On Wed, 29.08.07 20:38, Jan Kasprzak (kas at fi.muni.cz) wrote: Hi! > on my home workstation I use a dual-seated setup (two monitors, two > keyboards, two VGA cards, etc. - two independent users). I am > looking for a way of using the sound card by both users > simultaneously (I have problem that when one user's application > opens the sound device and keeps it opened, the other user's ekiga > cannot use it, which is quite annoying especially when receiving an > incoming call). > > I thought system-wide PulseAudio daemon might be the correct > answer. I have read > http://www.pulseaudio.org/wiki/SystemWideInstance, > but I am not sure about how to best configure it: > > * Is there any prebuilt init script for Fedora? Fedora RPMs does not > seem to have any (this is a minor problem, I can write it myself). Not that I knew of. > * How to tell all user's sessions "use this PulseAudio daemon"? > Should I set an environment variable PULSE_SERVER somewhere in GDM > session startup scripts? Or use the default-server directive in > /etc/pulse/client.conf? You have lot of different options: You could stick it in /etc/pulse/client.conf (which is probably what I'd). You could set $PULSE_SERVER. You could leave it out entirely if the PA daemon is running locally. You could store it in the X11 root window. (see pax11publish for that) If PULSE_SERVER is not set PA will try $DISPLAY as a fallback, too. So basically, I did my best to make it work even without too much manual configuration. > * What about authentication? Is a pulse-access group membership the > recommended way? Or should I copy ~/.pulse-cookie to the home > directories of users I want to have access to the system-wide > daemon? Both is fine. pulse-access is probably the best bay though. > * Should user apps access the system-wide daemon directly? I have > also thought about each user having his own daemon, connected to > the system-wide one by (e.g.) module-native-protocol-unix. Each time you add another layer of indirection audio latency becomes worse. Thus I'd suggest using a single system-wide instance and that should be it. OTOH more and more policy is managed by the PA daemons and hence running it per-session is much better then running it system-wide. Inside RH we had a few disucssions how to handle multi-seat setups with regards to audio best. Our conclusion was that audio cards should be treated similar to mice and keyboards: i.e. each seat gets its own pair of boxes (or a headphone) and they are not shared with anyone else. OTOH I see how sharing a sound card would be handy. So in the end we might end up with the optional solution of running a tiny/dumbed-down pa system instance which sessions connect to. But that's way down on my TODO list, and will always stay optional since it is detrimental for latency. Lennart -- Lennart Poettering Red Hat, Inc. lennart [at] poettering [dot] net ICQ# 11060553 http://0pointer.net/lennart/ GnuPG 0x1A015CC4
