snd_hda multichannel support added

[Alexander Motin]

Hi.

As sound(4) got multichannel support since FreeBSD 8.0, I've implemented
multichannel (4.0, 5.1, 7.1) playback support for snd_hda(4) driver.
MPlayer now successfully plays 4/6-channel audio streams when running
with respective -channels option. The only thing you should configure,
is to inform vchans about present number of speakers by something like:
sysctl dev.pcm.0.play.vchanformat="s16le:7.1"

Code was recently added to 9-CURRENT. Patch for 8-STABLE can be found
here: http://people.freebsd.org/~mav/snd_hda.mch.patch

Have a nice sound! :)

PS: Stereo stream is no more duplicated to all connectors. If you loose
sound, check you are using right ones. Front speakers connector is
usually green, center/LFE - orange, rear - black, side - gray.

-- 
Alexander Motin