Clemens Ladisch wrote: > Andrea Guzzo wrote: >> we are wondering if it's possible to register an alsa device from >> userspace. > > It is not possible to register a kernel device from userspace, but it is > possible to write a plugin that is used by the alsa library like a > kernel device. > > Have a look into the alsa-plugins package. Might I raise the documentation issue here? Last time I checked (1.0.9) it was very difficult to understand what exactly was going on. Glancing at the current alsa-lib-plugins I see that there are some new ones that might help. > >> Is there any working or experimental one? > > The FreeBoB project is writing an ALSA plugin for some IEEE1394 devices. We could implement iSight support in our framework, it wouldn't be that much work I guess. The only issue could be that we have a more pro-audio point of view. However it is probably beneficial to both parties to use FreeBoB, as we have tried to make device support as easy as possible, abstracting everything related to audio API's and FireWire. If you know the device & the framework, implementing support is a matter of days. Note however that unless somebody starts to help out, the FreeBoB ALSA plugin might take some time. One major issue with userspace audio drivers is that stock/distro kernels are not good enough to make it work reliably with acceptable latencies (we're talking a videoconferencing device here). Having to install a RT kernel is IMHO only justifiable for (dedicated) 'audio' boxes, and should not be something that is required for videoconferencing. And if you would want to use them on stock kernels, you need a way to get SCHED_FIFO as an ordinary user, which again is not available on stock distro's. Pieter FreeBoB ------------------------------------------------------------------------- Take Surveys. Earn Cash. Influence the Future of IT Join SourceForge.net's Techsay panel and you'll get the chance to share your opinions on IT & business topics through brief surveys-and earn cash http://www.techsay.com/default.php?page=join.php&p=sourceforge&CID=DEVDEV _______________________________________________ Alsa-devel mailing list Alsa-devel@xxxxxxxxxxxxxxxxxxxxx https://lists.sourceforge.net/lists/listinfo/alsa-devel
