Todd Zullinger writes:
Except that you can't at the moment. :)
That's what I was saying in my reply to Sam. The
compat-ffmpeg28 package is not in the rpmfusion-free
repositories for f28. This is most likely just a matter of
things needing to be synced from what was in the
rpmfusion-free-rawhide repo.
It seems that firefox 60 has been patched to support ffmpeg-4.0, so none of
that would be needed, soon.