mencoder -of mpeg -mpegopts format=dvd -ovc lavc -oac lavc -lavcopts vcodec=mpeg2video:vrc_buf_size=1835:keyint=18:vrc_maxrate=9800:vbitrate=4900:aspect=4/3:acodec=ac3:abitrate=192 origen.avi -o parte_3.mpg

  mencoder -of mpeg -mpegopts format=dvd -ovc lavc -oac lavc -lavcopts \
  vcodec=mpeg2video:vrc_buf_size=1835:keyint=18:vrc_maxrate=9800:vbitrate=4900:aspect=4/3:acodec=ac3:abitrate=192 \
  origen.dv -o destino.mpg