Can FFmpeg work inside a toolbox?

I have installed the rpmfusion-free and rpmfusion-nonfree repositories via rpm-ostree.
(can these repositories be installed in a toolbox, or is that system only kind of stuff?)

I installed FFmpeg at the system level as a layered package. I can use FFmpeg from the CoreOS prompt, but not while inside the toolbox, it cannot use it. Even dnf cannot find it.

How do I get FFmpeg running in a toolbox? I need it in my workflow.

I think you need to install ffmpeg inside the toolbox. I think you need to add the rpmfusion repos inside toolbox first. Then use dnf to install ffmpeg.