audio over HDMI

[Rob Owens <rowens@ptd.net>]

I've got an nVidia Corporation G98 [GeForce 8400GS] and I'm trying to
get audio working over HDMI.  I'm running Squeeze and the proprietary
nVidia driver from non-free.

"alsamixer -c 1" shows me the card "HDA NVidia", but instead of mixer
controls I see "This sound device does not have any controls."

"aplay -l" only shows my Intel onboard audio card.  Same goes for "aplay
-L".

I've tried all of these with no success:

mplayer somefile.flac
aplay somefile.flac
aplay -c 1 somefile.flac

Any advice?

-Rob