[PlanetCCRMA] Jack crackle...

Fernando Pablo Lopez-Lezcano nando@ccrma.Stanford.EDU
Tue Mar 9 13:03:01 2004

> >>>>Generally, but there are different ways to write to soundcards under ALSA,
> >>>>and jack uses a particular one. Or something like that - I'm a bit hazy on
> >>>>the details :)
> >>>>
> >>>I'm using the same "card" without any of the described problems...
> >>>
> >>Interesting, what driver are you using for it?
> >>
> >Same as you, snd-intel8x0. What gives "/sbin/lsmod",
> >"more /proc/asound/version" and "more /proc/version" ?
> >
> I've put the relevant output of these below ... (do I need more from lsmod?)
> I also have been having problems with jack sometimes producing silence 
> ... restarting jack sometimes fixes it, sometimes not.
> Through this though I did notice that I had newer versions of alsa-libs 
> and alsa-utils than the rest of alsa...
> but changing these to the same versions (latest from ccrma) did not 
> affect the problem...
> [root@scir bin]# lsmod | grep snd
> snd-seq                47632   0  (unused)
> snd-intel8x0           23460   3
> snd-pcm                87392   2  [snd-intel8x0]
> snd-timer              20068   0  [snd-seq snd-pcm]
> snd-ac97-codec         50712   0  [snd-intel8x0]
> snd-mpu401-uart         5256   0  [snd-intel8x0]
> snd-rawmidi            19008   0  [snd-mpu401-uart]
> snd-seq-device          6332   0  [snd-seq snd-rawmidi]
> snd                    44676   1  [snd-seq snd-intel8x0 snd-pcm 
> snd-timer snd-ac97-codec snd-mpu401-uart snd-rawmidi snd-seq-device]
> soundcore               6500   0  [snd]
> snd-page-alloc         10356   0  [snd-intel8x0 snd-pcm]
> [root@scir bin]# cat /proc/asound/version
> Advanced Linux Sound Architecture Driver Version 0.9.6.
> Compiled on Sep 11 2003 for kernel 2.4.20-20.1.caps.rh90 with versioned 
> symbols.

This is quite old... both the kernel and sound drivers. Current
planetedge version is:

> cat /proc/asound/version
Advanced Linux Sound Architecture Driver Version 1.0.3.
Compiled on Feb 29 2004 for kernel 2.4.25-1.ll.rh90.ccrmasmp (SMP) with
versioned symbols.

(or kernel 2.4.20-30.1.caps.rh90.ccrma for the capabilities enabled
RedHat kernel). 

> [root@scir bin]# cat /proc/version
> Linux version 2.4.20-20.1.caps.rh90 (root@cmn19.Stanford.EDU) (gcc 
> version 3.2.2 20030222 (Red Hat Linux 3.2.2-5)) #1 Wed Sep 10 12:51:47 
> PDT 2003
> [root@scir bin]# rpm -qa | egrep '^alsa'
> alsa-utils-1.0.2-2
> alsaplayer-0.99.76-1.rhfc1.ccrma
> alsa-driver-1.0.1-1.cvs.rhfc1.ccrma
> alsa-patch-bay-1.0.0-1.rhfc1.ccrma
> alsa-kernel-2.4.20-20.1.caps.rh90-0.9.6-2.cvs.rh90
> alsa-lib-1.0.2-2
> alsa-firmware-1.0.1-1.cvs.rhfc1.ccrma
> alsa-kernel-2.4.24-1.ll.rhfc1.ccrma-1.0.1-1.cvs.rhfc1.ccrma
> alsa-lib-devel-1.0.2-2
> alsa-tools-1.0.1-1.cvs.rhfc1.ccrma
> jack-audio-connection-kit-0.94.0-1.rhfc1.ccrma

You seem to have a rather unorthodox mix of packages :-)

alsa-utils, alsa-driver, alsa-kernel*, alsa-lib* and alsa-tools should
all be the same version for best results. While a mix of versions may
work we would never know if that is the problem. Let me guess, you are
probably using freshrpms as well, which has a newer version of the alsa
driver (but no kernel modules for the custom Planet CCRMA kernels). 

I would suggest upgrading to the latest kernel and kernel sound drivers,
at least the previous paragraph output of /proc/asound/version suggests
you are using a quite old kernel module set. 

I you want to use the RedHat kernels you would need to:
  apt-get install planetccrma-core-redhat
for the capabilities enabled RedHat kernel or
  apt-get install planetccrma-core
for the Planet CCRMA kernel. 

You will probably get conflicts, I don't know how apt will react with
your mix of packages. Let me know and I'll help you navigate around

BTW, I don't think you mentioned trying different Jack buffer size (!=
1024) and number of periods (> 2), did you do that?

-- Fernando