How to dynamically add texture to an object in a video and get a new video?
If I understand you correctly, this is traditionally done by compositing programs such as Adobe After Effects.  You could track the wall and then replace the wall with an image but it's going to be a lot trickier if anything is moving in front of the wall.  (You would need to make a rotoscope mask to tell it where not to render the image.)  You could then simply change out the image that is being applied to the wall.