src/third_party/WebKit/LayoutTests/webaudio/channelmerger-channel-limit.html

   1 <!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
   2 <html>
   3   <head>
   4     <script src="resources/compatibility.js"></script>
   5     <script src="resources/audio-testing.js"></script>
   6     <script src="../resources/js-test.js"></script>
   7   </head>
   8
   9   <body>
  10     <div id="description"></div>
  11     <div id="console"></div>
  12
  13     <script>
  14       description("Test that ChannelMergerNode can handle many input channels");
  15
  16       var sampleRate = 44100;
  17
  18       // Number of samples to render
  19       var renderLengthSamples = 2048;
  20
  21       // This is the max number of channels that blink WebAudio currently supports.  (Would be nice
  22       // to be able to query something to get this value.)
  23       var maxNumberOfChannels = 32;
  24
  25       // Number of channels in the source.  Should be different from maxNumberOfChannels but more
  26       // than half of maxNumberOfChannels so we can verify that the ChannelMergerNode is behaving
  27       // correctly.
  28       var numberOfSourceChannels = 25;
  29
  30       var context;
  31       var merger;
  32       var source;
  33       var buffer;
  34       var renderedData;
  35       var timeData = Array(maxNumberOfChannels);
  36
  37       function generateSourceBuffer() {
  38           // Create a buffer with |numberOfSourceChannels| channels, with each channel containing a
  39           // constant value depending on the channel number.
  40           var buffer = context.createBuffer(numberOfSourceChannels, renderLengthSamples, sampleRate);
  41           for (k = 0; k < buffer.numberOfChannels; ++k) {
  42               var data = buffer.getChannelData(k);
  43               for (var n = 0; n < data.length; ++n) {
  44                   data[n] = k + 1;
  45               }
  46           }
  47           return buffer;
  48       }
  49
  50       function hasCorrectData(channelNumber, buffer) {
  51           var isCorrect = true;
  52           var expectedValue = 1 + (channelNumber % numberOfSourceChannels);
  53
  54           for (var k = 0; k < buffer.length; ++k) {
  55               if (buffer[k] != expectedValue) {
  56                   isCorrect = false;
  57                   break;
  58               }
  59           }
  60           return isCorrect;
  61       }
  62
  63       function checkResult(event) {
  64           renderedData = event.renderedBuffer;
  65           var success = true;
  66
  67           // If we get here, the merger node accepted many input channels.
  68           testPassed("ChannelMergerNode accepted many input channels.");
  69
  70           // Verify that the outputs have the expected values.
  71           for (var k = 0; k < renderedData.numberOfChannels; ++k) {
  72              timeData[k] = renderedData.getChannelData(k);
  73              if (hasCorrectData(k, timeData[k])) {
  74                  testPassed("Channel " + k + " has the expected data.");
  75              } else {
  76                  success = false;
  77                  testFailed("Channel " + k + " did not have the expected data.");
  78              }
  79           }
  80
  81           if (renderedData.numberOfChannels != maxNumberOfChannels) {
  82               testFailed("Not all channels could be tested because OfflineAudioContext only supports "
  83                          + renderedData.numberOfChannels + " channels.");
  84           }
  85
  86           if (success)
  87               testPassed("ChannerMergerNode handled many input channels correctly.");
  88           else
  89               testFailed("ChannerMergerNode failed to handle many input channels correctly.");
  90
  91           finishJSTest();
  92       }
  93
  94       function runTest() {
  95           if (window.testRunner) {
  96               testRunner.dumpAsText();
  97               testRunner.waitUntilDone();
  98           }
  99
 100           window.jsTestIsAsync = true;
 101
 102           // Create offline audio context.
 103           context = new OfflineAudioContext(maxNumberOfChannels, renderLengthSamples, sampleRate);
 104
 105           // This is a slightly simplified test case from crbug.com/345174.
 106           merger = context.createChannelMerger();
 107           source = context.createBufferSource();
 108
 109           source.buffer = generateSourceBuffer();
 110
 111           // Connect the source to the merger at two different inputs so that sum of the channels on
 112           // the inputs exceeds the maximum number of channels.
 113           source.connect(merger, 0, 3);
 114           source.connect(merger);
 115
 116           merger.connect(context.destination);
 117           source.start();
 118           context.oncomplete = checkResult;
 119           context.startRendering();
 120       }
 121
 122       runTest();
 123       successfullyParsed = true;
 124
 125     </script>
 126   </body>
 127 </html>