audiofile

Dead easy audio

Factsheet

• Permissive MIT license
• Designed both for app UI and game usecases
• Automatic caching and preloading
• Audiofiles are replayable
• Rapid fire sound support
• Play multiple audiofiles simultaneously
• Maintains the user's background music on mobile (a killer feature if you want to allow the user to play their own music or podcasts while playing your app/game)
• Promise support
• npm/browserify/webpack and global browser module support
• Desktop and mobile browsers support
• Chaining support
• Demo included

Prerequisites

• Promise : thenable and es6-promise are good polyfills
• fetch() : whatwg-fetch is a good polyfill
• Web Audio API : Native support for the Web Audio API is required in order to produce the audio

Installation

Install with npm:

npm install audiofile

Alternatively, you can just download audiofile.js and use <script> tags.

Usage

Initialisation

The library exposes the Audiofile object, from which you can create instances:

var af = new Audiofile({ /* options... */ });

The use of the new keyword is optional, so you could instead do:

var audiofile = require('audiofile');
var af = audiofile({ /* options... */ });

The options object can contain these fields:

• url : The URL of the audio (mandatory if using fetch).
• fetch : A fetch init options object, allowing you to customise the request headers et cetera (fetch defaults are default here, i.e. plain HTTP GET).
• load : An alternative to fetch. When specified, fetch is ignored the load promise is used to get the file. The promise is expected to resolve to a Blob.
• preload : Whether or not to load the audio on object creation (default true).
• loop : Whether to infinitely loop the audio (default false).
• volume : The volume of the audio in percent (0 to 1 inclusive; default 1). Values greater than 1 boost the volume.
• output : Redirects the output of the audiofile to the specified AudioNode, allowing for postprocessing of the audio (system audio is the default).

Audiofile.killUserAudio()

If you want to disable the user's own background audio (e.g. music, podcasts), then you must call this function. This is useful in games with their own background music. By default, the user's background audio is respected.

Audiofile.killUserAudio();

You may alternatively call this:

Audiofile.resetUserAudio();

af.clone()

Calling af.clone() returns a new audiofile that has the same cached audio as the calling audiofile. The cloned audiofile can be played independently of the calling audiofile. This is especially useful for rapid fire usecases.

var af2 = af.clone();

af.load()

Calling af.load() returns a promise that is fulfilled when loading is completed. It's useful if you want to load the audio at a particular time, and it's generally useful for detecting when you can play.

af.load().then(function(){
  console.log('audiofile loaded');
});

If you want a quick synchronous check if the audiofile is loaded or not, just read af.loaded:

if( af.loaded ){
  console.log('do something');
} else {
  console.log('do something else');
}

af.play()

Play the audiofile at its current progress level.

af.play();

af.pause()

Pause the audiofile at its current progress level. It can be resumed via af.play().

af.pause();

af.stop()

Stop playback of the audiofile and resets its progress to the beginning.

af.stop();

af.progress()

Get or set the progress of the audiofile in milliseconds.

var time = af.progress(); // get progress

af.progress( 2*time ); // progress twice as far

af.progressDelta()

Set the progress of the audiofile relatively in milliseconds. Positive values fastforward the audiofile, and negative values rewind the audiofile.

af.progressDelta( 1000 ); // fastforward 1 second

There are also aliases:

af.rewind( 1000 ); // same as af.progressDelta( -1000 )
af.fastforward( 1000 ); // same as af.progressDelta( 1000 )

af.volume()

Get or set the volume level as a percent (0 to 1 inclusive). Values greater than 1 boost the volume.

var vol = af.volume(); // current level

af.volume(0.5); // set level to 50%

af.loop()

Get or set whether looping is enabled. This is useful if you want to reconfigure an audiofile.

var looping = af.loop();

af.loop( false ); // turn off looping