use .avi extension

dvdrip.sh

@@ -13,4 +13,4 @@ read title
 mencoder dvd://"$title" -ovc lavc -af volnorm=1 \
     -alang en -oac mp3lame -lameopts cbr:preset=128 \
     -lavcopts threads=4:vbitrate=1200:v4mv:vhq:vcodec=mpeg4 -vf \
-    pp=de,scale=720:-2 -nosub -forceidx -o "$name.mpg"
+    pp=de,scale=720:-2 -nosub -forceidx -o "$name.avi"