Implement support for ID3v2 chapter frames

[Okxa]

What's missing?

As far as I know, currently puddletag does not support editing id3v2 chapter frames.

This document describes a method for signalling chapters and a table of contents within an audio file using two new ID3v2 frames. The frames allow listeners to navigate to specific locations in an audio file and can provide descriptive information, URLs and images related to each chapter.
https://id3.org/id3v2-chapters-1.0

Your solution

Create UI for editing chapters, mutagen seems to have support for these frames.

mutagen docs has an example on how to add chapter info

As far as for UI, I am not sure what info a chapter can contain (atleast text and timestamps), but it should be some sort of list.

Any alternatives?

This is in the id3v2 spec and already supported by good number of players. (for examle mpv shows them currently and vlc should in the 4.0 version)

Anything else?

Some other formats support chapters too (like m4a & ogg) and AFAIK there is no support in puddletag for those either? In that case the UI probably should be designed to be used with those too.