Newbie seeks help: with AC3 0.70B, How to select 'SPDIF'

[Duncan]

Hello,

I have some Divx/Xvid movies with ac3 and I want to select 'SPDIF' as the audio output in BS Player 2.15, to pass the compressed ac3 from BSPlayer to the sound card and then 'SPDIF Pass-through' from the sound card to my external hardware decoder, as I read somewhere that this was the only way to get 6 channels through an optical/coax cable.

To do the 'SPDIF Pass-through' in the sound card I know how to to, but in BSPlayer I don´t know, can you help me?

I have been reding some posts but I am still confused.
Through that reading I discover that my AC3 Filter is the 0.70b version, witch some guys say it´s the most stable version and the best, is that right?


Other question, how do we know witch audio system (ac3,mp3 etc) the movies has? By the movie proprieties or there are programs for that?