In the
File Attachments and/or
Filebank add-ons there is possible to set up/allow any file type for uploading; this also includes video file types.
But you must make sure your hosting plan/server allows to upload big size files. Some video files could be truly big. For big files, another uploading solution should be used. Those add-ons are only for basic to medium hosting plans.
If you'd like to upload and
embed videos on your thread page, it very depends on the 3rd party player you'd like to use. Each software like
JW Player provides its own set of embedding codes, which would allow a video file to appear straight on the forum's thread page. These codes could be tied up with a BB code, which could be used to embed videos straight, and so they could use a File Reference from the File Bank.
All this is very specific. I suppose, I could think about writing a quick article or topic on how to upload and embed short videos (for example like those 1-minute shots from a smartphone) using a certain online HTML5 player, and refer BB codes from the File Bank for it...
But if we speak about something more advanced, if your videos are legal, nowadays Youtube or Vimeo are better places to keep and share your videos. They are not limited in space and they have proved tools to upload, edit and promote files. If you mean we could try to code a premium add-on similar to Youtube functions, it would mean re-inventing the bycicle. And so, for Youtube or Vimeo, miniBB already has free add-ons, which allow mostly all kinds of embedding approaches.