dom/media/webaudio/test/test_mediaElementAudioSourceNodeFidelity.html
author Jim Blandy <jimb@red-bean.com>
Thu, 30 Mar 2023 16:23:26 +0000
changeset 658645 9754c55103ef774188e1e813a3ef5d4f5487b35c
parent 469641 ba6f655fd68963530c866d0d4a48c3db3d307777
permissions -rw-r--r--
Bug 1825449: Don't warn on mismatched WebGPU error scope push/pop. r=webgpu-reviewers,teoxoy In the graphics process, don't warn on receipt of mismatched DevicePushErrorScope/DevicePopErrorScope messages, since these can be easily caused by ordinary content and do not indicate anything wrong with Firefox. Differential Revision: https://phabricator.services.mozilla.com/D174045

<!DOCTYPE HTML>
<html>
<meta charset="utf-8">
<head>
  <title>Test MediaStreamAudioSourceNode doesn't get data from cross-origin media resources</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 binIndexForFrequency(frequency, analyser) {
  return 1 + Math.round(frequency *
                        analyser.fftSize /
                        analyser.context.sampleRate);
}

function debugCanvas(analyser) {
  var cvs = document.createElement("canvas");
  document.body.appendChild(cvs);

  // Easy: 1px per bin
  cvs.width = analyser.frequencyBinCount;
  cvs.height = 256;
  cvs.style.border = "1px solid red";

  var c = cvs.getContext('2d');
  var buf = new Uint8Array(analyser.frequencyBinCount);

  function render() {
    c.clearRect(0, 0, cvs.width, cvs.height);
    analyser.getByteFrequencyData(buf);
    for (var i = 0; i < buf.length; i++) {
      c.fillRect(i, (256 - (buf[i])), 1, 256);
    }
    requestAnimationFrame(render);
  }
  requestAnimationFrame(render);
}


function checkFrequency(an) {
  an.getFloatFrequencyData(frequencyArray);
  // We should have no energy when checking the data largely outside the index
  // for 440Hz (the frequency of the sine wave), start checking an octave above,
  // the Opus compression can add some harmonics to the pure since wave.
  var maxNoiseIndex = binIndexForFrequency(880, an);
  for (var i = maxNoiseIndex + 1; i < frequencyArray.length; i++) {
    if (frequencyArray[i] > frequencyArray[maxNoiseIndex]) {
       maxNoiseIndex = i;
    }
  }

  // On the other hand, we should find a peak at 440Hz. Our sine wave is not
  // attenuated, we're expecting the peak to reach 0dBFs.
  var index = binIndexForFrequency(440, an);
  info("energy at 440: " + frequencyArray[index] +
       ", threshold " + (an.maxDecibels - 10) +
       "; max noise at index " + maxNoiseIndex +
       ": " + frequencyArray[maxNoiseIndex] );
  if (frequencyArray[index] < (an.maxDecibels - 10)) {
    return false;
  }
  // Let some slack, there might be some noise here because of int -> float
  // conversion or the Opus encoding.
  if (frequencyArray[maxNoiseIndex] > an.minDecibels + 40) {
    return false;
  }

  return true;
}

var audioElement = new Audio();
audioElement.src = 'sine-440-10s.opus'
audioElement.loop = true;
var ac = new AudioContext();
var mediaElementSource = ac.createMediaElementSource(audioElement);
var an = ac.createAnalyser();
// Use no smoothing as this would just average with previous
// getFloatFrequencyData() calls.  Non-seamless looping would introduce noise,
// and smoothing would spread this into calls after the loop point.
an.smoothingTimeConstant = 0;
frequencyArray = new Float32Array(an.frequencyBinCount);

// Uncomment this to check what the analyser is doing.
// debugCanvas(an);

mediaElementSource.connect(an)

audioElement.play();
// We want to check the we have the expected audio for at least two loop of
// the HTMLMediaElement, piped into an AudioContext. The file is ten seconds,
// and we use the default FFT size.
var lastCurrentTime = 0;
var loopCount = 0;
audioElement.onplaying = function() {
  audioElement.ontimeupdate = function() {
    // We don't run the analysis when close to loop point or at the
    // beginning, since looping is not seamless, there could be an
    // unpredictable amount of silence
    var rv = checkFrequency(an);
    info("currentTime: " + audioElement.currentTime);
    if (audioElement.currentTime < 4 ||
        audioElement.currentTime > 8){
      return;
    }
    if (!rv) {
      ok(false, "Found unexpected noise during analysis.");
      audioElement.ontimeupdate = null;
      audioElement.onplaying = null;
      ac.close();
      audioElement.src = '';
      SimpleTest.finish()
      return;
    }
    ok(true, "Found correct audio signal during analysis");
    info(lastCurrentTime + " " + audioElement.currentTime);
    if (lastCurrentTime > audioElement.currentTime) {
      info("loopCount: " + loopCount);
      if (loopCount > 1) {
        audioElement.ontimeupdate = null;
        audioElement.onplaying = null;
        ac.close();
        audioElement.src = '';
        SimpleTest.finish();
      }
      lastCurrentTime = audioElement.currentTime;
      loopCount++;
    } else {
      lastCurrentTime = audioElement.currentTime;
    }
  }
}

</script>