[LAU] [ANNOUNCE] jack_autoconnect

Jannis Achstetter jannis_achstetter at web.de
Thu Dec 11 21:40:12 UTC 2014

Hi list,

I recently decided to try the following setup:
mpd is running on my NAS machine with jack audio outputs and ympd as web
interface. The jack server uses the dummy backend but has the netmanager
The problem is that mpd sometimes deletes its jack ports and created a
new pair. And since the number and names of the connected net slaves
varies, I thought a classic session manager might not fit (admitting
that I didn't really try it).

So I created a small program that registers as slave without ports but
watches for new port registrations. If a pair of out- and input ports
matches their regular expressions specified on the command line, they
are connected.

I used Qt to solve the problem that ports cannot be connected in the
same thread that the notification-callback is executed. Using the
QueuedConnection, the SLOT (reaction to a SIGNAL event) is executed in
the receiver's thread.

To solve the challenge I'm using this command now:
jack_autoconnect "Music Player Daemon:left" ".*:to_slave_1" "Music
Player Daemon:right" ".*:to_slave_2"

The system is working pretty well. The music and playlists can be
controlled from any device with webbrowser and multiple playout machines
connect via NetJack to the NAS. And the synchronization between all of
them is just perfect!

The code is on github:

Comments are welcome :D

A big "Thank you!" too everyone who makes all of this possible!

Best regards,

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