You don’t need to understand much of ffmpeg to build a media centre. Your requirements here are extremely simplified and there are hundreds of guides online on how to use it for very simple transcoding.
replyBut if you don’t want to use ffmpeg directly then use one of the many ffmpeg wrappers. Or a different lib entirely like gstreamer or VLC.
Around 15 years ago I built a media centre for my car and the media playback part turned out to be the easiest part of the project.
Do you still maintain it?
replyNo. It was built before Android / Apple integrations existed and was built around tactile controls and voice interactions. But I think Apple Car play is a far far more useful product these days than anything I built 15 years ago. Even if their touch controls are an ergonomic step backwards.
replyi had media center powered by a few perl script that would transcode all videos into formats that ps3 supported in 2007-ish. Yes ffmpeg had a lot of options, 99% of them does not matter, there really only 3 ways to stream to client: as is, repack streams into something client support (i.e. your source is mkv) or transcode into something client support (clients know which formats they support).
replyPeople that run these services don't want "dynamic stream quality selection".