dom/media/webaudio/test/test_audioParamExponentialRamp.html
author Emilio Cobos Álvarez <emilio@crisal.io>
Tue, 28 Mar 2023 08:20:09 +0000
changeset 658112 702d4a62e5d03a2b36b3a17645718208a30ddb08
parent 491143 3b3c5e0e1bc4a58d8a7d5718745cc41153e06a76
permissions -rw-r--r--
Bug 1824304 - Fix PiP window type hint after bug 1823350. r=stransky Differential Revision: https://phabricator.services.mozilla.com/D173677

<!DOCTYPE HTML>
<html>
<head>
  <title>Test AudioParam.exponentialRampToValue</title>
  <script src="/tests/SimpleTest/SimpleTest.js"></script>
  <script type="text/javascript" src="webaudio.js"></script>
  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />
</head>
<body>
<pre id="test">
<script class="testbody" type="text/javascript">

var V0 = 0.1;
var V1 = 0.9;
var T0 = 0;

var gTest = {
  length: 2048,
  numberOfChannels: 1,
  createGraph(context) {
    var sourceBuffer = context.createBuffer(1, 2048, context.sampleRate);
    for (var i = 0; i < 2048; ++i) {
      sourceBuffer.getChannelData(0)[i] = 1;
    }

    var source = context.createBufferSource();
    source.buffer = sourceBuffer;

    var gain = context.createGain();
    gain.gain.setValueAtTime(V0, 0);
    gain.gain.exponentialRampToValueAtTime(V1, 2048/context.sampleRate);

    source.connect(gain);

    source.start(0);
    return gain;
  },
  createExpectedBuffers(context) {
    var T1 = 2048 / context.sampleRate;
    var expectedBuffer = context.createBuffer(1, 2048, context.sampleRate);
    for (var i = 0; i < 2048; ++i) {
      var t = i / context.sampleRate;
      expectedBuffer.getChannelData(0)[i] = V0 * Math.pow(V1 / V0, (t - T0) / (T1 - T0));
    }
    return expectedBuffer;
  },
};


SimpleTest.waitForExplicitFinish();
// Comparing different AudioContexts may result in different timing reated information being reported
// when we jitter time, as they are on different Relative Timelines.
SpecialPowers.pushPrefEnv({"set": [["privacy.resistFingerprinting.reduceTimerPrecision.jitter", false]]}, runTest);

</script>
</pre>
</body>
</html>