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transferred-buffer-output.html (3611B)

      1 <!doctype html>
      2 <html>
      3  <head>
      4    <title>
      5      Test Convolver Output with Transferred Buffer
      6    </title>
      7    <script src="/resources/testharness.js"></script>
      8    <script src="/resources/testharnessreport.js"></script>
      9    <script src="/webaudio/resources/audit-util.js"></script>
     10    <script src="/webaudio/resources/audit.js"></script>
     11  </head>
     12 
     13  <body>
     14    <script>
     15      // Arbitrary sample rate.
     16      const sampleRate = 16000;
     17 
     18      // Number of frames to render.  Just need to have at least 2 render
     19      // quanta.
     20      const lengthInFrames = 10 * RENDER_QUANTUM_FRAMES;
     21 
     22      let audit = Audit.createTaskRunner();
     23 
     24      // Buffer to use for the impulse response of a ConvolverNode.
     25      let impulseBuffer;
     26 
     27      // This sets up a worker to receive one channel of an AudioBuffer.
     28      function setUpWorkerForTest() {
     29        impulseBuffer = new AudioBuffer({
     30          numberOfChannels: 2,
     31          length: 2 * RENDER_QUANTUM_FRAMES,
     32          sampleRate: sampleRate
     33        });
     34 
     35        // Just fill the buffer with a constant value; the contents shouldn't
     36        // matter for this test since we're transferring one of the channels.
     37        impulseBuffer.getChannelData(0).fill(1);
     38        impulseBuffer.getChannelData(1).fill(2);
     39 
     40        // We're going to transfer channel 0 to the worker, making it
     41        // unavailable for the convolver
     42        let data = impulseBuffer.getChannelData(0).buffer;
     43 
     44        let string = [
     45          'onmessage = function(e) {', '    postMessage(\'done\');', '};'
     46        ].join('\n');
     47 
     48        let blobURL = URL.createObjectURL(new Blob([string]));
     49        let worker = new Worker(blobURL);
     50        worker.onmessage = workerReply;
     51        worker.postMessage(data, [data]);
     52      }
     53 
     54      function workerReply() {
     55        // Worker has received the message.  Run the test.
     56        audit.run();
     57      }
     58 
     59      audit.define(
     60          {
     61            label: 'Test Convolver with transferred buffer',
     62            description: 'Output should be all zeroes'
     63          },
     64          async (task, should) => {
     65            // Two channels so we can capture the output of the convolver with a
     66            // stereo convolver.
     67            let context = new OfflineAudioContext({
     68              numberOfChannels: 2,
     69              length: lengthInFrames,
     70              sampleRate: sampleRate
     71            });
     72 
     73            // Use a simple constant source so we easily check that the
     74            // convolver output is correct.
     75            let source = new ConstantSourceNode(context);
     76 
     77            // Create the convolver with the desired impulse response and
     78            // disable normalization so we can easily check the output.
     79            let conv = new ConvolverNode(
     80                context, {disableNormalization: true, buffer: impulseBuffer});
     81 
     82            source.connect(conv).connect(context.destination);
     83 
     84            source.start();
     85 
     86            let renderedBuffer = await context.startRendering();
     87 
     88            // Get the actual data
     89            let c0 = renderedBuffer.getChannelData(0);
     90            let c1 = renderedBuffer.getChannelData(1);
     91 
     92            // Since one channel was transferred, we must behave as if all were
     93            // transferred.  Hence, the output should be all zeroes for both
     94            // channels.
     95            should(c0, `Convolver channel 0 output[0:${c0.length - 1}]`)
     96                .beConstantValueOf(0);
     97 
     98            should(c1, `Convolver channel 1 output[0:${c1.length - 1}]`)
     99                .beConstantValueOf(0);
    100 
    101            task.done();
    102          });
    103 
    104      setUpWorkerForTest();
    105    </script>
    106  </body>
    107 </html>