Hypothetical (probably common): You have a really big movie (say Gettysburg) that fills a whole regular DVD without any extras. You want to back it up onto a DVD+R (2 DVD+Rs due to space (assuming DVD Shrink can't shrink enough to fit on 1 without nasty video results). Can you split the movie itself in two? How and what happens with playback?
If you are using DVDxCopy or DVDxPress (with the entire disk option checked) then what happens is at the point in the film when it needs to go to the next disk, you will get a screen that says to put in the next disc. This is always placed in between chapters of the DVD and sometimes right at suspencefull climaxs ( just by chance). So using these softwares you will know as it will tell you. You can also compress without massive loss, I have been able to get all 208mins of Seven samuri on one disc using DVDxPress and the picture quality is great (but this is a black and white movie).
