[PlanetCCRMA] Try to configure Qjackctl, may be bug, etc.

Fernando Lopez-Lezcano nando at ccrma.Stanford.EDU
Thu Jan 29 09:51:16 PST 2009

On Thu, 2009-01-29 at 12:52 +0100, Aznar Jocelyn wrote:
> 2009/1/29 Fernando Lopez-Lezcano <nando at ccrma.stanford.edu>:
> > A bit old, I would install the newer rt13.4 - I don't remember exactly
> > but I think rt13.1 still had problems with midi i/o (it did not work).
> > So, first upgrade your rt kernel.
> >
> > First see if the new kernel changes things.
> >
> > If the computer is still very very slow it can mean that the processor
> > is not fast enough for what you are trying to do. Try with a less
> > demanding setting for jack and start it from the command line like this:
> >
> > /usr/bin/jackd -v -R -d alsa -d hw:0 -r 48000 -p1024 -n3
> >
> > There is no need to tweak the priority of the jack process if you are
> > using the combination of Planet CCRMA kernel and jackd (and that could
> > be the cause of your problems). And 192Khz sampling rate is a bit of
> > overkill, start with something lower and work up if you actually need
> > it.
> >
> > Let's see what happens with those settings.
> > -- Fernando
> >
> Ok, I changed to the new kernel and I started jackd the way you told me.
> Well, it seems to work well, as far as I don't stop jackd which would still
> slow my computer, but not as slow as it was, my mouse cursor moves
> like 2 cm per 5 seconds.

Uh? So the computer slows down when you _stop_ jack? Strange. Do you see
any error messages in the output of dmesg or in /var/log/messages?

> About connecting my digital piano by MIDI to my computer and using
> ZynAddSubFx, well, I can play music with ZynAddSubFx but I can't
> with my piano. :(

Are you connecting the midi output of your piano to the midi input of
Zyn? If you start qjackctl you should see both in the "ALSA" tab of the
connections dialog. You could also start kmidimonitor and connect the
output of the keyboard to it to see if you are getting midi messages...

-- Fernando

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