[PD] a/d/a and jackd alsa low-latency problems

[Frank Barknecht]

Hallo,
julien.breval at tremplin-utc.net hat gesagt: // julien.breval at tremplin-utc.net wrote:

> I don't know, but you can avoid them running jack as USER and Pd as ROOT in 
> order to set it to realtime mode with the "-rt" flag
> 
> % su
> % password :
> % pd -jack -rt
> 
> with this solution, I don't get A/D/A errors, except if I open/close Pd files 
> (and some Pd sub-windows with graphic arrays or tables, for example)

The clean way is, not to run jackd nor Pd as root, but give both
higher priorities. For Pd this unfortunatly means "chmod +s
/usr/bin/pd" which is still more secure than running as root, and
jackd can be started as normal user through "jackstart" if you have a
capabilities-patched 2.4 or 2.6 kernel, or as user, if you use the
realtime-lsm module.

> > Alsa says it cannot allocate a buffersize of 32. 64 seems as
> > small as I can go. How can I circumvent this?
> 
> which sound card do you have ? mine doesn't even have 32 smp as buffer size

Whooho, 64 already is *very* small. I never heard of anybody run jack with 32.
That's almost hard-realtime!

Ciao
-- 
 Frank Barknecht                               _ ______footils.org__