test_mediaElementAudioSourceNode.html

Enable keyboard shortcuts

<!DOCTYPE HTML>

<html>

<meta charset="utf-8">

<head>

  <title>Test MediaElementAudioSourceNode</title>

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

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

</head>

<body>

<pre id="test">

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

SimpleTest.waitForExplicitFinish();

function test() {

  var audio = new Audio("small-shot.ogg");

  var context = new AudioContext();

  var expectedMinNonzeroSampleCount;

  var expectedMaxNonzeroSampleCount;

  var nonzeroSampleCount = 0;

  var complete = false;

  var iterationCount = 0;

  // This test ensures we receive at least expectedSampleCount nonzero samples

  function processSamples(e) {

    if (complete) {

      return;

    if (iterationCount == 0) {

      // Don't start playing the audio until the AudioContext stuff is connected

      // and running.

      audio.play();

    ++iterationCount;

    var buf = e.inputBuffer.getChannelData(0);

    var nonzeroSamplesThisBuffer = 0;

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

      if (buf[i] != 0) {

        ++nonzeroSamplesThisBuffer;

    nonzeroSampleCount += nonzeroSamplesThisBuffer;

    is(e.inputBuffer.numberOfChannels, 1,

       "Checking data channel count (nonzeroSamplesThisBuffer=" +

       nonzeroSamplesThisBuffer + ")");

    ok(nonzeroSampleCount <= expectedMaxNonzeroSampleCount,

       "Too many nonzero samples (got " + nonzeroSampleCount + ", expected max " + expectedMaxNonzeroSampleCount + ")");

    if (nonzeroSampleCount >= expectedMinNonzeroSampleCount &&

        nonzeroSamplesThisBuffer == 0) {

      ok(true,

       "Check received enough nonzero samples (got " + nonzeroSampleCount + ", expected min " + expectedMinNonzeroSampleCount + ")");

      SimpleTest.finish();

      complete = true;

  audio.onloadedmetadata = function() {

    var node = new MediaElementAudioSourceNode(context, { mediaElement: audio });

    var sp = context.createScriptProcessor(2048, 1);

    node.connect(sp);

    // Use a fuzz factor of 100 to account for samples that just happen to be zero

    expectedMinNonzeroSampleCount = Math.floor(audio.duration*context.sampleRate) - 100;

    expectedMaxNonzeroSampleCount = Math.floor(audio.duration*context.sampleRate) + 500;

    sp.onaudioprocess = processSamples;

};

SpecialPowers.pushPrefEnv({"set": [["media.preload.default", 2], ["media.preload.auto", 3]]}, test);

</script>

</pre>

</body>

</html>