k-rate-audioworklet.https.html

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This test has a WPT meta file that expects 6 subtest issues.
This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audioparam-interface/k-rate-audioworklet.https.html - WPT Dashboard Interop Dashboard

<!doctype html>

<html>

  <head>

    <title>Test k-rate AudioParam of AudioWorkletNode</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>

      const audit = Audit.createTaskRunner();

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

      const filePath =

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

      // Context for testing

      let context;

      audit.define('Create Test Worklet', (task, should) => {

        // Arbitrary sample rate and duration.

        const sampleRate = 8000;

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

        const testDuration = 4 * 128 / sampleRate;

        context = new OfflineAudioContext({

          numberOfChannels: 3,

          sampleRate: sampleRate,

          length: testDuration * sampleRate

});

        should(

            context.audioWorklet.addModule(filePath),

            'Construction of AudioWorklet')

            .beResolved()

            .then(() => task.done());

});

      audit.define('AudioWorklet k-rate AudioParam', (task, should) => {

        let src = new ConstantSourceNode(context);

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

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

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

        kRateParam.automationRate = 'k-rate';

        // Automate the gain

        kRateParam.setValueAtTime(0, 0);

        kRateParam.linearRampToValueAtTime(

            10, context.length / context.sampleRate);

        src.start();

        context.startRendering()

            .then(audioBuffer => {

              let output = audioBuffer.getChannelData(0);

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

              // constant.

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

                should(

                    output.slice(k, k + 128),

                    ` k-rate output [${k}: ${k + 127}]`)

                    .beConstantValueOf(output[k]);

})

            .then(() => task.done());

});

      audit.run();

    </script>

  </body>

</html>