These VJ loops are free to use in any project in any way. The public domain (CC0) license even allows commercial use, as long as you don't sell the content itself. No credit is required, but is always appreciated.
Videos are available in 2 variants. The h264 encoded files have smaller file sizes and are limited to 2K resolution. The MJPG encoded ones are bigger files but allow you to make any derivatives you might need. If you're having any issues playing them back I recommend downloading VLC. All source files are meant to be used with Blender.