[ardour-users] Xruns, and buffer sizes... Continued recording problems.

[Wolfgang Woehl]

Jason Jones <j at poeticintensity.com>:

> Good to know.  Is the -p setting the "buffer"?  or is it the
> combination of the recording frequency, the frames, and the periods?

In a commandline like
/usr/local/bin/jackstart -R -p512 -dalsa -dhw:0 -r44100 -p1024 -n2
you see 2 p's. The first is an option to jackd: how much memory to 
allocate for ports -- "port maximum" on qjackctl's setup page. The 
second is an option to the alsa driver: size in bytes; p * n will be =< 
what the alsa driver knows about your hardware buffer's size in order 
to work; p * n / samplerate = jackd's latency, 46.4 msecs in this case.

> Great info.    Would you mind describing to me exactly what an "xrun"
> is?  What are it's causes?  Maybe a fact vs. myth thread?

An xrun is something that gives me the creeps. Seriously, read 
jackit-devel at lists.sourceforge.net -- they know all about it, almost.

Wolfgang