These are the packages that would be merged, in order:

Calculating dependencies ... done!
Dependency resolution took 1.00 s (backtrack: 0/20).

[ebuild  N     ] media-libs/libdvdcss-1.4.3:1.2::gentoo  USE="-doc" 380 KiB
[ebuild  N     ] media-libs/libdvdread-7.1.1:0/8::gentoo  USE="css -static-libs" 101 KiB
[ebuild  N     ] media-video/dvdbackup-0.4.2-r2::gentoo  USE="nls" 175 KiB

Total: 3 packages (3 new), Size of downloads: 654 KiB