1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
<!DOCTYPE html>
<html>
<head>
<title>
Test DelayNode when maxDelayTime requires rounding
</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 id="layout-test-code">
let sampleRate = 44100;
let inputLengthSeconds = 1;
let renderLengthSeconds = 2;
// Delay for one second plus 0.4 of a sample frame, to test that
// DelayNode is properly rounding up when calculating its buffer
// size (crbug.com/1065110).
let delayTimeSeconds = 1 + 0.4 / sampleRate;
let audit = Audit.createTaskRunner();
audit.define(
{
label: 'maxdelay-rounding',
description: 'Test DelayNode when maxDelayTime requires rounding',
},
(task, should) => {
let context = new OfflineAudioContext({
numberOfChannels: 1,
length: sampleRate * renderLengthSeconds,
sampleRate: sampleRate,
});
// Create a constant source to use as input.
let src = new ConstantSourceNode(context);
// Create a DelayNode to delay for delayTimeSeconds.
let delay = new DelayNode(context, {
maxDelayTime: delayTimeSeconds,
delayTime: delayTimeSeconds,
});
src.connect(delay).connect(context.destination);
src.start();
context.startRendering()
.then(renderedBuffer => {
let renderedData = renderedBuffer.getChannelData(0);
// The first delayTimeSeconds of output should be silent.
let expectedSilentFrames = Math.floor(
delayTimeSeconds * sampleRate);
should(
renderedData.slice(0, expectedSilentFrames),
`output[0:${expectedSilentFrames - 1}]`)
.beConstantValueOf(0);
// The rest should be non-silent: that is, there should
// be at least one non-zero sample. (Any reasonable
// interpolation algorithm will make all these samples
// non-zero, but I don't think that's guaranteed by the
// spec, so we use a conservative test for now.)
should(
renderedData.slice(expectedSilentFrames),
`output[${expectedSilentFrames}:]`)
.notBeConstantValueOf(0);
})
.then(() => task.done());
});
audit.run();
</script>
</body>
</html>
|
