On Tue, Dec 16, 2008 at 01:30:02AM +0200, Alexey Suslikov wrote: > Jacob Meuser wrote: > >> On Sun, Dec 14, 2008 at 06:09:24PM +0100, Martin Toft wrote: >>> A small follow-up: >>> >>> The problem only occurs when opening the audio device. If I queue a >>> number of tracks in mpd's playlist and let it play, then it does not >>> suddenly start making noise from one track to the next. It only happens >>> when I manually start a track (and only sometimes). I suspect that mpd >>> does not close the audio device between tracks if it is playing from its >>> playlist, and that is probably why the problem does not occur in that >>> setting. >> >> thanks for this and your other response. > > The issue I see regularly with azalia+vlc+jackd may be related maybe not. > > nice jackd --silent --nozombies -t 10000 -d sun -p 4096 2>&1 1>/dev/null & > > - this is how I run jackd. > > Here is the scenario: > > - I start vlc and play something, > - I start heavy application (like Thunderbird/Firefox @ hw.setperf=0), > - sound stutters (threads blocking?), > - at this point, with ~20% probability, I hear cyclic audio fragment > which overlaps main sound, > - the issue can be remedied by restarting jack entirely or by starting > any heavy application again (~20% probability). > > For me, it looks like a junk data somewhere in a buffer.
probably jackd. upstream bungled around with some releases. I think they are finally done. I'll take a look at getting jack updated. > Our audio layer and NetBSD are different wrt buffers handling so I > took a deeper look and discovered the following commit > > http://cvsweb.netbsd.org/bsdweb.cgi/src/sys/dev/audio.c.diff?r1=1.184&r2=1.184.2.27&f=h > > For me, the interesting part here is > > ... > /* > * "used <= cb->usedlow" should be "used < blksize" ideally. > * Some HW drivers such as uaudio(4) does not call audio_pint() > * at accurate timing. If used < blksize, uaudio(4) already > * request transfer of garbage data. > */ > if (used <= cb->usedlow && !cb->copying && sc->sc_npfilters > 0) { > /* we might have data in filter pipeline */ ^^^^^^^^^^^^^^^ we have no such filer pipeline. -- jake...@sdf.lonestar.org SDF Public Access UNIX System - http://sdf.lonestar.org
