webrtc/protocol/h265-level-id.https.html

<!doctype html>
<meta charset=utf-8>
<title>RTX codec integrity checks</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../RTCPeerConnection-helper.js"></script>
<script>
'use strict';

const kProfileIdKey = 'profile-id';
const kLevelIdKey = 'level-id';

// The level-id value for Level X.Y is calculated as (X * 10 + Y) * 3.
// The lowest Level, 1.0, is thus (1 * 10 + 0) * 3 = 30.
const kH265Level1dot0 = '30';

function parseFmtpMap(sdpFmtpLine) {
  const map = new Map();
  // For each entry (semi-colon separated key=value).
  for (let i = 0; i < sdpFmtpLine.length; ++i) {
    let entryEnd = sdpFmtpLine.indexOf(';', i);
    if (entryEnd == -1) {
      entryEnd = sdpFmtpLine.length;
    }
    const entryStr = sdpFmtpLine.substring(i, entryEnd);
    const keyValue = entryStr.split('=');
    if (keyValue.length != 2) {
      throw 'Failed to parse sdpFmtpLine';
    }
    map.set(keyValue[0], keyValue[1]);
    i = entryEnd;
  }
  return map;
}

function findCodecWithProfileId(codecs, mimeType, profileId) {
  return codecs.find(codec => {
    if (codec.mimeType != mimeType) {
      return false;
    }
    return parseFmtpMap(codec.sdpFmtpLine).get(kProfileIdKey) == profileId;
  });
}

// Returns `[h265SendCodec, h265RecvCodec]` or aborts the calling test with
// [PRECONDITION_FAILED].
function getH265CodecsOrFailPrecondition() {
  const h265SendCodec = RTCRtpSender.getCapabilities('video').codecs.find(
      c => c.mimeType == 'video/H265');
  assert_implements_optional(
      h265SendCodec !== undefined,
      `H265 is not available for sending.`);

  const h265SendCodecFmtpMap = parseFmtpMap(h265SendCodec.sdpFmtpLine);
  const profileId = h265SendCodecFmtpMap.get(kProfileIdKey);
  assert_not_equals(profileId, undefined,
                    `profile-id is missing from sdpFmtpLine`);

  const h265RecvCodec = findCodecWithProfileId(
      RTCRtpReceiver.getCapabilities('video').codecs, 'video/H265', profileId);
  assert_implements_optional(
      h265RecvCodec !== undefined,
      `H265 profile-id=${profileId} is not available for receiving.`);

  return [h265SendCodec, h265RecvCodec];
}

function sdpModifyFmtpLevelId(sdp, newLevelId) {
  const lines = sdp.split('\r\n');
  for (let i = 0; i < lines.length; ++i) {
    if (!lines[i].startsWith('a=fmtp:')) {
      continue;
    }
    const spaceIndex = lines[i].indexOf(' ');
    if (spaceIndex == -1) {
      continue;
    }
    const fmtpMap = parseFmtpMap(lines[i].substring(spaceIndex + 1));
    if (!fmtpMap.has(kLevelIdKey)) {
      continue;
    }
    fmtpMap.set(kLevelIdKey, newLevelId);
    const sdpFmtpLine =
        Array.from(fmtpMap, ([key,value]) => `${key}=${value}`).join(';');
    lines[i] = lines[i].substring(0, spaceIndex) + ' ' + sdpFmtpLine;
  }
  return lines.join('\r\n');
}

promise_test(async t => {
  const [h265SendCodec, h265RecvCodec] = getH265CodecsOrFailPrecondition();

  const pc1 = new RTCPeerConnection();
  t.add_cleanup(() => pc1.close());
  const pc2 = new RTCPeerConnection();
  t.add_cleanup(() => pc2.close());

  const pc1Transceiver = pc1.addTransceiver('video', {direction: 'sendonly'});
  pc1Transceiver.setCodecPreferences([h265SendCodec]);

  await pc1.setLocalDescription();
  await pc2.setRemoteDescription(pc1.localDescription);
  await pc2.setLocalDescription();
  // Modify SDP to tell `pc1` that `pc2` can only receive level-id=30.
  await pc1.setRemoteDescription({
    type: 'answer',
    sdp: sdpModifyFmtpLevelId(pc2.localDescription.sdp, kH265Level1dot0)
  });

  // Confirm level-id=30 was negotiated regardless of sender capabilities.
  const sender = pc1Transceiver.sender;
  const params = sender.getParameters();
  assert_equals(params.codecs.length, 1);
  const negotiatedFmtpMap = parseFmtpMap(params.codecs[0].sdpFmtpLine);
  assert_equals(negotiatedFmtpMap.get(kLevelIdKey), kH265Level1dot0);
}, `Offer to send H265, answer to receive level-id=30 results in level-id=30`);

promise_test(async t => {
  const [h265SendCodec, h265RecvCodec] = getH265CodecsOrFailPrecondition();

  const pc1 = new RTCPeerConnection();
  t.add_cleanup(() => pc1.close());
  const pc2 = new RTCPeerConnection();
  t.add_cleanup(() => pc2.close());

  const pc1Transceiver = pc1.addTransceiver('video', {direction: 'recvonly'});
  pc1Transceiver.setCodecPreferences([h265RecvCodec]);

  await pc1.setLocalDescription();
  // Modify SDP to tell `pc2` that `pc1` can only receive level-id=30.
  await pc2.setRemoteDescription({
    type: 'offer',
    sdp: sdpModifyFmtpLevelId(pc1.localDescription.sdp, kH265Level1dot0)
  });
  const [pc2Transceiver] = pc2.getTransceivers();
  pc2Transceiver.direction = 'sendonly';
  await pc2.setLocalDescription();
  await pc1.setRemoteDescription(pc2.localDescription);

  // Confirm level-id=30 was negotiated regardless of sender capabilities.
  const sender = pc2Transceiver.sender;
  const params = sender.getParameters();
  assert_equals(params.codecs.length, 1);
  const negotiatedFmtpMap = parseFmtpMap(params.codecs[0].sdpFmtpLine);
  assert_equals(negotiatedFmtpMap.get(kLevelIdKey), kH265Level1dot0);
  // Setting a codec that was negotiated should always work, regardless of the
  // level-id in sender capabilities.
  params.encodings[0].codec = params.codecs[0];
  await sender.setParameters(params);
  assert_equals(sender.getParameters().encodings[0].codec.mimeType,
                params.codecs[0].mimeType);
  assert_equals(sender.getParameters().encodings[0].codec.sdpFmtpLine,
                params.codecs[0].sdpFmtpLine);
}, `Offer to receive level-id=30 and set codec from getParameters`);

promise_test(async t => {
  const [h265SendCodec, h265RecvCodec] = getH265CodecsOrFailPrecondition();

  const pc1 = new RTCPeerConnection();
  t.add_cleanup(() => pc1.close());
  const pc2 = new RTCPeerConnection();
  t.add_cleanup(() => pc2.close());

  const pc1Transceiver = pc1.addTransceiver('video', {direction: 'recvonly'});
  pc1Transceiver.setCodecPreferences([h265RecvCodec]);

  await pc1.setLocalDescription();
  // Modify SDP to tell `pc2` that `pc1` can only receive level-id=30.
  await pc2.setRemoteDescription({
    type: 'offer',
    sdp: sdpModifyFmtpLevelId(pc1.localDescription.sdp, kH265Level1dot0)
  });
  const [pc2Transceiver] = pc2.getTransceivers();
  pc2Transceiver.direction = 'sendonly';
  await pc2.setLocalDescription();
  await pc1.setRemoteDescription(pc2.localDescription);

  // Confirm level-id=30 was negotiated regardless of sender capabilities.
  const sender = pc2Transceiver.sender;
  const params = sender.getParameters();
  assert_equals(params.codecs.length, 1);
  const negotiatedFmtpMap = parseFmtpMap(params.codecs[0].sdpFmtpLine);
  assert_equals(negotiatedFmtpMap.get(kLevelIdKey), kH265Level1dot0);
  // Setting a codec from getCapabilities should work, even if a lower level-id
  // was negotiated.
  params.encodings[0].codec = h265SendCodec;
  await sender.setParameters(params);
  assert_equals(sender.getParameters().encodings[0].codec.mimeType,
                h265SendCodec.mimeType);
  assert_equals(sender.getParameters().encodings[0].codec.sdpFmtpLine,
                h265SendCodec.sdpFmtpLine);
}, `Offer to receive level-id=30 and set codec from getCapabilities`);
</script>