[ardour-users] jackd problem: pcm failed

R Parker rtp405 at yahoo.com
Sat May 29 23:58:30 PDT 2004


> switched to root and entered jackd -R -d alsa -
> sblive.
> jackd aborts with the message:"pcm.c:690:
> snd_pcm_nonblock: Assertion 
> 'pcm' failed."
> What am I missing?

I would suggest installing qjackctl. It's a good
application for managing the startup, shutdown and
routing for jackd.
I think qjackctl will kill ARTS for you if it's

> Philcordia asked:  Is ARTS or esound running?
> Answer: I don't believe so.  top shows only one
> active file, top itself.
> Philcordia asked: Have you tried jack with -S or -P?
>  Does jackd without 
> -d sblive do anything?
> Answer:  When I started jack it wanted to rip a cd.

That's another application that has nothing to do with
> jackd -R -d alsa 
> and jackd -R -d alsa -d hw:0 give the same result as
> above.
> Philcordia asked:  Maybe some stale temporary files.
>  Where did you 
> configure jact?
> Answer:  I didn't.  I used apt-get install jackd to
> get the debian 
> package and read user-howto.gz.  There is no mention
> of configuration or 
> temporary files and I cannot locate jact in my
> system.

There is no jact, it's a typo error. I think the point
is to find your jack tmp dir and remove "stale"
temporary files.

>From my RH9 PLANET CCRMA /etc/fstab:
none                    /var/lib/jack/tmp       tmpfs 
 defaults         0 0

[root at stepdaddy studio]# ls /var/lib/jack/tmp/
jack_0      jack-ack-fifo-5866-0  jack-ack-fifo-5866-2
jack_ack_0  jack-ack-fifo-5866-1

These files left behind from a crash or whatever can
cause problems. 

> A final note:  My objective is to capture input from
> my phonograph, 
> remove cracks and clicks and write the result to a
> cd.  The phonograph 
> input is to the sblive card, the output from the
> card is to my stereo 
> system.

I know this has been discussed on the Linux Audio User
lists and it sounded like a good solution exists. I
guess search those list archives.

You should note that jackd is a lowlatency solution
designed for professional audio work. It certainly can
be used to capture any data including your phonograph
sources coming through an sblive and into alsa. My
point is, you may find it much easier to not use
jackd. Just stick with alsa and Audacity or whatever
you dig out of the Linux Audio User archives.

If you're determined to use jackd and Ardour, these
present greater challanges. You will need to tune that
computer for lowlatency performance. It can be a
challanging task, depending on your hardware. Also,
Ardour is a beta tool. It's a challange to get it
working. There are tools out there that are so much
simpler for what you describe. Save yourself the
headache unless you want to experiment and learn.


> Tom George
> _______________________________________________
> ardour-users-ardour.org mailing list
> ardour-users at lists.ardour.org

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