Hardware:
Ryzen 3900x
Geforce 2060 RTX
32GB ram
Video output - no option for Nvidia x264?
It is available in the windows version, how do I install?
M.
Did you compile yourself?
To enable NVENC-based hardware accelerated H.264 and HEVC encoders in Avidemux, you need to clone, build and install https://github.com/FFmpeg/nv-codec-headers prior to compiling Avidemux. In order to use it, you need also very current NVIDIA graphics drivers (435.21, provided for Ubuntu 18.04.x LTS as package nvidia-driver-435, or newer).
I tried several methods of compiling AVIDemux 2.7.x and 2.6.x in Linux Mint 19.3, the last one totally borked my system and I had to restore from backups.
Is there a step-by-step somewhere?
M.
Sure: https://avidemux.org/smif/index.php/topic,18371.0.html
Please mind the additional steps mentioned in https://avidemux.org/smif/index.php/topic,18371.msg87089.html#msg87089
Currently, work-in-progress changes related to handling of field encoded video streams might impose some restrictions on the experience with Avidemux, which is also the reason for the absence of fresh nightly builds, but apart from that the git master is in a workable state.
If you are the sole user on the PC and you don't need the Jobs GUI, you could also do without actually installing Avidemux by running createRpmFromSourceFedora.bash with the option --no-install
https://github.com/mean00/avidemux2/blob/master/run_avidemux_template.sh
The above script executes avidemux3_qt5 in portable mode and sets required env variables accordingly.