Some Youtube video's for me where draging my CPU and memory and videos kept on stoping starting and realy annoying so I searched for something to help and got this and it works great and I have had no more videos dragging resources. Thank you

по крайней мере, аппаратное ускорение работает.

Tekee sen mitä lupaa

avc1 (h.264) codec been acting laggy for me for some reason, after disabling it everything's back to normal:)

Tested on 08 May 2022, doesn't change youtube codec - I disabled avc but youtube doesn't care.

Using this addon to disable h264 was the only way I could get certain YT videos to play on OpenSUSE for some reason.

VP9 on youtube is causing it to drop frames especially on livestreams, disabling it results in avc1 being used and solved my problems for now.

wow, great addon

Thanks !
Solve a big problem with Waterfox classic + Youtube 360° and Nivida driver:
Youtube video seems to crash Waterfox content proces [Github].
Solution:
Install "enhanced-h264ify":
https://addons.mozilla.org/en-US/firefox/addon/enhanced-h264ify/
Open about:config:
1 - Set media.windows-media-foundation.allow-d3d11-dxva:false
2 - reset media.hardware-video-decoding.failed to false

I found HUGE (5000->500 kbp/s) download speed drop after using this. Useless. Deleted.