[PlanetCCRMA] Re: Problem with /usr/bin/jackstart

Ron Pepper feffer777@yahoo.com
Sat Aug 6 22:08:01 2005

--- Mark Knecht <markknecht@gmail.com> wrote:

> Right. You can see from the message above that it doesn't like n=4
> and
> sseems to want you to use n=2.
> In terms of latency, n=2/p=1024 is the same as n=4/p=512.

> So realtime is loaded but apparently your user account is not able
> to
> access the capability...

> I load realtime like this:
> modprobe realtime gid=408 any=1
> This grants group 408 the rights to use realtime capabilities. In
> my
> /etc/group file I have this line:
> realtime:x:408:mark 

> which places user mark in group 408. With my laptop I can then run
> jackd -R

Thanks for breaking it down for me. So I added a group and then got:
[rp@localhost ~]$ jackd -d alsa -r 44100 -n 2 -p 1024 -d hw
result: a long string of "**** alsa_pcm: xrun of at least 0.031

Then tried:
[rp@localhost ~]$ jackd -d alsa -r 44100 -n 4 -p 1024 -d hw
jackd 0.99.36
Copyright 2001-2003 Paul Davis and others.
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details

JACK compiled with System V SHM support.
`default' server already active

Does this mean jack is already running or that another sound server
is running and blocking it? When I then try to run xmms, I must quit
the terminal and use the ALSA plugin for output. The Jack plugin
freezes xmms when I try it.

> What confuses me about all of this is that I thought Fernando's
> scripts set all this up automatically...

My system is somewhat of a hybrid. When I first installed FC3, it
didn't recognize the soundcard. I found the ALSA site and finally
sorted out that I needed to configure a module for my "special" sound
chip. While struggling to do this, I was helped by Rick B. who also
pointed me to CCRMA. I then loaded a CCRMA kernel and pointed
Synaptic to Fernando's repositories. Since I finally got xmms etc
working, I was worried about tearing it all down again to install a
pure CCRMA system. I intend to do this at some point, but want to get
more familiar with CLI and Linux in general first. Am I right in
thinking that I need to use Jack as my sound server in order to do
the dual activities of playing an audio-stream from xmms and
recording it?


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