[MPlayer-users] Efficiently cutting black border above and adding below

[Thomas Heuving]

Hello,
I have a MGEG2-Video which I want to burn on DVD. The format is
correct, but there are subtitles below the picture (in a black
border) which aren't shown entirely on a TV screen. Therefore I want
to cut a part of the black border above the picture and to add the same
amount of black border below.
I can do that with 

mencoder -oac lavc -ovc lavc -of mpeg -mpegopts format=dvd -ofps \
30000/1001 -vf crop=720:456:0:24,expand=720:480:0:0,harddup -lavcopts \
acodec=ac3:abitrate=128:dc=10:vcodec=mpeg2video:vrc_buf_size=1835:\
vrc_maxrate=9000:vbitrate=2600:keyint=15:trell:mbd=2:aspect=4/3 \
-af-adv force=1 -srate 48000 -af lavcresample=48000,volnorm -o \
"$newfile" "$file"

but this will recode the whole file. Is there any way to do it more
efficiently?
-- 
Thomas Heuving