vDesktop

[appsuser]

This software is obviously not portable even though the author says it is, as it's not saving settings in the program directory. However, it could probably easily be made portable with a wrapper.

vDesktop - VDesktop is a powerful desktop solution that allows users to have animated wallpaper on their Windows desktop. VDesktop supports Windows 7, 8, 10.



Key Features:

• - Very low CPU and memory usage: It is designed for continuous use without slowing down your computer.
  - No Battery and Performance Impact: Using Intelligent algorithm focused on saving battery and no performance impact, identify and stop playing the video when one or more windows cover a large part of the screen ( include game) or when not interacting with the computer in a certain time period.
  - Automatically hide desktop icons and Taskbar when viewing video on the desktop (when not interacting with the computer in 5 seconds)
  - Video slideshow
  - and more …

http://vdesktop.byethost11.com

Tip: Works well with League of Legends login screens. Just put the mp4 version in the program folder.

[webfork]

I liked how they included a direct Virustotal report right on the page.

Unfortunately, Softpedia is listing that this isn't freeware:
http://www.softpedia.com/get/Desktop-En ... KTOP.shtml