@applee @domubpkm : thank you very much for sharing your experience. This uVideo seems to be new to me, I don't remember there was another movie player than UTmedia and the original Media player, I have to test it !
There is also some issues I meet currently (mainly Nextcloud CalDAV), I think I may post a new thread if I don't succeed to solve the issue.
EDIT : I confirm that my videos taken from my camera can be played on uVideo, this app handles .mp4, .webm, and .ogv extensions so that's cool ! I don't know if this app handles subtitles, but with this and support of .mkv, then, it would be a perfect app.