A quick one, ffmpeg is enable by rpmfusion for license:
❯ LANG=C dnf info ffmpeg
Last metadata expiration check: 0:00:11 ago on Mon Jun 1 13:01:07 2020.
Name : ffmpeg
Version : 4.2.3
Release : 2.fc32
Architecture : x86_64
Size : 1.9 M
Source : ffmpeg-4.2.3-2.fc32.src.rpm
Repository : @System
From repo : rpmfusion-free-updates
Summary : Digital VCR and streaming server
URL : http://ffmpeg.org/
License : GPLv2+
Description : FFmpeg is a complete and free Internet live audio and video
: broadcasting solution for Linux/Unix. It also includes a digital
: VCR. It can encode in real time in many formats including MPEG1
: audio and video, MPEG4, h263, ac3, asf, avi, real, mjpeg, and
As you see, you don’t have rpmfusion-free repository.
So, as said by @hhlp you should enable it.
As you can read in the document linked by @hhlp, this is the command to install the rpmfusion-free repository: sudo dnf install https://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-$(rpm -E %fedora).noarch.rpm