You are welcome. These are the extremes. The reality is usually somewhere in between. And always messy. Some of our resident legal eagles can chime in but I am unaware of a definite answer on whether a sign prominently displayed on or adjacent an entrance constitutes proper notification/consent. Some businesses have warnings about video and/or audio recording on the premises but I don't know how much water that holds in md courts, especially wrt to audio.Thanks for the important clarification.
I can say that a sign on your property that you are taping won't hold up well. A friend wanted to use the audio from his cameras (indoor) in a civil action and was not allowed. Some video was, but limited.