audiobuffersource-multi-channels.html

Enable keyboard shortcuts

This WPT test may be referenced by the following Test IDs:
- /webaudio/the-audio-api/the-audiobuffersourcenode-interface/audiobuffersource-multi-channels.html - WPT Dashboard Interop Dashboard

<!DOCTYPE html>

<html>

  <head>

    <title>

      Test AudioBufferSourceNode supports 5.1 channel playback

    </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/mix-testing.js"></script>

  </head>

  <body>

    <script>

      // Test AudioBufferSourceNode supports 5.1 channel.

      // Creating context and fetching expected audio.

      promise_test(async () => {

        const sampleRate = 44100.0;

        const context = new OfflineAudioContext(

            6, sampleRate * toneLengthSeconds, sampleRate);

        let expectedAudio;

        const response = await fetch(

            'resources/audiobuffersource-multi-channels-expected.wav');

        const arrayBuffer = await response.arrayBuffer();

        try {

          expectedAudio = await context.decodeAudioData(arrayBuffer);

        } catch (error) {

          assert_unreached(

              `Could not decode audio data due to ${error.message}`);

        // Render and verify output.

        const toneBuffer = createToneBuffer(context, 440, toneLengthSeconds, 6);

        const source = new AudioBufferSourceNode(context, {buffer:toneBuffer});

        source.connect(context.destination);

        source.start();

        const renderedAudio = await context.startRendering();

        // Compute a threshold based on the maximum error, |maxUlp|,

        // in ULP. This is experimentally determined. Assuming that

        // the reference file is a 16-bit wav file, the max values in

        // the wave file are +/- 32768.

        const maxUlp = 1;

        const threshold = maxUlp / 32768;

        for (let k = 0; k < renderedAudio.numberOfChannels; ++k) {

          assert_array_approx_equals(

              renderedAudio.getChannelData(k),

              expectedAudio.getChannelData(k),

              threshold,

              `Rendered audio for channel ${k}`);

      }, 'AudioBufferSourceNode 5.1 channel playback verification');

    </script>

  </body>

</html>