Multichannel Sound output

[Matt Stegmeir]

I've been playing around with multichannel sound output in FreeBSD 
recently and wnated to share a bit of what worked for me, because I 
don't see a lot on this list about stuff that works, more about stuff 
people are going to try or are working on.  I'm using the backported 
sound stuff from http://people.freebsd.org/~ariff/ with the emu_10kx 
driver on an old sblive! value.  The driver exposes front and rear 
outputs as separately when compiled with options 
SND_EMU10KX_MULTICHANNEL.  In order to expose that functionality to 
applications, I'm using the pulseaudio (formerly polypaudio) port with 
the module-combine capability to relink the front and rear channels into 
a virtual multichannel source.  Xine from ports/packages has pulseaudio 
support enabled out of the box.  Mplayer, as of now, still supports 
polypaudio instead.  There's a patch out there to convert it to 
pulseaudio, but I had compile issues, even when using the same svn 
release that the patch was against.

I just wanted to share this in case anyone else was working to get 
multichannel output working for them.