Cmedia, SPDIF, AC3 = How??

[ShockValue]

HI all, I have a CMEDIA 8737 soundcard with coaxial SPDIF out.
I am using Kernel 2.6 with ALSA.

I have managed to get 2 channel data (PCM) to work through the SPDIF out on the card, but for the life of me can't seem to get 5.1 working (AC3).
Playing my flac music this way (mythmusic) works and sounds great!

I've tried flipping every switch in alsamixer according to many fragments I've found on various forums and IRC. All resulted in either 1) no sound, or 2) 2 channel PCM sound.

currently I've been playing with both mplayer and xine to get this to work.

mplayer dvd:// -ac -hwac3 -ao alsa9:spdif
This will sometimes freeze up mplayer, and other times i get 2 channel sound (or no sound depending on which variations of switches Ive used.)

Xine: When I enable a52_passthrough I get no sound. When i turn this option off, I get 2 channel sound.

Is there a verbose HOWTO on getting AC3 properly passed through SPDIF on a cmedia 8738 card somewhere in the world? Does anyone have any other suggestions to try?

Basically I'm trying to build a HTPC machine, but this no 5.1 from DVD is kind of killing my will to live (spent all weekend flipping switches and surfing the web...)

Other info:

Sound data being decoded by Marantz SR8000.
Sound card is: Zoltrix Nightengale
DVD Player: LiteOn 16x DVD

I'm not at my HTPC machine at the moment so I can't give specific config file info, but if it is needed I will post as soon as I get home!

Thanks so much in advance for any help or pointers ->

[bombcar]

The first thing I'd try to do is get 6 channel working on the normal connections (miniplug). If you can get that working, then the only hurdle is getting SPDIF working.

[ShockValue]

I don't believe that the card I have has a miniplug digital out.

Has: Line, Mic, SpK, Rear, SpDIF, GamePort.

The SPDIF does work, at least in part, as I am able to use it to play 2 channel PCM audio currently.

[bombcar]

Ooops! By normal I meant non-digital! If you can get the analog 5.1 to work, then that means the software (mplayer, etc.) is using AC3 o.k., and you can then hunt down the driver problem.

[ShockValue]

Well, I finally gave in.

I threw an old SBLive! Value in last night. Rebuilt my kernel with em10k1 support, and fired it up.

2 clicks later I had AC3 through the spdif and was watching the matrix in 5.1.

I'm not particularly happy with the situation, since I was sure I could get the cmedia card to work... But I was tired of fighting with it and just threw more hardware at it instead

[phantom74]

I bought this card as a cheap way to get digital out through spdif. I installed it in an existing gentoo setup (using 2.4.20 kernel) with KDE. Surprisingly, I got it to output ac3 through spdif in little time.

Since then, I removed kde and it stopped working. Now the only way to get non-AC3 streams out of it is to use a utility to enable the SPDIF OUT (which I didn't have to do earlier). If I try get mplayer to output AC3 using -ac hwac3 , it freezes up.

I'd love to get it working again. I've reinstalled KDE thinking that was it, but no luck.