audio-stream-meter

Simple meter for showing audio stream volume.

 

Installation

``sh
$ npm install audio-stream-meter
`

Quick start

`sh
var AudioStreamMeter = require('audio-stream-meter');

navigator.mediaDevices.getUserMedia({audio:true})
.then(stream => {
var audioContext = new AudioContext();

var mediaStream = audioContext.createMediaStreamSource(stream);
var volume = document.getElementById('volume');

var meter = AudioStreamMeter.audioStreamProcessor(audioContext, function() {
volume.style.width = meter.volume * 100 + '%';
});

mediaStream.connect(meter);
stream.onended = meter.close.bind(meter);
});

`

Configuration

`sh
var config = {
bufferSize: 1024, // default: 1024, interval: {0, 256, 512, 1024, 2048, 4096, 8192, 16384}
inputChannels: 1, // default: 1, interval: [1, 32]
volumeFall: 0.95, // default: 0.95, interval: (0,1)
throttle: 1, // default: 1, interval: [1, 10]
};

var meter = AudioStreamMeter.audioStreamProcessor(audioContext, callbackFn(), config);
``
> - bufferSize - more value create higher latency of audio sample-frames,
> - inputChannels - how many input channels should be handling, passing more channels then exists in stream will flatten volume,
> - volumeFall - more means volume wave will be fall slower.
> - throttle - sets step for which will be take samples for calculations, see percent of calculated samples by means of formula f(x) = 1 / x * 100,

Controls

> - callbackFn() - function is invoke after each processing audio samples and can use within data from 'Output data' paragraph. For example: callbackFn(){ console.log(meter.volume)}
> - meter.close() - close and disconnect audio processing

Output data

> - meter.volume - gives info about volume of the last package of samples - intervals [0, 1],

Licence

MIT