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<!doctype html>
<html>
<head>
<title>Test Flushing of NaN to Zero in AudioParams</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/webaudio/resources/audit-util.js"></script>
<script src="/webaudio/resources/audit.js"></script>
</head>
<body>
<script>
let audit = Audit.createTaskRunner();
// See
// https://webaudio.github.io/web-audio-api/#computation-of-value.
//
// The computed value must replace NaN values in the output with
// the default value of the param.
audit.define('AudioParam NaN', async (task, should) => {
// For testing, we only need a small number of frames; and
// a low sample rate is perfectly fine. Use two channels.
// The first channel is for the AudioParam output. The
// second channel is for the AudioParam input.
let context = new OfflineAudioContext(
{numberOfChannels: 2, length: 256, sampleRate: 8192});
let merger = new ChannelMergerNode(
context, {numberOfInputs: context.destination.channelCount});
merger.connect(context.destination);
// A constant source with a huge value.
let mod = new ConstantSourceNode(context, {offset: 1e30});
// Gain nodes with a huge positive gain and huge negative
// gain. Combined with the huge offset in |mod|, the
// output of the gain nodes are +Infinity and -Infinity.
let gainPos = new GainNode(context, {gain: 1e30});
let gainNeg = new GainNode(context, {gain: -1e30});
mod.connect(gainPos);
mod.connect(gainNeg);
// Connect these to the second merger channel. This is a
// sanity check that the AudioParam input really is NaN.
gainPos.connect(merger, 0, 1);
gainNeg.connect(merger, 0, 1);
// Source whose AudioParam is connected to the graph
// that produces NaN values. Use a non-default value offset
// just in case something is wrong we get default for some
// other reason.
let src = new ConstantSourceNode(context, {offset: 100});
gainPos.connect(src.offset);
gainNeg.connect(src.offset);
// AudioParam output goes to channel 1 of the destination.
src.connect(merger, 0, 0);
// Let's go!
mod.start();
src.start();
let buffer = await context.startRendering();
let input = buffer.getChannelData(1);
let output = buffer.getChannelData(0);
// Have to test manually for NaN values in the input because
// NaN fails all comparisons.
let isNaN = true;
for (let k = 0; k < input.length; ++k) {
if (!Number.isNaN(input[k])) {
isNaN = false;
break;
}
}
should(isNaN, 'AudioParam input contains only NaN').beTrue();
// Output of the AudioParam should have all NaN values
// replaced by the default.
should(output, 'AudioParam output')
.beConstantValueOf(src.offset.defaultValue);
task.done();
});
audit.run();
</script>
</body>
</html>
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