Easily convert PAL subs to NTSC?

[InfoCynic]

So I'm doing a movie from an R1 DVD that for deinterlacing reasons, has to be kept at 29.970 fps. Now, because R1 DVDs are generally lousy with subtitles (English-only anyone?), I asked my friends with the R2 DVDs if they could rip me some subs since theirs had a lot more languages. They sent me the IFO, IDX, and RARred sub (using an old Vobsub, what can I say, but beggars can't be choosers) with all the language streams in it. I'd rather not convert to text-based because then I have to spell-check and what-not, and a few mb is a small price to pay for quality subs. Without chaning anything, the subs are a little off, presumably because of the FPS difference. I've tried using subresync with Vobsub 2.18, setting the FPS to 29.970 before opening a file, then saving the file, but that doesn't work either. Any easy fix for this, short of trying to adjust a sub every few minutes manually?

[gabest]

Try the "rundll32 vobsub.dll,Cutter" function. Since pal movies are speeded up by 25/24 times, save a new file (on the whole time range) with 25 as the original and 23.976 as the new fps (ntsc is slowed down to 23.976... :)). But this may not help you either if the syncing problems have another root like missing/extra scenes.

[InfoCynic]

Thanks -- that gets very close, but there's progresive decay -- by the end of the clip, the subs are significantly ahead of the film. Through trial and error I was able to get it work at 23.952 fps. But for another clip, 23.976 worked fine for about the first 30 minutes, and then it was off, so I guess there's just slight differences in the postproduction or something, and it would take too much work to find the break points and resynch, so I guess I live with just English. :) Need to convince r1 dvd publishers to include more languages! :)