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

Calculating dependencies ... done!
Dependency resolution took 0.97 s (backtrack: 0/20).

[ebuild  N     ] media-libs/x264-0.0.20240513-r1:0/164::gentoo  USE="interlaced -opencl -static-libs" 822 KiB
[ebuild  N     ] media-video/x264-encoder-0.0.20240513-r1::gentoo  USE="interlaced -avs -custom-cflags -ffmpeg -ffmpegsource -mp4" 0 KiB

Total: 2 packages (2 new), Size of downloads: 822 KiB