On Tue, 17 May 2005 22:58:08 +0100, Paul Brossier wrote: > I sent this mail a few days ago to debian-powerpc but had no reply. Maybe > someone here will have an idea. > > bye, Paul > > ----- Forwarded message from Paul Brossier <[EMAIL PROTECTED]> ----- > > Date: Sat, 14 May 2005 21:56:40 +0100 From: Paul Brossier > <[EMAIL PROTECTED]> To: [email protected] > Subject: alsa and jack latency > > Hi all, > > Trying to reduce the latency of jack on my ibook G4, i realised i can go > down to 8.7ms using the oss mode, which is really good. But alsa won't > accept running with less than 22ms and click on most X request: > > $ jackd -R -doss -r44100 -p128 -n3 -w16 works perfectly, 128*3/44100=8.7ms > latency, hardly any xrun on heavy load > > $ jackd -R -doss -r44100 -p256 -n2 -w16 works fine, 11.6ms latency > > $ jackd -R -dalsa -r44100 -p128 -n3 -S runs but no clients can connect > > $ jackd -R -dalsa -r44100 -p256 -n2 -S fails saying ... > ALSA: cannot set number of periods to 2 for capture ALSA: cannot configure > capture channel > > $ jackd -R -dalsa -r44100 -p256 -n4 -S would run with 23.2ms latency, but > xruns on most X queries > > It looks to me that this is related to the pmac driver. I have similar > problems with snd-usb-audio and an edirol usb, which will only let jack > run in oss mode. > > I wonder what prevents the pmac module to do so while the oss emulation > layer does it very well. I am running 2.6.12-rc4, but had this problem > with earlier 2.6 kernels. Any thoughts?
I have the same configuration (powerbook) and also problems but never took any real effort to fix them. If you are using the realtime-lsm (or as root), you should be fine. Someone currently having issues as well (but amd64): http://boudicca.tux.org/hypermail/jackit-devel/2005-May/0121.html You could try to get latency-test running on ppc: http://www.alsa-project.org/~iwai/alsa.html#LatencyTest But that seems to require some special RTC functions. I uploaded a newer JACK (0.99.61) to experimental. But that is binary incompatible to the current one. So you have to recompile you applications. Robert. -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
