feat: add disableTwcc helper function (#19)

* feat: add disableTwcc helper function * chore: update typo and modifies disableRemb
webex · Dec 20, 2023 · c9ec114 · c9ec114
1 parent cf5061c
commit c9ec114
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Showing 4 changed files with 407 additions and 9 deletions.
diff --git a/cspell.json b/cspell.json
@@ -67,6 +67,7 @@
     "trackingid",
     "transcoding",
     "transpiled",
+    "twcc",
     "typedoc",
     "ufrag",
     "ulpfec",

diff --git a/src/munge.spec.ts b/src/munge.spec.ts
@@ -1,6 +1,13 @@
 import * as fs from 'fs';
 import { AvMediaDescription, CodecInfo, Sdp } from './model';
-import { removeCodec, retainCandidates, retainCodecs } from './munge';
+import {
+  removeCodec,
+  retainCandidates,
+  retainCodecs,
+  disableRtcpFbValue,
+  disableRemb,
+  disableTwcc,
+} from './munge';
 import { parse } from './parser';
 
 /**
@@ -31,6 +38,25 @@ const validateOfferCodecs = (offer: Sdp): boolean => {
   return true;
 };
 
+/**
+ * Check that the sdp offer contains rtcpFbValue or not.
+ *
+ * @param offer - The {@link Sdp} or {@link AvMediaDescription} to validate.
+ * @param rtcpFbValue - The rtcp-fb value to check.
+ * @returns True if the offer contains rtcp-fb value.
+ */
+const checkOfferContainsRtcpFeedback = (
+  offer: Sdp | AvMediaDescription,
+  rtcpFbValue: string
+): boolean => {
+  const mediaDescriptions = offer instanceof Sdp ? offer.avMedia : [offer];
+  return mediaDescriptions.some((av: AvMediaDescription) => {
+    return [...av.codecs.values()].some((ci: CodecInfo) => {
+      return ci.feedback.includes(rtcpFbValue);
+    });
+  });
+};
+
 describe('munging', () => {
   describe('removeCodec', () => {
     it('should remove codecs correctly when passing in an SDP', () => {
@@ -119,4 +145,82 @@ describe('munging', () => {
       });
     });
   });
+
+  describe('disableRtcpFbValue', () => {
+    it('should remove rtcp feedback correctly when passing in an SDP', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      disableRtcpFbValue(parsed, 'transport-cc');
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(false);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(true);
+    });
+    it('should remove rtcp feedback correctly when passing in an AvMediaDescription', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      parsed.avMedia
+        .filter((av) => av.type === 'audio')
+        .forEach((av) => {
+          disableRtcpFbValue(av, 'transport-cc');
+          expect(checkOfferContainsRtcpFeedback(av, 'transport-cc')).toBe(false);
+        });
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(true);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(true);
+    });
+  });
+
+  describe('disableTwcc', () => {
+    it('should disable twcc when passing in an SDP', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      disableTwcc(parsed);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(false);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(true);
+    });
+    it('should disable twcc when passing in an AvMediaDescription', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      parsed.avMedia
+        .filter((av) => av.type === 'audio')
+        .forEach((av) => {
+          disableTwcc(av);
+          expect(checkOfferContainsRtcpFeedback(av, 'transport-cc')).toBe(false);
+        });
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(true);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(true);
+    });
+  });
+
+  describe('disableRemb', () => {
+    it('should disable remb when passing in an SDP', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      disableRemb(parsed);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(false);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(true);
+    });
+    it('should disable remb when passing in an AvMediaDescription', () => {
+      expect.hasAssertions();
+      const offer = fs.readFileSync('./src/sdp-corpus/offer_with_rtcp_feedback.sdp', 'utf-8');
+      const parsed = parse(offer);
+
+      parsed.avMedia
+        .filter((av) => av.type === 'video')
+        .forEach((av) => {
+          disableRemb(av);
+          expect(checkOfferContainsRtcpFeedback(av, 'goog-remb')).toBe(false);
+        });
+      expect(checkOfferContainsRtcpFeedback(parsed, 'goog-remb')).toBe(false);
+      expect(checkOfferContainsRtcpFeedback(parsed, 'transport-cc')).toBe(true);
+    });
+  });
 });
diff --git a/src/munge.ts b/src/munge.ts
@@ -17,13 +17,14 @@
 import { AvMediaDescription, CodecInfo, MediaDescription, Sdp } from './model';
 
 /**
- * Disable an rtcp-fb value from all media blocks in the given SDP.
+ * Disable an rtcp-fb value from the media blocks in the given SDP or audio/video media description.
  *
- * @param sdp - The SDP from which to filter an rtcp-fb value.
+ * @param sdpOrAv - The {@link Sdp} or {@link AvMediaDescription} from which to filter an rtcp-fb value.
  * @param rtcpFbValue - The rtcp-fb value to filter.
  */
-export function disableRtcpFbValue(sdp: Sdp, rtcpFbValue: string) {
-  sdp.avMedia.forEach((media: AvMediaDescription) => {
+export function disableRtcpFbValue(sdpOrAv: Sdp | AvMediaDescription, rtcpFbValue: string) {
+  const mediaDescriptions = sdpOrAv instanceof Sdp ? sdpOrAv.avMedia : [sdpOrAv];
+  mediaDescriptions.forEach((media: AvMediaDescription) => {
     media.codecs.forEach((codec: CodecInfo) => {
       // eslint-disable-next-line no-param-reassign
       codec.feedback = codec.feedback.filter((fb) => fb !== rtcpFbValue);
@@ -32,12 +33,21 @@ export function disableRtcpFbValue(sdp: Sdp, rtcpFbValue: string) {
 }
 
 /**
- * Disable REMB from all media blocks in the given SDP.
+ * Disable REMB from the media blocks in the given SDP or audio/video media description.
+ *
+ * @param sdpOrAv - The {@link Sdp} or {@link AvMediaDescription} from which to filter REMB.
+ */
+export function disableRemb(sdpOrAv: Sdp | AvMediaDescription) {
+  disableRtcpFbValue(sdpOrAv, 'goog-remb');
+}
+
+/**
+ * Disable TWCC from the media blocks in the given SDP or audio/video media description.
  *
- * @param sdp - The SDP from which to filter REMB.
+ * @param sdpOrAv - The {@link Sdp} or {@link AvMediaDescription} from which to filter TWCC.
  */
-export function disableRemb(sdp: Sdp) {
-  disableRtcpFbValue(sdp, 'goog-remb');
+export function disableTwcc(sdpOrAv: Sdp | AvMediaDescription) {
+  disableRtcpFbValue(sdpOrAv, 'transport-cc');
 }
 
 /**