The Video Acceleration API, developed by Intel, has been enjoying widespread support in a variety of software, including the latest versions of Mozilla Firefox. The VA-API is an API for hardware acceleration that allows a computer to offload video decoding and encoding tasks to a system's video card, a task that historically has taken place in the CPU.
This is a companion discussion topic for the original entry at https://linuxconfig.org/firefox-with-va-api-on-linux