When my Soundcard plays normal Windows Sound, I only get stereo PCM on my digital audio output. But when i watch some Movie with AC3 or DTS Sound, this formats with 5.1 channels are transmitted on the digital audio output.

This means that "normal" 3d sound from EAX for example, only get transmitted as stereo. So there is the option to use 6 normal analog cinch cables.

And i thought of something else:
What if i could encode all sound from windows to AC3 or DTS and send it the digital output, via software?
This way i would get the 6 channel information on the digital output, without my soundcard doing this.

Any opinions on this? Would this be possible to make (read program), or are there programs for something like there out already?

If you encoded all the audio as AC3 or DTS in realtime, you would likely get a 1-2 frame lag from what you see and what you hear. Whether you can hear the delay is another story.

I think the latest version (somewhere past 1.0) of AC3Filter will do real time software encoding to DD.

There are cards available that can do realtime DD encoding and now DTS encoding too. You'd be better buying on of these cards.

Check this thread or more info:

http://www.avsforum.com/avs-vb/showthread.php?t=605522

Hmm seems to be the right direction, but i thought about a pure software based solution. AC3Filter only recodes audio for media player, not all sound and it seems to mix-up any stereo to 5.1, wich sounds pretty weird on some video files.

I wasa thinking of just taking all sound output and just encode it to AC3, without altering it. So if we just have stereo output, we just send stereo (might switch back to pcm in this case) and only use the encode ability to send surround sound from games and such via AC3 to the amplifier, if the game really gives us a surround signal.

Should be possible, I'm not completly sure how. But the biggest problem i see programing wise, is to send the ready encoded AC3 to the S/P Dif, cause that could be Soundcard specific.