third_party/WebKit/LayoutTests/webaudio/audiobuffersource-grain.html

   1 <!doctype html>
   2 <html>
   3   <head>
   4     <title>Test Start Grain with Delayed Buffer Setting </title>
   5     <script src="resources/compatibility.js"></script>
   6     <script src="resources/audio-testing.js"></script>
   7     <script src="../resources/js-test.js"></script>
   8   </head>
   9
  10   <body>
  11     <script>
  12       description("Test setting the source buffer after starting the grain");
  13
  14       var context;
  15       var source;
  16       var buffer;
  17       var renderedData;
  18
  19       var sampleRate = 44100;
  20
  21       var testDurationSec = 1;
  22       var testDurationSamples = testDurationSec * sampleRate;
  23       var startTime = 0.9 * testDurationSec;
  24
  25       function runTest() {
  26           window.jsTestIsAsync = true;
  27
  28           context = new OfflineAudioContext(1, testDurationSamples, sampleRate);
  29           context.oncomplete = checkResult;
  30
  31           buffer = createConstantBuffer(context, testDurationSamples, 1);
  32           source = context.createBufferSource();
  33           source.connect(context.destination);
  34
  35           // Start the source BEFORE we set the buffer. The grain offset and duration aren't
  36           // important, as long as we specify some offset.
  37           source.start(startTime, .1);
  38           source.buffer = buffer;
  39
  40           // Render it!
  41           context.startRendering();
  42       }
  43
  44       function checkResult(event) {
  45           var success = false;
  46
  47           renderedData = event.renderedBuffer.getChannelData(0);
  48
  49           // Check that the rendered data is not all zeroes.  Any non-zero data means the test
  50           // passed.
  51           var startFrame = Math.round(startTime * sampleRate);
  52           for (k = 0; k < renderedData.length; ++k) {
  53               if (renderedData[k]) {
  54                   success = true;
  55                   break;
  56               }
  57           }
  58
  59           if (success)
  60               testPassed("Buffer was played.");
  61           else
  62               testFailed("Buffer was not played.");
  63
  64           finishJSTest();
  65       }
  66
  67       runTest();
  68       successfullyParsed = true;
  69     </script>
  70   </body>
  71 </html>