Pure HTML5 Audio Driver

Opinionated low level functional bindings to control html5 audio

Constraints (or what you won't find here)

• Full functional audio player with controls and all the fuzz, instead you should use mediaelement
• Support for multiple sounds and ambient control, instead you should use howler.js
• No WebAudio, instead you should use pizzicato

Features (or what you will find here)

• Full control over the audio element
• Functional bindings to all necessary events
• Composability for all audio actions
• Helper functions to get relevant audio element properties
• Written in vanilla es6 with only one dependency to ramda

Installation

npm install html5-audio-driver or yarn add html5-audio-driver

Usage

Creating an AudioElement

If you have already an audio element defined, good for you, skip this and use the dom reference. Otherwise you can use this helper, the helper will create an audio element without controls, preloading and loops:

import { audio } from '@podlove/html5-audio-driver'

const myAudioElement = audio([{
  url: 'audio-files/example.m4a',
  mimeType: 'audio/mp4'
}, {
  url: 'audio-files/example.mp3',
  mimeType: 'audio/mp3'
}, {
  url: 'audio-files/example.ogg',
  mimeType: 'audio/ogg'
}])

mimeType is needed so the browser can decide what source is appropriated to use.

Interacting with the audio element

All audio element actions are curried and accept as their first parameter the audio element. Also each action returns the audio element:

import { compose } from 'ramda'
import { play, setPlaytime } from '@podlove/html5-audio-driver/actions'

const setPlaytimeAndPlay = compose(play, setAudioPlaytime)(myAudioElement)
// Sets the playtime to 50 seconds and plays the audio
setPlaytimeAndPlay(50)

For convenience also a action composer is available:

import { actions } from '@podlove/html5-audio-driver'

const audioActions = actions(myAudioElement)

audioActions.load()
audioActions.play()
audioActions.pause()
audioActions.setPlaytime(50)
audioActions.setRate(1.5)
audioActions.mute()
audioActions.unmute()

Available Actions:

Function	Action	parameters
play	Safeplays the audio, initiates load if not already loaded	void
pause	pauses the audio	void
load	loads the audio	void
mute	mutes the audio	void
unmute	unmutes the audio	void
setRate	sets the play rate	number: [0.5 ... 4]
setPlaytime	sets the current play time	number: [0 ... duration]

Reacting to audio events

All audio events are curried and accept as their first parameter the audio element. The second parameter is always the callback function. Each event returns a different set of audio properties, depending on the event scope:

import { onPlay } from '@podlove/html5-audio-driver/events'

const playEvent = onPlay(myAudioElement)

playEvent(console.log) // similar to onPlay(myAudioElement, console.log)
/**
* Will log audio properties on audio play:
* {
*  duration,
*  buffered,
*  volume,
*  state,
*  playtime,
*  ended,
*  rate,
*  muted,
*  src,
*  paused,
*  playing
* }
*/

For convenience also a events composer is available:

import { events } from '@podlove/html5-audio-driver'

const audioEvents = events(myAudioElement)

audioEvents.onLoading(console.log)
audioEvents.onLoaded(console.log)
audioEvents.onReady(console.log)
audioEvents.onPlay(console.log)
audioEvents.onPause(console.log)
audioEvents.onBufferChange(console.log)
audioEvents.onBuffering(console.log)
audioEvents.onPlaytimeUpdate(console.log)
audioEvents.onVolumeChange(console.log)
audioEvents.onError(console.log)
audioEvents.onDurationChange(console.log)
audioEvents.onRateChange(console.log)
audioEvents.onEnd(console.log)

Available Events:

Function	Event	Original	Callback Payload	Once
onLoading	When browser starts audio loading	progress	All props	true
onLoaded	When browser loaded the entire file	canplaythrough	All props	true
onReady	When browser has enough data to play	canplay	All props	false
onPlay	When browser starts playing audio	play	All props	false
onPause	When browser pauses audio	pause	All props	false
onEnd	When browser reaches end of audio	ended	All props	false
onBufferChange	When browser buffered a new audio segment	progress	buffered segments	false
onBuffering	When browser waits for audio segments to play	waiting	All props	false
onPlaytimeUpdate	When currentTime of audio changes	timeupdate	playtime	false
onVolumeChange	When volume of audio changes	volumechange	volume	false
onError	When an error occurred while playing the audio	error	NETWORK_NO_SOURCE, NETWORK_EMPTY, NETWORK_LOADING, MEDIA_ERROR	false
onDurationChange	When browser has new information on audio duration	durationchange	duration	false
onRateChange	When browser detects a change in audio playback rate	ratechange	rate	false
onFilterUpdate	When a filter has been changed	filterUpdated	All props	false

Audio Element Properties

Multiple different functions are provided to give you easy access to audio element properties. Initially most of them are undefined:

import { volume } from '@podlove/html5-audio-driver/props'

isPlaying(myAudioElement) // Will return false

For convenience also a composed version is available giving you all available properties:

import { props } from '@podlove/html5-audio-driver/props'

props(myAudioElement)
/**
* {
*  duration,
*  buffered,
*  volume,
*  state,
*  playtime,
*  ended,
*  rate,
*  muted,
*  src,
*  paused,
*  playing
* }
*/

Available Properties:

Function	Description	Return Value	Initial Value
duration	Duration of audio in seconds	number	undefined
buffered	Buffered audio segments start and end in seconds	[[number, number], ...]	[]
volume	Audio volume	number: [0...1]	undefined
state	Network State	HAVE_NOTHING, HAVE_METADATA, HAVE_CURRENT_DATA, HAVE_FUTURE_DATA, HAVE_ENOUGH_DATA	undefined
playtime	Current audio playtime position in sconds	number	undefined
ended	Indicates if audio has ended	boolean	undefined
rate	Audio playback rate	number: [0.5 ... 4]	undefined
muted	Indicates if audio is muted	boolean	undefined
src	Used audio source	string	undefined
paused	Indicates if audio is paused	boolean	undefined
channels	Available audio channels	number	undefined
playing	Indicates if audio is playing	boolean	false

Handled HTML5 Quirks and Limitations (the nasty part :/)

HTML5 audio was a needed addition to get rid of the flash hell. Although it is already multiple years implemented in all the different browsers each implementation has it's flaws. If you want to dive deeper into the topic I recommend you the following article.

Play Action

Using the play action will give you a safe function that surpresses most of the errors. One source is that older browsers doesn't implement audio.play() as a promise. Also there is a race condition between play and pause that needs to be .catched.

Playtime (CurrentTime)

In Safari and mobile Safari it isn't possible to set the currentTime before loading the audio. You can set it but it won't mutate the audio currentTime value. html5-audio-driver therefore uses a custom playtime attribute that is synced wit the currentTime.

Mobile Environments

To play audio on mobile devices you have to trigger use a direct user interaction to trigger the audio. Also volume is not available on mobile devices.

Legacy Browser Support (IE11)

In case you need IE11 support you have to provide some polyfills in your application. Have a look at the test polyfills to see a working example.

Publishing

Run npm publish:prepare move to the dist/ folder and run npm publish --public

License