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AudioBuffer: length property

The length property of the AudioBuffer interface returns an integer representing the length, in sample-frames, of the PCM data stored in the buffer.

Value

An integer.

Examples

js

// Stereo
const channels = 2;

// Create an empty two second stereo buffer at the
// sample rate of the AudioContext
const frameCount = audioCtx.sampleRate * 2.0;
const myArrayBuffer = audioCtx.createBuffer(2, frameCount, audioCtx.sampleRate);

button.onclick = () => {
  // Fill the buffer with white noise;
  // just random values between -1.0 and 1.0
  for (let channel = 0; channel < channels; channel++) {
    // This gives us the actual ArrayBuffer that contains the data
    const nowBuffering = myArrayBuffer.getChannelData(channel);
    for (let i = 0; i < frameCount; i++) {
      // Math.random() is in [0; 1.0]
      // audio needs to be in [-1.0; 1.0]
      nowBuffering[i] = Math.random() * 2 - 1;
    }
  }

  console.log(myArrayBuffer.length);
};

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
length 14 12 25 No 15 6 4.4.3 18 25 14 6 1.0

See also

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Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/AudioBuffer/length