21 Jan
2004
21 Jan
'04
7:18 a.m.
On Wed, Jan 21, 2004 at 03:01:19 -0800, Andrew Morton wrote:
The default sampe rate is 48kHz, so 1024 samples/block gives 21ms between
interupts. Jack easts a bit of that, but you'd have ~20ms before an
underrun occured.
I just wanted
to elaborate abit; -R in the argument line indicates that jack
should be running SCHED_FIFO, and since there are no specific settings for
period-size and number of periods, jack is probably defaulting to 2-periods
and 1024 samples period size. 2.4 works rather reliably with period-sizes
quite a bit smaller than that. I think 256 is commonly used, with good
hardware+drivers I suppose you could go even lower.
I don't know what these numbers mean...
What does this transalate to in interval-in-milliseconds, and after how
many milliseconds delay will an underrun occur? And what else is happening on the system at the time?
The original poster would have to anwer that. Jack itsself is just messing
with SYSV SHM and occasioanly touching fifos.
As someone else said, jack runs reliably on most 2.4+ll+o(1)sched systems
with 5ms (256 sample) interupt fequencies and usually lower.
- Steve