Because Roon OS (the operating system behind
Roon Optimized Core Kit) is optimized to do nothing but run Roon in the most efficient manner possible, it doesn't contain the general-purpose packages that come along with a large server or desktop Linux OS install.
If you visit the
web UI of Roon OS, it may tell you that you are missing codecs (with a link to this page.) To rectify this situation, you will need to make the codecs accessible to Roon OS. This is done by placing the `ffmpeg` file in the `Codecs` folder of Roon OS's shared `data` directory.