mencoder ignore bitrate (1000 fps file)

Today I found my mencoder ignore bitrate option when I try to recode some file. After research I want to save here two links - http://lists.mplayerhq.hu/pipermail/mencoder-users/2006-April/003102.html and http://www.mplayerhq.hu/DOCS/HTML-single/en/MPlayer.html#id2910636 which show me to obligatory using "-ofps" option in case we have variable framerate in source file and fixed one in destination.