To play DVDs is a prerogative of BSplayer PRO v2.xx
It's still possible to watch DVDs with free versions of the program, but not all the contents will be available (such as menus etc).
I tried some DVDs in the past (with BSplayer v1.xx) and I was able to switch the audio streams in the 80% of the cases and to choose the subtitles in 10% of them..
I used Elecard decoder (available also in K-Lite Mega Codec Pack).
Maybe you'll find
this topic (and also
this one) of interest to you (even if they don't provide answers your question)