test_channelSplitterNodeWithVolume.html

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<!DOCTYPE HTML>

<html>

<head>

  <title>Test ChannelSplitterNode</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">

// We do not use our generic graph test framework here because

// the splitter node is special in that it creates multiple

// output ports.

SimpleTest.waitForExplicitFinish();

addLoadEvent(function() {

  var context = new AudioContext();

  var buffer = context.createBuffer(4, 2048, context.sampleRate);

  var expectedBuffer = context.createBuffer(4, 2048, context.sampleRate);

  for (var j = 0; j < 4; ++j) {

    for (var i = 0; i < 2048; ++i) {

      buffer.getChannelData(j)[i] = Math.sin(440 * 2 * (j + 1) * Math.PI * i / context.sampleRate);

      expectedBuffer.getChannelData(j)[i] = buffer.getChannelData(j)[i] / 2;

  var emptyBuffer = context.createBuffer(1, 2048, context.sampleRate);

  var destination = context.destination;

  var source = context.createBufferSource();

  var splitter = context.createChannelSplitter();

  is(splitter.channelCount, 6, "splitter node has 2 input channels by default");

  is(splitter.channelCountMode, "explicit", "Correct channelCountMode for the splitter node");

  is(splitter.channelInterpretation, "discrete", "Correct channelCountInterpretation for the splitter node");

  source.buffer = buffer;

  var gain = context.createGain();

  gain.gain.value = 0.5;

  source.connect(gain);

  gain.connect(splitter);

  var channelsSeen = 0;

  function createHandler(i) {

    return function(e) {

      is(e.inputBuffer.numberOfChannels, 1, "Correct input channel count");

      if (i < 4) {

        compareBuffers(e.inputBuffer.getChannelData(0), expectedBuffer.getChannelData(i));

      } else {

        compareBuffers(e.inputBuffer.getChannelData(0), emptyBuffer.getChannelData(0));

      e.target.onaudioprocess = null;

      ++channelsSeen;

      if (channelsSeen == 6) {

        SimpleTest.finish();

};

  for (var i = 0; i < 6; ++i) {

    var sp = context.createScriptProcessor(2048, 1);

    splitter.connect(sp, i);

    sp.onaudioprocess = createHandler(i);

    sp.connect(destination);

  source.start(0);

});

</script>

</pre>

</body>

</html>