Why is the input black and the video is not displayed?

Question

ubuntu

Hello, I ran into 2 problems at once. Recently moved to Ubuntu and Firefox

1. Some inputs turn black
   
2. Some videos are not displayed (on YouTube the same garbage. Writes that there is a problem with h.264)
   

What can be done about it?

Answer 1

The problem is either with Youtube, although this is unlikely, or with your browser, try reinstalling your browser, if it does not help, then download a new one.