how can i improve the picture quality of my dvd+r's(crappy brands) movies without re-renting and re-burning(is that even possible) or will I just need to burn again on a better dvd+r disc from their orginal dvd? what program(s) do i need to do this? i have dvd shrink and dvd decryptor
What kind of picture quality problems are you having? Either way there is no way to improve any problems on a backup. If freezing, pausing, or pixelating are the problems you will need to completely redo onto better media and keep the burn speed at 4x, 8x max. If over compression is the problem you will need to completely redo with better software. I recommend rb/cce.
Concur with Mort81's advice - old adage 'Cannot make a silk purse out of a sows ear' In more modern terminology - crap in = crap out. You will need to reburn on quality media.