How to insert an autoplay video into wordpress site in this manner

[ Moderator note: moved to Fixing WordPress. ]

Hi there! Does anyone know how to insert a video in a manner done in websites such as https://www.leadpages.net?

Btw I am referring to the autoplayed video on the left, above the fold of the site where there is no play button. It just looks like a gif that keeps repeating.

Any ideas on how this is done would be awesome! thanks

[ No bumping please. ]