I'm adding some deleted scenes back into a widescreen movie. The scenes have black bars but the video is actually fullscreen, so I used Tmpgenc to change the format to match movie. I simultaneously cropped top and bottom 60 pixels and changed aspect to 16/9. The picture looks good enough, but the motion isn't smooth (has that slight incremental look). I didn't change the other settings, except to match the bitrate (9500 in Constant Bitrate) to the original movie. What am I doing wrong?