#Cordova Native Audio Plugin

Cordova / PhoneGap 3.5+ extension for Native Audio playback, aimed at HTML5 gaming and audio applications which require minimum latency, polyphony and concurrency.

Contents

1. Description
2. History
3. Roadmap
4. Integration
5. Supported Platforms
6. Installation
7. Usage
8. API
9. Demo

Description

This Cordova / PhoneGap (3.5+) plugin enables concurrency (multi-channel playback), polyphony (multi-voice playback) and minimized latency (via caching) in audio-based applications, by leveraging native audio APIs. Designed for the use in HTML5-based cross-platform games and mobile/hybrid audio applications.

History

Community-driven, clean fork of the Low Latency Audio Plugin for Cordova / PhoneGap, initially published by Andrew Trice and then maintained by Raymond Xie and Sidney Bofah.

This project cleans up a lot of legacy code, and adds success, error and completion callbacks. It also features integration in AngularJS projects via ngCordova.

Roadmap

Following the Cordova philosophy, this is a shim for a web audio implementation (on mobile) which is as fast and feature-rich as native mobile APIs. Currently, neither HTML5 Audio or the more recent Web Audio API offer a cross-platform solution which 1) is fast, 2) supports polyphony, 3) concurrency and 4) maintains a low overhead.

It should be replaced by a standardised W3C solution as soon as such an implementation offers comparable performance across (mobile) devices, which is crucial for HTML5-based games.

Integration

This plugin is available as an AngularJS service module, facilitating the usage in AngularJS-based Cordova/PhoneGap projects.

It extends the ngCordova project, an effort by the great guys at Drifty, creators of the Ionic Framework. Download it at the ngCordova website or the repository.

Supported Platforms

• iOS (tested with 7.1.2, 8.1.3)
• Android (tested in API levels 14 - 21)

Installation

Via Cordova CLI:

cordova plugin add cordova-plugin-nativeaudio

##Usage

1. Wait for deviceReady.
2. Preload an audio asset and assign an id - either optimized for single-shot style short clips (preloadSimple()) or looping, ambient background audio (preloadComplex())
3. play() the audio asset via its id.
4. unload() the audio asset via its id.

##API

###Preloading

preloadSimple: function ( id, assetPath, successCallback, errorCallback)

Loads an audio file into memory. Optimized for short clips / single shots (up to five seconds). Cannot be stopped / looped.

Uses lower-level native APIs with small footprint (iOS: AudioToolbox/AudioServices). Fully concurrent and multichannel.

• params
• id - string unique ID for the audio file
• assetPath - the relative path or absolute URL (inluding http://) to the audio asset.
• successCallback - success callback function
• errorCallback - error callback function

preloadComplex: function ( id, assetPath, volume, voices, delay, successCallback, errorCallback)

Loads an audio file into memory. Optimized for background music / ambient sound. Uses highlevel native APIs with a larger footprint. (iOS: AVAudioPlayer). Can be stopped / looped and used with multiple voices. Can be faded in and out using the delay parameter.

####Volume & Voices

The default volume is 1.0, a lower default can be set by using a numerical value from 0.1 to 1.0.

By default, there is 1 vice, that is: one instance that will be stopped & restarted on play(). If there are multiple voices (number greater than 0), it will cycle through voices to play overlapping audio.

Change the float-based delay parameter to increase the fade-in/fade-out timing.

###Playback

• params
• id - string unique ID for the audio file
• assetPath - the relative path to the audio asset within the www directory
• volume - the volume of the preloaded sound (0.1 to 1.0)
• voices - the number of multichannel voices available
• successCallback - success callback function
• errorCallback - error callback function

play: function (id, successCallback, errorCallback, completeCallback)

Plays an audio asset.

• params:
• id - string unique ID for the audio file
• successCallback - success callback function
• errorCallback - error callback function
• completeCallback - error callback function

loop: function (id, successCallback, errorCallback)

Loops an audio asset infinitely - this only works for assets loaded via preloadComplex.

• params
• ID - string unique ID for the audio file
• successCallback - success callback function
• errorCallback - error callback function

stop: function (id, successCallback, errorCallback)

Stops an audio file. Only works for assets loaded via preloadComplex.

• params:
• ID - string unique ID for the audio file
• successCallback - success callback function
• errorCallback - error callback function

unload: function (id, successCallback, errorCallback)

Unloads an audio file from memory.

• params:
• ID - string unique ID for the audio file
• successCallback - success callback function
• errorCallback - error callback function

setVolumeForComplexAsset: function (id, volume, successCallback, errorCallback)

Changes the volume for preloaded complex assets.

• params:
• ID - string unique ID for the audio file
• volume - the volume of the audio asset (0.1 to 1.0)
• successCallback - success callback function
• errorCallback - error callback function

Example Code

In this example, the resources reside in a relative path under the Cordova root folder "www/".

if( window.plugins && window.plugins.NativeAudio ) {
	
	// Preload audio resources
	window.plugins.NativeAudio.preloadComplex( 'music', 'audio/music.mp3', 1, 1, 0, function(msg){
	}, function(msg){
		console.log( 'error: ' + msg );
	});
	
	window.plugins.NativeAudio.preloadSimple( 'click', 'audio/click.mp3', function(msg){
	}, function(msg){
		console.log( 'error: ' + msg );
	});


	// Play
	window.plugins.NativeAudio.play( 'click' );
	window.plugins.NativeAudio.loop( 'music' );


	// Stop multichannel clip after 60 seconds
	window.setTimeout( function(){

		window.plugins.NativeAudio.stop( 'music' );
			
		window.plugins.NativeAudio.unload( 'music' );
		window.plugins.NativeAudio.unload( 'click' );

	}, 1000 * 60 );
}

Demo

The Drumpad in the examples directory is a first starting point.

[sudo] npm install plugin-verify -g
plugin-verify cordova-plugin-nativeaudio ios
plugin-verify cordova-plugin-nativeaudio android

Or, type the commands step by step:

cordova create drumpad com.example.nativeaudio drumpad
cd drumpad
cordova platform add ios
cordova plugin add cordova-plugin-nativeaudio
rm -r www/*
cp -r plugins/cordova-plugin-nativeaudio/test/* www
cordova build ios
cordova emulate ios