Have been looking to host videos ourselves, not depend also on AWS lambda video processing libs. Probably in combination with using a better video player in the LMS (like GitHub - appsembler/xblock-video: Universal Video XBlock with pluggable backend for many video hosting).
Something likes GitHub - openfun/marsha: A self-hosted opensource LTI video provider looks interesting, but this code sadly depends on AWS also, when I have time (now very busy with delivering a big project) I will be looking into hacking in there some ffmpeg or gstreamer scripts for generating a HSL / Dash encoding ladder (Apple Developer Documentation) and chunking, probably also see if we can put some form of protection (DRM and / or watermarking/branding on delivery of the videos).
Other links among many I found interesting: