A production house that was supposed to key out an actor instead provided the actor over grey. They also provided a separate matte layer (video), which looks like a perfect key.
How do I apply that matte to the video so that it keys out the actor?
I tried keying out the gray, and did a pretty good job, but there's artifacts like underneath the arm cracks that I have no clue how to remedy despite extensive online research. So I figure that matte video they provided must have purpose. If I can apply that and call it a day, it'd be great.