Is it possible to convert from bluray...

[rdefino]

to an AC3 video file? I want to be able to convert a bluray that uses DTS to another file say, MKV, AVI, whatever but use AC3 audio?

Can DVDfab do that, if so how?

thanks

[Complication]

DVDFab Blu-ray Ripper (not Video Converter) using "to MKV" and the profile mkv.h264.ac3 would likely do what you want. Try posting in the Ripper forum if you have issues.