<!DOCTYPE html>
<html>
<head>
<title>
offlineaudiocontext-suspend-resume-graph-manipulation.html
</title>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<script src="../resources/audit-util.js"></script>
<script src="../resources/audit.js"></script>
</head>
<body>
<script id="layout-test-code">
let audit = Audit.createTaskRunner();
let context;
let renderQuantum = 128;
let renderDuration = 3;
// The sample rate is multiple of the rendering quantum, so suspension
// times fall in to the render quantum boundary.
let sampleRate = renderQuantum * 100;
// Suspend at 1 second and activate the source node. The audio output
// should be 1.0 from |suspendTime1| to the next suspension.
let suspendTime1 = 1;
// Suspend at 2 seconds and disconnect the node. The audio output should
// be 0.0 from |suspendTime2| to the end.
let suspendTime2 = 2;
audit.define(
{
label: 'test',
description:
'Synchronous graph manipulation with suspend() and resume()'
},
(task, should) => {
context = new OfflineAudioContext(
1, sampleRate * renderDuration, sampleRate);
// Create a constant buffer of 1.0.
let constantBuffer = createConstantBuffer(context, 1, 1.0);
let constantSource = context.createBufferSource();
constantSource.buffer = constantBuffer;
constantSource.loop = true;
// The audio output from the beginning (0.0 second) to the first
// suspend time should be 0.0 because there is no connection to the
// destination.
context.suspend(suspendTime1).then(function() {
if (context.currentTime === suspendTime1) {
should(
context.currentTime * sampleRate,
'Frame at which context is suspended')
.beEqualTo(suspendTime1 * sampleRate)
}
should(
() => {
constantSource.connect(context.destination);
constantSource.start()
},
'Connecting a constant buffer to destination and starting at ' +
suspendTime1 * sampleRate + ' frame')
.notThrow();
;
context.resume();
});
context.suspend(suspendTime2).then(function() {
if (context.currentTime === suspendTime2) {
should(context.currentTime * sampleRate, 'Context is suspended')
.beEqualTo(suspendTime2 * sampleRate);
}
should(
() => constantSource.disconnect(),
'Disconnecting a constant buffer at ' +
suspendTime2 * sampleRate + ' frame')
.notThrow();
context.resume();
});
context.startRendering()
.then(function(buffer) {
verifyResult(should, buffer);
})
.then(() => task.done());
});
function verifyResult(should, buffer) {
let data = buffer.getChannelData(0);
let suspendIndex1 = suspendTime1 * sampleRate;
let suspendIndex2 = suspendTime2 * sampleRate;
let endIndex = renderDuration * sampleRate;
// Split the rendered buffer into 3 segments:
// [0, suspendIndex1), [suspendIndex1, suspendIndex2), [suspendIndex2,
// endIndex).
let subarray0 = data.subarray(0, suspendIndex1);
let subarray1 = data.subarray(suspendIndex1, suspendIndex2);
let subarray2 = data.subarray(suspendIndex2, endIndex);
// Each segment should contain a constant value of 0, 1 and 0
// respectively.
should(subarray0, 'Buffer frame [0, ' + suspendIndex1 + ')')
.beConstantValueOf(0);
should(
subarray1,
'Buffer frame [' + suspendIndex1 + ', ' + suspendIndex2 + ')')
.beConstantValueOf(1);
should(
subarray2, 'Buffer frame [' + suspendIndex2 + ', ' + endIndex + ')')
.beConstantValueOf(0);
}
audit.run();
</script>
</body>
</html>