Thanks for the suggestions! I have already used MusicBrainz Picard to identify most of the media in my library. It is just the somewhat subjective mood and style tags that didnt get populated from Picard.

I may give Beets a go and see how far I get. If it isn’t what I’m after, it sounds like kde kid3 will probably get the job done.

I believe that jellyfin has been transcoding using jellyfin-ffmpeg. I do have logs labelled “FFmpeg.Transcode-…” which seem to look fine. I have just turned on hardware acceleration though. Is that what you meant by “hardware transcoding”?

Ill check to see if the buffering is improved and will let you know how it goes! Thanks for the advice!