extract movie and audio files to mpeg2 and ac3 files --> 10 minutes
multiplex video and audio files --> 5 minutes
encode to avi, so subtilte program works properly 1h
write subtitles (with help from original subs of course) 4h-10h
re-author DVD to implant new subtitles (have never done this but it is supposed to work) 2h
time needed: at least 7 1/2h