[PlanetCCRMA] Fedora Core 3 and CCRMA

[Fernando Lopez-Lezcano]

On Tue, 2005-01-11 at 09:09, Raphael wrote:
> Hi all, I'm very new to all this so please bear with me...
> I've just discovered the wonderful world of ccrma and proceeded straight away to
> install apps...
> Unfortunately I came to a bit of a stop as I can't get jack to work.
> Tried with 2.6.9+realtime, 2.6.10-rdt and 2.6.10-ll
> The latter seems to be a bit better but still not working

That one would be the best choice to start with...
(2.6.10-2.1.ll)

> At the moment I've got the stuff installed from an apt-get install
> planetccrma-dore on the CCRMA/FC3 repository
> There are 2 problems really..
> First: jack refuses to identify any of the above kernels as having realtime
> capabilities as shown below
> /~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> 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"

This is fine, in the sense that the new kernel method for giving
realtime privileges to non-root users does not need you to use
jackstart. It will work, but jackstart will complain. To eliminate the
warning just use "jackd" instead of "jackstart". 

> back from read, ret = 1 errno == Success
> jackstart: could not give capabilities: Operation not permitted
> jackd 0.99.36
> Copyright 2001-2003 Paul Davis and others.
> jackd comes with ABSOLUTELY NO WARRANTY
> 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.
> loading driver ..
> creating alsa driver ... hw:0|hw:0|1024|2|48000|0|0|nomon|swmeter|-|32bit
> control device hw:0
> configuring for 48000Hz, period = 1024 frames, buffer = 2 periods
> Couldn't open hw:0 for 32bit samples trying 24bit instead
> Couldn't open hw:0 for 24bit samples trying 16bit instead
> nperiods = 2 for capture
> Couldn't open hw:0 for 32bit samples trying 24bit instead
> Couldn't open hw:0 for 24bit samples trying 16bit instead
> nperiods = 2 for playback
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~/
> ...my assumption is that I have to turn something on but couldn't find the
> relevant doc...
> 
> Second if choosing alsa I get inundated with xruns, oss seems fine 
> (although if I understand correctly that should be provided by alsa via oss
> emulation...???)
> Increasing the buffer to something in the order of 8-16k stops this at 
> first but after a little while the flood begins again.
> The machine is a 2.8 GHz P4 with 1Gb RAM so it shouldn't have a problem with
> essentially doing nothing....
> /~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
> **** alsa_pcm: xrun of at least 0.026 msecs
> **** alsa_pcm: xrun of at least 0.064 msecs
> **** alsa_pcm: xrun of at least 0.029 msecs
> **** alsa_pcm: xrun of at least 0.025 msecs
> **** alsa_pcm: xrun of at least 0.043 msecs
> **** alsa_pcm: xrun of at least 0.040 msecs
> **** alsa_pcm: xrun of at least 0.028 msecs
> **** alsa_pcm: xrun of at least 0.030 msecs
> **** alsa_pcm: xrun of at least 0.025 msecs
> **** alsa_pcm: xrun of at least 0.036 msecs
> **** alsa_pcm: xrun of at least 0.051 msecs
> **** alsa_pcm: xrun of at least 0.029 msecs
> **** alsa_pcm: xrun of at least 0.031 msecs
> **** alsa_pcm: xrun of at least 0.085 msecs
> **** alsa_pcm: xrun of at least 0.063 msecs
> **** alsa_pcm: xrun of at least 0.039 msecs
> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~/
> ...not too sure what this entails but doesn't sound too good...

Some soundcards don't deal very well with using just 2 periods in jack
(the "Periods/Buffer" option in the "Setup" screen of Qjackctl, or the
"-n" command line option when running jackd from a terminal). Try
incrementing it from 2 to 3, see what happens. Most probably that will
eliminate the xruns. 

-- Fernando