test_convolverNodeWithGain.html

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<head>

  <title>Test ConvolverNode after a GainNode - Bug 891254 </title>

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

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

</head>

<body>

<pre id="test">

<script src="webaudio.js" type="text/javascript"></script>

<script class="testbody" type="text/javascript">

const signalLength = 2048;

const responseLength = 100;

const outputLength = 4096; // > signalLength + responseLength

var gTest = {

  length: outputLength,

  numberOfChannels: 1,

  createGraph(context) {

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

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

      buffer.getChannelData(0)[i] = Math.sin(2 * Math.PI * i / signalLength);

    var source = context.createBufferSource();

    source.buffer = buffer;

    source.start(0);

    var response = context.createBuffer(1, responseLength, context.sampleRate);

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

      response.getChannelData(0)[i] = i / responseLength;

    var gain = context.createGain();

    gain.gain.value = -1;

    source.connect(gain);

    var convolver1 = context.createConvolver();

    convolver1.buffer = response;

    gain.connect(convolver1);

    var convolver2 = context.createConvolver();

    convolver2.buffer = response;

    source.connect(convolver2);

    // The output of convolver1 should be the inverse of convolver2, so blend

    // them together and expect silence.

    var blend = context.createGain();

    convolver1.connect(blend);

    convolver2.connect(blend);

    return blend;

},

};

runTest();

</script>

</pre>

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