42 lines
1.4 KiB
HTML
42 lines
1.4 KiB
HTML
<!DOCTYPE html>
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<html class="a">
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<head>
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<title>Feedback cycle with delay in audio node graph</title>
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<script src="/resources/testharness.js"></script>
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<script src="/resources/testharnessreport.js"></script>
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</head>
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<body>
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<script>
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function doTest() {
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var off = new OfflineAudioContext(1, 512, 48000);
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var b = off.createBuffer(1, 1, 48000);
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b.getChannelData(0)[0] = 1;
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var impulse = new AudioBufferSourceNode(off, {buffer: b});
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impulse.start(0);
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var delay = new DelayNode(off, {delayTime: 128 / 48000});
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var fb = new GainNode(off);
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impulse.connect(fb).connect(delay).connect(fb).connect(off.destination);
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var samples;
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return off.startRendering().then((b) => {
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return Promise.resolve(b.getChannelData(0));
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});
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}
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promise_test(() => {
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return doTest().then(samples => {
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for (var i = 0; i < samples.length; i++) {
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if ((i % 128) != 0) {
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assert_equals(
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samples[i], 0.0,
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'Non-silent audio found in between delayed impulses');
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} else {
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assert_equals(
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samples[i], 1.0,
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'Silent audio found instead of a delayed impulse');
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}
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}
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});
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}, 'Test that a DelayNode allows a feedback loop of a single rendering quantum');
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</script>
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</body>
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</html>
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