third_party/WebKit/LayoutTests/webaudio/audionode-connect-order.html

   1 <!DOCTYPE html>
   2
   3 <html>
   4 <head>
   5 <script src="../resources/js-test.js"></script>
   6 <script src="resources/compatibility.js"></script>
   7 <script src="resources/audio-testing.js"></script>
   8 </head>
   9
  10 <body>
  11
  12 <div id="description"></div>
  13 <div id="console"></div>
  14
  15 <script>
  16 description("This tests that we don't trigger an assertion failure due to AudioNode connection order.");
  17
  18 var sampleRate = 44100.0;
  19 var renderLengthSeconds = 0.125;
  20 var delayTimeSeconds = 0.1;
  21
  22 function createSinWaveBuffer(context, lengthInSeconds, frequency) {
  23     var audioBuffer = context.createBuffer(1, lengthInSeconds * sampleRate, sampleRate);
  24
  25     var n = audioBuffer.length;
  26     var data = audioBuffer.getChannelData(0);
  27
  28     for (var i = 0; i < n; ++i) {
  29         data[i] = Math.sin(frequency * 2 * Math.PI * i / sampleRate);
  30     }
  31
  32     return audioBuffer;
  33 }
  34
  35 function runTest() {
  36     if (window.testRunner) {
  37         testRunner.dumpAsText();
  38         testRunner.waitUntilDone();
  39     }
  40
  41     window.jsTestIsAsync = true;
  42
  43     // Create offline audio context.
  44     var context = new OfflineAudioContext(1, sampleRate * renderLengthSeconds, sampleRate);
  45     var toneBuffer = createSinWaveBuffer(context, renderLengthSeconds, 880);
  46
  47     var bufferSource = context.createBufferSource();
  48     bufferSource.buffer = toneBuffer;
  49     bufferSource.connect(context.destination);
  50
  51     var delay = context.createDelay();
  52     delay.delayTime.value = delayTimeSeconds;
  53
  54     // We connect delay node to gain node before anything is connected to delay node itself.
  55     // We do this because we try to trigger the ASSERT which might be fired due to AudioNode connection order,
  56     // especially when gain node and delay node is involved e.g. https://bugs.webkit.org/show_bug.cgi?id=76685.
  57
  58     var gain = context.createGain();
  59     gain.connect(context.destination);
  60     delay.connect(gain);
  61
  62     bufferSource.start(0);
  63
  64     context.oncomplete = finishJSTest;
  65     context.startRendering();
  66 }
  67
  68 runTest();
  69
  70 </script>
  71
  72 </body>
  73 </html>