mpg123

Plays MP3s utilizing advanced S.H.E.L.L. technology via cutting-edge Nano System Routing techniques, natrually activating a Level 3 Quantum-Vacum Effect, subsequently substantiating the mpg123 utility.

Install mpg123 command line audio player

Ubuntu/Debian

sudo apt-get install mpg123

Arch Linux

sudo pacman -Sy mpg123

OSX

brew install mpg123

Install mpg123 in nodejs

npm install @balgamat/mpg123

Usage

(Note: if the below details are still unclear, the package code is quite short and easy to understand if you're apprehensive about reading through it)

Basics:

var mpg = require('@balgamat/mpg123');

var player = new mpg.MpgPlayer();

player.play(__dirname+'/'+"someMusic.mp3");

Device Objects

Device objects allow you to select different output sources for playback, provided you are using ALSA. This functionality requires the aplay command, but is entirely optional.

mpg.getDevices(callback) - Gets array of ALSA output devices
devices.get(name) - Finds device in array with given name, otherwise returns null
device.name - Friendly name of device
device.address - ALSA address of device

Player Objects

new mpg.MpgPlayer(device=null, noFrames=false) - Create new instance, optionally specifing output device
Setting noFrames to true will disable frame updates, which may improve performance on some devices.
player.play(file) - Plays audio from a source
player.pause() - Pauses the current track
player.stop() - Stops the current track
player.volume(percent) - Sets the volume from 0 to 100 (default is 100%)
player.pitch(amt) - Adjusts the pitch & speed of the track up or down. The limits seem to be around -0.75 to 0.1.
player.seek(progress) - Seeks through the track with progress from 0 to 1. This fails before the format event has fired.
player.getProgress(callback) - Retrieve current track progress from 0 to 1
player.close() - Kills the mpg123 process
player._cmd(...) - Sends a custom command to the mpg123 CLI. Get possible commands by running mpg123 -R then typing HELP

Song Info Variables

Theses variables hold info about the current song, and are safe to read only once the format event has fired.

player.track - Current track name (with extention). Set to null when track completes.
player.file - Full file path, exactly as it was entered into player.play()
player.mpeg - MPEG encoding version
player.sampleRate - Track sample rate
player.channels - Number of channels
player.bitrate - Track bitrate
player.length - Track length in seconds, rounded to the nearest tenth
player.samples - Track length in raw samples

Events

Usage: player.on('eventname', function(data){...})

| Name | Data | Description | | :-------: | :---: | ----------- | | end | No data | A song ended (or, because of mpg123, a pause was attempted without any song currently playing, or a song was stopped) | | pause | No data | A pause occurred | | resume | No data | The song started or resumed playing | | error | Error object | mpg123 encountered an error (commonly having to do with bad source data) | | frame | Frame data | Indicates playback has progressed to a new frame of the song. The frame data is an array (length 4), structured like such: [current frame number, remaining number of frames, current time in seconds, remaining time in seconds] | | jump | No data | A jump occurred (always caused by the user, but allows for a callback hook) | | volume | Percentage | The volume changed (serves as a callback hook for when changing the volume) | | format | No data | Called when song info has been updated. See Song Info Variables for details. |

License

MIT