Outside of GIF, other file formats, like MP4, AVI, WMV are not repeatable on it’s own accord.
Actual dedicated video players, like VLC as @D_S had stated, will loop your video. VLC is a very powerful resource. You can create playlists, and can loop several videos together.
You can also loop them inside of Chrome & Firefox. Just drag/drop file into a browser window.
In Google Chrome
In Mozilla Firefox
Not sure about IE, or Edge, Opera, or Safari.