Casshern2,
You're right, I have not seen this technique yet used on any JAV. To be honest I had never even encountered this idea in video editing before. I managed to find that "spirton" page resource on my own, and even attempted to install the apps and recreate the process, but something got hung up along the way, even though I followed the instructions to the letter. One of the programs is having problems updating, which I confirmed on other forums is a persistent problem lately, so perhaps that was what went wrong. Working with scripts I have always found to be tricky, though to be honest.
Sure, I would be willing to check out any examples you could post. I suppose something ideal would be a fast-moving scene, perhaps a medium-closeup of an actress bouncing up and down like crazy in cowgirl position? That type of scene usually winds up stressing the framerates of cameras, heh.
As a side note, however, I looked very carefully at that"sample" posted on the spirton page - the one with the two guys waling in the tow truck show scene? I have a few things to say about that. First of all, there's not really much motion in that scene - just two guys walking against a fairly static background - so it's not really a great example of such a technique in action, IMO. Although I do see how it looks "smoother".
Also, it looks like the re-encode might have been done at a super-high quality setting - to avoid artifacts and to make it look as good as possible. That might be fine for a 30 second clip, or maybe even a 22 minute show, but when we're talking about 2-4 hour videos, it becomes a lot more problematic and not so cut and dried, I'd think.
Finally, I really could find very little talk about this on the net, in spite of the fact that the spirton page was first posted six years ago, so this idea has been around at least that long. The little bit that I did find discussing it, had most people taking a cautious or even dismissive view of it, with lots of discussions about artifacts in the re-encodes, etc.
As well, I found some talk about programs that do such framerate-doubling on the fly (and it is doubling, I mean, I don't know why you need to be so shy about using that term, just count the frames - they're doubled, right?). It didn't really impress me, and my system is powerful enough to make it work right.
I dunno, 30 fps is pretty fast, and it's not like we're all sitting around complaining about how jerky our porn is - unlike, say, sex cams, which could certainly make good use of this technology, I think!