WaveShaperNode

The WaveShaperNode interface represents a non-linear distorter. It is an AudioNode that uses a curve to apply a wave shaping distortion to the signal. Beside obvious distortion effects, it is often used to add a warm feeling to the signal.

A WaveShaperNode always has exactly one input and one output.

Number of inputs 1
Number of outputs 1
Channel count mode "max"
Channel count 2 (not used in the default count mode)
Channel interpretation "speakers"

Constructor

WaveShaperNode()
Creates a new instance of an WaveShaperNode object.

Properties

Inherits properties from its parent, AudioNode.

WaveShaperNode.curve
Is a Float32Array of numbers describing the distortion to apply.
WaveShaperNode.oversample
Is an enumerated value indicating if oversampling must be used. Oversampling is a technique for creating more samples (up-sampling) before applying the distortion effect to the audio signal.

Methods

No specific method; inherits methods from its parent, AudioNode.

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 'WaveShaperNode' in that specification.
Working Draft  

Browser compatibility

FeatureChromeEdgeFirefoxInternet ExplorerOperaSafari
Basic support14 Yes25 No156
WaveShaperNode() constructor551 ?53 No42 ?
curve14 Yes25 No156
oversample14 Yes26 No156
FeatureAndroid webviewChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic support1414 Yes26 No15 ?
WaveShaperNode() constructor551551 ?53 No42 ?
curve Yes14 Yes26 No15 ?
oversample Yes14 Yes26 No15 ?

1. Before Chrome 59, the default values were not supported.

See also

Document Tags and Contributors

 Last updated by: fscholz,