glavin001 / node-record-lpcm16

Records a 16-bit signed-integer linear pulse modification code encoded audio file.

Record 16-bit WAVE audio with Node.js

Description

Records a 16-bit signed-integer linear pulse modification 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

download the binaries

Options

sampleRate : 16000, // audio sample rate
threshold  : 0.5,   // silence threshold
verbose    : false  // log info to the console

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));