Keying background of a moving scene? HEEELLLPPPPP :)

[saltyd]

I've been going nuts trying to figure this out. Truly appreciate any help the community can provide :)

Screenshot of example below...

The Goal:
- Remove the background from a camera source - in order to replace it with a scene/source that is under the camera.
- The camera source is showing a moving scene (a wrestling event, with a ring and wrestlers and people in the foreground, and the inside of the building location is the background)

The Issues:
- Regular background removal plugins won't work, as there is lots of constant movement.
- Lots of movement between the crowd and the wrestlers in the ring. Using an image mask for specific areas to show won't work.
- Colors will vary (wrestler/crowd attire), so color keying isn't a solution.
= using an image with transparent/black parts (with alpha filters) doesn't work for keying out, as the background isn't "fixed" (ie, people will be moving and going into the areas of the background that would be keyed out completely)

What I've Tried:
- A screenshot of the building before the people/wrestlers are in the camera scene. Using this as an image mask, with subtraction filtering. Then a color key filter to remove black (which removes the matching parts between the screenshot and camera source, leaving the difference of the people). This does work sorta, but the people come out transluscent and fade into the background I put beneath the camera source.
- A billion different combinations of filtering/keying/blending modes - with the screenshot idea and camera source.

Anyone have recommendations on how to accomplish this?

The camera source:

Example Of Subtraction Image Mask & Camera Source Translucent:

 

[koala]

No chance.

You are certainly able to remove the stuff outside the ring, at the bottom and to the right and left, as well as the ceiling simply with a mask. But the area that shows through the ropes is impossible to clean. I don't see any way for any app to distinguish between the people in the ring and the people behind/around it. Both show through the ropes, both have arbitrary colors.

I saw setups similar to this in movie filming sets. In that case everything was carefully colored, green screens everywhere, actors also dressed in proper colors, so postprocessing is able to pick up and remove every required part of the scene with color/chroma keying.