For presenting videos, you will need a still image (for the inventory and the catalogue) in 2D, inserted in the 1st tab, and the actual video file as MP4 or mov in the 4th tab, MEDIA.
Like for audio files, you can adjust the default radius.
Make sure to compress the video files to an optimum and try not to exceed 50 MB in total data size for all your media files in one exhibition to keep loading times pleasant for your viewers.