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<!DOCTYPE HTML>
<html>
<head>
<title>Test DynamicsCompressorNode</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 class="testbody" type="text/javascript">
function near(a, b, msg) {
ok(Math.abs(a - b) < 1e-4, msg);
}
SimpleTest.waitForExplicitFinish();
addLoadEvent(function() {
var context = new AudioContext();
var osc = context.createOscillator();
var sp = context.createScriptProcessor();
var compressor = new DynamicsCompressorNode(context);
osc.connect(compressor);
osc.connect(sp);
compressor.connect(context.destination);
is(compressor.channelCount, 2, "compressor node has 2 input channels by default");
is(compressor.channelCountMode, "clamped-max", "Correct channelCountMode for the compressor node");
is(compressor.channelInterpretation, "speakers", "Correct channelCountInterpretation for the compressor node");
// Verify default values
ok(compressor.threshold instanceof AudioParam, "treshold is an AudioParam");
near(compressor.threshold.defaultValue, -24, "Correct default value for threshold");
ok(compressor.knee instanceof AudioParam, "knee is an AudioParam");
near(compressor.knee.defaultValue, 30, "Correct default value for knee");
ok(compressor.ratio instanceof AudioParam, "knee is an AudioParam");
near(compressor.ratio.defaultValue, 12, "Correct default value for ratio");
is(typeof compressor.reduction, "number", "reduction is a number");
near(compressor.reduction, 0, "Correct default value for reduction");
ok(compressor.attack instanceof AudioParam, "attack is an AudioParam");
near(compressor.attack.defaultValue, 0.003, "Correct default value for attack");
ok(compressor.release instanceof AudioParam, "release is an AudioParam");
near(compressor.release.defaultValue, 0.25, "Correct default value for release");
compressor.threshold.value = -80;
osc.start();
var iteration = 0;
sp.onaudioprocess = function(e) {
if (iteration > 10) {
ok(compressor.reduction < 0,
"Feeding a full-scale sine to a compressor should result in an db" +
"reduction.");
sp.onaudioprocess = null;
osc.stop(0);
SimpleTest.finish();
}
iteration++;
}
});
</script>
</pre>
</body>
</html>