a few questions about encoding

Hi there. Recently I try to transcode a dvd using xvid for video codec(I
think it's free while open source). My source dvd is 4G, but only
elapsed 1 hour and 20 minutes. Since I'm a noob in video encoding, so I
almosted use the default settings in dvd::rip. I tried two times: first
with "target size: 700M, BPP: 0.225", whose result is not made me
satisfied; and second with "target size: 1400M, BPP: 0.480", I found the
output also not good enough.

The topic of the dvd is a poem recite, so most of time it's static
pictures. But when someone or something moves, the edge of the moving
object has a lot of horizontal lines. I don't think the bitrate is not
enough, but I'm really confused. I read through the documentations but
found no answer. Could someone please give me a little advise? Thanks.

-- 
sssslang