13 Titles AVI

Hi there,

I have an instructional DVD that I want to convert to either AVI or one VOB.

The problem is there are 13 titles.

I have tried to convert them with DVDFAB but the AVI files are different sizes so cannot be merged.

The files cannot be made the same size as I have already tried that.

Cheers

I am not sure what are you after. AVI is generally understood as mpeg4 (DdvX or Xvid), if you are talking DVD, there are VOB files already.
To make one large VOB you can use DVD Decrypter in IFO mode or set it to rip to one VOB.
To convert to mpeg4, look at this page
http://www.videohelp.com/tools/sections/dvd-to-avi-divx-xvid
AutoGK is popular for that.
If you are talking about DVD with 13 VTS, than you will not be able to make one VOB file, since there was a reason to make it like that. Either different aspect ratio, different audio or some other difference in each VTS.