On Monday 18 February 2008, Sampo Savolainen wrote: > Quoting Arda Eden <ardaeden@xxxxxxxxx>: > > While Jackd is runnning, other applications like Amarok and system sound > > alerts cannot use Alsa at the same time. > > But JACK diagram given in it's web site shows that any non-jackified > > application can use Alsa Userspace Library at the same time. > > > > And, Sampo Savolainan told me that, other programs can use the ALSA > > library, > > but jack needs exclusive > > access to the audio hardware it uses. Nothing is stopping a non-jack > > program > > to access other sound interfaces you might have in your system. > > > > How is this exclusive access given to Jack ? > > Exclusive access is not given to it. Jack takes exclusive access when you > start it. If it's unable to get exclusive access it will fail to start. > > Once it has started, other programs will be unable to access that audio > device. The device is released when jack stops. I guess one should mention subsubdevices here. Soundcards like emu10k1 or cs46xx offer several subsubdevices per subdevice (e.g. 32 in case of cs46xx). So if an app opens a subdevice like hw:0,0, it implicitly opens a subsubdevice. If a soundcard driver offers only a single subsubdevice, then the subdevice cannot be opened anymore. Some people also use the term hardware mixing for this, though there's some possible confusion with the mixer device used to control volumes. So in a nutshell: On some cards, the alsa driver allows opening the hw device roe than once. Only few select devices offer this though.. Flo -- Palimm Palimm! http://tapas.affenbande.org _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/mailman/listinfo/linux-audio-user
