k-rate-audioworklet-connections.https.html

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This test has a WPT meta file that expects 1 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audioparam-interface/k-rate-audioworklet-connections.https.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <title>

      Test k-rate AudioParams with inputs for AudioWorkletNode

    </title>

    <script src="/resources/testharness.js"></script>

    <script src="/resources/testharnessreport.js"></script>

    <script src="/webaudio/resources/audit-util.js"></script>

  </head>

  <body>

    <script>

      // Use the worklet gain node to test k-rate parameters.

      const filePath =

          '../the-audioworklet-interface/processors/gain-processor.js';

      promise_test(async () => {

        // Arbitrary sample rate and duration.

        const sampleRate = 8000;

        // Only new a few render quanta to verify things are working.

        const testDuration = 4 * 128 / sampleRate;

        const context = new OfflineAudioContext({

          numberOfChannels: 3,

          sampleRate: sampleRate,

          length: testDuration * sampleRate,

});

        await context.audioWorklet.addModule(filePath);

        const src = new ConstantSourceNode(context);

        const kRateNode = new AudioWorkletNode(context, 'gain');

        src.connect(kRateNode).connect(context.destination);

        const kRateParam = kRateNode.parameters.get('gain');

        kRateParam.automationRate = 'k-rate';

        kRateParam.value = 0;

        const mod = new ConstantSourceNode(context);

        mod.offset.setValueAtTime(0, 0);

        mod.offset.linearRampToValueAtTime(

            10, context.length / context.sampleRate);

        mod.connect(kRateParam);

        mod.start();

        src.start();

        const audioBuffer = await context.startRendering();

        const output = audioBuffer.getChannelData(0);

        // Verify that the output isn't constantly zero.

        const allZero = !output.some((value) => value !== 0);

        assert_false(allZero, `output should not be all zeros`);

        // Verify that the output from the worklet is step-wise

        // constant.

        for (let k = 0; k < output.length; k += 128) {

          const slice = output.slice(k, k + 128);

          const expected = new Float32Array(slice.length).fill(slice[0]);

          assert_array_equals(

              slice, expected, `k-rate output [${k}: ${k + 127}]`);

      }, 'AudioWorklet k-rate AudioParam');

    </script>

  </body>

</html>