A pretty massive amount I imagine. I attended a lecture on single image steganography and they were able to store almost 25% of the image's size and it was bare

A pretty massive amount I imagine. I attended a lecture on single image steganography and they were able to store almost 25% of the image's size and it was barely visible. Even 50% didn't look too bad. Extending that into video files and it would likely be pretty massive, although you'd have some interesting time with youtube's compression algorithms