HD4350, HDMI audio issues

[axeman]

I can't seem to convince this card to output anything other than PCM stereo over the HDMI output in XP. I know it *is possible* to get it to pass AC3 and DTS over the HDMI connection, because I got it to work with Mplayer in Linux - but I'm having other unrelated issues with my setup since I'm running Karmic alpha/beta/whatever.

So, I have latest Ati (9.9) Catalyst drivers, and HDMI audio drivers. I've tried the ATi HDMI audio driver and the "ATI HDMI" driver on realtek's site. I've tried to set ffdshow's audio decoder to use SP/DIF for AC3, but this results in aweful static, and setting SP/DIF using MPC-HC builtin audio decoder gives silence. What gives? I didn't have this kind of trouble getting 5.1 audio over HDMI when I used an Nvidia integrated-graphics setup. I've installed a fresh copy of Windows XP too. On the fresh XP install, I haven't even installed drivers for the mobo audio chip, so I shouldn't be having any sort of conflicts there... but still, the only thing I can get is 2 channel PCM stereo.

[Flying Fox]

What kind of files were you trying to play?

[axeman]

Physical DVDs, .avi files, .mkv, all with AC3 audio streams. Trouble seems to be I have no way to "enable" digital out. It apparently is a bit of a problem with Realtek and ATi cards on XP. Apparently on Vista, there is somewhere you can specify that the output can accept dolby digital (AC3) streams, but there doesn't seem to be a way for me to do that - with an Nvidia setup, in the realtek control panel in XP, there was a place to enable digital out. Unfortunately that doesn't seem to be an option for me. Oddly enough you'd think it would be easy since apparently ATi cards are using realtek chip right on the card whereas the nvidia method somehow just piggybacks onto the existing sound's SPDIF output IIRC.

[mmmmmdonuts21]

Axeman, I feel all your problems as well. The only difference is I am trying to get my 4350 to work with windows 7. I can get 5.1 pcm, but I can't get the dts or ac3 pass through to work. I really want to get my htpc to work with this soon.

[Flying Fox]

Axeman, I feel all your problems as well. The only difference is I am trying to get my 4350 to work with windows 7. I can get 5.1 pcm, but I can't get the dts or ac3 pass through to work. I really want to get my htpc to work with this soon.

When I was using the 4550 with Win7 RC, I really needed to mess with ffdshow's settings to get that going. Once that is done the passthrough works. I don't have 5.1 LPCM material so I can't really test that, but the receiver defaults to 5.1 LPCM mode anyways and when I'm playing AC3 materials the DD sign lights up.

Still need to figure how to upmix all stereo stuff to 5.1 automagically though, but I'm happy with those H.264+AC3-in-MKV stuff.

[mmmmmdonuts21]

Thanks for your help Flying Fox. While searching how to use ffdshow I stumbled upon this website: http://shark007.net/index.html

From there I then installed the 32bit package and then the 64 bit package. I changed three settings in the audio tab

1) Changed speakers from 2 channel to 5.1
2) checked set AC3 fliter to use spdif passthrough
3) clicked use passthrough under the ffdshow option area.

I recommend trying this option if your having problems. It was a beautiful sight seeing the red lights DD on my receiver light up. I did it on windows 7 x64.