choose my own video/audio codecs

[lerman01]

being able to choose another codec from my computer,
i'm using S/PDIF for example but when i see a movie with 5.1 channels the receiver doesnt recognize it,
but if i play the same movie that i downloaded just from another player (that using FFdshow) the reciever recognize the 5.1 channels,
so if i could play the movie through Popcorn time and choose the FFdshow codec in it could figure it out.