Otherwise, start with opening some pdf or djvu file in Emacs (pdf-tools and djvu package recommended). Find the pagenumbers for the TOC. Then type M-x toc-extract-pages, or M-x toc-extract-pages-ocr ...

Interactively open a PDF file, optionally at a specific TOC entry. options: -h, --help show this help message and exit -f, --full-path show full paths of the pdf files during selection -nt, --no-toc ...