Hi, which are the snaps doing playback of videos for raspberry on ubuntu core 18?
snap info omxplayer-pi
make sure to read the instructions in the description, make the required changes to your installation (config.txt) and reboot …
then:
snap install omxplayer-pi
and you should be set (note that there is a newer version in the edge channel that is also compiled with NEON support and the proper floating point unit for even better results, i didnt get around to fully test it yet to let it out of the edge channel).