node-record-lpcm-16
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.
Installation
npm install node-record-lpcm16
Dependencies
Generally, running npm install should suffice.
This module requires you to install SoX and it must be available in your $PATH.
For Mac OS
brew install sox
For most linux disto's
sudo apt-get install sox libsox-fmt-all
For Windows
Working version for Windows is 14.4.1. You can download the binaries or use chocolately to install the package
choco install sox.portable
Options
sampleRate : 16000 // audio sample rate
channels : 1 // number of channels
threshold : 0.5 // silence threshold (rec only)
endOnSilence : false // automatically end on silence (if supported)
thresholdStart : null // silence threshold to start recording, overrides threshold (rec only)
thresholdEnd : null // silence threshold to end recording, overrides threshold (rec only)
silence : '1.0' // seconds of silence before ending
recorder : 'sox' // Defaults to 'sox'
device : null // recording device (e.g.: 'plughw:1')
audioType : 'wav' // audio type to record
Please note that
arecordmight not work on all operating systems. If you can't capture any sound witharecord, try to change device (arecord -l).
Usage
const recorder = require('node-record-lpcm16')
const fs = require('fs')
const file = fs.createWriteStream('test.wav', { encoding: 'binary' })
recorder.record({
sampleRate: 44100
})
.stream()
.pipe(file)You can pause, resume and stop the recording manually.
const recorder = require('node-record-lpcm16')
const fs = require('fs')
const file = fs.createWriteStream('test.wav', { encoding: 'binary' })
const recording = recorder.record()
recording.stream().pipe(file)
// Pause recording after one second
setTimeout(() => {
recording.pause()
}, 1000)
// Resume another second later
setTimeout(() => {
recording.resume()
}, 2000)
// Stop recording after three seconds
setTimeout(() => {
recording.stop()
}, 3000)Recorders
The following recorders are included:
- rec
- sox
- arecord
Note: not all recorders support all features!
Error handling
Some recorders might be logging errors to stderr and throw an exit code.
You can catch early termination by adding an error event listener to the stream.
To debug the recorder see debugging below.
recording.stream()
.on('error', err => {
console.error('recorder threw an error:', err)
})
.pipe(file)Debugging
Debug logging is implemented with visionmedia/debug
DEBUG=record node examples/file.js
Example
Here's how you can write your own Siri in just 10 lines of code.
const recorder = require('../')
const request = require('request')
const witToken = process.env.WIT_TOKEN // get one from wit.ai!
function parseResult (err, resp, body) {
if (err) console.error(err)
console.log(body)
}
const recording = recorder.record({
recorder: 'arecord'
})
recording
.stream()
.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'
}
}, parseResult))
setTimeout(() => {
recording.stop()
}, 3000) // Stop after three seconds of recording