test_waveDecoder.html

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<meta charset=utf-8>

<head>

  <title>Test that we decode uint8 and sint16 wave files with correct conversion to float64</title>

  <script src="/tests/SimpleTest/SimpleTest.js"></script>

  <link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css" />

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<pre id="test">

<script class="testbody" type="text/javascript">

var testsDone = 0;

var tests = ["UklGRjUrAABXQVZFZm10IBAAAAABAAEAESsAABErAAABAAgAZGF0YQMAAAD/AIA=",

             "UklGRkZWAABXQVZFZm10IBAAAAABAAEAESsAACJWAAACABAAZGF0YQYAAAD/fwCAAAA="];

SimpleTest.waitForExplicitFinish();

function base64ToUint8Buffer(b64) {

  var str = atob(b64)

  var u8 = new Uint8Array(str.length);

  for (var i = 0; i < str.length; ++i) {

    u8[i] = str.charCodeAt(i);

  return u8;

function fixupBufferSampleRate(u8, rate) {

  u8[24] = (rate & 0x000000ff) >> 0;

  u8[25] = (rate & 0x0000ff00) >> 8;

  u8[26] = (rate & 0x00ff0000) >> 16;

  u8[27] = (rate & 0xff000000) >> 24;

function finishTest() {

  testsDone += 1;

  if (testsDone == tests.length) {

    SimpleTest.finish();

function decodeComplete(b) {

  ok(true, "Decoding succeeded.");

  is(b.numberOfChannels, 1, "Should have 1 channel.");

  is(b.length, 3, "Should have three samples.");

  var samples = b.getChannelData(0);

  ok(samples[0] >  0.99 && samples[0] <  1.01, "Check near  1.0. Got " + samples[0]);

  ok(samples[1] > -1.01 && samples[1] < -0.99, "Check near -1.0. Got " + samples[1]);

  ok(samples[2] > -0.01 && samples[2] <  0.01, "Check near  0.0. Got " + samples[2]);

  finishTest();

function decodeFailed() {

  ok(false, "Decoding failed.");

  finishTest();

addLoadEvent(function() {

  var context = new AudioContext();

  for (var i = 0; i < tests.length; ++i) {

    var u8 = base64ToUint8Buffer(tests[i]);

    fixupBufferSampleRate(u8, context.sampleRate);

    context.decodeAudioData(u8.buffer, decodeComplete, decodeFailed);

});

</script>

</pre>

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