simple-input-output.https.html

Enable keyboard shortcuts

This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audioworklet-interface/simple-input-output.https.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <title>

      Test Simple AudioWorklet I/O

    </title>

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

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

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

  </head>

  <body>

    <script>

      // Arbitrary sample rate

      const sampleRate = 48000;

      // The offset to be applied by the worklet to its inputs.

      const offset = 1;

      // Location of the worklet's code

      const filePath = 'processors/add-offset.js';

      // Context to be used for the tests.

      let context;

      promise_test(async () => {

        // Two channels for testing.  Channel 0 is the output of the

        // AudioWorklet.  Channel 1 is the oscillator so we can compare

        // the outputs.

        context = new OfflineAudioContext(

            {numberOfChannels: 2, length: sampleRate, sampleRate: sampleRate});

        // Load up the code for the worklet.

        await context.audioWorklet.addModule(filePath);

      }, 'Initialize worklet: Creation of AudioWorklet');

      promise_test(async () => {

        const merger = new ChannelMergerNode(

            context, {numberOfChannels: context.destination.channelCount});

        merger.connect(context.destination);

        const src = new OscillatorNode(context);

        const worklet = new AudioWorkletNode(

            context, 'add-offset-processor',

            {processorOptions: {offset: offset}});

        src.connect(worklet).connect(merger, 0, 0);

        src.connect(merger, 0, 1);

        // Start and stop the source.  The stop time is fairly arbitrary,

        // but use a render quantum boundary for simplicity.

        const stopFrame = RENDER_QUANTUM_FRAMES;

        src.start();

        src.stop(stopFrame / context.sampleRate);

        const resultBuffer = await context.startRendering();

        const ch0 = resultBuffer.getChannelData(0);

        const ch1 = resultBuffer.getChannelData(1);

        const shifted = ch1.slice(0, stopFrame).map(x => x + offset);

        // The initial part of the output should be the oscillator

        // shifted by |offset|.

        assert_array_equal_within_eps(

            ch0.slice(0, stopFrame),

            shifted,

            {absoluteThreshold: 0},

            `AudioWorklet output[0:${stopFrame - 1}]`);

        // Output should be constant after the source has stopped.

        assert_array_equals(

            ch0.slice(stopFrame),

            new Float32Array(ch0.slice(stopFrame).length).fill(offset),

            `AudioWorklet output[${stopFrame}:]`);

      }, 'test: Simple AudioWorklet I/O');

    </script>

  </body>

</html>