This is an OpenWrt package feed containing video / graphics (as in 'higher than just curses') related libraries and applications which are not considered to be so called "core" packages.
To use these packages, add the following line to the feeds.conf in the OpenWrt buildroot:
src-git video https://github.com/openwrt/video.git
This feed should be included and enabled by default in the OpenWrt buildroot. To install all its package definitions, run:
./scripts/feeds update video
./scripts/feeds install -a -p video
The video packages should now appear in menuconfig in section 'Video'.