Подключить EPEL и RPM Fusion

# dnf install --nogpgcheck https://dl.fedoraproject.org/pub/epel/epel-release-latest-8.noarch.rpm
# dnf install --nogpgcheck https://mirrors.rpmfusion.org/free/el/rpmfusion-free-release-8.noarch.rpm https://mirrors.rpmfusion.org/nonfree/el/rpmfusion-nonfree-release-8.noarch.rpm

При ошибке

# dnf install ffmpeg                                                                                                                                                               628 kB/s | 115 kB     00:00    
Error: 
 Problem: conflicting requests
  - nothing provides libSDL2-2.0.so.0()(64bit) needed by ffmpeg-4.2.4-1.el8.x86_64
(try to add '--skip-broken' to skip uninstallable packages or '--nobest' to use not only best candidate packages)

сделать следующее

# dnf config-manager --set-enabled PowerTools

EOM