Spdif output format?

[pauls898]

I have a DELL Dimension 9200 running Windows Media Centre 2005, I have got this set-up with my Panasonic 42 inch plasma and downloaded some cracking HD Demos and they play fine in all that hd glory, however my next problem is with the sound? This machine has an integrated 7.1 channel sound card including an spdif optical output which I have connected to my Denon surround amp using an optical cable.

The sound seems to come though fine, but its just in stereo, even when I play a windows media file which states the sound track is recorded in 5.1 surround, I still only get this in stereo Is there any way I can configure this sound card to output Dolby 5.1 though this optical output, instead of me having to connect up six analogue cables which would be prone to noise pickup etc
.

[Andy98765]

The simple answer is NO. Basic PC sound cards will not produce 5.1, 6.1 or 7.1 through SPDIF from a file running on the hard drive as it has no encoding capabilities. It will from a DVD drive as this will pass the DVD sound track through the SPDIF output with good software like Power DVD or WINDVD.
The way to get 5.1 - 7.1 from a PC hard drive is to have a direct analogue outputs, your PC may even be capable of that but you will need an AV amp with 5.1 - 7.1 direct in.

[pauls898]

Thanks Andy, was very nearly gona re-install windows MC thinking there was a problem lol. You might have saved me a bit of wasted time then.

I have got 6 seperate inputs, but there over 10 m away and didn't think 10 meters of audio cables would be a good idea but then again I am hardly gona watch movies from this PC in anger, its really just to have a play lol

[mugsy]

Well actually, you can pass 5.1 soundtracks through the spdif

You need to be using an audio codec which supports spdif output - I'm using the on board sound on a gigabyte motherboard with an optical cable running from the spdif output to my processor (Tag Mclaren). I use ffdshow to decode audio/video within media center and VLC player for anything that doesn't play in media center. Enabled spdif output on both apps and if a video has a 5.1 soundtrack (Lost, Heroes downloads etc *cough*) it passes this to the processor which picks it up and decodes it as dolby digital 5.1. If I then play a video with standard 2 channel audio or an MP3 it goes back to stereo through the spdif.

There is also an AC3 encode program - http://www.free-codecs.com/download/AC3_Filter.htm

...if you google ac3 encode or ac3 filter or search on here you'll find more info. I don't have it installed and as above, I can get 5.1 through the spdif fine

[simkna]

I use the same approach as Mugsy for non-DD video (using ffdshow). Doesn't help for games 'n' stuff though.

Si.

[mackym]

Yep, it works in 5.1, I have a shuttle with integrated audio and SPDIF connection to a home cinema system - excellent surround sound on file playback. Dunno about 7.1

[pauls898]

Thanks Mugsy, I downloaded that AC3 filter and it works great, I now have Dolby D on my Denon AV Amp

Thanks again for your help.

Paul

[mugsy]

Nice work - glad it's all working