[PlanetCCRMA] Problem with Jack?

Joe Dell'Orfano fullgo@dellorfano.net
Tue May 13 13:48:01 2003

Thank you so much for your help. I did of course go through your
excellent section on optimizing for low latency. I got Jack to work by
increasing the -n to 3. I use the default buffer size of 1024. This
works very well.

Eventually I will add a real sound card to the system.

Thanks again.


On Tue, 2003-05-13 at 17:19, Fernando Pablo Lopez-Lezcano wrote:
> > I am sorry if I'm covering old ground here. I have recently configured
> > my system with all of the Planet CCRMA packages (running RH 8.0 on an
> > AMD processor with on-board via82xx sound). All packages appear to work
> > properly except Jack. When I run Jack in a terminal I get a screen of 
> > 
> > **** alsa_pcm: xrun of at least 0.0xx seconds
> > 
> > When Jack runs as such, I can get ardour to work, but when recording
> > from the pcm source, there is a lot of noise. I have not been able to
> > get rid of this noise by turning off different channels on the mixer.
> > The noise is heard whenever I turn a track on for recording. I have no
> > problem recording with Audacity or Cinelerra,
> They are using oss emulation over the alsa drivers and most probably use
> a lot more buffering than the default for jack. 
> > so I think the problem is
> > with Jack and not with Alsa or my hardware. I have not identified any
> > IRQ conflicts.
> Did you go through the web page on optimizing for low latency? If so,
> there's not much to do except raise the number of periods per buffer or
> the size of the buffer in jack (but that will, of course, raise the
> latency). 
> -- Fernando
Joe Dell'Orfano <fullgo@dellorfano.net>