transferred-buffer-output.html | Explore in Territory

<!doctype html>
<html>
  <head>
    <title>
      Test Convolver Output with Transferred Buffer
    </title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="/webaudio/resources/audit-util.js"></script>
    <script src="/webaudio/resources/audit.js"></script>
  </head>

  <body>
    <script>
      // Arbitrary sample rate.
      const sampleRate = 16000;

      // Number of frames to render.  Just need to have at least 2 render
      // quanta.
      const lengthInFrames = 10 * RENDER_QUANTUM_FRAMES;

      let audit = Audit.createTaskRunner();

      // Buffer to use for the impulse response of a ConvolverNode.
      let impulseBuffer;

      // This sets up a worker to receive one channel of an AudioBuffer.
      function setUpWorkerForTest() {
        impulseBuffer = new AudioBuffer({
          numberOfChannels: 2,
          length: 2 * RENDER_QUANTUM_FRAMES,
          sampleRate: sampleRate
        });

        // Just fill the buffer with a constant value; the contents shouldn't
        // matter for this test since we're transferring one of the channels.
        impulseBuffer.getChannelData(0).fill(1);
        impulseBuffer.getChannelData(1).fill(2);

        // We're going to transfer channel 0 to the worker, making it
        // unavailable for the convolver
        let data = impulseBuffer.getChannelData(0).buffer;

        let string = [
          'onmessage = function(e) {', '    postMessage(\'done\');', '};'
        ].join('\n');

        let blobURL = URL.createObjectURL(new Blob([string]));
        let worker = new Worker(blobURL);
        worker.onmessage = workerReply;
        worker.postMessage(data, [data]);
      }

      function workerReply() {
        // Worker has received the message.  Run the test.
        audit.run();
      }

      audit.define(
          {
            label: 'Test Convolver with transferred buffer',
            description: 'Output should be all zeroes'
          },
          async (task, should) => {
            // Two channels so we can capture the output of the convolver with a
            // stereo convolver.
            let context = new OfflineAudioContext({
              numberOfChannels: 2,
              length: lengthInFrames,
              sampleRate: sampleRate
            });

            // Use a simple constant source so we easily check that the
            // convolver output is correct.
            let source = new ConstantSourceNode(context);

            // Create the convolver with the desired impulse response and
            // disable normalization so we can easily check the output.
            let conv = new ConvolverNode(
                context, {disableNormalization: true, buffer: impulseBuffer});

            source.connect(conv).connect(context.destination);

            source.start();

            let renderedBuffer = await context.startRendering();

            // Get the actual data
            let c0 = renderedBuffer.getChannelData(0);
            let c1 = renderedBuffer.getChannelData(1);

            // Since one channel was transferred, we must behave as if all were
            // transferred.  Hence, the output should be all zeroes for both
            // channels.
            should(c0, `Convolver channel 0 output[0:${c0.length - 1}]`)
                .beConstantValueOf(0);

            should(c1, `Convolver channel 1 output[0:${c1.length - 1}]`)
                .beConstantValueOf(0);

            task.done();
          });

      setUpWorkerForTest();
    </script>
  </body>
</html>
chromium/third_party/blink/web_tests/external/wpt/webaudio/the-audio-api/the-convolvernode-interface/transferred-buffer-output.html
