With even free software that exists now that can hide data in live streams and recorded ones, I wonder if the audio or video are carriers for data? It could be text, compressed files, etc etc, or nothing, for that matter, too.

It's not really my area of expertise, but it looks like these are a couple of possible software packages to use?

http://embeddedsw.net/OpenPuff_Steganography_Home.html

https://sourceforge.net/projects/rtstegvideo/