That's one of the "psychovisual enhancements" employed by modern codecs. Here [0] is a nice explanation I could among in top search results: "... x264’s psycho

That's one of the "psychovisual enhancements" employed by modern codecs. Here [0] is a nice explanation I could among in top search results: "... x264’s psychovisual enhancements do a pretty good job of keeping detail where you’d notice it (the face), at the expense of the stuff you normally wouldn’t notice while watching (like those background areas)." [0] https://mattgadient.com/comparing-x264-rf-settings-in-handbrake-examples/ https://mattgadient.com/comparing-x264-rf-settings-in-handbr...