[SOLVED] Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!

[hansdevr]

Re: Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!!!!!!

Well, all of your replies did help a lot. I finally managed to get qjackctl running jackd, and I managed to get some audio from hydrogen into ardour with the patching in qjackctl. I am really interested in finding out what the real time kernel can do for me, but I decided to wait untill after the next kubuntu release. I use a quad core AMD, some 8 gigs of RAM and a good quality sound card. So, it should work!
Thanks again, and I will keep you updated on my progress in Audio Land!!

[hansdevr]

Re: Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!!!!!!

I add the following lines to /etc/security/limits.conf (as superuser)
@audio - rtprio 99
@audio - memlock 512000
@audio - nice -19

Then add yourself to the audio group (systemsettings > advanced > user management)

Hi Ken,

I managed to add myself to the audio group.
I understand the rtprio and memlock entries, but what does nice -19 exactly stand for and what is the way to add those lines as "super user"?!?

Thank you very much!!

[rfakhrai]

Re: Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!!!!!!

I don't know what the nice -19 stands for but, to add those lines as super user, simply open the file in kate as root.

kdesudo kate /etc/security/limits.conf

[lcorken]

Re: Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!!!!!!

I don't know the correct way to edit limits.conf but I do it this way from a terminal (konsole)

kdesudo kate /etc/security/limits.conf

ubuntu shows this other way

sudo su -c 'echo @audio - rtprio 99 >> /etc/security/limits.conf'
sudo su -c 'echo @audio - memlock 250000 >> /etc/security/limits.conf'
sudo su -c 'echo @audio - nice -10 >> /etc/security/limits.conf'

https://help.ubuntu.com/community/Ub...GettingStarted

The last part of the file looks something like this.

#* soft core 0
#root hard core 100000
#* hard rss 10000
#@student hard nproc 20
#@faculty soft nproc 20
#@faculty hard nproc 50
#ftp hard nproc 0
#ftp - chroot /ftp
#@student - maxlogins 4
@audio - rtprio 99
@audio - memlock 512000
@audio - nice -19
# End of file

nice -19. The way I understand it the nice level is how nice a process is at giving up CPU time to other processes. -19 being not-very-nice. A + number would be nicer. Normally you want processes to be nice about sharing CPU time. For DAW work audio needs to be more greedy with CPU time to prevent clicks, pops, drop-outs and other audio artifacts. For background music it's not a problem but music production is a different story. With your Fast machine it may be less an issue, maybe.

Don't remember where I read it but some people have debated the need for this "nice" thing.
If I find that will post it.

Have fun.
Ken.

[hansdevr]

Re: Jackd/qjackctl/jack/Alsa/qtractor/rosegarden/ardour HELP!!!!!!

I could not wait until the next release, so I decided to get the real time kernel. I managed to get everything working!! All of the edits Ken suggested were done and qtractor and ardour work like a charm. I will download Rosegarden, but I am waiting for the new Thorn version to be released into the packages.

Thank you all very much!! As soon as I produce some audio, I will post a link!!

This thread has solved problems I have been wrestling with for almost a year, and - as always - if you understand the steps, it isn't hard anymore. Thanks again!