Hosting HTML5 video on Youtube/Vimeo, without using player

Vimeo has the option to give you a link if you have a paid account. You can generate a privaté download link to do this for multiple resolutions if needed.

An other option would be to just embed there player and add the "?background=1" in the embed link as explained here:

https://vimeo.zendesk.com/hc/en-us/articles/115011183028-Embedding-background-and-chromeless-videos