how to get rid of..??

[Yamagata]

sometimes when I rip a dvd for material and i try to convert it to avi, lines will appear in some frames. It looks like 2 frames 'woven' into each other. Is this called interlacing???
How can I prevent it from happening? (It really ugly with fast moving clips)

thx

[lichtspieler]

yes, its called interlaced.
Use a deinterlace filter like the one in virtualdub (http://www.virtualdub.org).