tor-browser

The Tor Browser
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mediaElementAudioSourceToScriptProcessorTest.html (4844B)

      1 <!doctype html>
      2 
      3 <!--
      4 Tests that a create MediaElementSourceNode that is passed through
      5 a script processor passes the stream data.
      6 The script processor saves the input buffers it gets to a temporary
      7 array, and after the playback has stopped, the contents are compared
      8 to those of a loaded AudioBuffer with the same source.
      9 
     10 Somewhat similiar to a test from Mozilla:
     11 https://searchfox.org/mozilla-central/source/dom/media/webaudio/test/test_mediaElementAudioSourceNode.html
     12 -->
     13 
     14 <html class="a">
     15 <head>
     16  <title>MediaElementAudioSource interface test (to scriptProcessor)</title>
     17  <script src="/resources/testharness.js"></script>
     18  <script src="/resources/testharnessreport.js"></script>
     19  <script src="/webaudio/js/helpers.js"></script>
     20  <script src="/webaudio/js/buffer-loader.js"></script>
     21 </head>
     22 <body class="a">
     23  <div id="log"></div>
     24  <script>
     25 var elementSourceTest = async_test(function(elementSourceTest) {
     26 
     27   var src = '/webaudio/resources/sin_440Hz_-6dBFS_1s.wav';
     28   var BUFFER_SIZE = 2048;
     29   var context = null;
     30   var actualBufferArrayC0 = new Float32Array(0);
     31   var actualBufferArrayC1 = new Float32Array(0);
     32   var audio = null, source = null, processor = null
     33 
     34   function loadExpectedBuffer(event) {
     35     bufferLoader = new BufferLoader(
     36       context,
     37       [src],
     38       elementSourceTest.step_func(bufferLoadCompleted)
     39     );
     40     bufferLoader.load();
     41   };
     42 
     43   function bufferLoadCompleted(buffer) {
     44     runTests(buffer);
     45   };
     46 
     47   function concatTypedArray(arr1, arr2) {
     48     var result = new Float32Array(arr1.length + arr2.length);
     49     result.set(arr1);
     50     result.set(arr2, arr1.length);
     51     return result;
     52   }
     53 
     54   // Create Audio context.  The reference wav file is sampled at 44.1 kHz so
     55   // use the same rate for the context to remove extra resampling that might
     56   // be required.
     57   context = new AudioContext({sampleRate: 44100});
     58 
     59   // Create an audio element, and a media element source
     60   audio = document.createElement('audio');
     61   audio.src = src;
     62   source = context.createMediaElementSource(audio);
     63 
     64   function processListener (e) {
     65     actualBufferArrayC0 = concatTypedArray(actualBufferArrayC0, e.inputBuffer.getChannelData(0));
     66     actualBufferArrayC1 = concatTypedArray(actualBufferArrayC1, e.inputBuffer.getChannelData(1));
     67   }
     68 
     69   // Create a processor node to copy the input to the actual buffer
     70   processor = context.createScriptProcessor(BUFFER_SIZE);
     71   source.connect(processor);
     72   processor.connect(context.destination);
     73   let audioprocessListener = elementSourceTest.step_func(processListener);
     74   processor.addEventListener('audioprocess', audioprocessListener);
     75 
     76   context.addEventListener('statechange', elementSourceTest.step_func(() => {
     77     assert_equals(context.state, "running", "context.state");
     78     audio.play();
     79   }), {once: true});
     80 
     81   // When media playback ended, save the begin to compare with expected buffer
     82   audio.addEventListener("ended", elementSourceTest.step_func(function(e) {
     83     // Setting a timeout since we need audioProcess event to run for all samples
     84     window.setTimeout(elementSourceTest.step_func(loadExpectedBuffer), 50);
     85   }));
     86 
     87   function runTests(expected) {
     88     source.disconnect();
     89     processor.disconnect();
     90 
     91     // firefox seems to process events after disconnect
     92     processor.removeEventListener('audioprocess', audioprocessListener)
     93 
     94     // Note: the expected result is from a mono source file.
     95     var expectedBuffer = expected[0];
     96 
     97     // Trim the actual elements because we don't have a fine-grained
     98     // control over the start and end time of recording the data.
     99     var actualTrimmedC0 = trimEmptyElements(actualBufferArrayC0);
    100     var actualTrimmedC1 = trimEmptyElements(actualBufferArrayC1);
    101     var expectedLength = trimEmptyElements(expectedBuffer.getChannelData(0)).length;
    102 
    103     // Test that there is some data.
    104     test(function() {
    105       assert_greater_than(actualTrimmedC0.length, 0,
    106                           "processed data array (C0) length greater than 0");
    107       assert_greater_than(actualTrimmedC1.length, 0,
    108                           "processed data array (C1) length greater than 0");
    109     }, "Channel 0 processed some data");
    110 
    111     // Test the actual contents of the 1st and second channel.
    112     test(function() {
    113       assert_array_approx_equals(
    114         actualTrimmedC0,
    115         trimEmptyElements(expectedBuffer.getChannelData(0)),
    116         1e-4,
    117         "comparing expected and rendered buffers (channel 0)");
    118       assert_array_approx_equals(
    119         actualTrimmedC1,
    120         trimEmptyElements(expectedBuffer.getChannelData(0)),
    121         1e-4,
    122         "comparing expected and rendered buffers (channel 1)");
    123     }, "All data processed correctly");
    124 
    125     elementSourceTest.done();
    126   };
    127 }, "Element Source tests completed");
    128  </script>
    129 </body>
    130 </html>