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

Calculating dependencies ... done!
Dependency resolution took 0.96 s (backtrack: 0/20).

[ebuild  N     ] media-libs/dav1d-1.4.2:0/7::gentoo  USE="8bit 10bit asm -test -xxhash" 948 KiB

Total: 1 package (1 new), Size of downloads: 948 KiB