Detelecined this OP which has a different pattern every scenes for clean-frames, clean-frames, clean-frames, combed-frames, combed-frames, adjusting levels, converting SD matrix -> HD matrix, shifting chroma, deblocking, denoising, deringing, motion interpolation by QTGMC to display a smoother video, upscaling 480p -> 576p by nnedi3_rpow2, debanding and regraining. it was a good training to deal with SD content, but yeah, it's annoying.