Firefox: Cant open .mp4 - Couldn't open avcodec

[miabbott (Micah Abbott)]

Found an existing thread with this problem and I verified the workaround works with Fedora 40 Silverblue:

Unable to install ffmpeg-libs on Fedora 38 Silverblue beta

More for reference at this point: rpm-ostree override remove libavcodec-free libavfilter-free libavformat-free libavutil-free libpostproc-free libswresample-free libswscale-free --install ffmpeg