How to add chapters for a single "All-in-One"-mp3 File

[Gru0810]

Sometimes I download mp3-Files from archive.org or convert it from youtube.
I always got one file. But sometimes I find informations about the Track like this:

How can/must I transform these information to add them to the OPF-File I use to define the Book?

[nichwall]

I'm not finding a standard on how chapters should be added to an OPF file for audiobooks.
https://idpf.org/epub/20/spec/OPF_2.0_final_spec.html

You can embed the metadata into the audio file, edit the chapter info using ABS, or edit metadata.json directly. If you're not embedding metadata, you will need to have some sort of converter script for other tools that might need the chapter information though.

[Gru0810]

I was able to add the chapter by using the builtIn-functionality. Works fine! Thanks!