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-libs/libdvdnav-6.1.1::gentoo  USE="-static-libs" 359 KiB

Total: 3 packages (3 new), Size of downloads: 839 KiB