third_party/WebKit/LayoutTests/webaudio/resources/scriptprocessornode-testing.js

   1 // For the current implementation of JavaScriptAudioNode, when it works with OfflineAudioContext (which runs much faster
   2 // than real-time) the event.inputBuffer might be overwrite again before onaudioprocess ever get chance to be called.
   3 // We carefully arrange the renderLengthInFrames and bufferSize to have exactly the same value to avoid this issue.
   4 var renderLengthInFrames = 512;
   5 var bufferSize = 512;
   6
   7 var context;
   8
   9 function createBuffer(context, numberOfChannels, length) {
  10     var audioBuffer = context.createBuffer(numberOfChannels, length, sampleRate);
  11
  12     fillData(audioBuffer, numberOfChannels, audioBuffer.length);
  13     return audioBuffer;
  14 }
  15
  16 function processAudioData(event) {
  17     buffer = event.outputBuffer;
  18     if (buffer.numberOfChannels != outputChannels)
  19         testFailed("numberOfOutputChannels doesn't match!");
  20
  21     if (buffer.length != bufferSize)
  22         testFailed("length of buffer doesn't match!");
  23
  24     buffer = event.inputBuffer;
  25
  26     var success = checkStereoOnlyData(buffer, inputChannels, buffer.length);
  27
  28     if (success) {
  29         testPassed("onaudioprocess was called with correct input data.");
  30     } else {
  31         testFailed("onaudioprocess was called with wrong input data.");
  32     }
  33 }
  34
  35 function fillData(buffer, numberOfChannels, length) {
  36     for (var i = 0; i < numberOfChannels; ++i) {
  37         var data = buffer.getChannelData(i);
  38
  39         for (var j = 0; j < length; ++j)
  40             if (i < 2)
  41                 data[j] = i * 2 - 1;
  42             else
  43                 data[j] = 0;
  44     }
  45 }
  46
  47 // Both 2 to 8 upmix and 8 to 2 downmix are just directly copy the first two channels and left channels are zeroed.
  48 function checkStereoOnlyData(buffer, numberOfChannels, length) {
  49     for (var i = 0; i < numberOfChannels; ++i) {
  50         var data = buffer.getChannelData(i);
  51
  52         for (var j = 0; j < length; ++j) {
  53             if (i < 2) {
  54                 if (data[j] != i * 2 - 1)
  55                     return false;
  56             } else {
  57                 if (data[j] != 0)
  58                     return false;
  59             }
  60         }
  61     }
  62     return true;
  63 }
  64
  65 function runJSNodeTest()
  66 {
  67     // Create offline audio context.
  68     context = new OfflineAudioContext(2, renderLengthInFrames, sampleRate);
  69
  70     var sourceBuffer = createBuffer(context, sourceChannels, renderLengthInFrames);
  71
  72     var bufferSource = context.createBufferSource();
  73     bufferSource.buffer = sourceBuffer;
  74
  75     var scriptNode = context.createScriptProcessor(bufferSize, inputChannels, outputChannels);
  76
  77     bufferSource.connect(scriptNode);
  78     scriptNode.connect(context.destination);
  79     scriptNode.onaudioprocess = processAudioData;
  80
  81     bufferSource.start(0);
  82     context.oncomplete = finishJSTest;
  83     context.startRendering();
  84 }