first you should convert the avi & mpeg1 files to mpeg2 with
TMPGEncoder , then make the dvd from the mpeg2 file with
TMPGEnc DVD Author or
ulead dvd movie factory.
I think the new version of ulead dvd movie factory will do the convert job (avi->mpeg2) but it's too big for me to download (100MB), so I can't confirm it.