x265 - staxrip/staxrip GitHub Wiki
StaxRip uses x265 builds modified by DJATOM and Patman86, but generally also supports unmodified original x265 builds.
x265 Patman Mod
Website: https://github.com/Patman86/x265-Mod-by-Patman
Download: https://github.com/Patman86/x265-Mod-by-Patman/releases
x265 DJATOM Mod
Website: https://github.com/DJATOM/x265-aMod