Andreas Mohr wrote: > as I'm trying to improve support for my el-cheapo USB audio adapter, > I found that one of the bigger issues is swapping of Center/LFE vs. > rear speakers, as can be seen when running > > speaker-test -c 6 -D pcm.USBAudio > > My theory is that since wave extensible is an established format with different > channel ordering that some soundcards chose to use this swapped ordering in hardware. Some do, some don't. > And ALSA didn't care much since it didn't want to have to expensively remix samples > into correct order? Rerouting channels is actually quite cheap. > But OTOH *if* the comment above is correct and ALSA *does* employ a modified channel > order vs. Windows and Mac OS X, then it seems as if it might be speaker-test which > *doesn't* obey this ALSA ordering??? speaker-test _does_ obey the ALSA ordering. However, USB devices do not, and there is not yet an ALSA configuration file for remapping channels on USB devices. This is a bug in the ALSA library. > Could we please try to put an end to this insanity? I'm working on this. > Is there anyone who has extensive experience with 5.1 surround channel ordering status > of many different soundcards on ALSA? How many "ok", how many swapped? AFAIK USB devices are the only ones where channels are swapped. > Oh, and if the answer is that I should try to fix this on a per-driver (per-card) > basis, then could anyone tell me where the heck I'd have to tweak snd-usb-audio > for correct channel order? You would have to write /usr/share/alsa/cards/USB-Audio.conf. HTH Clemens ------------------------------------------------------------------------- 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
