On Tue, 18 Nov 2003, Giuliano Pochini wrote: > > On 15-Nov-2003 Jaroslav Kysela wrote: > > On Sat, 15 Nov 2003, Giuliano Pochini wrote: > > > >> My hardware can start/stop multiple indipendent substreams at the same time. > >> Does the ALSA driver API support that feature ? > > > > Yes, use snd_pcm_set_sync() function in open() callback and add necessary > > code to the trigger() callback. See to alsa-kernel/pci/ens1370.c code for > > more details (this hardware has three streams which can be controlled > > simultaneously) as a good example. > > Fine. > Is that feature used by the upper ALSA driver to create multichannel > substreams when the hw hasn't this capability ?
It can be used in alsa-lib (for example in multi plugin which does exactly what you want). > Older Echoaudio > soundcards can only do mono and stereo operation, while newer series can > manage mono and any even number of channels. Since all cards can run any > number of substreams at the same time, I can emulate large substream on > older cards by starting several mono substream simultaneously > (MMAP_NONINTERLEAVED in this case). If the upper layer already has this > feature, I can avoid wasteing my time :) Don't do this. Our goal is describe hardware in the driver not create another abstraction layer. Jaroslav ----- Jaroslav Kysela <[EMAIL PROTECTED]> Linux Kernel Sound Maintainer ALSA Project, SuSE Labs ------------------------------------------------------- This SF. Net email is sponsored by: GoToMyPC GoToMyPC is the fast, easy and secure way to access your computer from any Web browser or wireless device. Click here to Try it Free! https://www.gotomypc.com/tr/OSDN/AW/Q4_2003/t/g22lp?Target=mm/g22lp.tmpl _______________________________________________ Alsa-devel mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/alsa-devel