regl-audio v1.1.0

regl-audio

Tools for working with audio in regl. This module has the following components:

• An analyser
• A microphone connection

Examples:

• Beat detection
• Cepstrum
• Pitch detection

Examples

Here is a simple beat detector:

const regl = require('regl')()

const drawBeats = regl({
  vert: `
  precision highp float;

  attribute vec2 position;
  varying vec2 uv;

  void main () {
    uv = position;
    gl_Position = vec4(position, 0, 1);
  }
  `,

  frag: `
  precision highp float;

  varying vec2 uv;

  uniform float beats[16];

  void main () {
    float intensity = 0.0;

    float bin = floor(8.0 * (1.0 + uv.x));

    for (int i = 0; i < 16; ++i) {
      if (abs(float(i) - bin) < 0.25) {
        intensity += step(0.25 * abs(uv.y), beats[i]);
      }
    }
    gl_FragColor = vec4(intensity, 0, 0, 1);
  }
  `,

  attributes: {
    position: [
      -4, 0,
      4, 4,
      4, -4
    ]
  },

  count: 3
})

require('regl-audio/microphone')({
  regl,
  beats: 16,
  name: '',
  done: (microphone) => {
    regl.frame(() => {
      microphone(({beats}) => {
        drawBeats()
      })
    })
  }
})

regl-audio/analyser

This module takes a WebAudio analyser node and returns a scope command giving convenient access to stats from the analyser.

• PCM time domain data
• STFT frequency domain data
• Beats
• Pitch

API

const audio = require('regl-audio/analyser')(options)

The constructor for the analyser takes the following arguments:

audio(block)

The result is a regl scope command with the following properties:

Note that these context variables are optionally prefixed depending on the name parameter.

regl-audio/microphone

A short cut which gives you an analyser node connected to the microphone input from the computer. Note that this must be run on a secure domain.

API

const mic = require('regl-audio/microphone')(options)

The options are the same as above, except that it takes a webaudio context via the options.audioContext parameter instead of an analyser node. By default everything is prefixed with mic_ though this can be changed by passing some alternative to name.

License

(c) 2016 Mikola Lysenko. MIT License