audio-2.0.0/test/readme.js

Class for high-level audio manipulations

//possible use-cases for audiojs
const Audio = require('../')
const t = require('tape')
const lena = require('audio-lena')
const Waveform = require('../../gl-waveform')
const eases = require('eases')

let wf = Waveform({scale: 1024})


//Basic processing: trim, normalize, fade, save
t('Basic', t => {
	Audio(lena.mp3).on('load', (a) => {
		a.trim(.05).normalize().fade(4).fade(-4)//.save('lena-processed.wav', t.end())

		wf.push(a.read().getChannelData(0))
	})
})

//concat multiple remote sources
t('multiple remotes', t => {
	Audio.load('./a.mp3', './b.mp3')
})


t.skip('record mic', t => {
	//Record 4s of mic input
	navigator.getUserMedia({audio: true}, stream =>	Audio(stream, {duration: 4}).download());
	//- unobvious when downloading will actually happen.
	//By fact what there happens is audio.on('end', audio => audio.download());
})

t.skip('record web-audio', t => {
	//Record, process and download web-audio experiment
	let ctx = new AudioContext();
	let osc = ctx.createOscillator();
	osc.type = 'sawtooth';
	osc.frequency.value = 440;
	osc.start();
	osc.connect(ctx.destination);
	let audio = Audio(osc);
	setTimeout(() => {
		osc.stop();
		audio.end().download();
	}, 2000);
	//so there is just basically a writing mode - whether from mic or stream, or xml http request (which is also a stream by fact), and after it ends - viola, you can download the thing
})

t.skip('process offline context', t => {
	//Download AudioBuffer returned from offlineContext
	let offlineCtx = new OfflineAudioContext(2,44100*40,44100);
	osc.connect(offlineCtx);
	offlineCtx.startRendering().then((audioBuffer) => {
		Audio(audioBuffer).download();
	});
	//offlineCtx interface is pretty much similar to audio btw, we wait for data to load and then we handle it
})

t.skip('montage', t => {
	//Montage audio
	let audio = Audio('./record.mp3');
	audio.set(Audio(audio.get(2.1, 1)).scale(.9), 3.1); //repeat slowed down fragment
	audio.delete(2.4, 2.6).fadeOut(.3, 2.1); //delete fragment, fade out
	audio.splice(2.4, Audio('./other-record.mp3')); //insert other fragment not overwriting the existing data
	//unclear when the set method is going to start and what that actually it, to vague. Better call write or read.
	//and also handle data only when loaded.
	//also wtf is splice, why is it here, it is not an array. Call it merge or mix.
	audio.load(res).then(audio => {
		audio.write(Audio(audio.read(2.1, 1)).scale(.9), 3.1)
		audio.delete()
	});
})