Welcome to the forum
This issue has been discussed very many times on the forum. Please, use search function.
Anyway, what you call bup, vob and ifo is a so-called "video DVD".
To convert an avi into a video dvd you must follow two steps
1) Convert avi in mpeg
2) Convert mpeg in video dvd (the so-called dvd authoring).
To convert avi in mpeg you need a mpeg encoder, like TMPGEnc. If you have already an mpeg, you can skip this step.
Finally, from mpeg to video dvd you can use TMPGEnc DVD Author.
Too bad these programs are not free.
Some users on this forum suggest to use DVD Santa (sorry, I never used it, so I can't give you any suggestion on this)
Hope this can help