Audica

Extract Bytetime/Frequency data from audio or video elements, to create awesome audio visualizations.

What is it?

Audica is a lightweight abstraction around AudioContext and webkitAudioContext. It allows for quick and easy extraction of data via WebAudioAPI's AnalyserNode to capture data into an array so you can easily create fun and beautiful audio visualizations.

Features

Dead simple API
Use either bytetime data, frequency data, or both!
Connects to either <audio> or <video> HTML elements
Built in TypeScript support for IDE embedded documentation in VSCode.

How to use

Install with npm install audica if you're using Node.js

Bundled client side applications

const audica = require('audica');
// OR
import audica from 'audica';

Client side app

<!-- Install via unpkg -->

<script src="https://unpkg.com/audica"></script>
<!-- Your HTML here -->

<script>
  const myAudica = audica({ /* options */});
</script>

Examples of usage

Barebones/Minimum

const myAudica = audica({
  element: document.getElementById('audio-element'),
  size: 256
});

const animationLoop = () => {
  window.requestAnimationFrame(animationLoop);

  // array of ByteTime data
  const data = myAudica.getData();

  for (let i = 0; i < 256; i++) {
    // Do something with this array of integers representing byte time data
  }
}

Get frequency data and show some bars moving at 60 FPS

const myAudica = audica({
  element: document.getElementById('audio-element'),
  size: 256,
  dataType: 'hz' // defaults to 'time' if left undefined
});

const animationLoop = () => {
  window.requestAnimationFrame(animationLoop);

  // array of ByteTime data
  const data = myAudica.getData();

  // Get 256 divs that are on the DOM
  const bars = Array.from(document.querySelectorAll('.bar'));

  for (let i = 0; i < bars.length; i++) {
    // Color every bar white and make it as tall as the frequency data
    bars[i].style = `height: ${data[i]}px; width: 3px; background-color: white;`;
  }
}

Audica API

Create a new Audica instance

const options = {
  /**
   * Size of the array of audio data to be returned from Audica.
   * A larger number means more fine grained control, but lowers performance.
   * This number must be larger than 8, and divisible by 8.
   *
   * NOTE FOR NERDS: This value becomes analyzer.fftSize.
   * analyzer.fftSize = size * 2
   *
   * @default 256
   */
  size: 256,

  /**
   * The Audio or video element to draw audio data from. This value cannot
   * be null or falsy.
   * @required
   */
   element: document.querySelector('audio'),

   /**
   * Type of Frequency data to retrieve.
   * 'time' returns byte time frequency data (think waveform)
   * 'hz' returns frequency data, where data[0] starts with lower (bass) frequencies,
   * and the later elements in the array (data[255]) are higher (treble) frequencies
   *
   * @default 'time'
   */
    dataType: 'time' || 'hz';
}
const myAudica = audica(audicaOptions);

/**
 *  The heart of Audica - retrives bytetime or frequency data from the attached
 *  audio/video element at the current time
 */
myAudica.getData();

/**
 * Change the type of data Audica is returning, can be set to 'time' or 'hz'
 * */
myAudica.setDataType('time' || 'hz');

Created with <3 by Ben Junya @MrBenJ

MrBenJ/audica