If I’m reading it right, occasionally something in the video, moves over the logo and you don’t want that obscured by your still image. Yes, use rotobrush.
Take your video layer, duplicate and place it at the top of the layer stack. Now roto the things that move over the logo, that were obscured by the still image. It may be easier to make multiple duplicates of your video layer for each instance you need to roto.
Johnny Cuevas, Editor
Thinkck.com
“I have not failed 700 times. I have succeeded in proving that those 700 ways will not work. When I have eliminated the ways that will not work, I will find the way that will work.”
—THOMAS EDISON on inventing the light bulb.