Removes the local SSRC replacement hack and fixes video muting/unmuting when simulcast is enabled.

Conflicts:
	modules/xmpp/JingleSessionPC.js
	modules/xmpp/LocalSSRCReplacement.js
	modules/xmpp/TraceablePeerConnection.js

modules/util/RandomUtil.js

@@ -67,7 +67,8 @@ var RandomUtil = {
         return ret;
     },
     randomElement: randomElement,
-    randomAlphanumStr: randomAlphanumStr
+    randomAlphanumStr: randomAlphanumStr,
+    randomInt: randomInt
 };
 
 module.exports = RandomUtil;

modules/xmpp/JingleSessionPC.js

@@ -10,7 +10,6 @@ var async = require("async");
 var transform = require("sdp-transform");
 var XMPPEvents = require("../../service/xmpp/XMPPEvents");
 var RTCBrowserType = require("../RTC/RTCBrowserType");
-var SSRCReplacement = require("./LocalSSRCReplacement");
 var RTC = require("../RTC/RTC");
 
 // Jingle stuff
@@ -274,8 +273,6 @@ JingleSessionPC.prototype.accept = function () {
             //logger.log('setLocalDescription success');
             self.setLocalDescription();
 
-            SSRCReplacement.processSessionInit(accept);
-
             self.connection.sendIQ(accept,
                 function () {
                     var ack = {};
@@ -373,8 +370,6 @@ JingleSessionPC.prototype.sendIceCandidate = function (candidate) {
                     self.initiator == self.me ? 'initiator' : 'responder',
                     ssrc);
 
-                SSRCReplacement.processSessionInit(init);
-
                 self.connection.sendIQ(init,
                     function () {
                         //logger.log('session initiate ack');
@@ -491,8 +486,6 @@ JingleSessionPC.prototype.createdOffer = function (sdp) {
             init,
             this.initiator == this.me ? 'initiator' : 'responder');
 
-        SSRCReplacement.processSessionInit(init);
-
         self.connection.sendIQ(init,
             function () {
                 var ack = {};
@@ -793,8 +786,6 @@ JingleSessionPC.prototype.createdAnswer = function (sdp, provisional) {
                     self.initiator == self.me ? 'initiator' : 'responder',
                     ssrcs);
 
-                SSRCReplacement.processSessionInit(accept);
-
                 self.connection.sendIQ(accept,
                     function () {
                         var ack = {};
@@ -1349,11 +1340,6 @@ JingleSessionPC.prototype.notifyMySSRCUpdate = function (old_sdp, new_sdp) {
     );
     var removed = sdpDiffer.toJingle(remove);
 
-    // Let 'source-remove' IQ through the hack and see if we're allowed to send
-    // it in the current form
-    if (removed)
-        remove = SSRCReplacement.processSourceRemove(remove);
-
     if (removed && remove) {
         logger.info("Sending source-remove", remove);
         this.connection.sendIQ(remove,
@@ -1380,11 +1366,6 @@ JingleSessionPC.prototype.notifyMySSRCUpdate = function (old_sdp, new_sdp) {
     );
     var added = sdpDiffer.toJingle(add);
 
-    // Let 'source-add' IQ through the hack and see if we're allowed to send
-    // it in the current form
-    if (added)
-        add = SSRCReplacement.processSourceAdd(add);
-
     if (added && add) {
         logger.info("Sending source-add", add);
         this.connection.sendIQ(add,

modules/xmpp/LocalSSRCReplacement.js

@@ -1,292 +0,0 @@
-/* global $ */
-var logger = require("jitsi-meet-logger").getLogger(__filename);
-
-
-/*
- Here we do modifications of local video SSRCs. There are 2 situations we have
- to handle:
-
- 1. We generate SSRC for local recvonly video stream. This is the case when we
-    have no local camera and it is not generated automatically, but SSRC=1 is
-    used implicitly. If that happens RTCP packets will be dropped by the JVB
-    and we won't be able to request video key frames correctly.
-
- 2. A hack to re-use SSRC of the first video stream for any new stream created
-    in future. It turned out that Chrome may keep on using the SSRC of removed
-    video stream in RTCP even though a new one has been created. So we just
-    want to avoid that by re-using it. Jingle 'source-remove'/'source-add'
-    notifications are blocked once first video SSRC is advertised to the focus.
-
- What this hack does:
-
- 1. Stores the SSRC of the first video stream created by
-   a) scanning Jingle session-accept/session-invite for existing video SSRC
-   b) watching for 'source-add' for new video stream if it has not been
-      created in step a)
- 2. Exposes method 'mungeLocalVideoSSRC' which replaces any new video SSRC with
-    the stored one. It is called by 'TracablePeerConnection' before local SDP is
-    returned to the other parts of the application.
- 3. Scans 'source-remove'/'source-add' notifications for stored video SSRC and
-    blocks those notifications. This makes Jicofo and all participants think
-    that it exists all the time even if the video stream has been removed or
-    replaced locally. Thanks to that there is no additional signaling activity
-    on video mute or when switching to the desktop stream.
- */
-
-var SDP = require('./SDP');
-var RandomUtil = require('../util/RandomUtil');
-var RTCBrowserType = require('../RTC/RTCBrowserType');
-
-/**
- * The hack is enabled on all browsers except FF by default
- * FIXME finish the hack once removeStream method is implemented in FF
- * @type {boolean}
- */
-var isEnabled = !RTCBrowserType.isFirefox();
-
-
-/**
- * Stored SSRC of local video stream.
- */
-var localVideoSSRC;
-
-/**
- * SSRC used for recvonly video stream when we have no local camera.
- * This is in order to tell Chrome what SSRC should be used in RTCP requests
- * instead of 1.
- */
-var localRecvOnlySSRC, localRecvOnlyMSID, localRecvOnlyMSLabel, localRecvOnlyLabel;
-
-/**
- * cname for <tt>localRecvOnlySSRC</tt>
- */
-var localRecvOnlyCName;
-
-/**
- * Method removes <source> element which describes <tt>localVideoSSRC</tt>
- * from given Jingle IQ.
- * @param modifyIq 'source-add' or 'source-remove' Jingle IQ.
- * @param actionName display name of the action which will be printed in log
- *        messages.
- * @returns {*} modified Jingle IQ, so that it does not contain <source> element
- *          corresponding to <tt>localVideoSSRC</tt> or <tt>null</tt> if no
- *          other SSRCs left to be signaled after removing it.
- */
-var filterOutSource = function (modifyIq, actionName) {
-    var modifyIqTree = $(modifyIq.tree());
-
-    if (!localVideoSSRC)
-        return modifyIqTree[0];
-
-    var videoSSRC = modifyIqTree.find(
-        '>jingle>content[name="video"]' +
-        '>description>source[ssrc="' + localVideoSSRC + '"]');
-
-    if (!videoSSRC.length) {
-        return modifyIqTree[0];
-    }
-
-    logger.info(
-        'Blocking ' + actionName + ' for local video SSRC: ' + localVideoSSRC);
-
-    videoSSRC.remove();
-
-    // Check if any sources still left to be added/removed
-    if (modifyIqTree.find('>jingle>content>description>source').length) {
-        return modifyIqTree[0];
-    } else {
-        return null;
-    }
-};
-
-/**
- * Scans given Jingle IQ for video SSRC and stores it.
- * @param jingleIq the Jingle IQ to be scanned for video SSRC.
- */
-var storeLocalVideoSSRC = function (jingleIq) {
-    var videoSSRCs =
-        $(jingleIq.tree())
-            .find('>jingle>content[name="video"]>description>source');
-
-    videoSSRCs.each(function (idx, ssrcElem) {
-        if (localVideoSSRC)
-            return;
-        // We consider SSRC real only if it has msid attribute
-        // recvonly streams in FF do not have it as well as local SSRCs
-        // we generate for recvonly streams in Chrome
-        var ssrSel = $(ssrcElem);
-        var msid = ssrSel.find('>parameter[name="msid"]');
-        if (msid.length) {
-            var ssrcVal = ssrSel.attr('ssrc');
-            if (ssrcVal) {
-                localVideoSSRC = ssrcVal;
-                logger.info('Stored local video SSRC' +
-                             ' for future re-use: ' + localVideoSSRC);
-            }
-        }
-    });
-};
-
-/**
- * Generates new label/mslabel attribute
- * @returns {string} label/mslabel attribute
- */
-function generateLabel() {
-    return RandomUtil.randomHexString(8) + "-" + RandomUtil.randomHexString(4) +
-        "-" + RandomUtil.randomHexString(4) + "-" +
-        RandomUtil.randomHexString(4) + "-" + RandomUtil.randomHexString(12);
-}
-
-/**
- * Generates new SSRC for local video recvonly stream.
- * FIXME what about eventual SSRC collision ?
- */
-function generateRecvonlySSRC() {
-
-    localVideoSSRC = localRecvOnlySSRC =
-        localVideoSSRC ?
-            localVideoSSRC : Math.random().toString(10).substring(2, 11);
-
-    localRecvOnlyCName =
-        Math.random().toString(36).substring(2);
-
-    localRecvOnlyMSLabel = generateLabel();
-    localRecvOnlyLabel = generateLabel();
-    localRecvOnlyMSID = localRecvOnlyMSLabel + " " + localRecvOnlyLabel;
-
-    logger.info(
-        "Generated local recvonly SSRC: " + localRecvOnlySSRC +
-        ", cname: " + localRecvOnlyCName);
-}
-
-var LocalSSRCReplacement = {
-    /**
-     * Method must be called before 'session-initiate' or 'session-invite' is
-     * sent. Scans the IQ for local video SSRC and stores it if detected.
-     *
-     * @param sessionInit our 'session-initiate' or 'session-accept' Jingle IQ
-     *        which will be scanned for local video SSRC.
-     */
-    processSessionInit: function (sessionInit) {
-        if (!isEnabled)
-            return;
-
-        if (localVideoSSRC) {
-            logger.error("Local SSRC stored already: " + localVideoSSRC);
-            return;
-        }
-        storeLocalVideoSSRC(sessionInit);
-    },
-    /**
-     * If we have local video SSRC stored searched given
-     * <tt>localDescription</tt> for video SSRC and makes sure it is replaced
-     * with the stored one.
-     * @param localDescription local description object that will have local
-     *        video SSRC replaced with the stored one
-     * @returns modified <tt>localDescription</tt> object.
-     */
-    mungeLocalVideoSSRC: function (localDescription) {
-        if (!isEnabled)
-            return localDescription;
-
-        if (!localDescription) {
-            logger.warn("localDescription is null or undefined");
-            return localDescription;
-        }
-
-        // IF we have local video SSRC stored make sure it is replaced
-        // with old SSRC
-        var sdp = new SDP(localDescription.sdp);
-        if (sdp.media.length < 2)
-            return;
-
-        if (localVideoSSRC && sdp.media[1].indexOf("a=ssrc:") !== -1 &&
-            !sdp.containsSSRC(localVideoSSRC)) {
-            // Get new video SSRC
-            var map = sdp.getMediaSsrcMap();
-            var videoPart = map[1];
-            var videoSSRCs = videoPart.ssrcs;
-            var newSSRC = Object.keys(videoSSRCs)[0];
-
-            logger.info(
-                "Replacing new video SSRC: " + newSSRC +
-                " with " + localVideoSSRC);
-
-            localDescription.sdp =
-                sdp.raw.replace(
-                    new RegExp('a=ssrc:' + newSSRC, 'g'),
-                    'a=ssrc:' + localVideoSSRC);
-        }
-        else if (sdp.media[1].indexOf('a=ssrc:') === -1 &&
-                 sdp.media[1].indexOf('a=recvonly') !== -1) {
-            // Make sure we have any SSRC for recvonly video stream
-            if (!localRecvOnlySSRC) {
-                generateRecvonlySSRC();
-            }
-
-            logger.info('No SSRC in video recvonly stream' +
-                         ' - adding SSRC: ' + localRecvOnlySSRC);
-
-            sdp.media[1] += 'a=ssrc:' + localRecvOnlySSRC +
-                            ' cname:' + localRecvOnlyCName + '\r\n' +
-                            'a=ssrc:' + localRecvOnlySSRC +
-                            ' msid:' + localRecvOnlyMSID + '\r\n' +
-                            'a=ssrc:' + localRecvOnlySSRC +
-                            ' mslabel:' + localRecvOnlyMSLabel + '\r\n' +
-                            'a=ssrc:' + localRecvOnlySSRC +
-                            ' label:' + localRecvOnlyLabel + '\r\n';
-
-            localDescription.sdp = sdp.session + sdp.media.join('');
-        }
-        return localDescription;
-    },
-    /**
-     * Method must be called before 'source-add' notification is sent. In case
-     * we have local video SSRC advertised already it will be removed from the
-     * notification. If no other SSRCs are described by given IQ null will be
-     * returned which means that there is no point in sending the notification.
-     * @param sourceAdd 'source-add' Jingle IQ to be processed
-     * @returns modified 'source-add' IQ which can be sent to the focus or
-     *          <tt>null</tt> if no notification shall be sent. It is no longer
-     *          a Strophe IQ Builder instance, but DOM element tree.
-     */
-    processSourceAdd: function (sourceAdd) {
-        if (!isEnabled)
-            return sourceAdd;
-
-        if (!localVideoSSRC) {
-            // Store local SSRC if available
-            storeLocalVideoSSRC(sourceAdd);
-            return sourceAdd;
-        } else {
-            return filterOutSource(sourceAdd, 'source-add');
-        }
-    },
-    /**
-     * Method must be called before 'source-remove' notification is sent.
-     * Removes local video SSRC from the notification. If there are no other
-     * SSRCs described in the given IQ <tt>null</tt> will be returned which
-     * means that there is no point in sending the notification.
-     * @param sourceRemove 'source-remove' Jingle IQ to be processed
-     * @returns modified 'source-remove' IQ which can be sent to the focus or
-     *          <tt>null</tt> if no notification shall be sent. It is no longer
-     *          a Strophe IQ Builder instance, but DOM element tree.
-     */
-    processSourceRemove: function (sourceRemove) {
-        if (!isEnabled)
-            return sourceRemove;
-
-        return filterOutSource(sourceRemove, 'source-remove');
-    },
-
-    /**
-     * Turns the hack on or off
-     * @param enabled <tt>true</tt> to enable the hack or <tt>false</tt>
-     *                to disable it
-     */
-    setEnabled: function (enabled) {
-        isEnabled = enabled;
-    }
-};
-
-module.exports = LocalSSRCReplacement;

modules/xmpp/TraceablePeerConnection.js

@@ -1,10 +1,8 @@
 /* global $ */
 var RTC = require('../RTC/RTC');
-
 var logger = require("jitsi-meet-logger").getLogger(__filename);
 var RTCBrowserType = require("../RTC/RTCBrowserType.js");
 var XMPPEvents = require("../../service/xmpp/XMPPEvents");
-var SSRCReplacement = require("./LocalSSRCReplacement");
 
 function TraceablePeerConnection(ice_config, constraints, session) {
     var self = this;
@@ -138,6 +136,47 @@ var dumpSDP = function(description) {
     return 'type: ' + description.type + '\r\n' + description.sdp;
 };
 
+var insertRecvOnlySSRC = function (desc) {
+    if (typeof desc !== 'object' || desc === null ||
+        typeof desc.sdp !== 'string') {
+        console.warn('An empty description was passed as an argument.');
+        return desc;
+    }
+
+    var transform = require('sdp-transform');
+    var RandomUtil = require('../util/RandomUtil');
+
+    var session = transform.parse(desc.sdp);
+    if (!Array.isArray(session.media))
+    {
+        return;
+    }
+
+    var modded = false;
+    session.media.forEach(function (bLine) {
+        if (bLine.direction != 'recvonly')
+        {
+            return;
+        }
+
+        modded = true;
+        if (!Array.isArray(bLine.ssrcs) || bLine.ssrcs.length === 0)
+        {
+            var ssrc = RandomUtil.randomInt(1, 0xffffffff);
+            bLine.ssrcs = [{
+                id: ssrc,
+                attribute: 'cname',
+                value: ['recvonly-', ssrc].join(' ')
+            }];
+        }
+    });
+
+    return (!modded) ? desc : new RTCSessionDescription({
+        type: desc.type,
+        sdp: transform.write(session),
+    });
+};
+
 /**
  * Takes a SessionDescription object and returns a "normalized" version.
  * Currently it only takes care of ordering the a=ssrc lines.
@@ -216,10 +255,6 @@ var getters = {
     localDescription:  function() {
         var desc = this.peerconnection.localDescription;
 
-            // FIXME this should probably be after the Unified Plan -> Plan B
-            // transformation.
-        desc = SSRCReplacement.mungeLocalVideoSSRC(desc);
-
         this.trace('getLocalDescription::preTransform', dumpSDP(desc));
 
         // if we're running on FF, transform to Plan B first.
@@ -370,7 +405,11 @@ TraceablePeerConnection.prototype.createOffer
                 self.trace('createOfferOnSuccess::postTransform (Plan B)', dumpSDP(offer));
             }
 
-            offer = SSRCReplacement.mungeLocalVideoSSRC(offer);
+            if (RTCBrowserType.isChrome())
+            {
+                offer = insertRecvOnlySSRC(offer);
+                self.trace('createOfferOnSuccess::mungeLocalVideoSSRC', dumpSDP(offer));
+            }
 
             if (self.session.room.options.enableSimulcast && self.simulcast.isSupported()) {
                 offer = self.simulcast.mungeLocalDescription(offer);
@@ -399,8 +438,11 @@ TraceablePeerConnection.prototype.createAnswer
                 self.trace('createAnswerOnSuccess::postTransform (Plan B)', dumpSDP(answer));
             }
 
-            // munge local video SSRC
-            answer = SSRCReplacement.mungeLocalVideoSSRC(answer);
+            if (RTCBrowserType.isChrome())
+            {
+                answer = insertRecvOnlySSRC(answer);
+                self.trace('createAnswerOnSuccess::mungeLocalVideoSSRC', dumpSDP(answer));
+            }
 
             if (self.session.room.options.enableSimulcast && self.simulcast.isSupported()) {
                 answer = self.simulcast.mungeLocalDescription(answer);