feat: Make the p2p H.264 high profile stripping configurable.

modules/RTC/MockClasses.ts

@@ -132,6 +132,10 @@ export class MockPeerConnection {
      * @internal
      */
     _midsWithSentTrack: Set<string>;
+    /**
+     * {@link TraceablePeerConnection.codecSettings}.
+     */
+    codecSettings?: { codecList: string[]; mediaType: MediaType; };
     /**
      * Constructor.
      *
@@ -195,6 +199,15 @@ export class MockPeerConnection {
         return false;
     }
 
+    /**
+     * {@link TraceablePeerConnection.usesCodecSelectionAPI}.
+     *
+     * @returns {boolean}
+     */
+    usesCodecSelectionAPI(): boolean {
+        return false;
+    }
+
     /**
      * Returns the list of the codecs negotiated.
      * @returns {Array<string>}

modules/RTC/TPCUtils.spec.ts

@@ -1,4 +1,6 @@
 /* eslint-disable max-len */
+import transform from 'sdp-transform';
+
 import { CodecMimeType } from '../../service/RTC/CodecMimeType';
 import { MediaType } from '../../service/RTC/MediaType';
 import { SIM_LAYERS } from '../../service/RTC/StandardVideoQualitySettings';
@@ -208,6 +210,58 @@ describe('TPCUtils', () => {
         });
     });
 
+    describe('mungeCodecOrder()', () => {
+        const sdpStr = [
+            'v=0',
+            'o=- 814997227879783433 5 IN IP4 127.0.0.1',
+            's=-',
+            't=0 0',
+            'm=video 9 RTP/SAVPF 100 102 96',
+            'c=IN IP4 0.0.0.0',
+            'a=rtpmap:100 H264/90000',
+            'a=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f',
+            'a=rtpmap:102 H264/90000',
+            'a=fmtp:102 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=640028',
+            'a=rtpmap:96 VP8/90000',
+            'a=mid:0',
+            ''
+        ].join('\r\n');
+
+        const createTpcUtils = (videoQuality = {}) => {
+            const pc = new MockPeerConnection('1', true, false /* simulcast */);
+
+            pc.codecSettings = {
+                codecList: [ CodecMimeType.H264, CodecMimeType.VP8 ],
+                mediaType: MediaType.VIDEO
+            };
+
+            return new TPCUtils(pc, {
+                isP2P: true,
+                videoQuality
+            });
+        };
+
+        it('strips the high profile H.264 payload types on p2p by default', () => {
+            const tpcUtils = createTpcUtils();
+            const mungedSdp = tpcUtils.mungeCodecOrder(transform.parse(sdpStr));
+            const mLine = mungedSdp.media.find(m => m.type === 'video');
+
+            expect(mLine.rtp.some(pt => pt.payload === 100)).toBe(true);
+            expect(mLine.rtp.some(pt => pt.payload === 102)).toBe(false);
+            expect(mLine.fmtp.some(f => f.payload === 102)).toBe(false);
+        });
+
+        it('keeps the high profile H.264 payload types when videoQuality.h264.stripHighProfile is disabled', () => {
+            const tpcUtils = createTpcUtils({ h264: { stripHighProfile: false } });
+            const mungedSdp = tpcUtils.mungeCodecOrder(transform.parse(sdpStr));
+            const mLine = mungedSdp.media.find(m => m.type === 'video');
+
+            expect(mLine.rtp.some(pt => pt.payload === 100)).toBe(true);
+            expect(mLine.rtp.some(pt => pt.payload === 102)).toBe(true);
+            expect(mLine.fmtp.some(f => f.payload === 102)).toBe(true);
+        });
+    });
+
     describe('Test encodings when default settings are used for', () => {
         let pc, tpcUtils;
         let activeState, height, maxBitrates, scalabilityModes, scaleFactor;

modules/RTC/TPCUtils.ts

@@ -30,6 +30,7 @@ export interface ICodecConfig {
         [key: string]: number;
     };
     scalabilityModeEnabled?: boolean;
+    stripHighProfile?: boolean;
     useKSVC?: boolean;
     useSimulcast?: boolean;
 }
@@ -92,6 +93,9 @@ export class TPCUtils {
                     continue; // eslint-disable-line no-continue
                 }
 
+                typeof codecConfig.stripHighProfile !== 'undefined'
+                    && (this.codecSettings[codec].stripHighProfile = codecConfig.stripHighProfile);
+
                 const scalabilityModeEnabled = this.codecSettings[codec].scalabilityModeEnabled
                     && (typeof codecConfig.scalabilityModeEnabled === 'undefined'
                         || codecConfig.scalabilityModeEnabled);
@@ -837,7 +841,11 @@ export class TPCUtils {
                     // 2. There are multiple VP9 payload types generated by the browser, more payload types are added
                     //   if the endpoint doesn't have a local video source. Therefore, strip all the high profile codec
                     //   variants for VP9 so that only one payload type for VP9 is negotiated between the peers.
-                    if (codec === CodecMimeType.H264 || codec === CodecMimeType.VP9) {
+                    // The H.264 strip can be disabled through config.js (videoQuality.h264.stripHighProfile=false)
+                    // for deployments that want to negotiate Main/High profile, e.g. for hardware encoders that do
+                    // not support the baseline profiles.
+                    if ((codec === CodecMimeType.H264 && this.codecSettings[codec].stripHighProfile)
+                            || codec === CodecMimeType.VP9) {
                         SDPUtil.stripCodec(mLine, codec, true /* high profile */);
                     }
 

service/RTC/StandardVideoQualitySettings.ts

@@ -70,7 +70,10 @@ export const STANDARD_CODEC_SETTINGS = {
             standard: 800000,
             ultraHd: 8000000,
         },
-        scalabilityModeEnabled: browser.supportsScalabilityModeAPI()
+        scalabilityModeEnabled: browser.supportsScalabilityModeAPI(),
+
+        // Whether the Main/High profile H.264 payload types are stripped from the SDP on p2p connections.
+        stripHighProfile: true
     },
     vp8: {
         maxBitratesVideo: {