>>6938853>Short GNU/Linux Guide
You can use mpv or gifview from the gifsicle package to draw to the root window (the screen sized desktop space underneath everything else where the wallpaper is drawn).
You also need a compositor like compton (if you use a DE you probably have one running already) and xwinwrap to make it work with the compositor (see this thread for more details https://github.com/chjj/compton/issues/226
You can download the xwinwrap source code here https://launchpad.net/xwinwrap
- a PKGBUILD in the AUR: https://aur.archlinux.org/packages/shantz-xwinwrap-bzr
- a deb package in some PPA repo: https://launchpad.net/~madnessmike-deactivatedaccount/+archive/ubuntu/madnessmike/+build/2457574
- and an rpm package: https://fedora.pkgs.org/25/rpm-sphere/xwinwrap-0.3-2.2.x86_64.rpm.html
mpv command:> xwinwrap -ov -fs -- mpv -wid WID --loop=inf --no-osc --no-terminal /path/to/video
gifview command:> xwinwrap -ov -fs -- gifview -w WID -a /path/to/gif
Put the command in a startup script (.xinitrc if you're using startx to enter a graphical session) and end it with an '&' sign (to put the process in the background).
Although you can use mpv to play GIFs, it might be better performance-wise to use gifview instead, but that might require editing the gif to fit your screen nicely.
Wayland users get fucked.