gets the codec payload type from an a=rtpmap:X line.
function getCodecPayloadType(sdpLine) {
var pattern = new RegExp('a=rtpmap:(\\d+) \\w+\\/\\d+');
var result = sdpLine.match(pattern);
return (result && result.length === 2) ? result[1] : null;
}
function setVideoBitrates(sdp, params) {
if (isMobileDevice) {
return sdp;
}
params = params || {};
var xgoogle_min_bitrate = params.min;
var xgoogle_max_bitrate = params.max;
var sdpLines = sdp.split('\r\n');
// VP8
var vp8Index = findLine(sdpLines, 'a=rtpmap', 'VP8/90000');
var vp8Payload;
if (vp8Index) {
vp8Payload = getCodecPayloadType(sdpLines[vp8Index]);
}
if (!vp8Payload) {
return sdp;
}
var rtxIndex = findLine(sdpLines, 'a=rtpmap', 'rtx/90000');
var rtxPayload;
if (rtxIndex) {
rtxPayload = getCodecPayloadType(sdpLines[rtxIndex]);
}
if (!rtxIndex) {
return sdp;
}
var rtxFmtpLineIndex = findLine(sdpLines, 'a=fmtp:' + rtxPayload.toString());
if (rtxFmtpLineIndex !== null) {
var appendrtxNext = '\r\n';
appendrtxNext += 'a=fmtp:' + vp8Payload + ' x-google-min-bitrate=' + (xgoogle_min_bitrate || '228') + '; x-google-max-bitrate=' + (xgoogle_max_bitrate || '228');
sdpLines[rtxFmtpLineIndex] = sdpLines[rtxFmtpLineIndex].concat(appendrtxNext);
sdp = sdpLines.join('\r\n');
}
return sdp;
}
function setOpusAttributes(sdp, params) {
if (isMobileDevice) {
return sdp;
}
params = params || {};
var sdpLines = sdp.split('\r\n');
// Opus
var opusIndex = findLine(sdpLines, 'a=rtpmap', 'opus/48000');
var opusPayload;
if (opusIndex) {
opusPayload = getCodecPayloadType(sdpLines[opusIndex]);
}
if (!opusPayload) {
return sdp;
}
var opusFmtpLineIndex = findLine(sdpLines, 'a=fmtp:' + opusPayload.toString());
if (opusFmtpLineIndex === null) {
return sdp;
}
var appendOpusNext = '';
appendOpusNext += '; stereo=' + (typeof params.stereo != 'undefined' ? params.stereo : '1');
appendOpusNext += '; sprop-stereo=' + (typeof params['sprop-stereo'] != 'undefined' ? params['sprop-stereo'] : '1');
if (typeof params.maxaveragebitrate != 'undefined') {
appendOpusNext += '; maxaveragebitrate=' + (params.maxaveragebitrate || 128 * 1024 * 8);
}
if (typeof params.maxplaybackrate != 'undefined') {
appendOpusNext += '; maxplaybackrate=' + (params.maxplaybackrate || 128 * 1024 * 8);
}
if (typeof params.cbr != 'undefined') {
appendOpusNext += '; cbr=' + (typeof params.cbr != 'undefined' ? params.cbr : '1');
}
if (typeof params.useinbandfec != 'undefined') {
appendOpusNext += '; useinbandfec=' + params.useinbandfec;
}
if (typeof params.usedtx != 'undefined') {
appendOpusNext += '; usedtx=' + params.usedtx;
}
if (typeof params.maxptime != 'undefined') {
appendOpusNext += '\r\na=maxptime:' + params.maxptime;
}
sdpLines[opusFmtpLineIndex] = sdpLines[opusFmtpLineIndex].concat(appendOpusNext);
sdp = sdpLines.join('\r\n');
return sdp;
}
function preferVP9(sdp) {
if (sdp.indexOf('SAVPF 100 101') === -1 || sdp.indexOf('VP9/90000') === -1) {
return sdp;
}
return sdp.replace('SAVPF 100 101', 'SAVPF 101 100');
}
return {
removeVPX: removeVPX,
disableNACK: disableNACK,
prioritize: prioritize,
removeNonG722: removeNonG722,
setApplicationSpecificBandwidth: function(sdp, bandwidth, isScreen) {
return setBAS(sdp, bandwidth, isScreen);
},
setVideoBitrates: function(sdp, params) {
return setVideoBitrates(sdp, params);
},
setOpusAttributes: function(sdp, params) {
return setOpusAttributes(sdp, params);
},
preferVP9: preferVP9
};
})();
// backward compatibility
window.BandwidthHandler = CodecsHandler;