test_bug1735300.html

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<!DOCTYPE HTML>

<html>

<head>

  <meta charset="utf-8">

  <title>Test audio at the start of an MP4 with video edit-list pre-roll</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <script src="../webaudio/test/webaudio.js"></script>

  <script src="rms-utils.js"></script>

  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css">

</head>

<body>

<script>

"use strict";

const MIME_TYPE = 'video/mp4; codecs="vp09.00.10.08, fLaC"';

const RMS_THRESHOLD = 0.01;

const CURRENT_TIME_LIMIT = 0.25;

add_task(async function testAudioAudibleAtMediaStart() {

  const video = document.createElement("video");

  let audioContext;

  let source;

  try {

    if (!video.canPlayType(MIME_TYPE)) {

      ok(true, `${MIME_TYPE} is not supported`);

      return;

    video.preload = "auto";

    video.src = "bug1735300-vp9-flac-edit-list.mp4";

    document.body.appendChild(video);

    audioContext = new AudioContext();

    source = audioContext.createMediaElementSource(video);

    await audioContext.resume();

    await video.play();

    const measuredRms = await RMSUtils.waitForRmsOverThreshold(

      audioContext,

      source,

      RMS_THRESHOLD

);

ok(

      measuredRms > RMS_THRESHOLD && video.currentTime < CURRENT_TIME_LIMIT,

      `audio should be audible near currentTime 0; ` +

        `currentTime=${video.currentTime}, rms=${measuredRms}`

);

  } finally {

    video.pause();

    video.removeAttribute("src");

    video.load();

    source?.disconnect();

    await audioContext?.close();

    video.remove();

});

</script>

</body>

</html>