Dvd shrink

I been using avi2dvd to change avi to dvd. When I use dvd shrink to try to shrink it down to make it fit on a 4.7 g disk it says invaild filename. What am I doing wrong?

Try DVD Flick and save yourself a few steps…Convert, compress and burn all in one step.

http://club.cdfreaks.com/f59/dvd-flick-basic-guide-228005/