MediaRecorder-blob-timecode.https.html

Enable keyboard shortcuts

This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /mediacapture-record/MediaRecorder-blob-timecode.https.html - WPT Dashboard Interop Dashboard

<!doctype html>

<html>

<head>

  <title>MediaRecorder Blob event timecode</title>

  <link rel="help" href="https://w3c.github.io/mediacapture-record/MediaRecorder.html#dom-mediarecorder-start">

  <script src="/resources/testharness.js"></script>

  <script src="/resources/testharnessreport.js"></script>

  <script src="/resources/testdriver.js"></script>

  <script src="/resources/testdriver-vendor.js"></script>

  <script src="../mediacapture-streams/permission-helper.js"></script>

</head>

<body>

<script>

  promise_test(async t => {

    await setMediaPermission();

    const stream = await navigator.mediaDevices.getUserMedia({video:true, audio:true});

    t.add_cleanup(() => stream.getTracks().forEach(tr => tr.stop()));

    const recorder = new MediaRecorder(stream);

    // Sets 0 timeslice will call the first chunk to be triggered immediately.

    recorder.start(0);

    let combinedSize = 0;

    let previous_timecode = 0;

    while (combinedSize < 2000) {

      const {data, timecode} = await new Promise(r => recorder.ondataavailable = r);

      if (combinedSize === 0) {

        assert_equals(timecode, 0, "first chunk timecode must be 0");

      } else {

        assert_greater_than(timecode, previous_timecode, "timecode must increase monotonically");

      previous_timecode = timecode;

      combinedSize += data.size;

    recorder.stop();

  }, "MediaRecorder Blob timecode for first chunk must be 0 and monotonically increasing");

</script>

</body>

</html>