nice -n 19 mencoder -ss 00:03:00 -endpos 70 -vf scale=352:288 <source_file> ofps 23.976 -oac mp3lame -lameopts abr:br=92 -ovc xvid -xvidencopts pass=2:bitrate=100 -o <dest_file>
where
nice is to increase process priority
-ss start time
-endpos stop after 70 seconds
-vf scale to resize original to quarter PAL
bitrate for web from 100 to 150 is ok
