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<meta charset=utf-8>
<meta name="timeout" content="long">
<title>RTCRtpParameters encodings</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/webrtc/dictionary-helper.js"></script>
<script src="/webrtc/RTCRtpParameters-helper.js"></script>
<script src="../webrtc/RTCPeerConnection-helper.js"></script>
<script>
  'use strict';

  // Test is based on the following editor draft:
  // https://w3c.github.io/webrtc-svc/

  promise_test(async t => {
    const pc = new RTCPeerConnection();
    t.add_cleanup(() => pc.close());
    const { sender } = pc.addTransceiver('video', {
      sendEncodings: [{scalabilityMode: 'L1T3'}],
    });

    const param = sender.getParameters();
    const encoding = param.encodings[0];

    assert_equals(encoding.scalabilityMode, 'L1T3');

    encoding.scalabilityMode = 'L1T2';
    await sender.setParameters(param);

    const updatedParam = sender.getParameters();
    const updatedEncoding = updatedParam.encodings[0];

    assert_equals(updatedEncoding.scalabilityMode, 'L1T2');
  }, `Setting and updating scalabilityMode to a legal value should be accepted`);

  promise_test(async t => {
    const pc = new RTCPeerConnection();
    t.add_cleanup(() => pc.close());
    const { sender } = pc.addTransceiver('video');
    const param = sender.getParameters();
    const encoding = param.encodings[0];
    assert_true(!('scalabilityMode' in encoding));
  }, 'Not setting sendEncodings results in no mode info before negotiation');

  promise_test(async t => {
    const pc = new RTCPeerConnection();
    t.add_cleanup(() => pc.close());
    const { sender } = pc.addTransceiver('video', {
      sendEncodings: [{}],
    });
    const param = sender.getParameters();
    const encoding = param.encodings[0];
    assert_true(!('scalabilityMode' in encoding));
  }, 'Not setting a scalability mode results in no mode set before negotiation');

  promise_test(async t => {
      const pc = new RTCPeerConnection();
    t.add_cleanup(() => pc.close());
    assert_throws_dom('OperationError', () => {
      pc.addTransceiver('video', {
        sendEncodings: [{scalabilityMode: 'TotalNonsense'}],
      });
    });
  }, 'Setting a scalability mode to nonsense throws an exception');

  promise_test(async t => {
    const v = document.createElement('video');
    v.autoplay = true;
    const pc1 = new RTCPeerConnection();
    const pc2 = new RTCPeerConnection();
    t.add_cleanup(() => pc1.close());
    t.add_cleanup(() => pc2.close());
    const transceiver = pc1.addTransceiver('video', {
      sendEncodings: [{ scalabilityMode: 'L3T3' }],
    });
    // Before negotiation, the mode should be preserved.
    const param = transceiver.sender.getParameters();
    const encoding = param.encodings[0];
    assert_true('scalabilityMode' in encoding);
    // If L3T3 is not supported at all, abort test.
    assert_implements_optional(encoding.scalabilityMode === 'L3T3');
    // Pick a codec known to not have L3T3 support
    const capabilities = RTCRtpSender.getCapabilities('video');
    const codec = capabilities.codecs.find(c => c.mimeType === 'video/VP8');
    assert_true(codec !== undefined);
    transceiver.setCodecPreferences([codec]);
    exchangeIceCandidates(pc1, pc2);
    await exchangeOfferAnswer(pc1, pc2);
    const sendParams = pc1.getSenders()[0].getParameters();
    assert_not_equals(sendParams.encodings[0].scalabilityMode, 'L3T3');
  }, 'L3T3 on VP8 should return something other than L3T3');
</script>
