uplayer

µ-player

A programatic audio player written in JavaScript.

About

µ-player is a minimal audio player for web browsers with no dependencies that directly uses WebAudio API.

It's meant to be used programatically, so it provides no UI, just a basic API and access to WebAudio objects, really useful if you want to modify or analyze the audio source.

It also provides keyboard bindings that can be enabled if required.

Install

npm i uplayer

Usage

const Player = require('uplayer')
const player = new Player('http://server/some.mp3')
player
  .on('ended', () => console.log('Ended.'))
  .load()
  .play()

API

Constructor params: uplayer(src, debugState):

• src: A URL to an audio file.
• debugState: Enables console log for debugging when true. False by default.

src can be a URL to be resolved by fetch or an ArrayBuffer.

µ-player provides the following methods:

• load(src): Loads passed audio source or the one set on constructor.
• play(offset): Starts playback of loaded audio file at specified offset seconds.
• pause(): Pauses playback.
• stop(): Stops playback.
• rewind(seconds): Rewinds audio specified amount of seconds, 5 by default.
• forward(seconds): Forwards audio specified amount of seconds, 5 by default.
• useKeyboard(selector): Enables keyboard bindings adding listeners to passed selector. Uses body by default.
• loop(loopState): Enables / disables looping based on loopState.
• toggleLoop(): Toggles looping.
• on(eventName, callback): Adds event listener on WebAudio source.
• debug(debugState): Enables / disables debug mode based on debugState.

µ-player provides the following properties:

• src: The audio file URL.
• context: WebAudio context.
• loaded: True when audio file was loaded, false when not.
• buffer: WebAudio buffer data.
• source: WebAudio source.

Events

Use the method on(eventName, callback) to set event listeners on the WebAudio source.

• ended: Fired when the whole file finished playing. This is not fired if looping is enabled.

For more info about events check MDN documentation.

µ-player also offers the following internal events:

• load: Fired when loading starts.
• loaded: Fired when loading ends.
• play: Fired when playback starts.
• stop: Fired when playback stops.
• pause: Fired when playback is paused.
• forward: Fired when forwarding; passed seconds to callback.
• rewind: Fired when forwarding; passed seconds to callback.

Key bindings

• z: Stop.
• x: Play.
• c: Pause.
• l: Toggle looping.
• ArrowRight: Forward.
• ArrowLeft: Rewind.

Using with file reader

Since src can be an ArrayBuffer you can easily drop audio files in the browser and play them with µ-player.

Here's an example using the excellent drag-drop module from Feross:

const dragDrop = require('drag-drop')

dragDrop('body', function (files) {
  const file = files[0]
  console.log('GOT FILE:', file)

  const reader = new window.FileReader()
  reader.addEventListener('load', e => {
    const data = e.target.result
    const player = new Player(data, true)
    player.load().play()
  })
  reader.addEventListener('error', err => {
    console.error('FileReader error' + err)
  })
  reader.readAsArrayBuffer(file)
})

Have fun!