using libdvdread to get info about VOB files

hello all
does anyone know if it is possible to use libdvdread to get information 
about VOB files (ripped from DVD to HD)? i tried it with the tools in 
/src but they only operate on DVD-drives. specifically i'm interested 
in the running time...
if not, does anyone know if there is any other way to 
(programmatically) obtain this information from HD-stored VOB-files?
thanks in advance, julian