AudioContext.createWaveShaper()

The createWaveShaper() method of the AudioContext interface creates a WaveShaperNode, which represents a non-linear distortion. It is used to apply distortion effects to your audio.

Syntax

var audioCtx = new AudioContext();
var distortion = audioCtx.createWaveShaper();

Returns

A WaveShaperNode.

Example

The following example shows basic usage of an AudioContext to create a wave shaper node. For applied examples/information, check out our Voice-change-O-matic demo (see app.js for relevant code).

Note: Distortion curves are not the easiest thing to work out, and you will probably need to look around to find such algorithms. We found the below distortion curve code on Stack Overflow.

var audioCtx = new (window.AudioContext || window.webkitAudioContext)();
var distortion = audioCtx.createWaveShaper();

  ...

function makeDistortionCurve(amount) {
  var k = typeof amount === 'number' ? amount : 50,
    n_samples = 44100,
    curve = new Float32Array(n_samples),
    deg = Math.PI / 180,
    i = 0,
    x;
  for ( ; i < n_samples; ++i ) {
    x = i * 2 / n_samples - 1;
    curve[i] = ( 3 + k ) * x * 20 * deg / ( Math.PI + k * Math.abs(x) );
  }
  return curve;
};

  ...

distortion.curve = makeDistortionCurve(400);
distortion.oversample = '4x';

Specifications

Specification Status Comment
Web Audio API
The definition of 'createWaveShaper()' in that specification.
Working Draft  

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 10.0webkit 25.0 (25.0)  Not supported 15.0webkit
22 (unprefixed)
6.0webkit
Feature Android Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support ? 26.0 1.2 ? ? ? 33.0

See also

License

© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-us/docs/web/api/audiocontext/createwaveshaper