For those interested: ffmpeg-compat package for Fedora is still alive.
The package is a very old version of ffmpeg whose most recent release is 4.0.2 (as of September 2018). It was maintained by RPM Fusion but it has been retired since the release for Fedora 27 (the last supported Fedora version was 26). If you need this binary for Fedora 28, for example because you use old applications which need it, you can download it from our Downloads section. The .spec file (the source used to build the RPM package) can be downloaded from the GitHub repository.
Oh, by the way, this means that now we have our Downloads section.