8.1till2023andthenLinux

Това е по-лесното ръководство, защото не се налага създаване на нови стойности и съответно е по-малко вероятно да се сгреши нещо - https://www.reddit.com/r/firefox/comments/33ewyx/webm_vp9_support_in_firefox/. If you want to try it out, you can enable "MSE & WebM VP9" on the "about:config"-page (Just type it in the titlebar / adressbar without the ""). Search for "webm" and it should come up with 4 results - double click on "media.mediasource.webm.enabled" to change it from "false" to "true". Now check the the Youtube HTML5 Page again - everything should be enabled now and therefore every feature should work on Youtube - well, I only can say that it works for me till now without any problems or bugs :-)