<!DOCTYPE HTML>
<html>
<head>
  <script type="application/javascript" src="pc.js"></script>
</head>
<body>
<pre id="test">
<script type="application/javascript">
  createHTML({
    bug: "1244913",
    title: "Scale resolution down on a PeerConnection",
    visible: true
  });

  async function checkForH264Support() {
    const pc = new RTCPeerConnection();
    const offer = await pc.createOffer({offerToReceiveVideo: true});
    return offer.sdp.match(/a=rtpmap:[1-9][0-9]* H264/);
  }

  let resolutionAlignment = 1;

  var mustRejectWith = (msg, reason, f) =>
    f().then(() => ok(false, msg),
             e => is(e.name, reason, msg));

  async function testScale(codec) {
    var pc1 = new RTCPeerConnection();
    var pc2 = new RTCPeerConnection();

    var add = (pc, can, failed) => can && pc.addIceCandidate(can).catch(failed);
    pc1.onicecandidate = e => add(pc2, e.candidate, generateErrorCallback());
    pc2.onicecandidate = e => add(pc1, e.candidate, generateErrorCallback());

    info("testing scaling with " + codec);

    let stream = await navigator.mediaDevices.getUserMedia({ video: true });

    var v1 = createMediaElement('video', 'v1');
    var v2 = createMediaElement('video', 'v2');

    var ontrackfired = new Promise(resolve => pc2.ontrack = e => resolve(e));
    var v2loadedmetadata = new Promise(resolve => v2.onloadedmetadata = resolve);

    is(v2.currentTime, 0, "v2.currentTime is zero at outset");

    v1.srcObject = stream;
    var sender = pc1.addTrack(stream.getVideoTracks()[0], stream);
    let parameters = sender.getParameters();
    is(parameters.encodings.length, 1, "Default number of encodings should be 1");
    parameters.encodings[0].scaleResolutionDownBy = 0.5;

    await mustRejectWith(
        "Invalid scaleResolutionDownBy must reject", "RangeError",
        () => sender.setParameters(parameters)
    );

    parameters = sender.getParameters();
    parameters.encodings[0].scaleResolutionDownBy = 2;
    parameters.encodings[0].maxBitrate = 60000;

    await sender.setParameters(parameters);

    parameters = sender.getParameters();
    is(parameters.encodings[0].scaleResolutionDownBy, 2, "Should be able to set scaleResolutionDownBy");
    is(parameters.encodings[0].maxBitrate, 60000, "Should be able to set maxBitrate");

    let offer = await pc1.createOffer();
    if (codec == "VP8") {
      offer.sdp = sdputils.removeAllButPayloadType(offer.sdp, 126);
    }
    await pc1.setLocalDescription(offer);
    await pc2.setRemoteDescription(pc1.localDescription);

    let answer = await pc2.createAnswer();
    await pc2.setLocalDescription(answer);
    await pc1.setRemoteDescription(pc2.localDescription);
    let trackevent = await ontrackfired;

    v2.srcObject = trackevent.streams[0];

    await v2loadedmetadata;

    await waitUntil(() => v2.currentTime > 0);
    ok(v2.currentTime > 0, "v2.currentTime is moving (" + v2.currentTime + ")");

    ok(v1.videoWidth > 0, "source width is positive");
    ok(v1.videoHeight > 0, "source height is positive");
    const expectedWidth =
      v1.videoWidth / 2 - (v1.videoWidth / 2 % resolutionAlignment);
    const expectedHeight =
      v1.videoHeight / 2 - (v1.videoHeight / 2 % resolutionAlignment);
    is(v2.videoWidth, expectedWidth,
       "sink is half the width of the source");
    is(v2.videoHeight, expectedHeight,
       "sink is half the height of the source");
    stream.getTracks().forEach(track => track.stop());
    v1.srcObject = v2.srcObject = null;
    pc1.close()
    pc2.close()
  }

  runNetworkTest(async () => {
    await matchPlatformH264CodecPrefs();
    const hasH264 = await checkForH264Support();
    if (hasH264 && navigator.userAgent.includes("Android")) {
      // Android only has a hw encoder for h264
      resolutionAlignment = 16;
    }
    await pushPrefs(['media.peerconnection.video.lock_scaling', true]);
    await testScale("VP8");
    if (hasH264) {
      await testScale("H264");
    }
  });
</script>
</pre>
</body>
</html>
