third_party/WebKit/LayoutTests/webaudio/convolution-mono-mono.html

   1 <!DOCTYPE html>
   2
   3 <html>
   4 <head>
   5 <script src="resources/compatibility.js"></script>
   6 <script type="text/javascript" src="resources/audio-testing.js"></script>
   7 <script src="../resources/js-test.js"></script>
   8 <script src="resources/convolution-testing.js"></script>
   9 </head>
  10
  11 <body>
  12
  13 <div id="description"></div>
  14 <div id="console"></div>
  15
  16 <script>
  17 description("Tests ConvolverNode processing a mono channel with mono impulse response.");
  18
  19 // To test the convolver, we convolve two square pulses together to
  20 // produce a triangular pulse.  To verify the result is correct we
  21 // check several parts of the result.  First, we make sure the initial
  22 // part of the result is zero (due to the latency in the convolver).
  23 // Next, the triangular pulse should match the theoretical result to
  24 // within some roundoff.  After the triangular pulse, the result
  25 // should be exactly zero, but round-off prevents that.  We make sure
  26 // the part after the pulse is sufficiently close to zero.  Finally,
  27 // the result should be exactly zero because the inputs are exactly
  28 // zero.
  29 function runTest() {
  30     if (window.testRunner) {
  31         testRunner.dumpAsText();
  32         testRunner.waitUntilDone();
  33     }
  34
  35     window.jsTestIsAsync = true;
  36
  37     // Create offline audio context.
  38     var context = new OfflineAudioContext(2, sampleRate * renderLengthSeconds, sampleRate);
  39
  40     var squarePulse = createSquarePulseBuffer(context, pulseLengthFrames);
  41     var trianglePulse = createTrianglePulseBuffer(context, 2 * pulseLengthFrames);
  42
  43     var bufferSource = context.createBufferSource();
  44     bufferSource.buffer = squarePulse;
  45
  46     var convolver = context.createConvolver();
  47     convolver.normalize = false;
  48     convolver.buffer = squarePulse;
  49
  50     bufferSource.connect(convolver);
  51     convolver.connect(context.destination);
  52
  53     bufferSource.start(0);
  54
  55     context.oncomplete = checkConvolvedResult(trianglePulse);
  56     context.startRendering();
  57 }
  58
  59 runTest();
  60 successfullyParsed = true;
  61
  62 </script>
  63
  64 </body>
  65 </html>