It would take all people who own copyrights of code in VLC. That would include the VLC authors, but might also include authors of other GPL code that the VLC authors used.

If a GPL project hasn't planned from the start to allow for the possibility of granting license exemptions, it is fairly easy to let outside GPL code get into the project without its authorship being carefully tracked and documented.

Yes. That might be quite a lot of people though.