There is no AVI on a DVD. Copy the VOB files from DVD to hard disk and import it or use a DV camera as pass-through.
As Harm points out, what is inside the .VOB's is MPEG-2, plus other things. This ARTICLE will give you some background on .VOB's.
Now, if you have CS4.1 (you did not mention the version of PrPro), and your DVD is 100% DVD-compliant, you can Import the .VOB's to PrPro. For earlier versions, you will need to rip the DVD via software, or hardware, as Harm mentions.
The_wine_snob article gives a great insight into DVD/VOB files, well worth reading and digesting.
I use VirtualDub with appropriate MPEG plugin to convert the VOB file(s) retrieved from an unprotected DVD to avi before importing to PrePro CS3. It does not take long and avoids potential problems in PrePro later.
Thanks for the kind words, and also the rec. for VirtualDub w/ MPEG module. Many recommend it for many conversions. As I tend to use some other workflows and methods, I have to admit that I have never explored it. I'll have to remember your advice and share it with others, who have the same issues.
You are very welcome.
Jeff Bellune has made and posted tutorials wrt using VirtualDub and Avisynth amongst other things, both before the forum changes and after. These were invaluable to me, I took copious notes, but yes, you've guessed it, my links are either broken or non-existant. If you could persuade Mr Bellune to re-post all old and current tutorials under the Premier Pro Tutorial Section the silent majority would be well pleased.
Similarly links to Dan Isaac's updated material, if not already available, would be extremely useful. (dv2film/hd2sd/sd2hd etc)
Sorry for hijacking this thread, but it is related and relevant.
"Sorry for hijacking this thread, but it is related and relevant"
Absolutly nothing to be sorry for John. Good students carefully listen to the teachers lecturing.
Great students carefully listen to them having coffees.