fix(SDP) Add trackID if its missing in msid. (#2667)

* fix(SDP) Add missing trackID if its missing in msid.
This is needed for older versions of Chrome. Also skip performance optimizations if encode resolution is missing in the stats.

* squash: address review comments

modules/qualitycontrol/QualityController.ts

@@ -301,8 +301,12 @@ export class QualityController {
         if (!this._enableAdaptiveMode) {
             return;
         }
-
         const { encodeResolution, localTrack, qualityLimitationReason, tpc } = sourceStats;
+
+        // Older browser versions might not report the resolution in the stats.
+        if (Number.isNaN(encodeResolution)) {
+            return;
+        }
         const trackId = localTrack.rtcId;
 
         if (encodeResolution === tpc.calculateExpectedSendResolution(localTrack)) {
@@ -382,7 +386,7 @@ export class QualityController {
             const track = tpc.getTrackBySSRC(ssrc);
             const trackId = track.rtcId;
             let existingStats = statsPerTrack.get(trackId);
-            const encodeResolution = Math.min(resolution.height, resolution.width);
+            const encodeResolution = Math.min(resolution?.height, resolution?.width);
             const ssrcStats = {
                 encodeResolution,
                 encodeTime,

modules/sdp/SDP.js

@@ -40,6 +40,28 @@ export default class SDP {
         this.removeUdpCandidates = false;
     }
 
+    /**
+     * Adjusts the msid semantic for a remote source based on the media type and the index of the m-line.
+     * This is needed for browsers that need both the streamId and trackId to be reported in the msid attribute.
+     *
+     * @param {String} msid - The msid attribute value.
+     * @param {Number} idx - The index of the m-line in the SDP.
+     * @returns {String} - The adjusted msid semantic.
+     */
+    _adjustMsidSemantic(msid, mediaType, idx) {
+        if (mediaType === MediaType.AUDIO || !browser.isChromiumBased() || browser.isEngineVersionGreaterThan(116)) {
+            return msid;
+        }
+
+        const msidParts = msid.split(' ');
+
+        if (msidParts.length === 2) {
+            return msid;
+        }
+
+        return `${msid} ${msid}-${idx}`;
+    }
+
     /**
      * Updates the media and session sections of the SDP based on the raw SDP string.
      *
@@ -95,15 +117,7 @@ export default class SDP {
             updatedMidIndices.push(idx);
 
             if (isAdd) {
-                let updatedMsid = msid;
-
-                // If the msid is not in the <stream ID> <track ID> format, create msid in that format.
-                // Chrome's older versions (upto 117) expect the msid to be in this format.
-                if (msid.split(' ').length !== 2
-                    && browser.isChromiumBased()
-                    && browser.isEngineVersionLessThan(117)) {
-                    updatedMsid = `${msid} ${msid}-${idx}`;
-                }
+                const updatedMsid = this._adjustMsidSemantic(msid, mediaType, idx);
 
                 ssrcList.forEach(ssrc => {
                     this.media[idx] += `a=ssrc:${ssrc} msid:${updatedMsid}\r\n`;
@@ -259,12 +273,18 @@ export default class SDP {
                 const group = mLine.ssrcGroups?.find(g => g.ssrcs.includes(ssrcId));
 
                 if (group) {
+                    if (ssrc.attribute === 'msid') {
+                        ssrc.value = this._adjustMsidSemantic(ssrc.value, type, newMline.mid);
+                    }
                     newMline.ssrcs.push(ssrc);
                     const otherSsrc = group.ssrcs.split(' ').find(s => s !== ssrcId);
 
                     if (otherSsrc) {
                         const otherSource = mLine.ssrcs.find(source => source.id.toString() === otherSsrc);
 
+                        if (otherSource.attribute === 'msid') {
+                            otherSource.value = this._adjustMsidSemantic(otherSource.value, type, newMline.mid);
+                        }
                         newMline.ssrcs.push(otherSource);
                     }
                     newMline.ssrcGroups.push(group);
@@ -373,6 +393,7 @@ export default class SDP {
         let sdp = '';
         const sctp = transport.find(`>sctpmap[xmlns='${XEP.SCTP_DATA_CHANNEL}']`);
         const media = { media: desc.attr('media') };
+        const mid = content.attr('name');
 
         media.port = '9';
         if (content.attr('senders') === 'rejected') {
@@ -445,7 +466,7 @@ export default class SDP {
             sdp += `a=${MediaDirection.SENDRECV}\r\n`;
             break;
         }
-        sdp += `a=mid:${content.attr('name')}\r\n`;
+        sdp += `a=mid:${mid}\r\n`;
 
         // <description><rtcp-mux/></description>
         // see http://code.google.com/p/libjingle/issues/detail?id=309 -- no spec though
@@ -516,6 +537,9 @@ export default class SDP {
                         value = SDPUtil.filterSpecialChars(value);
                         sourceStr += `a=ssrc:${ssrc} ${name}`;
 
+                        if (name === 'msid') {
+                            value = this._adjustMsidSemantic(value, media.media, mid);
+                        }
                         if (value && value.length) {
                             sourceStr += `:${value}`;
                         }