node-cubeb

This is a node.js native binding module to the cross-platform audio library cubeb.

The purpose of this module is to allow you to write to the user's soundcard.

Installation

You need to install cubeb in order for node-cubeb to work. Refer to directions provided in cubeb on how to do that.

After installing cubeb, installing node-cubeb works like installing any other library in npm:

$ npm install cubeb

Usage

cubeb is quite a low level library, so that applies to node-cubeb as well. cubeb has two main concepts, contexts and streams. Ideally, you should use one context per program, while the context can have multiple streams. In order to setup a basic example of playing back pure noise, you would do as follows:

var SAMPLE_FORMAT = CUBEB.SAMPLE_INT16LE
var CHANNEL_COUNT = 1
var SAMPLE_RATE = 44100
var BUFFER_SIZE = 4096
var PLAY_TIME = 4000
var LATENCY = 250
var CTX_NAME = "my cubeb context"
var STREAM_NAME = "noisy stream"

function stateCallback (stateID) {
	/* here you can report the state */
}

function dataCallback (frameCount) {
	/* int16 is 2 bytes, doh */
	stream.write(new Buffer(frameCount * 2))

	/*
	 note that we get the noise for free because
	 node buffers aren't initialized to zero.
	*/
}

var ctx = new CUBEB.Context(CTX_NAME)
var stream = new CUBEB.Stream(
	ctx,
	STREAM_NAME,
	SAMPLE_FORMAT,
	CHANNEL_COUNT,
	SAMPLE_RATE,
	BUFFER_SIZE,
	LATENCY,
	datacb,
	statecb
)