webrtc wpt: add test for direction-based filtering of codecs

to supplement the discussion in w3c/webrtc-pc#2937 BUG=324930413 Change-Id: Iebf02aade64030e11590af211fa7bc90f976c592
web-platform-tests · Feb 16, 2024 · 48bff5c · 48bff5c
1 parent e6dbd29
commit 48bff5c
Showing 1 changed file with 128 additions and 0 deletions.
diff --git a/webrtc/protocol/codecs-filtered-by-direction.https.html b/webrtc/protocol/codecs-filtered-by-direction.https.html
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+<!doctype html>
+<meta charset=utf-8>
+<meta name="timeout" content="long">
+<title>RTCPeerConnection Codecs in offer get filtered by direction</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="../third_party/sdp/sdp.js"></script>
+<script>
+'use strict';
+
+function codecEquals(c1, c2) {
+  return c1.mimeType === c2.mimeType &&
+          c1.sdpFmtpLine === c2.sdpFmtpLine &&
+          c1.clockRate === c2.clockRate &&
+          c1.channels === c2.channels;
+}
+
+function h264ProfileMatches(c1, c2) {
+  if (c1.mimeType !== 'video/H264' || c2.mimeType !== 'video/H264') {
+    return false;
+  }
+  if (!(c1.sdpFmtpLine && c2.sdpFmtpLine)) {
+    // In practice the sdpFmtpLine should be set for H264.
+    return false;
+  }
+  const parseFmtp = line => {
+    const parameters = {};
+    line.split(';')
+      .map(kv => kv.split('='))
+      .forEach(([key, value]) => parameters[key] = value);
+    return parameters
+  };
+  const p1 = parseFmtp(c1.sdpFmtpLine);
+  const p2 = parseFmtp(c2.sdpFmtpLine);
+  if (p1['packetization-mode'] !== p2['packetization-mode']) {
+    return false;
+  }
+  const levelid1 = p1['profile-level-id'];
+  const levelid2 = p2['profile-level-id'];
+  // profile level id should be a hex string with length 6.
+  if (!(levelid1 && levelid2) || !(levelid1.length == 6 && levelid2.length === 6)) {
+    return false;
+  }
+  if (levelid1 === levelid2) {
+    return true;
+  }
+  // Check profile idc and iop in the first two hex-encoded bytes are the same.
+  return levelid1.substring(0,4) == levelid2.substring(0, 4);
+}
+
+function splitCodecs() {
+  const sendCodecs = RTCRtpSender.getCapabilities('video').codecs;
+  const receiveCodecs = RTCRtpReceiver.getCapabilities('video').codecs;
+  const codecs = {
+    sendrecv: [],
+    sendonly: [],
+    recvonly: [],
+  };
+  // Ignore RTX since it is present in capabilities once and has no apt.
+  for (const receiveCodec of receiveCodecs) {
+    if (receiveCodec.mimeType === 'video/rtx') continue;
+    if (sendCodecs.find(sendCodec => codecEquals(sendCodec, receiveCodec)
+        || h264ProfileMatches(sendCodec, receiveCodec))) {
+      codecs.sendrecv.push(receiveCodec);
+    }
+  }
+
+  for (const sendCodec of sendCodecs) {
+    if (sendCodec.mimeType === 'video/rtx') continue;
+    if (!receiveCodecs.find(receiveCodec => codecEquals(sendCodec, receiveCodec))) {
+      codecs.sendonly.push(sendCodec);
+    }
+  }
+  for (const receiveCodec of receiveCodecs) {
+    if (receiveCodec.mimeType === 'video/rtx') continue;
+    if (!sendCodecs.find(sendCodec => codecEquals(sendCodec, receiveCodec))) {
+      codecs.recvonly.push(receiveCodec);
+    }
+  }
+  return codecs;
+}
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+
+  const allCodecs = splitCodecs();
+  const transceiver = pc.addTransceiver('video');
+
+  transceiver.direction = 'sendrecv';
+  let offer = await pc.createOffer();
+  let mediaSection = SDPUtils.getMediaSections(offer.sdp)[0];
+  let rtpParameters = SDPUtils.parseRtpParameters(mediaSection);
+  const sendrecvCodecs = rtpParameters.codecs.filter(c => c.name !== 'rtx');
+  assert_equals(sendrecvCodecs.length, allCodecs.sendrecv.length);
+}, 'Codecs get filtered by direction for sendrecv');
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+
+  const allCodecs = splitCodecs();
+  const transceiver = pc.addTransceiver('video');
+
+  transceiver.direction = 'sendonly'
+  const offer = await pc.createOffer();
+  const mediaSection = SDPUtils.getMediaSections(offer.sdp)[0];
+  const rtpParameters = SDPUtils.parseRtpParameters(mediaSection);
+  const sendonlyCodecs = rtpParameters.codecs.filter(c => c.name !== 'rtx');
+  assert_equals(sendonlyCodecs.length, allCodecs.sendrecv.length + allCodecs.sendonly.length);
+}, 'Codecs get filtered by direction for sendonly');
+
+promise_test(async t => {
+  const pc = new RTCPeerConnection();
+  t.add_cleanup(() => pc.close());
+
+  const allCodecs = splitCodecs();
+  const transceiver = pc.addTransceiver('video');
+
+  transceiver.direction = 'recvonly'
+  const offer = await pc.createOffer();
+  const mediaSection = SDPUtils.getMediaSections(offer.sdp)[0];
+  const rtpParameters = SDPUtils.parseRtpParameters(mediaSection);
+  const recvonlyCodecs = rtpParameters.codecs.filter(c => c.name !== 'rtx');
+  assert_equals(recvonlyCodecs.length, allCodecs.sendrecv.length + allCodecs.recvonly.length);
+}, 'Codecs get filtered by direction for recvonly');
+
+</script>