node-lame

NodeJS native bindings to libmp3lame & libmpg123

Fork of TooTallNate/node-lame with patches for Node 12+. The package and prebuilt binaries are published in this GitHub repository.

For all your async streaming MP3 encoding/decoding needs, there's node-lame! This module hooks into libmp3lame, the library that the lame command uses, to provide Encoder and Decoder streams to NodeJS.

Installation

node-lame comes bundled with its own copy of libmp3lame and libmpg123, so there's no need to have them installed on your system.

This package is not published on NPM. Install it from GitHub packages by creating an .npmrc in your project's root:

@schneefux:registry=https://npm.pkg.github.com`

You might need to log in to GitHub via npm once. See GitHub's documentation for details.

Then, install node-lame using npm:

$ npm install @schneefux/lame

Example

Here's an example of using node-lame to encode some raw PCM data coming from process.stdin to an MP3 file that gets piped to process.stdout:

var lame = require('lame');

// create the Encoder instance
var encoder = new lame.Encoder({
  // input
  channels: 2,        // 2 channels (left and right)
  bitDepth: 16,       // 16-bit samples
  sampleRate: 44100,  // 44,100 Hz sample rate

  // output
  bitRate: 128,
  outSampleRate: 22050,
  mode: lame.STEREO // STEREO (default), JOINTSTEREO, DUALCHANNEL or MONO
});

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

// the generated MP3 file gets piped to stdout
encoder.pipe(process.stdout);

See the examples directory for some more example code.

API

Decoder class

The Decoder class is a Stream subclass that accepts MP3 data written to it, and outputs raw PCM data. It also emits a "format" event when the format of the MP3 file is determined (usually right at the beginning).

Encoder class

The Encoder class is a Stream subclass that accepts raw PCM data written to it, and outputs a valid MP3 file. You must specify the PCM data format when creating the encoder instance. Only 16-bit signed samples are currently supported (rescale before passing to the encoder if necessary)...