On Wed, Feb 25, 2004 at 12:53:47PM +0100, Takashi Iwai wrote: > oh well, this thread can be a troll... maybe, but all this is for targeting your attention to some weak points of ALSA ;-(. I am using ALSA on 2.6.3 kernel and testing it all the time.
> - PCM mixing and software MIDI rendering in the kernel space are > evil. if you doubt it, ask on LKML :) It's just my personal opinion. I am using ALSA mixing in lib and can observe that this solution is not perfect. Also synchronizing PCM streams at the sample position means that we couldn't use MMX or other streaming CPU extensions to optimize mixing. If you don't want kernel sound mixing then just don't load appropriate module - and don't use it!! But I do need this possibility. Generally we could have any device which needs adequate access timing (video grabber, digital oscilloscope, etc..) so if we could have appropriate designed kernel interface for this type of devices using them would be easy. Now any of them need an additional suid daemon process which is working in realtime. It is a security risk and deadlock risk also. Generally there should be an ioctl in kernel by which process could inform scheduler how often it wants to get CPU and how long should it process its data. Now scheduler (read kernel) should decide if this is possible to honour such request and treat it appropriatelly. This approach could be applied to any critical data timing device access not only sound ones. It is better general approach then working on many deamon processes. Also if a process is doing another open call on sound device it should get additional virtual channel. > > - xmms's throughput problem is because of implementation of ALSA > plugin. it has no intermediate buffer and no dedicated audio > thread. > it has nothing to do with the design of ALSA itself. maybe but while using apps working with aoss in dma mode I could observe same effect - badly written aoss-lib ;-) ?! Regards -- Adam Tla/lka mailto:[EMAIL PROTECTED] ^v^ ^v^ ^v^ System & Network Administration Group ~~~~~~ Computer Center, Gdansk University of Technology, Poland PGP public key: finger [EMAIL PROTECTED] ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel
