Aaaargh. It Happened Again(TM). Do you remember http://music.columbia.edu/pipermail/linux-audio-user/2005-March/022049.html ? I have always suffered the same problem, (though much less now) along many jack, alsa and kernel versions and configurations... I got: Slackware 10.1 kernel 2.6.12.2 vanilla (but older versions worked equally well) ALSA 1.0.8 JACK 0.99.0 all compiled from sources AMD Athlon XP 3000+ AsRock K7S8X SB Live! Digital 5.1 (hw:0) SB Live! Player 5.1 (hw:1) ForteMedia FM801 (hw:2) RTL8139 Matrox G450 DualHead AGP every card runs on its own IRQ: root at slack101-sal:/home/salvuz# cat /proc/interrupts CPU0 0: 3067468 IO-APIC-edge timer 1: 4252 IO-APIC-edge i8042 8: 0 IO-APIC-edge rtc 9: 0 IO-APIC-level acpi 12: 68805 IO-APIC-edge i8042 14: 130386 IO-APIC-edge ide0 15: 107823 IO-APIC-edge ide1 16: 0 IO-APIC-level FM801 17: 2080 IO-APIC-level eth0 18: 1138 IO-APIC-level EMU10K1 19: 0 IO-APIC-level EMU10K1 20: 0 IO-APIC-level ohci_hcd:usb2 21: 0 IO-APIC-level ohci_hcd:usb3 23: 0 IO-APIC-level ehci_hcd:usb1 NMI: 0 LOC: 3067418 ERR: 0 MIS: 0 The problem in detail: Sometimes in occurence of a client being closed or added, but sometimes apparently randomly, without xruns and not necessarily under heavy load, I experience sudden corruption of sound, in form of crackling sound coming out of alsa_pcm:playback ports. Capture and client ones are not affected, i.e. I can record cleanly even under crackling sound condition: if I close every client, restart jack and play what I recorded just before, the sound is not corrupted at all, just (software) monitoring is horrible. I use my SB Lives always at 48kHz (but the problem arises at other SR too), I tried on the ForteMedia FM801, on the intel8x0 C-Media builtin soundcard (ugh!), on the PC of a friend of mine with NVidia chipset, nVidia builtin soundcard, SB Live and Agnula 1.2.1, I tried Agnula 1.2.1 along with my Slackware on my system, with various buffer, periods and other settings that jackd accepted. Nothing helped. The show-stopping noise, even if certainly not seldom, came out. Well, I noticed that continuing to open and close clients, or doing something apparently "heavy" such as choosing a PADsynth intsrument (such as ChoirPad 1) in Zynad (upon choosing PADsyn instruments Zynad GUI hangs for a moment, then the instrument is ready), I could screw the sound in the same identical manner (the sound appears distorted in the very same way), but also I could restore (after one, two or little more tries) the clean sound from alsa_pcm:playback ports. To make things easier, I wrote this little script that does the dirty work: itstarts jack_simple_client, than *stops the process* (do you hear the alarm siren?) then CONTinues it, then kills it (quite obvious) #!/bin/bash # Pound on broken TV set sudo jack_simple_client POUND! & sudo kill -STOP `ps -el|grep simple|awk '{print $4}'` sleep 0.2 sudo kill -CONT `ps -el|grep simple|awk '{print $4}'` sleep 0.1 sudo kill -9 `ps -el|grep simple|awk '{print $4}'` I know, with this script I am juggling chainsaws over Jack... sorry about that. But it somewhat works (I must admit sometimes jackd dies after the treatment, but there's a let's say 80% probability it doesn't). A painless,and "100% success cases, no jackd deaths" approach is to use jack_bufsize: I simply re-set jackd buffer size and voila, back to clean sound. Try that if you have the same problem: sudo jack_bufsize `ps aux|grep jack|grep " -p" \ | awk '{print $19}'|sed 's/-p//'|uniq` So I think it's a buffer issue that somewhat involves the hardware output ports... I lived satisfied with this setup...until I discovered that oss2jack 0.21 stops working upon executing jack_bufsize. Aaarghh! Maybe oss2jack 0.21 isn't happy with buffer resizing, whereas 0.15 was ok. Tooooooooo bad, because I had: Gnome Wave Cleaner Avidemux2 ReZound (playback only) Skype sox GNUsound (native JACK supports segfaults) ZynAdSubFX (it gives me rock solid performance even upon loading a PADsynt instrument) all working with jack... :( oss2jack 0.15 doesn't die with jack_bufsize, but doesn't handle capture. I then read this from Jesse Chappell: excerpt from http://music.columbia.edu/pipermail/linux-audio-user/2005-March/022074.html --------------------------------------------------------------------- Anyone who is having this problem, please try a version of JACK from CVS where the version is >= 0.99.52 (after 17 march). I made some fixes to jack's alsa driver that *might* help this problem. I know compiling your own jackd might be a little much to ask, but I'm very curious. --------------------------------------------------------------------- Now that jack 0.100.0 was out, I grabbed the source, ./configure --prefix=/usr --enable-stripped-jackd --disable-portaudio --disable-coreaudio --enable-capabilities --enable-optimize --enable-posix-shm --enable-resize --enable-timestamps --with-default-tmpdir=/mnt/ramfs make && make install and thought the end of my nightmare had finally come, but, unfortunately, that's not the case... As in subject, It Happened Again. And,worst of all, all jack clients (not only oss2jack), even ardour (even via his latency panel), die with cannot open shm segment /jack-1 (No such file or directory) cannot attach port segment shared memory (No such file or directory) Killed upon setting jack buffersize. I prepared two ogg files that will explain the weird sound: http://mio.discoremoto.virgilio.it/salvuz For those who don't speak Italian... - check the "Seleziona tutti" (select all) checkbox - then click on "Scarica" (download) button I had Jack running on hw:0 via qjackctl at 256 frames per buffer: /usr/bin/jackstart -v -R -p512 -t10000 -dalsa -dhw:0 -r48000 -p256 -n2 -s -S I fired up ZynAddSubFX, Hydrogen and two istances of qarecord, one with --jack, connected to Zyn and Hydrogen, the other one on another card (hw:1) with ALSA, capturing via "Line in" what came out of hw:0 "Line out", begin to record something (just a test case, as I am a guitarist that tries to play keyboards) then induced corruption with the "pound" script. Another couple of "pounds", and the sound comes clear again, but you know the story. I hope to have been of any help, and I wonder whan can be done... Thanks for your care! ciao -- salvuz POST FATA RESVRGO Linux registered user #291700 | machine #174619 get counted on ---> http://counter.li.org/ <---