[ardour-users] jackd, jackstart, qjackctl

Jack O'Quin joq at io.com
Fri Feb 4 10:17:11 PST 2005

Kevin Cosgrove <kevinc at doink.com> writes:

> I hope it's OK to ask a jack question here.

Sure.  Though, jackit-devel would be better.  :-)

> I'm running kernel 2.6.7 patched for multimedia use, and from the
> Mandrake contrib packages.  Myself I added the realcap patch and
> load that module with permissions for the audio group so that I
> don't have to run all my jack aware audio apps as root.  When I
> start jack like this:
>     jackd -R -d alsa -d hw -r 44100 -p 2048 -n 2
> I get no error messages.  When I start jack with jackstart through 
> qjackctl, then I get these errors:
> [...]
> Why would jackd not complain, but jackstart would complain?

Older versions of jackstart believed that these permissions were
necessary for jackd to work as non-root.  That is no longer the case.

So, jackstart was recently fixed to allow that situation.  You
probably don't have that version, yet.

The simplest workaround is just to run jackd, instead.  You don't need
jackstart with the realtime-lsm.

> If I start jackd before qjackctl, then qjackctl connects to the
> already running jackd.  If I look at the status window, it tells
> me "Realtime Mode: Yes".  I would think this says that my jackd
> is actually getting realtime capabilities, right?

Yes.  The realtime-lsm is just a different mechanism for achieving the
same result.

> I want to run qjackctl for the patchbay and connection features, and 
> if I have to run jackd first, that's OK.  But, I'd rather have it 
> work more simply.

Tell qjackctl to start jackd rather than jackstart.  It knows how.

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