live transcoding (MKV 480p -> MP4

Both MKV and MP4 are just container formats. The container contains an video stream and some audio and subtitle streams which are each encoded using a specific codec.

Converting from one container format to the other is very cheap, it’s the conversion between video codecs that requires a lot of resources. So converting from MKV to MP4 is pretty cheap if you keep the video stream as is.

Personally, I have never bothered with live transcoding. My videos are all encoded as H.262 or H.264 and stored in either an MKV or MP4 container. Direct Play works just fine. Without live transcoding, a >10 years old Intel Celeron is more than enough to run a jellyfin server.

It is also available for aarch64