full ram after processing a few video

[haniehakhavan]

out, _ = (ffmpeg.input(video_path)
          .filter('select', f'gte(scene, {threshold})')
          .output('pipe:', format='rawvideo', pix_fmt='rgb24')
          .run(capture_stdout=True))

i tried to run this piece of code for a few videos, but after processing each video part of the ram is filled and not emptied after finishing, therefore after a few video the ram is fully filled. i need to free up the ram after each video process. i also added .overwrite_output() to my code, the ram emptied after processing each video but at next process, comparing to previous video, more ram is filled so technically it did nothing.