I've just installed OBS software and started experimenting with it. First thing I did was changing output resolution in the settings to 640x400. But I was surprised that the output mp4 file was the same size as in the case of the previous resolution setting (something like 1040x640?, anyway, higher than 640x400). How is it possible at all? Also, the amount of storage the files were taking is roughly 20MB per minute of video, which is a little bit high. Is there an answer to this?