In the old days, the codec pack for movie playback was badly behaved, and on the contrary there was something like going to be stupid because the movie that was playable until now can not be played ...
OpenH264 is a codec library which supports H.264 encoding and decoding. It is suitable for use in real time applications such as WebRTC. See http://www.openh264.org ...
I installed Linux Mint MATE 20 64-bit in VirtualBox, without any Ethernet interface. Then, after the installation and the first reboot, Linux Mint proposed me to install the French Language packages ...