JACK audio server / Realtime Kernel / Rosegarden

English Applications
1

Hello everyone!

Hope you are all doing well!

A little back story is in order…
Looking for a Open Source music composition editor similar to
Sibelius.

I found and settled on Rosegarden.

Sound card is Creative Audigy 2 Platinum EX. I also have a midi
keyboard which I would like to use with rosegarden.

After downloading rosegarden, I found out in order to use the MIDI
sequencer, I have to compile and install a real time kernel.

I finally got my kernel configured and installed, recompiled all the
video/Ethernet drivers etc (after about a dozen tries lol!)

Now on to the issue…

As root, I can run the JACK audio server with realtime priority (as it
is needed by Rosegarden) with the command

JACKD -R -DALSA &

it starts up and seems to run.

Then as a regular user, I try to connect to the JACK audio server using
the qjackctl application. Qjackctl loads, but cannot seem to connect to
the jack server, giving me the message “UNABLE TO CONNECT TO SERVER AS
CLIENT”

HOWEVER, using the same procedure above as root, I can connect to the
jack audio server with qjackctl.

Rosegarden will start as a regular user but will also not connect to
the JACK audio server (therefore: no sound or midi sequencer)

Ive tried running Rosegarden as root (I didnt like having to do that),
but get a similar error.

Through some googling, I’ve found that JACK clients (qjackctl,
rosegarden etc.) must be executed by the same user who launched the JACK
server. – no problem…Except I cannot run a realtime application as a
regular user.

I read online that regular users can start realtime applications using
the LSM module (whatever that is, I couldn’t find all that much).

So my question is, how do I start the jack audio server in realtime
mode as a regular user? if that is not possible…Is there a way to
configure JACK so that it is started by root, but allows clients
launched by regular users to connect?

Sorry for not including the exact error messages as right now I am at
work.

Any help/comments would be greatly appreciated! Thanks in advance!

–
openSUSE 11.0 | Kernel 2.6.25.18-default | Intel Core 2 Quad Q9450 OC@ 3
Ghz | 2GB DDR2 | nVidia GeForce 8800 GT | Sound Blaster Audigy 2
Platinum | Seagate SATA x3 (1 TB total)

pimanac’s Profile: http://forums.opensuse.org/member.php?userid=5767
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2

Have you checked out the Jacklab project? They’ve got a bunch of pages
on the openSUSE wiki on setting up openSUSE for proaudio work with JACK
et al. I’m running it right now and it works great.

You can’t connect to a root JACK server with user apps. I think your
problem is that you haven’t edited your pam limits.conf. It’s very
simple, and it enables a normal user to run audio apps at high
privileges, like root can. This is documented in the wiki.

I’ll post a link later when I get time.

–
openSUSE 11.1 x86_64; Kernel 2.6.27-9; KDE 4.2.87; Intel Core 2 Quad
Q6600 @ 2.4Ghz; 6GB DDR2 RAM; 640GB SATA HDD.

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3

thank you very much for the prompt response! Ill take a look and advise

–
openSUSE 11.0 | Kernel 2.6.25.18-default | Intel Core 2 Quad Q9450 OC@ 3
Ghz | 2GB DDR2 | nVidia GeForce 8800 GT | Sound Blaster Audigy 2
Platinum | Seagate SATA x3 (1 TB total)

pimanac’s Profile: http://forums.opensuse.org/member.php?userid=5767
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4

the file to which you refer is /etc/security/limits.conf?

I was looking at that yesterday but wrote it off…

From what i get from the wiki…all i have to do is add the following
lines to limits.conf and then logout/login?

@audio - rtprio 90
@audio - nice 15
@audio - memlock 4000000

–
openSUSE 11.0 | Kernel 2.6.25.18-default | Intel Core 2 Quad Q9450 OC@ 3
Ghz | 2GB DDR2 | nVidia GeForce 8800 GT | Sound Blaster Audigy 2
Platinum | Seagate SATA x3 (1 TB total)

pimanac’s Profile: http://forums.opensuse.org/member.php?userid=5767
View this thread: http://forums.opensuse.org/showthread.php?t=405433

5

zak89 – Thanks for the help, I got it working. Took a little while
playing with the jack connections…then i finally got a sound out of
rosegarden. looking forward to playing with it more! Thanks again!

–
openSUSE 11.0 | Kernel 2.6.25.18-default | Intel Core 2 Quad Q9450 OC@ 3
Ghz | 2GB DDR2 | nVidia GeForce 8800 GT | Sound Blaster Audigy 2
Platinum | Seagate SATA x3 (1 TB total)

pimanac’s Profile: http://forums.opensuse.org/member.php?userid=5767
View this thread: http://forums.opensuse.org/showthread.php?t=405433

6

Glad you got it working! Sorry I didn’t get back to you, but it sounds
like you’ve got it all figured out anyway! :wink:

By the way, did you add your user account to the audio group? That
should have been on the same wiki page.

Enjoy the world of linux pro-audio! By the way, if you have questions
or problems, stop by the Jacklab forums at ‘JackLab Support • Index
page’ (http://forum.jacklab.net/). I hang out there pretty regularly,
and there’s a whole crew of linux audiophiles there supporting
multimedia production on openSUSE.

Have a lot of fun!

–
openSUSE 11.1 x86_64; Kernel 2.6.27-9; KDE 4.2.96; Intel Core 2 Quad
Q6600 @ 2.4Ghz; 6GB DDR2 RAM; 640GB SATA HDD.

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7

I ended up using the @audio group (if it aint broke…dont fix it)

I was up until almost 4 in the morning and the moment I got sound to
come out of the d*mned thing I figured i would quit while I was ahead,
so I will be diving in tonight to see what it can do.

Thanks for the link to the forum, Im certain Ill be in there checking
things out (probably asking questions too)

–
openSUSE 11.0 | Kernel 2.6.25.18-default | Intel Core 2 Quad Q9450 OC@ 3
Ghz | 2GB DDR2 | nVidia GeForce 8800 GT | Sound Blaster Audigy 2
Platinum | Seagate SATA x3 (1 TB total)

pimanac’s Profile: http://forums.opensuse.org/member.php?userid=5767
View this thread: http://forums.opensuse.org/showthread.php?t=405433