Ive done that before
take the frame you want and export it as a jpeg.
open it in photoshop and duplicate the layer so you have two pictures on top of each other. on the top layer, erase everything but your subject. disable that layer so you can see the bottom layer.
use the clone tool to fill the subject, it doesnt have to be perfect, just around the edges (if your subject has no indents, such as a square or circle, you can leave the bottom layer the same).
import the psd into after effects as a composition with cropped layers. open that comp and copy the layers back to the original comp. you can now scale and move the top layer to get this effect