I'd like to know if there is a method/application to further compress MP4 files without loss as compressed files (zip-like) for archival purposes, even if I had to make a bigger file before recompressing.
I don't need to play the videos immediately, it's to have a medium to long term backup, so the zipping/unzipping process wouldn't be an issue for me.
Thanks.
No. The last step in video compression is a lossless entropy encoder similar to zip. What you are asking to do has already been done to the file.