fix: Missed SSRCs in Unified Plan with several "ssrc-group:FID" groups. (#1658)

* fix: Missed SSRCs in Unified Plan with several "ssrc-group:FID" groups.

`TpcUtils.ensureCorrectOrderOfSsrcs()` takes into account only the first `ssrs-group`, and it causes missed `ssrs` attributes. It results in an error during `peerconnection.setRemoteDescription()`.

For fixing `ensureCorrectOrderOfSsrcs()`, all `ssrs-group` are traversed and all distinct `ssrs` are preserved with keeping their order.

* test: Added extra tests for `TpcUtils.ensureCorrectOrderOfSsrcs()`

modules/RTC/TPCUtils.js

@@ -129,7 +129,16 @@ export class TPCUtils {
             }
             let reorderedSsrcs = [];
 
-            mLine.ssrcGroups[0].ssrcs.split(' ').forEach(ssrc => {
+            const ssrcs = new Set();
+
+            mLine.ssrcGroups.map(group =>
+                group.ssrcs
+                    .split(' ')
+                    .filter(Boolean)
+                    .forEach(ssrc => ssrcs.add(ssrc)),
+            );
+
+            ssrcs.forEach(ssrc => {
                 const sources = mLine.ssrcs.filter(source => source.id.toString() === ssrc);
 
                 reorderedSsrcs = reorderedSsrcs.concat(sources);

modules/RTC/TPCUtils.spec.js

@@ -0,0 +1,211 @@
+/* eslint-disable max-len */
+import { MockPeerConnection } from './MockClasses';
+import { TPCUtils } from './TPCUtils';
+
+const TEST_VIDEO_BITRATES = {
+    low: 200000,
+    standard: 700000,
+    high: 2500000
+};
+
+describe('TPCUtils', () => {
+    describe('ensureCorrectOrderOfSsrcs()', () => {
+        const commonSdpLines = [
+            'v=0',
+            'o=- 814997227879783433 5 IN IP4 127.0.0.1',
+            's=-',
+            't=0 0',
+            'a=msid-semantic: WMS 0836cc8e-a7bb-47e9-affb-0599414bc56d',
+            'a=group:BUNDLE video',
+            'm=video 9 RTP/SAVPF 100 96',
+            'c=IN IP4 0.0.0.0',
+            'a=rtpmap:100 VP8/90000',
+            'a=fmtp:96 apt=100',
+            'a=rtcp:9 IN IP4 0.0.0.0',
+            'a=rtcp-fb:100 ccm fir',
+            'a=rtcp-fb:100 nack',
+            'a=rtcp-fb:100 nack pli',
+            'a=rtcp-fb:100 goog-remb',
+            'a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time',
+            'a=setup:passive',
+            'a=mid:video',
+            'a=sendrecv',
+            'a=ice-ufrag:adPg',
+            'a=ice-pwd:Xsr05Mq8S7CR44DAnusZE26F',
+            'a=fingerprint:sha-256 6A:39:DE:11:24:AD:2E:4E:63:D6:69:D3:85:05:53:C7:3C:38:A4:B7:91:74:C0:91:44:FC:94:63:7F:01:AB:A9'
+        ];
+
+        it('sort ssrcs associated with all FID ssrc-groups', () => {
+            const pc = new MockPeerConnection();
+            const tpcUtils = new TPCUtils(pc, TEST_VIDEO_BITRATES);
+
+            const source = new RTCSessionDescription({
+                type: 'offer',
+                sdp: getSourceSdp()
+            });
+            const result = tpcUtils.ensureCorrectOrderOfSsrcs(source);
+
+            expect(result.sdp).toBe(getExpectedSdp());
+
+            /**
+             * Test SDP with multiple FID groups
+             */
+            function getSourceSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1479742055 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1479742055 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1089111804 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1089111804 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:855213044 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:855213044 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:2963867077 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:2963867077 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=ssrc-group:FID 1479742055 855213044',
+                    'a=ssrc-group:FID 1089111804 2963867077',
+                    'a=ssrc-group:SIM 1757014965 1479742055 1089111804',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+
+            /**
+             * Expected SDP: all ssrc must be present and ordered
+             */
+            function getExpectedSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1479742055 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1479742055 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:855213044 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:855213044 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1089111804 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1089111804 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:2963867077 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:2963867077 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=ssrc-group:FID 1479742055 855213044',
+                    'a=ssrc-group:FID 1089111804 2963867077',
+                    'a=ssrc-group:SIM 1757014965 1479742055 1089111804',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+        });
+
+        it('sort ssrcs in case the first ssrc in the SIM group is not present at the top', () => {
+            const pc = new MockPeerConnection();
+            const tpcUtils = new TPCUtils(pc, TEST_VIDEO_BITRATES);
+
+            const source = new RTCSessionDescription({
+                type: 'offer',
+                sdp: getSourceSdp()
+            });
+            const result = tpcUtils.ensureCorrectOrderOfSsrcs(source);
+
+            expect(result.sdp).toBe(getExpectedSdp());
+
+            /**
+             * Test SDP with multiple FID groups where the first ssrc in the SIM group is not present at the top
+             */
+            function getSourceSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:1479742055 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1479742055 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1089111804 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1089111804 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:855213044 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:855213044 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:2963867077 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:2963867077 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=ssrc-group:FID 1479742055 855213044',
+                    'a=ssrc-group:FID 1089111804 2963867077',
+                    'a=ssrc-group:SIM 1757014965 1479742055 1089111804',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+
+            /**
+             * Expected SDP: all ssrc must be present and ordered
+             */
+            function getExpectedSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1479742055 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1479742055 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:855213044 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:855213044 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1089111804 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1089111804 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:2963867077 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:2963867077 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=ssrc-group:FID 1479742055 855213044',
+                    'a=ssrc-group:FID 1089111804 2963867077',
+                    'a=ssrc-group:SIM 1757014965 1479742055 1089111804',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+        });
+
+        it('sort ssrcs in case there is a single FID group', () => {
+            const pc = new MockPeerConnection();
+            const tpcUtils = new TPCUtils(pc, TEST_VIDEO_BITRATES);
+
+            const source = new RTCSessionDescription({
+                type: 'offer',
+                sdp: getSourceSdp()
+            });
+            const result = tpcUtils.ensureCorrectOrderOfSsrcs(source);
+
+            expect(result.sdp).toBe(getExpectedSdp());
+
+            /**
+             * Test SDP with the single FID group
+             */
+            function getSourceSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+
+            /**
+             * Expected SDP: all ssrc must be present and ordered
+             */
+            function getExpectedSdp() {
+                return `${[
+                    ...commonSdpLines,
+                    'a=ssrc:1757014965 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:1757014965 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc:984899560 msid:0836cc8e-a7bb-47e9-affb-0599414bc56d bdbd2c0a-7959-4578-8db5-9a6a1aec4ecf',
+                    'a=ssrc:984899560 cname:peDGrDD6WsxUOki/',
+                    'a=ssrc-group:FID 1757014965 984899560',
+                    'a=rtcp-mux'
+                ].join('\r\n')}\r\n`;
+            }
+        });
+    });
+});