offlineaudiocontext-incremental-rendering-data-integrity.html

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This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-offlineaudiocontext-interface/offlineaudiocontext-incremental-rendering-data-integrity.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<head>

<title>Test OfflineAudioContext incremental rendering data integrity</title>

</head>

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

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

<script>

"use strict";

const SAMPLE_RATE = 44100;

const TOTAL_FRAMES = 2048;

const NUM_CHANNELS = 2;

const CHUNK_SIZE = 410;

function setupContext() {

  const context = new OfflineAudioContext({

    numberOfChannels: NUM_CHANNELS,

    sampleRate: SAMPLE_RATE,

    length: TOTAL_FRAMES,

});

  const oscillator = new OscillatorNode(context);

  oscillator.connect(context.destination);

  oscillator.start(0);

  return context;

promise_test(async () => {

  const oneshotContext = setupContext();

  const oneshotBuffer = await oneshotContext.startRendering();

  const incrementalContext = setupContext();

  const chunkBuffers = [];

  while (incrementalContext.state !== 'closed') {

    const buffer = await incrementalContext.startRendering(CHUNK_SIZE);

    chunkBuffers.push(buffer);

  const totalIncrementalFrames = chunkBuffers.reduce(

      (sum, buffer) => sum + buffer.length, 0);

  assert_equals(totalIncrementalFrames, TOTAL_FRAMES,

      'Total incremental frames should equal the context length');

  assert_equals(totalIncrementalFrames, oneshotBuffer.length,

      'Total incremental frames should equal one-shot buffer length');

  for (let channel = 0; channel < NUM_CHANNELS; channel++) {

    const oneshotData = oneshotBuffer.getChannelData(channel);

    const incrementalData = new Float32Array(TOTAL_FRAMES);

    let offset = 0;

    for (const chunk of chunkBuffers) {

      incrementalData.set(chunk.getChannelData(channel), offset);

      offset += chunk.length;

    assert_array_equals(

        incrementalData, oneshotData,

        `Channel ${channel} data should match one-shot rendering`);

}, 'Incremental rendering produces identical data to one-shot rendering');

</script>

</html>