node-arecord

node-arecord
===========

ALSA arecord wrapper for Node.js

This module was initially intended to provide basic audio capabilities in the Raspbian distribution of Debian on a Raspberry Pi platform. Node-arecord should however work on any Debian/Ubuntu system providing ALSA support has been installed.

ALSA stands for Advanced Linux Sound Architecture. It is a suite of hardware drivers, libraries and utilities which provide audio and MIDI functionality for the Linux operating system.

arecord is a simple native ALSA wav recorder.

Installation
-----------

$3

#### Get ready ####

Before we start the real work, please update the system.
```
sudo apt-get update
sudo apt-get upgrade
``
If you are running on Raspberry Pi, please update Raspbian
``
sudo rpi-update
``

Install ALSA for audio playback
``
sudo apt-get install alsa-base alsa-utils
``

#### USB Audio on Raspberry Pi ####
If you are planning on using a USB audio on Raspberry Pi you will need to set your USB audio device as the default device.

Edit /etc/modprobe.d/alsa-base.conf and replaced the line:
``
options snd-usb-audio index=-2
``
With the following lines:
``
options snd-usb-audio index=0 nrpacks=1
options snd-bcm2835 index=-2
``

After a reboot of your Raspberry Pi
``
aplay -l
``
Should output the following:
``
* List of PLAYBACK Hardware Devices *
card 0: XXXX [XXXX], device 0: USB Audio [USB Audio]
Subdevices: 1/1
Subdevice #0: subdevice #0
``

Your device volume will be set to 0 by default. Use the ALSA mixer to adjust the volume using your arrow keys:
``
alsamixer
``

API
---
#### new Sound(options)

Start the process and save the stdout of ALSA arecord tool to file

(Example : new Sound({destination_folder: '/tmp', 'filename:'filename.wav'}).record();)

Example Usage
-------------

``javascript
var Sound = require('node-arecord');

var sound = new Sound({
debug: true, // Show stdout
destination_folder: '/tmp',
filename: '/path/to/the/file/filename.wav',
alsa_format: 'dat',
alsa_device: 'plughw:1,0'
});

sound.record();

setTimeout(function () {
sound.pause(); // pause the recording after five seconds
}, 5000);

setTimeout(function () {
sound.resume(); // and resume it two seconds after pausing
}, 7000);

setTimeout(function () {
sound.stop(); // stop after ten seconds
}, 10000);

// you can also listen for various callbacks:
sound.on('complete' function () {
console.log('Done with recording!');
});
```