test_delayNodeTailWithGain.html

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<html>

<head>

  <title>Test tail time lifetime of DelayNode indirectly connected to source</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();

const signalLength = 130;

const bufferSize = 1024;

// Delay should be long enough to allow CC to run

const delayBufferCount = 50;

const delayLength = delayBufferCount * bufferSize + 700;

var count = 0;

function applySignal(buffer, offset) {

  for (var i = 0; i < signalLength; ++i) {

    buffer.getChannelData(0)[offset + i] = Math.cos(Math.PI * i / signalLength);

function onAudioProcess(e) {

  switch(count) {

  case 5:

    SpecialPowers.forceGC();

    SpecialPowers.forceCC();

    break;

  case delayBufferCount:

    var offset = delayLength - count * bufferSize;

    var ctx = e.target.context;

    var expected = ctx.createBuffer(1, bufferSize, ctx.sampleRate);

    applySignal(expected, offset);

    compareBuffers(e.inputBuffer, expected);

    SimpleTest.finish();

  count++;

function startTest() {

  var ctx = new AudioContext();

  var processor = ctx.createScriptProcessor(bufferSize, 1, 0);

  processor.onaudioprocess = onAudioProcess;

  var delayDuration = delayLength / ctx.sampleRate;

  var delay = ctx.createDelay(delayDuration);

  delay.delayTime.value = delayDuration;

  delay.connect(processor);

  var gain = ctx.createGain();

  gain.connect(delay);

  // Short signal that finishes before garbage collection

  var buffer = ctx.createBuffer(1, signalLength, ctx.sampleRate);

  applySignal(buffer, 0);

  var source = ctx.createBufferSource();

  source.buffer = buffer;

  source.start();

  source.connect(gain);

};

startTest();

</script>

</pre>

</body>

</html>