Hello.
I have a question about privacy.
Does MKVToolNix put any private information in created .mkv files?
For example: user name, computer name, media file paths before muxing, any dates?
I mean something like LibreOffice puts some information in created files if you don’t change it in settings.
Welcome!
For example: user name, computer name, media file paths before muxing
None of those.
any dates?
Yes, by default it includes a single header field that contains the timestamp when muxing was done. Additionally there are several unique IDs for tracks & attachments that are chosen randomly at the start of the muxing process. Lastly there are two header fields containing the name & version numbers of MKVToolNix & the two libraries used for writing Matroska files, libMatroska & libEBML.
What can those pieces of data be used for? They can certainly be used to say that two copies of a file where those fields match most likely come from the same source. However, to the best of my knowledge none of those can be used to tie a file to a certain device or certain person as the place where a file was created or the person who did it.
The FAQ entry about creating byte-identical files is very relevant to your questions & explains further.
Thank you very much for your answer.