I am trying to recompile highly compressed DVD multi-movie collections

I have a collection of highly compressed Filipino movie DVDs that have 20 hours or more of movies on each. Some of the movies are faulty and some are of unwatchable quality so I want to customize the disks and recompile them into collections of my favorite movies with menus. Every DVD authoring package I have tried decompresses these files before recompiling them and will only let me fit the standard 6 hours on a single layer disk. Is there a package that will retain the high compression but allow me to create a text menu or preferrably a thumbnail menu for these disks or is there a package available that will just create a menu and link them to the existing DVD video files without modifying them? I would appreciate any assistance you could offer, Thanks !!!