The first script calculates the motion vectors of the frames of a video and demonstrates them by displayng white arrows on the frames for each moving object.
The second script assumes that the first frame of the video is the background, and then calculates the motion vectors of the rest of the frames and demonstrates them by hiding the moving objects (replacing the moving object's block with the corresponing background block).
Run the Python scripts in the same folder as the "video-sample.mp4".