5.1 sound
 

Which codec I should use to play 5.1 sound (InterVideo Audio decoder or CyberLinkAudio decoder). What else I have to set up? I have soundcart from Manli with M-CME8738-6ch chip and repro Hercules 5100.

First you must have an AC3 filter installed

The easiest way is to install the one you'll find at doom9's (www.doom9.net -> downloads -> filters -> audiofilters.zip ; [register iviaudio.ax and mpgaudio.ax only, you don't need mmswitch])
It is intervideo's AC3 filter

then you can set it up as you like in bsplayer's preferences (and when playing, right-click->properties->intervideo audio filter)

(I was told recently about another ac3 filter which can be found at doom9's too but I didn't have time to try it yet)