Ripping DVDs to Divx with mencoder (mplayer)

Direct Ripping

1. Play the DVD, calculate how long it last (including credits) in seconds, check if the volume is too low (because we can turn it up with software). Also, if the image looks strechted, maybe mplayer doesn't realize it's in 16:9 format, so we have to explicitly indicate it (with -aspect 16:9), and the image will be all right (this happened to me with "Crouching Tiger Hidden Dragon"). And don't forget to check in which "title id" does the movie start, usually movies start in id 1, but sometimes there are trailers and such so it starts in a different title id (i.e. Crouching Tiger.. started in number 10) (mplayer -dvd 10).
2. Calculate the rate to get the desired file size. Knowing how many seconds it lasts, you can use my script dvd-ripping (it's at the end) to get the rate. For example, if you want a file size below 700Mb, you have to calculate the best rate you can use to get a file under that size. "Rate" is the movie quality in kbits/s.
3. If the movie has black borders you can take them off. First, calculate the borders geometry whith option cropdetect:
   mencoder -aspect 16:9 -dvd 10 -ovc lavc -lavcopts vcodec=mpeg4:vhq:vbitrate=694 -vop cropdetect,scale -zoom -xy 640 -oac mp3lame -lameopts br=128:vol=9 -o tigreydragon.avi
   let it run for a while to make sure is ripping the real movie (and not just the credits) and you'll get the values you have to pass to crop option to take the black borders off (i.e. in Crouching Tiger.. I get crop=640:272:0:44). Keep in mind these values are relative to the output resolution.
4. Run mencoder with your parameters. Here are some parameters I used: vol=9 in -lameopts (this is because the volume was too low, so i gave it some gain. Valid values are between 1 and 10). -aspect 16:9 (this is because mplayer didn't realize this was the original format so i was getting a stretched image). vbitrate=694 in -lavcopts (video rate i got with my script dvd-ripping) -dvd 10 it's the title id where the movie starts (usually is number 1) crop=640:272:0:44 in -vop (to take the black borders off) So the full command is
   mencoder -aspect 16:9 -dvd 10 -ovc lavc -lavcopts vcodec=mpeg4:vhq:vbitrate=694 -vop crop=640:272:0:44,scale -zoom -xy 640 -oac mp3lame -lameopts br=128:vol=9 -o tigreydragon.avi
   This will rip the movie directly from the DVD to the Divx avi file in only one pass. Irecommend that at the same time you are ripping, play with mplayer the .avi in a different terminal to check you are getting the desired format (resolution, quality,volume...)

Three pass encoding

1. First the sound:
   mencoder -dvd 1 -ovc frameno -o frameno.avi -oac mp3lame -lameopts abr:br=128
2. First pass:
   mencoder -dvd 1 -nosound -oac copy -o /dev/null -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=800:vhq:vpass=1:vqmin=1:vqmax=31 -vop scale -zoom -xy 640 -npp lb
3. Second pass:
   mencoder -dvd 1 -oac copy -o file.avi -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=800:vhq:vpass=2:vqmin=1:vqmax=31 -vop scale -zoom -xy 640 -npp lb

Script dvd-ripping

#!/bin/bash

if [ $# != 1 ]; then
  echo "Use: dvd-ripping <movie size in seconds>"
  echo ""
  exit 1
fi

# Biggest file size is 700mb, which is
# 716800kbytes but just in case we use a little smaller size

MAXSIZE=700000
SEGUNDOS=$1
MINUTOS=$(($SEGUNDOS/60))

#Audio rate is 128bits/s which is 16kbytes/s
AUDIOSIZE=$((16*$SEGUNDOS))
LIBRE=$(($MAXSIZE - $AUDIOSIZE))
RATE=$((($LIBRE*8) / $SEGUNDOS))

echo "Calculating rate for movie which lasts $MINUTOS minutes..."
echo "Estimated rate: $RATE"
FINALSIZE=$(( ($RATE * $SEGUNDOS)/8 + $AUDIOSIZE))
echo "Estimated size: $FINALSIZE"
echo "The command is:"
echo "mencoder -dvd 1 -ovc lavc -lavcopts vcodec=mpeg4:vhq:vbitrate=$RATE \
 -vop scale -zoom -xy 640 -oac mp3lame -lameopts br=128 -o file.avi"