looped-constant-buffer.html

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This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audiobuffersourcenode-interface/looped-constant-buffer.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <meta charset="utf-8">

    <title>Looped AudioBufferSourceNode Keeps Rendering</title>

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

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

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

  </head>

  <body>

    <script>

      promise_test(async () => {

        const sampleRate = 44100;

        const renderFrames = 2048;

        const loopFrames = 64;

        const context = new OfflineAudioContext(1, renderFrames, sampleRate);

        const loopDuration = loopFrames / sampleRate;

        const src = new AudioBufferSourceNode(context, {

          buffer: createConstantBuffer(context, loopFrames, 1),

          loop: true,

          loopStart: 0,

          loopEnd: loopDuration,

});

        src.connect(context.destination);

        src.start();

        const resultBuffer = await context.startRendering();

        const result = resultBuffer.getChannelData(0);

        const expected = new Float32Array(result.length).fill(1);

        // WebAudio §1.9.5 requires that a looped region keeps playing until it is

        // stopped, so the rendered output should remain constant 1 even after

        // multiple loop passes.

        assert_array_equals(

          result,

          expected,

          'looped buffer should continue emitting ones even after first loop'

);

      }, 'looped-constant-buffer-keeps-rendering');

    </script>

  </body>

</html>