All video options
Slide background PRO
Turn on the Expert mode to see all options.
Slider background PRO
You can only use self-hosted videos in the given file format: MP4
Turn on the Expert mode to see this option.
You can also add a local video as the background of your whole slider at the Simple slider type's or Block slider type's settings. This way you could have a video playing in the background, while your slides containing only layers could slide over it.