[Clam-devel] problem with jackd

Roman Goj roman.goj at gmail.com
Sat Jun 9 15:45:45 PDT 2007


On 6/9/07, Andreas Calvo <flipy.bcn at gmail.com> wrote:
> A few days ago, I've tried to open NetworkEditor, and I always get the same
> message:
>
> "jackstart: cannot get realtime capabilities, current capabilities are:
>            =ep cap_setpcap-ep
>     probably running under a kernel with capabilities disabled,
>     a suitable kernel would have printed something like "=eip"
>
> jackstart: md5 checksum for /usr/bin/jackd does not match"
>
> I'm using Ubuntu Feisty, with regular repositories, and I didn't install any
> third-party software more than the qjackctl.
>
> I've tried to completely uninstall all dependencies of jackd and
> reinstalling them, without any luck.
>
> Is someone experiencing the same problem?

hullo!

I'm not experiencing the same problem and I'm on debian instead of
ubuntu feisty... but maybe I'll be able to help - I've been going
through configuring jack a lot lately...

First - if you try running qjackctl - do you have "realtime" checked
in the setup? Could you check whether it runs with and without the
realtime checked?
Or simply, through a console try:
jackd -d alsa
jackd -R -d alsa
(or similar, maybe the backend changes or you need to specify
something more, but it works for me)
this should probably fail with the realtime option and work ok without
it (if it doesn't work ok without realtime, then this beats me :( )

If jackd starts without the -R or realtime checked then just try
running jackd without realtime before running NetworkEditor, this
should work... (more or less, on my second sloooow computer jackd
disconnects NetworkEditor as soon as I try anything computationally
heavy, because (I guess) the xruns are just too long - even with
realtime enabled)

And if that was the case - meaning jackd works without realtime - then
(if you want to get realtime):

Do you have a kernel with the realtime patch? What does this output:
uname -a

I don't know much about ubuntu kernels, so I probably won't know for
sure if it's realtime patched (unless it clearly says realtime in
italics and bold... ;) ), but somebody will, I'm sure :) Also if it's
not patched then I don't know if ubuntu supplies ready made realtime
kernels... but I guess the kernels from ubuntustudio are a safe bet
(I'm running now a debian system with a kernel from 64studio, works
swell :) )

Then after the kernel you need libpam-modules (I guess it should be
the same package for ubuntu) and then edit your
/etc/security/limits.conf adding these lines (if they're not there):

@audio - rtprio 99
@audio - nice -10
@audio - memlock 250000

I haven't found a better overview of the realtime solutions then the
one here (helped me a lot):

http://forums.debian.net/viewtopic.php?t=15345&sid=07c855cb6a107b683878bdab14e8395f

Does this help at all? Maybe you have a completely different problem?
Or maybe I'm missing something in configuring jack and the kernel?

Good luck! :)
Roman




More information about the clam-devel mailing list