How rip one Full SBS to left/right separately?

[castana]

Hi all
I am trying DVDFab Video Converter and I have one problem.
I have a 3840 x 1080 AVI SidebySide file (full sbs) and I would need to rip it to both right and left eyes separately(1920 x 1080 each eye), for it, could anybody help me?
Thanks in advance !
Regards
castana