node-speaker

Output PCM audio data to the speakers

A Writable stream instance that accepts PCM audio data and outputs it to the speakers. The output is backed by libao, which supports a ton of audio backends.

Installation

You need libao installed on your system before installig node-speaker.

Debian

$ apt-get install libao-dev

OSX:

$ brew install libao

Now, simply compile and install node-speaker using npm:

$ npm install speaker

Example

Here's an example of piping stdin to the speaker, which should be 2 channel, 16-bit audio at 44,100 samples per second (a.k.a CD quality audio).

const Speaker = require('speaker');

// Create the Speaker instance
const speaker = new Speaker({
  channels: 2,          // 2 channels
  bitDepth: 16,         // 16-bit samples
  sampleRate: 44100     // 44,100 Hz sample rate
});

// PCM data from stdin gets piped into the speaker
process.stdin.pipe(speaker);

API

require('speaker') directly returns the Speaker constructor. It is the only interface exported by node-speaker.

new Speaker([ format ]) -> Speaker instance

Creates a new Speaker instance, which is a writable stream that you can pipe PCM audio data to. The optional format object may contain any of the Writable base class options, as well as any of these PCM formatting options:

channels - The number of audio channels. PCM data must be interleaved. Defaults to 2.
bitDepth - The number of bits per sample. Defaults to 16 (16-bit).
sampleRate - The number of samples per second per channel. Defaults to 44100.

"open" event

Fired when the backend open() call has completed. This happens once the first write() call happens on the speaker instance.

"close" event

Fired after the "flush" event, after the backend close() call has completed. This speaker instance is essentially finished after this point.

Audio Backend Selection

node-speaker is backed by libao's "output modules", which in turn use one of many popular audio backends like ALSA, pulseaudio, and lots more. The default backends for each operating system depend on libao configuration. Please check libao's documentation for more information.

raiscui / node-speaker