Ubuntu Linux Mint Debian Redhat Youtube Cannot Play HD or 4K videos, dropped frames or high CPU usage with Nvidia or AMD Driver

In a lot of distros, vdpau which accelerates video through the GPU is often not installed even in recent distros. This will result in Firefox with Youtube dropping frames when you check the "Stats for Nerds" and to the eye as jerky or slower video playback due to the dropped frames.

Some sites will say that because you are watching VP09 that there is no GPU support, but with vdpau installed and enabled, many GPUs will still be able to use hardware decoding for 4K Youtube videos. Information on this is spotty but you can clearly see the GPU utilization going up when watching Youtube GPUs, so the GPU is doing something to decode the video.

This will make you think that your GPU is not capable of playing even 1080P sometimes or 4K even though it is, as in many cases it is your CPU doing the video decoding and a lot of times some CPUs cannot reliably or consistently support 4K decoding in Youtube.

The easiest solution is to install vdpau and restart your browser:

sudo apt install vdpau-driver-all

I was surprised that this helped even on even much older cards including older Nvidia GPUs.

After doing the above and restarting Firefox, the stats for nerds showed 0 dropped frames when watching 4K, compared to some dropped frames at 1080P and many dropped at 4K before enabling vdpau.

One caveat that it may be that your video card is still too slow and may not be able to support decoding Youtube in fullscreen at certain resolutions. You may see the above but then on a weaker GPU, may find that it does drop frames when running fullscreen.

Sometimes frames will only drop when having the Stats for nerds on top, or the progress bar open.

In general VP09 full support and decoding is not guaranteed to work well or at all, and unfortunately Youtube has not stuck to normal standards that most GPUs support like H265 or H264, XVID, DIVX etc...