Re: [Jack-Devel] [LAU] running jackd from rc.local - JackAudio

18 Apr 2015

Hi Len,
i am using ubuntu studio.
the pc i refer to is used for audio processing and routing primarily - it
is a jack client server.
so without any user intervention apart from powering it ON , it gets audio
through ethernet from the jack master, processes it and sends it out
through its local soundcards.
on occasions I want to log on and use this computer for local audio
capturing and / or playback. so jack would ideally run independent of a
user session. Having said that, I usually don't need to log out and back
in, I tend to lock the system as I am a single user. no need to deal with
multiple user case now.

I use a locally compiled jack2 version without dbus support because I had a
version mismatch between windows and linux jack.
some audio applications (namely calf) need an X server so in my custom
startup scripts I start a vnc session as well.

The problem as I understand it is that after log on, pam.d elevates logged
in user's privileges to access hardware. The main problem is that
alsa_(in|out) is can not grab the local soundcards... and I do not know
what could be the conflict. people over at jack-devel mailing list said it
could bea number of things like pulseaudio or lightdm....

there seems  to be a conflict or ideologies because some one suggests I
make a system init script and another says jack is not designed to run as a
system service.

Personally, I think that jack is indeed not designed as a system service,
but I could be wrong. what is more a jack run as root, would never be
available to applications that I would start as a user. is that so?

I think I replied to everything :)

On Sat, Apr 18, 2015 at 6:01 PM, Len Ovens &lt;len(a)ovenwerks.net&gt; wrote:

...
  On Sat, 18 Apr 2015, Athanasios Silis wrote:

  Hi Len,
  unfortunately the .desktop file is not good for
me.
 it is only run after I have logged in, whereas I want my script to be
 started as
 me, but before I log in.
 Is there a way to achieve that, without resorting to autologin ?

 OK, perhaps a full description of what you are trying to acheive would
 help. little bits of info I think I have put together include:
  - You will be using a DE at some point.
  - You want to be able to access jack after logging in as well as before
  - jack is still to be used only by one user
  - jack2 is prefered?
  - what would jack be doing while logged out I don't know
  - should jack continue to run after logout?
         (that is do you normally logout and in)
  - Is most of the running done by script anyway and loggin in is used
 mostly for other things besides audio? Can all audio stuff be done by
 command line?
  - will jack be used as a device for pulseaudio...
  - will pulse run at all? if so will it ever touch the same device as jack
 has?
  - is your machine using sysv init, systemd, upstart? (upstart is going
 away BTW, leaving one to wonder about the future of MIR)

 As Jeremy has already suggested have you tried:

 export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/dbus/system_bus_socket
 jack_control start

 in the script run by your su user?

 --
 Len Ovens
 www.ovenwerks.net

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