The Types menu allows admins to control the type of user-uploaded media across the website.
Types menu in settings

Media Types Settings

The Allow Upload setting toggles uploads of photos, videos and audio clips. rtMedia supports the following media extensions:
Photo- jpg, jpeg, png, gif
Video- mp4
Music- mp3
The Set Featured toggles allow authors & contributors to set specific media highlights for their posts. This setting will only take effect in themes that support “Featured media” for posts.