From GNOME Bugzilla :
There should be a video meta MIME type which subclasses all video MIME
types (application/x-video or such). I don't think there yet exists such a parent
No, this is just wrong.
First, if we added such a thing for video, then we would need to add it for
images, audio files, word processor documents, game files formats, etc.
Furthermore, there's already the video/* supertype, as well as image/*, audio/*,
etc. So mime-types could (and should) be registered in video/* if they are of
the video type.