webrtc wpt: add test for codecs in subsequent offers

Asserting the "and also MUST include all currently available formats" https://www.rfc-editor.org/rfc/rfc8829.html#name-subsequent-offers See w3c/webrtc-pc#2938 BUG=None Change-Id: I7748ea94e58ba93cdf1043ee0235a7e560e260e2
web-platform-tests · Feb 15, 2024 · b89da50 · b89da50
1 parent 616d362
commit b89da50
Showing 1 changed file with 50 additions and 0 deletions.
diff --git a/webrtc/protocol/codecs-subsequent-offer.https.html b/webrtc/protocol/codecs-subsequent-offer.https.html
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+<!doctype html>
+<meta charset=utf-8>
+<meta name="timeout" content="long">
+<title>RTCPeerConnection Codecs in subsequent offer</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../third_party/sdp/sdp.js"></script>
+<script>
+'use strict';
+
+// A test for https://www.rfc-editor.org/rfc/rfc8829.html#name-subsequent-offers
+// The "m=" line and corresponding "a=rtpmap" and "a=fmtp" lines MUST only include
+// media formats that have not been excluded by the codec preferences of the
+// associated transceiver and also MUST include all currently available formats.
+
+// A VP8-only offer.
+const sdp = `v=0
+o=- 0 3 IN IP4 127.0.0.1
+s=-
+t=0 0
+a=fingerprint:sha-256 A7:24:72:CA:6E:02:55:39:BA:66:DF:6E:CC:4C:D8:B0:1A:BF:1A:56:65:7D:F4:03:AD:7E:77:43:2A:29:EC:93
+m=video 9 RTP/SAVPF 100
+c=IN IP4 0.0.0.0
+a=rtcp-mux
+a=sendrecv
+a=mid:video
+a=rtpmap:100 VP8/90000
+a=setup:actpass
+a=ice-ufrag:ETEn
+a=ice-pwd:OtSK0WpNtpUjkY4+86js7Z/l
+`;
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+
+  await pc.setRemoteDescription({type: 'offer', sdp});
+  await pc.setLocalDescription();
+  const transceiver = pc.getTransceivers()[0];
+  assert_not_equals(transceiver.stopped, true);
+  const offer = await pc.createOffer();
+  const mediaSection = SDPUtils.getMediaSections(offer.sdp)[0];
+  const rtpParameters = SDPUtils.parseRtpParameters(mediaSection);
+  const vp8 = rtpParameters.codecs.filter(codec => codec.name === 'VP8');
+  const h264 = rtpParameters.codecs.filter(codec => codec.name === 'H264');
+  assert_greater_than(vp8.length, 0);
+  assert_greater_than(h264.length, 0);
+}, 'A subsequent offer after a VP8-only negotiation includes at least all mandatory to implement codecs');
+
+</script>