Can Firefox meanwhile play video via hardware acceleration on Linux or does it still use the CPU?

Not sure if this is related but my firefox/linux experience with video is also bad:

  - tearing all the time (https://en.wikipedia.org/wiki/Screen_tearing)
  - Netflix doesn't support HD on linux
  - Amazon doesn't support HD on linux (for movies. But shows seem to be 1080p)

True that they don't support it, not true that it doesn't work, thanks to the wonderful people who take the time to fix other people's bugs. https://github.com/vladikoff/netflix-1080p-firefox