(cvlab:with-named-windows (main)
  (cvlab:with-open-video (nil "/media/1984/TV/Futurama Season 1-7 S01-S07-Movies DVDRip-1080p BluRay x264-MiXED/Futurama Season 6 S06 1080p BluRay x264-CtrlHD/Futurama.S06E03.1080p.BluRay.DTS.x264-CtrlHD.mkv")
    (loop for frame-number upfrom 0
          for frame = (cvlab:read-frame)
          while frame
          do (cvlab:circle frame (list (max 0
                                            (- (cvlab:cols frame)
                                               (mod frame-number
                                                    (cvlab:cols frame))))
                                       (- (cvlab:rows frame) 200))
                           50 '(0 255 0))
             (cvlab:imshow 'main frame)
             (when (eql #\Esc (cvlab:wait-key 33))
               (return)))))