jellyfin-plugin-bookshelf VS comicinfo

In case any value of the opf file is not parsed, you could create an issue about it here: https://github.com/jellyfin/jellyfin-plugin-bookshelf

You may want to create an issue about the title sort being ignored here. Thought I can't find anything related to a sort title in the specification. Is it perhaps something Calibre or some other tagging software added? Do you know how it looks like?

I haven't tried it out yet, but apparently Jellyfin has a book plugin that does books, comics, and audiobooks: https://github.com/jellyfin/jellyfin-plugin-bookshelf

E.g. metadata for books is handled in the bookshelf plugin (C#). You could look at already existing implementations (e.g. ComicBookInfo or the Epub provider for some easy things) and then implement your own. There are some open issues about missing book providers, but I would start with a file based provider first as look easier than online metadata providers.

This is a good start for comic info xml. If you want DM me and I can share my half finished comic metdata library I was working on in C#. The biggest hassle around it honestly is metdata storage. ComicRack could put an xml inside the zip, but since CBR is such a popular format and you're not allowed to make rar files without licensing fees (you are alllowed to read though) it was common to have a large singular xml file with metadata for each file comicrack tracked. If you're dealing with a large comic library parsing this could get quite expensive.

https://github.com/anansi-project/comicinfo this has some info, but ComicRack doesn’t support all the tags. But it should give you an idea of how the xml file looks.