'Twas brillig, and Spidey / Claudio at 20/06/11 14:11 did gyre and gimble: > Yeah. I've also taken the time to learn about Pulse Audio, it's > modules, it's configuration files. It's definitely cool. There is just > one thing I didn't understand fully. Is it ALSA that starts the PA > daemon? It can do. Basically PA is started on demand when needed by the client library. PA clients are any application that wants to use PA (all of these applications, so far and as thoroughly recommended, use the libpulse client library we ship). This would include volume control apps (e.g. pavucontrol, kmix, applets etc.) and sound output apps (e.g. rhythmbox, amarok etc.) Our bridging layer between applications which only speak to alsa (the alsa-pulse plugin) also uses libpulse and thus turns any alsa application into a pulse client too. So by following this logic, an alsa client can launch PA if needed. We also start PA in other ways too: Most notibly when X11 is initialised. Normally, an autospawned PA will exit after a period of being idle. With X11 involved we know the user is still there (even if they've gone to make a cup of tea!), so we don't want to exit PA until the user has logged out of X11. Therefore we also use an XDG autostart file to start PA when X11 inits, and also load some X11 specific modules into PA to prevent this automatic exit until X11 quits. There is something similar done for the KDE support module that is loaded into PA when KDE initialises. HTHs Col -- Colin Guthrie gmane(at)colin.guthr.ie http://colin.guthr.ie/ Day Job: Tribalogic Limited [http://www.tribalogic.net/] Open Source: Mageia Contributor [http://www.mageia.org/] PulseAudio Hacker [http://www.pulseaudio.org/] Trac Hacker [http://trac.edgewall.org/]
