jitsi_corner8/libs/colibri/colibri.focus.js

/* colibri.js -- a COLIBRI focus
 * The colibri spec has been submitted to the XMPP Standards Foundation
 * for publications as a XMPP extensions:
 * http://xmpp.org/extensions/inbox/colibri.html
 *
 * colibri.js is a participating focus, i.e. the focus participates
 * in the conference. The conference itself can be ad-hoc, through a
 * MUC, through PubSub, etc.
 *
 * colibri.js relies heavily on the strophe.jingle library available
 * from https://github.com/ESTOS/strophe.jingle
 * and interoperates with the Jitsi videobridge available from
 * https://jitsi.org/Projects/JitsiVideobridge
 */
/*
 Copyright (c) 2013 ESTOS GmbH

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in
 all copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 THE SOFTWARE.
 */
/* jshint -W117 */

ColibriFocus.prototype = Object.create(SessionBase.prototype);
function ColibriFocus(connection, bridgejid) {

    SessionBase.call(this, connection, Math.random().toString(36).substr(2, 12));

    this.bridgejid = bridgejid;
    this.peers = [];
    this.remoteStreams = [];
    this.confid = null;

    /**
     * Local XMPP resource used to join the multi user chat.
     * @type {*}
     */
    this.myMucResource = Strophe.getResourceFromJid(connection.emuc.myroomjid);

    /**
     * Default channel expire value in seconds.
     * @type {number}
     */
    this.channelExpire
        = ('number' === typeof(config.channelExpire))
            ? config.channelExpire
            : 15;
    /**
     * Default channel last-n value.
     * @type {number}
     */
    this.channelLastN
        = ('number' === typeof(config.channelLastN)) ? config.channelLastN : -1;

    // media types of the conference
    if (config.openSctp)
        this.media = ['audio', 'video', 'data'];
    else
        this.media = ['audio', 'video'];

    this.connection.jingle.sessions[this.sid] = this;
    this.bundledTransports = {};
    this.mychannel = [];
    this.channels = [];
    this.remotessrc = {};

    // container for candidates from the focus
    // gathered before confid is known
    this.drip_container = [];

    // silly wait flag
    this.wait = true;

    this.recordingEnabled = false;

    // stores information about the endpoints (i.e. display names) to
    // be sent to the videobridge.
    this.endpointsInfo = null;
}

// creates a conferences with an initial set of peers
ColibriFocus.prototype.makeConference = function (peers, errorCallback) {
    var self = this;
    if (this.confid !== null) {
        console.error('makeConference called twice? Ignoring...');
        // FIXME: just invite peers?
        return;
    }
    this.confid = 0; // !null
    this.peers = [];
    peers.forEach(function (peer) {
        self.peers.push(peer);
        self.channels.push([]);
    });

    this.peerconnection
        = new TraceablePeerConnection(
            this.connection.jingle.ice_config,
            this.connection.jingle.pc_constraints );

    if(this.connection.jingle.localAudio) {
        this.peerconnection.addStream(this.connection.jingle.localAudio);
    }
    if(this.connection.jingle.localVideo) {
        this.peerconnection.addStream(this.connection.jingle.localVideo);
    }
    this.peerconnection.oniceconnectionstatechange = function (event) {
        console.warn('ice connection state changed to', self.peerconnection.iceConnectionState);
        /*
        if (self.peerconnection.signalingState == 'stable' && self.peerconnection.iceConnectionState == 'connected') {
            console.log('adding new remote SSRCs from iceconnectionstatechange');
            window.setTimeout(function() { self.modifySources(); }, 1000);
        }
        */
        $(document).trigger('iceconnectionstatechange.jingle', [self.sid, self]);
    };
    this.peerconnection.onsignalingstatechange = function (event) {
        console.warn(self.peerconnection.signalingState);
        /*
        if (self.peerconnection.signalingState == 'stable' && self.peerconnection.iceConnectionState == 'connected') {
            console.log('adding new remote SSRCs from signalingstatechange');
            window.setTimeout(function() { self.modifySources(); }, 1000);
        }
        */
    };
    this.peerconnection.onaddstream = function (event) {
        // search the jid associated with this stream
        Object.keys(self.remotessrc).forEach(function (jid) {
            if (self.remotessrc[jid].join('\r\n').indexOf('mslabel:' + event.stream.id) != -1) {
                event.peerjid = jid;
            }
        });
        self.remoteStreams.push(event.stream);
        $(document).trigger('remotestreamadded.jingle', [event, self.sid]);
    };
    this.peerconnection.onicecandidate = function (event) {
        //console.log('focus onicecandidate', self.confid, new Date().getTime(), event.candidate);
        if (!event.candidate) {
            console.log('end of candidates');
            return;
        }
        self.sendIceCandidate(event.candidate);
    };
    this._makeConference(errorCallback);
    /*
    this.peerconnection.createOffer(
        function (offer) {
            self.peerconnection.setLocalDescription(
                offer,
                function () {
                    // success
                    $(document).trigger('setLocalDescription.jingle', [self.sid]);
                    // FIXME: could call _makeConference here and trickle candidates later
                    self._makeConference();
                },
                function (error) {
                    console.log('setLocalDescription failed', error);
                }
            );
        },
        function (error) {
            console.warn(error);
        }
    );
    */
};

// Sends a COLIBRI message which enables or disables (according to 'state') the
// recording on the bridge. Waits for the result IQ and calls 'callback' with
// the new recording state, according to the IQ.
ColibriFocus.prototype.setRecording = function(state, token, callback) {
    var self = this;
    var elem = $iq({to: this.bridgejid, type: 'set'});
    elem.c('conference', {
        xmlns: 'http://jitsi.org/protocol/colibri',
        id: this.confid
    });
    elem.c('recording', {state: state, token: token});
    elem.up();

    this.connection.sendIQ(elem,
        function (result) {
            console.log('Set recording "', state, '". Result:', result);
            var recordingElem = $(result).find('>conference>recording');
            var newState = ('true' === recordingElem.attr('state'));

            self.recordingEnabled = newState;
            callback(newState);
        },
        function (error) {
            console.warn(error);
        }
    );
};

/*
 * Updates the display name for an endpoint with a specific jid.
 * jid: the jid associated with the endpoint.
 * displayName: the new display name for the endpoint.
 */
ColibriFocus.prototype.setEndpointDisplayName = function(jid, displayName) {
    var endpointId = jid.substr(1 + jid.lastIndexOf('/'));
    var update = false;

    if (this.endpointsInfo === null) {
       this.endpointsInfo = {};
    }

    var endpointInfo = this.endpointsInfo[endpointId];
    if ('undefined' === typeof endpointInfo) {
        endpointInfo = this.endpointsInfo[endpointId] = {};
    }

    if (endpointInfo['displayname'] !== displayName) {
        endpointInfo['displayname'] = displayName;
        update = true;
    }

    if (update) {
        this.updateEndpoints();
    }
};

/*
 * Sends a colibri message to the bridge that contains the
 * current endpoints and their display names.
 */
ColibriFocus.prototype.updateEndpoints = function() {
    if (this.confid === null
        || this.endpointsInfo === null) {
        return;
    }

    if (this.confid === 0) {
        // the colibri conference is currently initiating
        var self = this;
        window.setTimeout(function() { self.updateEndpoints()}, 1000);
        return;
    }

    var elem = $iq({to: this.bridgejid, type: 'set'});
    elem.c('conference', {
        xmlns: 'http://jitsi.org/protocol/colibri',
        id: this.confid
    });

    for (var id in this.endpointsInfo) {
        elem.c('endpoint');
        elem.attrs({ id: id,
                     displayname: this.endpointsInfo[id]['displayname']
        });
        elem.up();
    }

    //elem.up(); //conference

    this.connection.sendIQ(
        elem,
        function (result) {},
        function (error) { console.warn(error); }
    );
};

ColibriFocus.prototype._makeConference = function (errorCallback) {
    var self = this;
    var elem = $iq({ to: this.bridgejid, type: 'get' });
    elem.c('conference', { xmlns: 'http://jitsi.org/protocol/colibri' });

    this.media.forEach(function (name) {
        var elemName;
        var elemAttrs = { initiator: 'true', expire: self.channelExpire };

        if ('data' === name)
        {
            elemName = 'sctpconnection';
            elemAttrs['port'] = 5000;
        }
        else
        {
            elemName = 'channel';
            if ('video' === name) {
                if (self.channelLastN >= 0) {
                    elemAttrs['last-n'] = self.channelLastN;
                }
                if (config.adaptiveLastN) {
                    elemAttrs['adaptive-last-n'] = 'true';
                }
                if (config.adaptiveSimulcast) {
                    elemAttrs['adaptive-simulcast'] = 'true';
                }
            }
        }

        elem.c('content', { name: name });

        elem.c(elemName, elemAttrs);
        elem.attrs({ endpoint: self.myMucResource });
        if (config.useBundle) {
            elem.attrs({ 'channel-bundle-id': self.myMucResource });
        }
        elem.up();// end of channel/sctpconnection

        for (var j = 0; j < self.peers.length; j++) {
            var peer = self.peers[j];
            var peerEndpoint = peer.substr(1 + peer.lastIndexOf('/'));

            elem.c(elemName, elemAttrs);
            elem.attrs({ endpoint: peerEndpoint });
            if (config.useBundle) {
                elem.attrs({ 'channel-bundle-id': peerEndpoint });
            }
            elem.up(); // end of channel/sctpconnection
        }
        elem.up(); // end of content
    });

    if (this.endpointsInfo !== null) {
        for (var id in this.endpointsInfo) {
            elem.c('endpoint');
            elem.attrs({ id: id,
                         displayname: this.endpointsInfo[id]['displayname']
            });
            elem.up();
        }
    }

    /*
    var localSDP = new SDP(this.peerconnection.localDescription.sdp);
    localSDP.media.forEach(function (media, channel) {
        var name = SDPUtil.parse_mline(media.split('\r\n')[0]).media;
        elem.c('content', {name: name});
        elem.c('channel', {initiator: 'false', expire: self.channelExpire});

        // FIXME: should reuse code from .toJingle
        var mline = SDPUtil.parse_mline(media.split('\r\n')[0]);
        for (var j = 0; j < mline.fmt.length; j++) {
            var rtpmap = SDPUtil.find_line(media, 'a=rtpmap:' + mline.fmt[j]);
            elem.c('payload-type', SDPUtil.parse_rtpmap(rtpmap));
            elem.up();
        }

        localSDP.TransportToJingle(channel, elem);

        elem.up(); // end of channel
        for (j = 0; j < self.peers.length; j++) {
            elem.c('channel', {initiator: 'true', expire: self.channelExpire }).up();
        }
        elem.up(); // end of content
    });
    */

    this.connection.sendIQ(elem,
        function (result) {
            self.createdConference(result);
        },
        function (error) {
            console.warn(error);
            errorCallback(error);
        }
    );
};

// callback when a colibri conference was created
ColibriFocus.prototype.createdConference = function (result) {
    console.log('created a conference on the bridge');
    var self = this;
    var tmp;

    this.confid = $(result).find('>conference').attr('id');
    var remotecontents = $(result).find('>conference>content').get();
    var numparticipants = 0;
    for (var i = 0; i < remotecontents.length; i++)
    {
        var contentName = $(remotecontents[i]).attr('name');
        var channelName
            = contentName !== 'data' ? '>channel' : '>sctpconnection';

        tmp = $(remotecontents[i]).find(channelName).get();
        this.mychannel.push($(tmp.shift()));
        numparticipants = tmp.length;
        for (j = 0; j < tmp.length; j++) {
            if (this.channels[j] === undefined) {
                this.channels[j] = [];
            }
            this.channels[j].push(tmp[j]);
        }
    }

    // save the 'transport' elements from 'channel-bundle'-s
    var channelBundles = $(result).find('>conference>channel-bundle');
    for (var i = 0; i < channelBundles.length; i++)
    {
        var endpointId = $(channelBundles[i]).attr('id');
        this.bundledTransports[endpointId] = $(channelBundles[i]).find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]');
    }

    console.log('remote channels', this.channels);

    // Notify that the focus has created the conference on the bridge
    $(document).trigger('conferenceCreated.jingle', [self]);

    var bridgeSDP = new SDP(
        'v=0\r\n' +
        'o=- 5151055458874951233 2 IN IP4 127.0.0.1\r\n' +
        's=-\r\n' +
        't=0 0\r\n' +
        /* Audio */
        (config.useBundle
            ? ('a=group:BUNDLE audio video' +
                (config.openSctp ? ' data' : '') +
               '\r\n')
            : '') +
        'm=audio 1 RTP/SAVPF 111 103 104 0 8 106 105 13 126\r\n' +
        'c=IN IP4 0.0.0.0\r\n' +
        'a=rtcp:1 IN IP4 0.0.0.0\r\n' +
        'a=mid:audio\r\n' +
        'a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\n' +
        'a=sendrecv\r\n' +
        'a=rtpmap:111 opus/48000/2\r\n' +
        'a=fmtp:111 minptime=10\r\n' +
        'a=rtpmap:103 ISAC/16000\r\n' +
        'a=rtpmap:104 ISAC/32000\r\n' +
        'a=rtpmap:0 PCMU/8000\r\n' +
        'a=rtpmap:8 PCMA/8000\r\n' +
        'a=rtpmap:106 CN/32000\r\n' +
        'a=rtpmap:105 CN/16000\r\n' +
        'a=rtpmap:13 CN/8000\r\n' +
        'a=rtpmap:126 telephone-event/8000\r\n' +
        'a=maxptime:60\r\n' +
        (config.useRtcpMux ? 'a=rtcp-mux\r\n' : '') +
        /* Video */
        'm=video 1 RTP/SAVPF 100 116 117\r\n' +
        'c=IN IP4 0.0.0.0\r\n' +
        'a=rtcp:1 IN IP4 0.0.0.0\r\n' +
        'a=mid:video\r\n' +
        'a=extmap:2 urn:ietf:params:rtp-hdrext:toffset\r\n' +
        'a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\n' +
        'a=sendrecv\r\n' +
        'a=rtpmap:100 VP8/90000\r\n' +
        'a=rtcp-fb:100 ccm fir\r\n' +
        'a=rtcp-fb:100 nack\r\n' +
        'a=rtcp-fb:100 goog-remb\r\n' +
        'a=rtpmap:116 red/90000\r\n' +
        'a=rtpmap:117 ulpfec/90000\r\n' +
        (config.useRtcpMux ? 'a=rtcp-mux\r\n' : '') +
        /* Data SCTP */
        (config.openSctp ?
            'm=application 1 DTLS/SCTP 5000\r\n' +
            'c=IN IP4 0.0.0.0\r\n' +
            'a=sctpmap:5000 webrtc-datachannel\r\n' +
            'a=mid:data\r\n'
            : '')
    );

    bridgeSDP.media.length = this.mychannel.length;
    var channel;
    /*
    for (channel = 0; channel < bridgeSDP.media.length; channel++) {
        bridgeSDP.media[channel] = '';
        // unchanged lines
        bridgeSDP.media[channel] += SDPUtil.find_line(localSDP.media[channel], 'm=') + '\r\n';
        bridgeSDP.media[channel] += SDPUtil.find_line(localSDP.media[channel], 'c=') + '\r\n';
        if (SDPUtil.find_line(localSDP.media[channel], 'a=rtcp:')) {
            bridgeSDP.media[channel] += SDPUtil.find_line(localSDP.media[channel], 'a=rtcp:') + '\r\n';
        }
        if (SDPUtil.find_line(localSDP.media[channel], 'a=mid:')) {
            bridgeSDP.media[channel] += SDPUtil.find_line(localSDP.media[channel], 'a=mid:') + '\r\n';
        }
        if (SDPUtil.find_line(localSDP.media[channel], 'a=sendrecv')) {
            bridgeSDP.media[channel] += 'a=sendrecv\r\n';
        }
        if (SDPUtil.find_line(localSDP.media[channel], 'a=extmap:')) {
            bridgeSDP.media[channel] += SDPUtil.find_lines(localSDP.media[channel], 'a=extmap:').join('\r\n') + '\r\n';
        }

        // FIXME: should look at m-line and group the ids together
        if (SDPUtil.find_line(localSDP.media[channel], 'a=rtpmap:')) {
            bridgeSDP.media[channel] += SDPUtil.find_lines(localSDP.media[channel], 'a=rtpmap:').join('\r\n') + '\r\n';
        }
        if (SDPUtil.find_line(localSDP.media[channel], 'a=fmtp:')) {
            bridgeSDP.media[channel] += SDPUtil.find_lines(localSDP.media[channel], 'a=fmtp:').join('\r\n') + '\r\n';
        }
        if (SDPUtil.find_line(localSDP.media[channel], 'a=rtcp-fb:')) {
            bridgeSDP.media[channel] += SDPUtil.find_lines(localSDP.media[channel], 'a=rtcp-fb:').join('\r\n') + '\r\n';
        }
        // FIXME: changed lines -- a=sendrecv direction, a=setup direction
    }
    */
    for (channel = 0; channel < bridgeSDP.media.length; channel++) {
        // get the mixed ssrc
        tmp = $(this.mychannel[channel]).find('>source[xmlns="urn:xmpp:jingle:apps:rtp:ssma:0"]');
        // FIXME: check rtp-level-relay-type

        var name = bridgeSDP.media[channel].split(" ")[0].substr(2); // 'm=audio ...'
        if (name === 'audio' || name === 'video') {
            // make chrome happy... '3735928559' == 0xDEADBEEF
            var ssrc = tmp.length ? tmp.attr('ssrc') : '3735928559';

            bridgeSDP.media[channel] += 'a=ssrc:' + ssrc + ' cname:mixed\r\n';
            bridgeSDP.media[channel] += 'a=ssrc:' + ssrc + ' label:mixedlabel' + name + '0\r\n';
            bridgeSDP.media[channel] += 'a=ssrc:' + ssrc + ' msid:mixedmslabel mixedlabel' + name + '0\r\n';
            bridgeSDP.media[channel] += 'a=ssrc:' + ssrc + ' mslabel:mixedmslabel\r\n';
        }

        // FIXME: should take code from .fromJingle
        var channelBundleId = $(this.mychannel[channel]).attr('channel-bundle-id');
        if (typeof channelBundleId != 'undefined') {
            tmp = this.bundledTransports[channelBundleId];
        } else {
            tmp = $(this.mychannel[channel]).find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]');
        }

        if (tmp.length) {
            bridgeSDP.media[channel] += 'a=ice-ufrag:' + tmp.attr('ufrag') + '\r\n';
            bridgeSDP.media[channel] += 'a=ice-pwd:' + tmp.attr('pwd') + '\r\n';
            tmp.find('>candidate').each(function () {
                bridgeSDP.media[channel] += SDPUtil.candidateFromJingle(this);
            });
            tmp = tmp.find('>fingerprint');
            if (tmp.length) {
                bridgeSDP.media[channel] += 'a=fingerprint:' + tmp.attr('hash') + ' ' + tmp.text() + '\r\n';
                bridgeSDP.media[channel] += 'a=setup:actpass\r\n'; // offer so always actpass
            }
        }
    }
    bridgeSDP.raw = bridgeSDP.session + bridgeSDP.media.join('');
    var bridgeDesc = new RTCSessionDescription({type: 'offer', sdp: bridgeSDP.raw});
    bridgeDesc = simulcast.transformRemoteDescription(bridgeDesc);

    this.peerconnection.setRemoteDescription(bridgeDesc,
        function () {
            console.log('setRemoteDescription success');
            self.peerconnection.createAnswer(
                function (answer) {
                    self.peerconnection.setLocalDescription(answer,
                        function () {
                            console.log('setLocalDescription succeeded.');
                            // make sure our presence is updated
                            $(document).trigger('setLocalDescription.jingle', [self.sid]);
                            var localSDP = new SDP(self.peerconnection.localDescription.sdp);
                            self.updateLocalChannel(localSDP);

                            // now initiate sessions
                            for (var i = 0; i < numparticipants; i++) {
                                self.initiate(self.peers[i], true);
                            }

                            // Notify we've created the conference
                            $(document).trigger(
                                'conferenceCreated.jingle', self);
                        },
                        function (error) {
                            console.warn('setLocalDescription failed.', error);
                        }
                    );
                },
                function (error) {
                    console.warn('createAnswer failed.', error);
                }
            );
            /*
            for (var i = 0; i < numparticipants; i++) {
                self.initiate(self.peers[i], true);
            }
            */
        },
        function (error) {
            console.log('setRemoteDescription failed.', error);
        }
    );

};

ColibriFocus.prototype.updateLocalChannel = function(localSDP, parts) {
    var self = this;
    var elem = $iq({to: self.bridgejid, type: 'get'});
    elem.c('conference', {xmlns: 'http://jitsi.org/protocol/colibri', id: self.confid});
    localSDP.media.forEach(function (media, channel) {
        var name = SDPUtil.parse_mid(SDPUtil.find_line(media, 'a=mid:'));
        elem.c('content', {name: name});
        var mline = SDPUtil.parse_mline(media.split('\r\n')[0]);
        if (name !== 'data') {
            elem.c('channel', {
                initiator: 'true',
                expire: self.channelExpire,
                id: self.mychannel[channel].attr('id'),
                endpoint: self.myMucResource
            });

            if (!parts || parts.indexOf('sources') !== -1) {
                // signal (through COLIBRI) to the bridge
                // the SSRC groups of the participant
                // that plays the role of the focus
                var ssrc_group_lines = SDPUtil.find_lines(media, 'a=ssrc-group:');
                var idx = 0;
                var hasSIM = false;
                ssrc_group_lines.forEach(function (line) {
                    idx = line.indexOf(' ');
                    var semantics = line.substr(0, idx).substr(13);
                    var ssrcs = line.substr(14 + semantics.length).split(' ');
                    if (ssrcs.length != 0) {
                        elem.c('ssrc-group', { semantics: semantics, xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                        ssrcs.forEach(function (ssrc) {
                            elem.c('source', { ssrc: ssrc })
                                .up();
                        });
                        elem.up();
                    }
                });

                if (!hasSIM && name == 'video') {
                    // disable simulcast with an empty ssrc-group element.
                    elem.c('ssrc-group', { semantics: 'SIM', xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                    elem.up();
                }
            }

            if (!parts || parts.indexOf('payload-type') !== -1) {
                // FIXME: should reuse code from .toJingle
                for (var j = 0; j < mline.fmt.length; j++) {
                    var rtpmap = SDPUtil.find_line(media, 'a=rtpmap:' + mline.fmt[j]);
                    if (rtpmap) {
                        elem.c('payload-type', SDPUtil.parse_rtpmap(rtpmap));
                        elem.up();
                    }
                }
            }
        }
        else
        {
            var sctpmap = SDPUtil.find_line(media, 'a=sctpmap:' + mline.fmt[0]);
            var sctpPort = SDPUtil.parse_sctpmap(sctpmap)[0];
            elem.c("sctpconnection",
                {
                    initiator: 'true',
                    expire: self.channelExpire,
                    id: self.mychannel[channel].attr('id'),
                    endpoint: self.myMucResource,
                    port: sctpPort
                }
            );
        }

        if (!parts || parts.indexOf('transport') !== -1) {
            localSDP.TransportToJingle(channel, elem);
        }

        elem.up(); // end of channel
        elem.up(); // end of content
    });

    self.connection.sendIQ(elem,
        function (result) {
            // ...
        },
        function (error) {
            console.error(
                "ERROR sending colibri message",
                error, elem);
        }
    );
};

// send a session-initiate to a new participant
ColibriFocus.prototype.initiate = function (peer, isInitiator) {
    var participant = this.peers.indexOf(peer);
    console.log('tell', peer, participant);
    var sdp;

    if (!(this.peerconnection !== null && this.peerconnection.signalingState == 'stable')) {
        console.error('can not initiate a new session without a stable peerconnection');
        return;
    }

    sdp = new SDP(this.peerconnection.remoteDescription.sdp);
    var localSDP = new SDP(this.peerconnection.localDescription.sdp);
    // throw away stuff we don't want
    // not needed with static offer
    if (!config.useBundle) {
        sdp.removeSessionLines('a=group:');
    }
    sdp.removeSessionLines('a=msid-semantic:'); // FIXME: not mapped over jingle anyway...
    for (var i = 0; i < sdp.media.length; i++) {
        if (!config.useRtcpMux) {
            sdp.removeMediaLines(i, 'a=rtcp-mux');
        }
        sdp.removeMediaLines(i, 'a=ssrc:');
        sdp.removeMediaLines(i, 'a=ssrc-group:');
        sdp.removeMediaLines(i, 'a=crypto:');
        sdp.removeMediaLines(i, 'a=candidate:');
        sdp.removeMediaLines(i, 'a=ice-options:google-ice');
        sdp.removeMediaLines(i, 'a=ice-ufrag:');
        sdp.removeMediaLines(i, 'a=ice-pwd:');
        sdp.removeMediaLines(i, 'a=fingerprint:');
        sdp.removeMediaLines(i, 'a=setup:');
    }

    // add stuff we got from the bridge
    for (var j = 0; j < sdp.media.length; j++) {
        var chan = $(this.channels[participant][j]);
        console.log('channel id', chan.attr('id'));

        tmp = chan.find('>source[xmlns="urn:xmpp:jingle:apps:rtp:ssma:0"]');

        var name = sdp.media[j].split(" ")[0].substr(2); // 'm=audio ...'
        if (name === 'audio' || name === 'video') {
            // make chrome happy... '3735928559' == 0xDEADBEEF
            var ssrc = tmp.length ? tmp.attr('ssrc') : '3735928559';

            sdp.media[j] += 'a=ssrc:' + ssrc + ' cname:mixed\r\n';
            sdp.media[j] += 'a=ssrc:' + ssrc + ' label:mixedlabel' + name + '0\r\n';
            sdp.media[j] += 'a=ssrc:' + ssrc + ' msid:mixedmslabel mixedlabel' + name + '0\r\n';
            sdp.media[j] += 'a=ssrc:' + ssrc + ' mslabel:mixedmslabel\r\n';
        }

        // In the case of bundle, we add each candidate to all m= lines/jingle contents,
        // just as chrome does
        if (config.useBundle){
            tmp = this.bundledTransports[chan.attr('channel-bundle-id')];
        } else {
            tmp = chan.find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]');
        }

        if (tmp.length) {
            if (tmp.attr('ufrag'))
                sdp.media[j] += 'a=ice-ufrag:' + tmp.attr('ufrag') + '\r\n';
            if (tmp.attr('pwd'))
                sdp.media[j] += 'a=ice-pwd:' + tmp.attr('pwd') + '\r\n';
            // and the candidates...
            tmp.find('>candidate').each(function () {
                sdp.media[j] += SDPUtil.candidateFromJingle(this);
            });
            tmp = tmp.find('>fingerprint');
            if (tmp.length) {
                sdp.media[j] += 'a=fingerprint:' + tmp.attr('hash') + ' ' + tmp.text() + '\r\n';
                /*
                if (tmp.attr('direction')) {
                    sdp.media[j] += 'a=setup:' + tmp.attr('direction') + '\r\n';
                }
                */
                sdp.media[j] += 'a=setup:actpass\r\n';
            }
        }
    }

    for (var i = 0; i < sdp.media.length; i++) {
        // re-add all remote a=ssrcs _and_ a=ssrc-group
        for (var jid in this.remotessrc) {
            if (jid == peer || !this.remotessrc[jid][i])
                continue;
            sdp.media[i] += this.remotessrc[jid][i];
        }

        // add local a=ssrc-group: lines
        lines = SDPUtil.find_lines(localSDP.media[i], 'a=ssrc-group:');
        if (lines.length != 0)
            sdp.media[i] += lines.join('\r\n') + '\r\n';

        // and local a=ssrc: lines
        sdp.media[i] += SDPUtil.find_lines(localSDP.media[i], 'a=ssrc:').join('\r\n') + '\r\n';
    }
    sdp.raw = sdp.session + sdp.media.join('');

    // make a new colibri session and configure it
    // FIXME: is it correct to use this.connection.jid when used in a MUC?
    var sess = new ColibriSession(this.connection.jid,
                                  Math.random().toString(36).substr(2, 12), // random string
                                  this.connection);
    sess.initiate(peer);
    sess.colibri = this;
    // We do not announce our audio per conference peer, so only video is set here
    sess.localVideo = this.connection.jingle.localVideo;
    sess.media_constraints = this.connection.jingle.media_constraints;
    sess.pc_constraints = this.connection.jingle.pc_constraints;
    sess.ice_config = this.connection.jingle.ice_config;

    this.connection.jingle.sessions[sess.sid] = sess;
    this.connection.jingle.jid2session[sess.peerjid] = sess;

    // send a session-initiate
    var init = $iq({to: peer, type: 'set'})
        .c('jingle',
            {xmlns: 'urn:xmpp:jingle:1',
             action: 'session-initiate',
             initiator: sess.me,
             sid: sess.sid
            }
    );
    sdp.toJingle(init, 'initiator');
    this.connection.sendIQ(init,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.log('got error');
        }
    );
};

// pull in a new participant into the conference
ColibriFocus.prototype.addNewParticipant = function (peer) {
    var self = this;
    if (this.confid === 0 || !this.peerconnection.localDescription)
    {
        // bad state
        if (this.confid === 0)
        {
            console.error('confid does not exist yet, postponing', peer);
        }
        else
        {
            console.error('local description not ready yet, postponing', peer);
        }
        window.setTimeout(function () { self.addNewParticipant(peer); }, 250);
        return;
    }
    var index = this.channels.length;
    this.channels.push([]);
    this.peers.push(peer);

    var elem = $iq({to: this.bridgejid, type: 'get'});
    elem.c(
        'conference',
        { xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid });
    var localSDP = new SDP(this.peerconnection.localDescription.sdp);
    localSDP.media.forEach(function (media, channel) {
        var name = SDPUtil.parse_mid(SDPUtil.find_line(media, 'a=mid:'));
        var elemName;
        var endpointId = peer.substr(1 + peer.lastIndexOf('/'));
        var elemAttrs
            = {
                initiator: 'true',
                expire: self.channelExpire,
                endpoint: endpointId
            };
        if (config.useBundle) {
            elemAttrs['channel-bundle-id'] = endpointId;
        }


        if ('data' == name)
        {
            elemName = 'sctpconnection';
            elemAttrs['port'] = 5000;
        }
        else
        {
            elemName = 'channel';
            if ('video' === name) {
                if (self.channelLastN >= 0) {
                    elemAttrs['last-n'] = self.channelLastN;
                }
                if (config.adaptiveLastN) {
                    elemAttrs['adaptive-last-n'] = 'true';
                }
                if (config.adaptiveSimulcast) {
                    elemAttrs['adaptive-simulcast'] = 'true';
                }
            }
        }

        elem.c('content', { name: name });
        elem.c(elemName, elemAttrs);
        elem.up(); // end of channel/sctpconnection
        elem.up(); // end of content
    });

    this.connection.sendIQ(elem,
        function (result) {
            var contents = $(result).find('>conference>content').get();
            var i;
            for (i = 0; i < contents.length; i++) {
                var channelXml = $(contents[i]).find('>channel');
                if (channelXml.length)
                {
                    tmp = channelXml.get();
                }
                else
                {
                    tmp = $(contents[i]).find('>sctpconnection').get();
                }
                self.channels[index][i] = tmp[0];
            }
            var channelBundles = $(result).find('>conference>channel-bundle');
            for (i = 0; i < channelBundles.length; i++)
            {
                var endpointId = $(channelBundles[i]).attr('id');
                self.bundledTransports[endpointId] = $(channelBundles[i]).find('>transport[xmlns="urn:xmpp:jingle:transports:ice-udp:1"]');
            }
            self.initiate(peer, true);
        },
        function (error) {
            console.warn(error);
        }
    );
};

// update the channel description (payload-types + dtls fp) for a participant
ColibriFocus.prototype.updateRemoteChannel = function (remoteSDP, participant, parts) {
    console.log('change allocation for', this.confid);
    var self = this;
    var change = $iq({to: this.bridgejid, type: 'set'});
    change.c('conference', {xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid});
    for (channel = 0; channel < this.channels[participant].length; channel++) {
        if (!remoteSDP.media[channel])
            continue;

        var name = SDPUtil.parse_mid(SDPUtil.find_line(remoteSDP.media[channel], 'a=mid:'));
        change.c('content', {name: name});
        if (name !== 'data') {
            change.c('channel', {
                id: $(this.channels[participant][channel]).attr('id'),
                endpoint: $(this.channels[participant][channel]).attr('endpoint'),
                expire: self.channelExpire
            });

            if (!parts || parts.indexOf('sources') !== -1) {
                // signal (throught COLIBRI) to the bridge the SSRC groups of this
                // participant
                var ssrc_group_lines = SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc-group:');
                var idx = 0;
                var hasSIM = false;
                ssrc_group_lines.forEach(function (line) {
                    idx = line.indexOf(' ');
                    var semantics = line.substr(0, idx).substr(13);
                    if (semantics == 'SIM') {
                        hasSIM = true;
                    }
                    var ssrcs = line.substr(14 + semantics.length).split(' ');
                    if (ssrcs.length != 0) {
                        change.c('ssrc-group', { semantics: semantics, xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                        ssrcs.forEach(function (ssrc) {
                            change.c('source', { ssrc: ssrc })
                                .up();
                        });
                        change.up();
                    }
                });

                if (!hasSIM && name == 'video') {
                    // disable simulcast with an empty ssrc-group element.
                    change.c('ssrc-group', { semantics: 'SIM', xmlns: 'urn:xmpp:jingle:apps:rtp:ssma:0' });
                    change.up();
                }
            }

            if (!parts || parts.indexOf('payload-type') !== -1) {
                var rtpmap = SDPUtil.find_lines(remoteSDP.media[channel], 'a=rtpmap:');
                rtpmap.forEach(function (val) {
                    // TODO: too much copy-paste
                    var rtpmap = SDPUtil.parse_rtpmap(val);
                    change.c('payload-type', rtpmap);
                    //
                    // put any 'a=fmtp:' + mline.fmt[j] lines into <param name=foo value=bar/>
                    /*
                     if (SDPUtil.find_line(remoteSDP.media[channel], 'a=fmtp:' + rtpmap.id)) {
                     tmp = SDPUtil.parse_fmtp(SDPUtil.find_line(remoteSDP.media[channel], 'a=fmtp:' + rtpmap.id));
                     for (var k = 0; k < tmp.length; k++) {
                     change.c('parameter', tmp[k]).up();
                     }
                     }
                     */
                    change.up();
                });
            }
        }
        else
        {
            var sctpmap = SDPUtil.find_line(remoteSDP.media[channel], 'a=sctpmap:');
            change.c('sctpconnection', {
                id: $(this.channels[participant][channel]).attr('id'),
                endpoint: $(this.channels[participant][channel]).attr('endpoint'),
                expire: self.channelExpire,
                port: SDPUtil.parse_sctpmap(sctpmap)[0]
            });
        }

        if (!parts || parts.indexOf('transport') !== -1) {
            // now add transport
            remoteSDP.TransportToJingle(channel, change);
        }

        change.up(); // end of channel/sctpconnection
        change.up(); // end of content
    }
    this.connection.sendIQ(change,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.log('got error');
        }
    );
};

/**
 * Switches video streams.
 * @param new_stream new stream that will be used as video of this session.
 * @param oldStream old video stream of this session.
 * @param success_callback callback executed after successful stream switch.
 */
ColibriFocus.prototype.switchStreams = function (new_stream, oldStream, success_callback) {

    var self = this;

    // Stop the stream to trigger onended event for old stream
    oldStream.stop();

    // Remember SDP to figure out added/removed SSRCs
    var oldSdp = null;
    if(self.peerconnection) {
        if(self.peerconnection.localDescription) {
            oldSdp = new SDP(self.peerconnection.localDescription.sdp);
        }
        self.peerconnection.removeStream(oldStream);
        self.peerconnection.addStream(new_stream);
    }

    self.connection.jingle.localVideo = new_stream;

    self.connection.jingle.localStreams = [];
    self.connection.jingle.localStreams.push(self.connection.jingle.localAudio);
    self.connection.jingle.localStreams.push(self.connection.jingle.localVideo);

    // Conference is not active
    if(!oldSdp || !self.peerconnection) {
        success_callback();
        return;
    }

    self.peerconnection.switchstreams = true;
    self.modifySources(function() {
        console.log('modify sources done');

        var newSdp = new SDP(self.peerconnection.localDescription.sdp);

        // change allocation on bridge
        self.updateLocalChannel(newSdp, ['sources']);

        console.log("SDPs", oldSdp, newSdp);
        self.notifyMySSRCUpdate(oldSdp, newSdp);

        success_callback();
    });
};

// tell everyone about a new participants a=ssrc lines (isadd is true)
// or a leaving participants a=ssrc lines
ColibriFocus.prototype.sendSSRCUpdate = function (sdpMediaSsrcs, fromJid, isadd) {
    var self = this;
    this.peers.forEach(function (peerjid) {
        if (peerjid == fromJid) return;
        console.log('tell', peerjid, 'about ' + (isadd ? 'new' : 'removed') + ' ssrcs from', fromJid);
        if (!self.remotessrc[peerjid]) {
            // FIXME: this should only send to participants that are stable, i.e. who have sent a session-accept
            // possibly, this.remoteSSRC[session.peerjid] does not exist yet
            console.warn('do we really want to bother', peerjid, 'with updates yet?');
        }
        var peersess = self.connection.jingle.jid2session[peerjid];
        if(!peersess){
            console.warn('no session with peer: '+peerjid+' yet...');
            return;
        }

        self.sendSSRCUpdateIq(sdpMediaSsrcs, peersess.sid, peersess.initiator, peerjid, isadd);
    });
};

/**
 * Overrides SessionBase.addSource.
 *
 * @param elem proprietary 'add source' Jingle request(XML node).
 * @param fromJid JID of the participant to whom new ssrcs belong.
 */
ColibriFocus.prototype.addSource = function (elem, fromJid) {

    var self = this;
    // FIXME: dirty waiting
    if (!this.peerconnection.localDescription)
    {
        console.warn("addSource - localDescription not ready yet");
        setTimeout(function() { self.addSource(elem, fromJid); }, 200);
        return;
    }

    this.peerconnection.addSource(elem);

    // NOTE(gp) this could be a useful thing to have in every Array object.
    var diffArray = function(a) {
        return this.filter(function(i) {return a.indexOf(i) < 0;});
    };

    var peerSsrc = this.remotessrc[fromJid];
    // console.log("On ADD", this.peerconnection.addssrc, peerSsrc);
    this.peerconnection.addssrc.forEach(function(val, idx){
        if(!peerSsrc[idx]){
            // add ssrc
            peerSsrc[idx] = val;
        } else if (val) {
            // NOTE(gp) we can't expect the lines in the removessrc SDP fragment
            // to be in the same order as in the lines in the peerSsrc SDP
            // fragment. So, here we remove the val lines and re-add them.

            var lines = peerSsrc[idx].split('\r\n');
            var diffLines = val.split('\r\n');

            // Remove ssrc
            peerSsrc[idx] = diffArray.apply(lines, [diffLines]).join('\r\n');

            // Add ssrc
            peerSsrc[idx] = peerSsrc[idx]+val;
        }
    });

    var oldRemoteSdp = new SDP(this.peerconnection.remoteDescription.sdp);
    this.modifySources(function() {
        // Notify other participants about added ssrc
        var remoteSDP = new SDP(self.peerconnection.remoteDescription.sdp);
        var newSSRCs = oldRemoteSdp.getNewMedia(remoteSDP);
        self.sendSSRCUpdate(newSSRCs, fromJid, true);
        // change allocation on bridge
        if (peerSsrc[1] /* video */) {
            // If the remote peer has changed its video sources, then we need to
            // update the bridge with this information, in order for the
            // simulcast manager of the remote peer to update its layers, and
            // any associated receivers to adjust to the change.
            var videoSDP = new SDP(['v=0', 'm=audio', 'a=mid:audio', peerSsrc[0]].join('\r\n') + ['m=video', 'a=mid:video', peerSsrc[1]].join('\r\n'));
            var participant = self.peers.indexOf(fromJid);
            self.updateRemoteChannel(videoSDP, participant, ['sources']);
        }
    });
};

/**
 * Overrides SessionBase.removeSource.
 *
 * @param elem proprietary 'remove source' Jingle request(XML node).
 * @param fromJid JID of the participant to whom removed ssrcs belong.
 */
ColibriFocus.prototype.removeSource = function (elem, fromJid) {

    var self = this;
    // FIXME: dirty waiting
    if (!self.peerconnection.localDescription)
    {
        console.warn("removeSource - localDescription not ready yet");
        setTimeout(function() { self.removeSource(elem, fromJid); }, 200);
        return;
    }

    this.peerconnection.removeSource(elem);

    // NOTE(gp) this could be a useful thing to have in every Array object.
    var diffArray = function(a) {
        return this.filter(function(i) {return a.indexOf(i) < 0;});
    };

    var peerSsrc = this.remotessrc[fromJid];
    // console.log("On REMOVE", this.peerconnection.removessrc, peerSsrc);
    this.peerconnection.removessrc.forEach(function(val, idx){
        if(peerSsrc[idx] && val){
            // NOTE(gp) we can't expect the lines in the removessrc SDP fragment
            // to be in the same order as in the lines in the peerSsrc SDP
            // fragment.
            var lines = peerSsrc[idx].split('\r\n');
            var diffLines = val.split('\r\n');
            // Remove ssrc
            peerSsrc[idx] = diffArray.apply(lines, [diffLines]).join('\r\n');
        }
    });

    var oldSDP = new SDP(self.peerconnection.remoteDescription.sdp);
    this.modifySources(function(){
        // Notify other participants about removed ssrc
        var remoteSDP = new SDP(self.peerconnection.remoteDescription.sdp);
        var removedSSRCs = remoteSDP.getNewMedia(oldSDP);
        self.sendSSRCUpdate(removedSSRCs, fromJid, false);
        // change allocation on bridge
        if (peerSsrc[1] /* video */) {
            // If the remote peer has changed its video sources, then we need to
            // update the bridge with this information, in order for the
            // simulcast manager of the remote peer to update its layers, and
            // any associated receivers to adjust to the change.
            var videoSDP = new SDP(['v=0', 'm=audio', 'a=mid:audio', peerSsrc[0]].join('\r\n') + ['m=video', 'a=mid:video', peerSsrc[1]].join('\r\n'));
            var participant = self.peers.indexOf(fromJid);
            self.updateRemoteChannel(videoSDP, participant, ['sources']);
        }
    });
};

ColibriFocus.prototype.setRemoteDescription = function (session, elem, desctype) {
    var participant = this.peers.indexOf(session.peerjid);
    console.log('Colibri.setRemoteDescription from', session.peerjid, participant);
    var remoteSDP = new SDP('');
    var channel;
    remoteSDP.fromJingle(elem);

    // ACT 1: change allocation on bridge
    this.updateRemoteChannel(remoteSDP, participant);

    // ACT 2: tell anyone else about the new SSRCs
    this.sendSSRCUpdate(remoteSDP.getMediaSsrcMap(), session.peerjid, true);

    // ACT 3: note the SSRCs
    this.remotessrc[session.peerjid] = [];
    for (channel = 0; channel < this.channels[participant].length; channel++) {
        //if (channel == 0) continue; FIXME: does not work as intended
        if (!remoteSDP.media[channel])
            continue;

        var lines = SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc-group:');
        if (lines.length != 0)
            // prepend ssrc-groups
            this.remotessrc[session.peerjid][channel] = lines.join('\r\n') + '\r\n';

        if (SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc:').length)
        {
            if (!this.remotessrc[session.peerjid][channel])
                this.remotessrc[session.peerjid][channel] = '';

            this.remotessrc[session.peerjid][channel] +=
                SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc:')
                        .join('\r\n') + '\r\n';
        }
    }

    // ACT 4: add new a=ssrc and s=ssrc-group lines to local remotedescription
    for (channel = 0; channel < this.channels[participant].length; channel++) {
        //if (channel == 0) continue; FIXME: does not work as intended
        if (!remoteSDP.media[channel])
            continue;

        var lines = SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc-group:');
        if (lines.length != 0)
            this.peerconnection.enqueueAddSsrc(
                channel, SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc-group:').join('\r\n') + '\r\n');

        if (SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc:').length) {
            this.peerconnection.enqueueAddSsrc(
                channel,
                SDPUtil.find_lines(remoteSDP.media[channel], 'a=ssrc:').join('\r\n') + '\r\n'
            );
        }
    }
    this.modifySources();
};

// relay ice candidates to bridge using trickle
ColibriFocus.prototype.addIceCandidate = function (session, elem) {
    var self = this;
    var participant = this.peers.indexOf(session.peerjid);
    //console.log('change transport allocation for', this.confid, session.peerjid, participant);
    var change = $iq({to: this.bridgejid, type: 'set'});
    change.c('conference', {xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid});
    $(elem).each(function () {
        var name = $(this).attr('name');

        // If we are using bundle, audio/video/data channel will have the same candidates, so only send them for
        // the audio channel.
        if (config.useBundle && name !== 'audio') {
            return;
        }

        var channel = name == 'audio' ? 0 : 1; // FIXME: search mlineindex in localdesc
        if (name != 'audio' && name != 'video')
            channel = 2; // name == 'data'

        change.c('content', {name: name});
        if (name !== 'data')
        {
            change.c('channel', {
                id: $(self.channels[participant][channel]).attr('id'),
                endpoint: $(self.channels[participant][channel]).attr('endpoint'),
                expire: self.channelExpire
            });
        }
        else
        {
            change.c('sctpconnection', {
                id: $(self.channels[participant][channel]).attr('id'),
                endpoint: $(self.channels[participant][channel]).attr('endpoint'),
                expire: self.channelExpire
            });
        }
        $(this).find('>transport').each(function () {
            change.c('transport', {
                ufrag: $(this).attr('ufrag'),
                pwd: $(this).attr('pwd'),
                xmlns: $(this).attr('xmlns')
            });
            if (config.useRtcpMux
                  && 'channel' === change.node.parentNode.nodeName) {
                change.c('rtcp-mux').up();
            }

            $(this).find('>candidate').each(function () {
                /* not yet
                if (this.getAttribute('protocol') == 'tcp' && this.getAttribute('port') == 0) {
                    // chrome generates TCP candidates with port 0
                    return;
                }
                */
                var line = SDPUtil.candidateFromJingle(this);
                change.c('candidate', SDPUtil.candidateToJingle(line)).up();
            });
            change.up(); // end of transport
        });
        change.up(); // end of channel/sctpconnection
        change.up(); // end of content
    });
    // FIXME: need to check if there is at least one candidate when filtering TCP ones
    this.connection.sendIQ(change,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.error('got error', err);
        }
    );
};

// send our own candidate to the bridge
ColibriFocus.prototype.sendIceCandidate = function (candidate) {
    var self = this;
    //console.log('candidate', candidate);
    if (!candidate) {
        console.log('end of candidates');
        return;
    }
    if (this.drip_container.length === 0) {
        // start 20ms callout
        window.setTimeout(
            function () {
                if (self.drip_container.length === 0) return;
                self.sendIceCandidates(self.drip_container);
                self.drip_container = [];
            },
            20);
    }
    this.drip_container.push(candidate);
};

// sort and send multiple candidates
ColibriFocus.prototype.sendIceCandidates = function (candidates) {
    var self = this;
    var mycands = $iq({to: this.bridgejid, type: 'set'});
    mycands.c('conference', {xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid});
    // FIXME: multi-candidate logic is taken from strophe.jingle, should be refactored there
    var localSDP = new SDP(this.peerconnection.localDescription.sdp);
    for (var mid = 0; mid < localSDP.media.length; mid++)
    {
        var cands = candidates.filter(function (el) { return el.sdpMLineIndex == mid; });
        if (cands.length > 0)
        {
            var name = cands[0].sdpMid;
            mycands.c('content', {name: name });
            if (name !== 'data')
            {
                mycands.c('channel', {
                    id: $(this.mychannel[cands[0].sdpMLineIndex]).attr('id'),
                    endpoint: $(this.mychannel[cands[0].sdpMLineIndex]).attr('endpoint'),
                    expire: self.channelExpire
                });
            }
            else
            {
                mycands.c('sctpconnection', {
                    id: $(this.mychannel[cands[0].sdpMLineIndex]).attr('id'),
                    endpoint: $(this.mychannel[cands[0].sdpMLineIndex]).attr('endpoint'),
                    port: $(this.mychannel[cands[0].sdpMLineIndex]).attr('port'),
                    expire: self.channelExpire
                });
            }
            mycands.c('transport', {xmlns: 'urn:xmpp:jingle:transports:ice-udp:1'});
            if (config.useRtcpMux && name !== 'data') {
                mycands.c('rtcp-mux').up();
            }
            for (var i = 0; i < cands.length; i++) {
                mycands.c('candidate', SDPUtil.candidateToJingle(cands[i].candidate)).up();
            }
            mycands.up(); // transport
            mycands.up(); // channel / sctpconnection
            mycands.up(); // content
        }
    }
    console.log('send cands', candidates);
    this.connection.sendIQ(mycands,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.error('got error', err);
        }
    );
};

ColibriFocus.prototype.terminate = function (session, reason) {
    console.log('remote session terminated from', session.peerjid);
    var participant = this.peers.indexOf(session.peerjid);
    if (!this.remotessrc[session.peerjid] || participant == -1) {
        return;
    }
    var ssrcs = this.remotessrc[session.peerjid];
    for (var i = 0; i < ssrcs.length; i++) {
        this.peerconnection.enqueueRemoveSsrc(i, ssrcs[i]);
    }
    // remove from this.peers
    this.peers.splice(participant, 1);
    // expire channel on bridge
    var change = $iq({to: this.bridgejid, type: 'set'});
    change.c('conference', {xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid});
    for (var channel = 0; channel < this.channels[participant].length; channel++) {
        var name = channel === 0 ? 'audio' : 'video';
        if (channel == 2)
            name = 'data';
        change.c('content', {name: name});
        if (name !== 'data')
        {
            change.c('channel', {
                id: $(this.channels[participant][channel]).attr('id'),
                endpoint: $(this.channels[participant][channel]).attr('endpoint'),
                expire: '0'
            });
        }
        else
        {
            change.c('sctpconnection', {
                id: $(this.channels[participant][channel]).attr('id'),
                endpoint: $(this.channels[participant][channel]).attr('endpoint'),
                expire: '0'
            });
        }
        change.up(); // end of channel/sctpconnection
        change.up(); // end of content
    }
    this.connection.sendIQ(change,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.error('got error', err);
        }
    );
    // and remove from channels
    this.channels.splice(participant, 1);

    // tell everyone about the ssrcs to be removed
    var sdp = new SDP('');
    var localSDP = new SDP(this.peerconnection.localDescription.sdp);
    var contents = SDPUtil.find_lines(localSDP.raw, 'a=mid:').map(SDPUtil.parse_mid);
    for (var j = 0; j < ssrcs.length; j++) {
        sdp.media[j] = 'a=mid:' + contents[j] + '\r\n';
        sdp.media[j] += ssrcs[j];
        this.peerconnection.enqueueRemoveSsrc(j, ssrcs[j]);
    }
    this.sendSSRCUpdate(sdp.getMediaSsrcMap(), session.peerjid, false);

    delete this.remotessrc[session.peerjid];
    this.modifySources();
};

ColibriFocus.prototype.sendTerminate = function (session, reason, text) {
    var term = $iq({to: session.peerjid, type: 'set'})
        .c('jingle',
            {xmlns: 'urn:xmpp:jingle:1',
            action: 'session-terminate',
            initiator: session.me,
            sid: session.sid})
        .c('reason')
        .c(reason || 'success');

    if (text) {
        term.up().c('text').t(text);
    }

    this.connection.sendIQ(term,
        function () {
            if (!session)
                return;

            if (session.peerconnection) {
                session.peerconnection.close();
                session.peerconnection = null;
            }

            session.terminate();
            var ack = {};
            ack.source = 'terminate';
            $(document).trigger('ack.jingle', [session.sid, ack]);
        },
        function (stanza) {
            var error = ($(stanza).find('error').length) ? {
                code: $(stanza).find('error').attr('code'),
                reason: $(stanza).find('error :first')[0].tagName,
            }:{};
            $(document).trigger('ack.jingle', [self.sid, error]);
        },
        10000);
    if (this.statsinterval !== null) {
        window.clearInterval(this.statsinterval);
        this.statsinterval = null;
    }
};

ColibriFocus.prototype.setRTCPTerminationStrategy = function (strategyFQN) {
    var self = this;

    // TODO(gp) maybe move the RTCP termination strategy element under the
    // content or channel element.
    var strategyIQ = $iq({to: this.bridgejid, type: 'set'});
    strategyIQ.c('conference', {
	    xmlns: 'http://jitsi.org/protocol/colibri',
	    id: this.confid,
    });

    strategyIQ.c('rtcp-termination-strategy', {name: strategyFQN });

    strategyIQ.c('content', {name: "video"});
    strategyIQ.up(); // end of content

    console.log('setting RTCP termination strategy', strategyFQN);
    this.connection.sendIQ(strategyIQ,
        function (res) {
            console.log('got result');
        },
        function (err) {
            console.error('got error', err);
        }
    );
};

/**
 * Sets the default value of the channel last-n attribute in this conference and
 * updates/patches the existing channels.
 */
ColibriFocus.prototype.setChannelLastN = function (channelLastN) {
    if (('number' === typeof(channelLastN))
            && (this.channelLastN !== channelLastN))
    {
        this.channelLastN = channelLastN;

        // Update/patch the existing channels.
        var patch = $iq({ to: this.bridgejid, type: 'set' });

        patch.c(
            'conference',
            { xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid });
        patch.c('content', { name: 'video' });
        patch.c(
            'channel',
            {
                id: $(this.mychannel[1 /* video */]).attr('id'),
                'last-n': this.channelLastN
            });
        patch.up(); // end of channel
        for (var p = 0; p < this.channels.length; p++)
        {
            patch.c(
                'channel',
                {
                    id: $(this.channels[p][1 /* video */]).attr('id'),
                    'last-n': this.channelLastN
                });
            patch.up(); // end of channel
        }
        this.connection.sendIQ(
            patch,
            function (res) {
                console.info('Set channel last-n succeeded:', res);
            },
            function (err) {
                console.error('Set channel last-n failed:', err);
            });
    }
};

/**
 * Sets the default value of the channel simulcast layer attribute in this
 * conference and updates/patches the existing channels.
 */
ColibriFocus.prototype.setReceiveSimulcastLayer = function (receiveSimulcastLayer) {
    if (('number' === typeof(receiveSimulcastLayer))
        && (this.receiveSimulcastLayer !== receiveSimulcastLayer))
    {
        // TODO(gp) be able to set the receiving simulcast layer on a per
        // sender basis.
        this.receiveSimulcastLayer = receiveSimulcastLayer;

        // Update/patch the existing channels.
        var patch = $iq({ to: this.bridgejid, type: 'set' });

        patch.c(
            'conference',
            { xmlns: 'http://jitsi.org/protocol/colibri', id: this.confid });
        patch.c('content', { name: 'video' });
        patch.c(
            'channel',
            {
                id: $(this.mychannel[1 /* video */]).attr('id'),
                'receive-simulcast-layer': this.receiveSimulcastLayer
            });
        patch.up(); // end of channel
        for (var p = 0; p < this.channels.length; p++)
        {
            patch.c(
                'channel',
                {
                    id: $(this.channels[p][1 /* video */]).attr('id'),
                    'receive-simulcast-layer': this.receiveSimulcastLayer
                });
            patch.up(); // end of channel
        }
        this.connection.sendIQ(
            patch,
            function (res) {
                console.info('Set channel simulcast receive layer succeeded:', res);
            },
            function (err) {
                console.error('Set channel simulcast receive layer failed:', err);
            });
    }
};