PDFmarks is a technique that accompanies PDF and that is used to
store metadata such as author or title, but also structural information
such as bookmarks or hyperlinks.

When Ghostscript reads the main PDF generated by the TEX system
with embedded PDF files and outputs the final PDF, the PDF page
mode and name targets etc. are not preserved. Therefore, when you
open the final PDF, it is not displayed correctly. Also, remote PDF
links do not work correctly.

This program is able to extract the page mode and named targets as
PDFmark from PDF. In this way, you can obtain embedded PDF files
that have kept this information.