I'm live streaming council meetings, and would like to add text on video stream. It has to be "on the fly", no restarting VLC and thus stopping stream. I ve been looking at marq but as I understand text has to be defined when starting vlc (is that correct?). I want to do that during streaming many times (every time speaker on stand changes).
Is it trivial and I'm missing something? Can anybody point me in the right direction with at least a few keywords

Thanks in advance!