[alsa-devel] [CONF] All C-Media Codecs based 5.1 Channel USB- Headsets

[thomas schorpp]

Report to devlist as requested from USB-Audio.conf header:

1. all this headsets with windriver inf files + manual showing c-media driver must have 
the cm106x series 7.1 channel usb-codec in. there's no other from c-media for the design of 5.1 
channel usb headsets available at this time, see:

http://www.cmedia.com.tw/?q=en/usb_audio

2. the headset interface shows up with 8 channels in lsusb -v , 1 8-ch pcm in /proc,
 and must be driven with 
surround7.1 pcm plug instead of surround5.1 or it will not work. speaker-test program 
works with -c6 -Dsurround7.1, test with -c8 works too, but shows that no SideL/R -speakers 
connected/routed/downmixed ( Speedlink Medusa 5.1 Mobile USB Headset, cm106L)

3. it works instantly without extra config using programs that allow specifying 
(-D)surround7.1 like VDR and MPlayer, VLC did not so far 
(maybe can do with special commandline) 
and therere maybe other unconfigurable (or buggy?) players that need a missing extra cm106 
CARD configfile showing those apps a 5.1 channel device instead a 7.1.

i've done none so far, the config file language (especially routing and mappings) 
is not well documented, sorry.

y
tom