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Decibel (WIP)

Networked audio player services.


A player process plays audio from URLs through the host's speakers. It maintains a queue of playable URLs and notifies connected clients whenever its state changes.

To start a player, run:

$ decibel-player

For available flags and options, run:

$ decibel-player -h

  Usage: decibel-player [options]


    -h, --help         output usage information
    -V, --version      output the version number
    -p, --port <port>  the port on which to listen (defaut 3000)
    -d, --debug        log debugging messages

The player process is controllable via a WebSocket connection:

var socket = new WebSocket('http://localhost:3000');
// RPC call (calls `play(0, 0)` on the server) 
socket.send(JSON.stringify({ name: 'play', args: [0, 0] }));
// Listen for state changes from the server 
socket.onmessage = function (msg) {
    var data = JSON.parse(;
    console.log(, data.args);


  • append([items]) - append the given items to the player queue (each item must have a URL property)
  • replace([items]) - replace the player queue with the given items
  • next() - advance to beginning of next item
  • prev() - advance to beginning of previous item (or current item if no previous item exists)
  • pause() - stop the playback but preserve the current item index and postiion
  • play(index, position) - play the item at the given index at the specified position (current index and position values will be used if left undefined)
  • stop() - stop the playback and reset the current item index and position


  • queue:reset - the player queue was reset with the items passed in the first arg
  • queue:add - the item passed in the first arg was appended to the player queue
  • state - the player state changed to the values in the first arg (object includes index, status and position properties)


Decibel uses multicast DNS-SD (i.e. Zeroconf/Bonjour) to discover services on the network. Decibel services all use the service type _decibel._tcp and include a name attribute in the TXT record corresponding to the specific type service (i.e. decibel-player).