Record 16-bit WAVE audio with Node.js
Description
Records a 16-bit signed-integer linear pulse modulation code WAV audio file.
This module uses Node.js streams to minimize memory usage and optimize speed, perfect for embedded devices and "the internet of things".
These audio files are fully compatible with both the Google Speech to Text API (v2) and the Wit.ai Speech API.
Don't like streams? Nostalgic for Ye Olde Callbacks?
Check out the no-streams branch for all your callback needs.
Installation
npm install node-record-lpcm16
Dependencies
Generally, running npm install
should suffice.
This module however, requires you to install SoX.
For Mac OS
brew install sox
For most linux disto's
sudo apt-get install sox libsox-fmt-all
For Windows
Options
sampleRate : 16000 // audio sample rate
threshold : 0.5 // silence threshold (rec only)
verbose : false // log info to the console
recordProgram : 'rec' // Defaults to 'rec' - also supports 'arecord' and 'sox'
Please not that arecord might not work on all operating systems
Usage
var record = require('node-record-lpcm16'),
fs = require('fs');
var file = fs.createWriteStream('test.wav', { encoding: 'binary' });
record.start({
sampleRate : 44100,
verbose : true
})
.pipe(file);
The library will automatically attempt to stop when it encounters silence, if not you can stop the recording manually.
var record = require('../index.js'),
fs = require('fs');
var file = fs.createWriteStream('test.wav', { encoding: 'binary' });
record.start();
// Stop recording after three seconds and write to file
setTimeout(function () {
record.stop().pipe(file);
}, 3000);
This module uses Node.js streams, if you're unfamiliar with them I'd suggest reading Substack's excellent stream handbook.
Example
Here's how you can write your own Siri in just 10 lines of code.
var rec = require('node-record-lpcm16'),
request = require('request');
var witToken = process.env.WIT_TOKEN; // get one from wit.ai!
exports.parseResult = function (err, resp, body) {
console.log(body);
};
rec.start().pipe(request.post({
'url' : 'https://api.wit.ai/speech?client=chromium&lang=en-us&output=json',
'headers' : {
'Accept' : 'application/vnd.wit.20160202+json',
'Authorization' : 'Bearer ' + witToken,
'Content-Type' : 'audio/wav'
}
}, exports.parseResult));