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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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