test_analyserScale.html

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<html>

<head>

  <title>Test AnalyserNode when the input is scaled </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">

SimpleTest.waitForExplicitFinish();

addLoadEvent(function() {

  var context = new AudioContext();

  var gain = context.createGain();

  var analyser = context.createAnalyser();

  var osc = context.createOscillator();

  osc.connect(gain);

  gain.connect(analyser);

  osc.start();

  var array = new Uint8Array(analyser.frequencyBinCount);

  function getAnalyserData() {

    gain.gain.setValueAtTime(currentGain, context.currentTime);

    analyser.getByteTimeDomainData(array);

    var max = -1;

    for (var i = 0; i < array.length; i++) {

      if (array[i] > max) {

        max = Math.abs(array[i] - 128);

    if (max <= currentGain * 128) {

      ok(true, "Analyser got scaled data for " + currentGain);

      currentGain = tests.shift();

      if (currentGain == undefined) {

        SimpleTest.finish();

        return;

    requestAnimationFrame(getAnalyserData);

  var tests = [1.0, 0.5, 0.0];

  var currentGain = tests.shift();

  requestAnimationFrame(getAnalyserData);

});

</script>

</pre>

</body>

</html>