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<html>
<head>
<title>Test the support of cycles.</title>
<script type="text/javascript" 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 src="webaudio.js" type="text/javascript"></script>
<script class="testbody" type="text/javascript">
SimpleTest.waitForExplicitFinish();
const sampleRate = 48000;
const inputLength = 2048;
addLoadEvent(function() {
function addSine(b) {
for (var i = 0; i < b.length; i++) {
b[i] += Math.sin(440 * 2 * Math.PI * i / sampleRate);
}
}
function getSineBuffer(ctx) {
var buffer = ctx.createBuffer(1, inputLength, ctx.sampleRate);
addSine(buffer.getChannelData(0));
return buffer;
}
function createAndPlayWithCycleAndDelayNode(ctx, delayFrames) {
var source = ctx.createBufferSource();
source.buffer = getSineBuffer(ctx);
var gain = ctx.createGain();
var delay = ctx.createDelay();
delay.delayTime.value = delayFrames/ctx.sampleRate;
source.connect(gain);
gain.connect(delay);
delay.connect(ctx.destination);
// cycle
delay.connect(gain);
source.start(0);
}
function createAndPlayWithCycleAndNoDelayNode(ctx) {
var source = ctx.createBufferSource();
source.loop = true;
source.buffer = getSineBuffer(ctx);
var gain = ctx.createGain();
var gain2 = ctx.createGain();
source.connect(gain);
gain.connect(gain2);
// cycle
gain2.connect(gain);
gain2.connect(ctx.destination);
source.start(0);
}
function createAndPlayWithCycleAndNoDelayNodeInCycle(ctx) {
var source = ctx.createBufferSource();
source.loop = true;
source.buffer = getSineBuffer(ctx);
var delay = ctx.createDelay();
var gain = ctx.createGain();
var gain2 = ctx.createGain();
// Their is a cycle, a delay, but the delay is not in the cycle.
source.connect(delay);
delay.connect(gain);
gain.connect(gain2);
// cycle
gain2.connect(gain);
gain2.connect(ctx.destination);
source.start(0);
}
var remainingTests = 0;
function finish() {
if (--remainingTests == 0) {
SimpleTest.finish();
}
}
function getOfflineContext(oncomplete) {
var ctx = new OfflineAudioContext(1, sampleRate, sampleRate);
ctx.oncomplete = oncomplete;
return ctx;
}
function checkSilentBuffer(e) {
var buffer = e.renderedBuffer.getChannelData(0);
for (var i = 0; i < buffer.length; i++) {
if (buffer[i] != 0.0) {
ok(false, "buffer should be silent.");
finish();
return;
}
}
ok(true, "buffer should be silent.");
finish();
}
function checkNoisyBuffer(e, aDelayFrames) {
delayFrames = Math.max(128, aDelayFrames);
var expected = new Float32Array(e.renderedBuffer.length);
for (var i = delayFrames; i < expected.length; i += delayFrames) {
addSine(expected.subarray(i, i + inputLength));
}
compareChannels(e.renderedBuffer.getChannelData(0), expected);
finish();
}
function expectSilentOutput(f) {
remainingTests++;
var ctx = getOfflineContext(checkSilentBuffer);
f(ctx);
ctx.startRendering();
}
function expectNoisyOutput(delayFrames) {
remainingTests++;
var ctx = getOfflineContext();
ctx.oncomplete = function(e) { checkNoisyBuffer(e, delayFrames); };
createAndPlayWithCycleAndDelayNode(ctx, delayFrames);
ctx.startRendering();
}
// This is trying to make a graph with a cycle and no DelayNode in the graph.
// The cycle subgraph should be muted, in this graph the output should be silent.
expectSilentOutput(createAndPlayWithCycleAndNoDelayNode);
// This is trying to make a graph with a cycle and a DelayNode in the graph, but
// not part of the cycle.
// The cycle subgraph should be muted, in this graph the output should be silent.
expectSilentOutput(createAndPlayWithCycleAndNoDelayNodeInCycle);
// Those are making legal graphs, with at least one DelayNode in the cycle.
// There should be some non-silent output.
expectNoisyOutput(sampleRate/4);
// DelayNode.delayTime will be clamped to 128/ctx.sampleRate.
// There should be some non-silent output.
expectNoisyOutput(0);
});
</script>
</pre>
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