>>290133707
VRchat devs are retarded. 
Basically how it works is it uses youtube-dl to process the link and then feeds the video data to a built-in windows video playing API. Which for 7 is bad and 10 is slightly less bad. 

The way I do movies is hardcoded subs, h264, mp4s. Host them online somewhere, like dropbox, and get a direct link.