iVCT and 3:2 pulldown

DJ_Izumi · Post by **DJ_Izumi** » Thu Dec 18, 2003 7:00 pm

iVCT is the magical wonder that converts 24fps progressive into a 30fps interlaced image for our primative dinosaur-in-a-wheel powered TVs.

Now... what can't the extra flags that get stuffed into an mpeg stream be simply stripped, presto-chango, the stream is 23.967fps?

NicholasDWolfwood · Post by **NicholasDWolfwood** » Thu Dec 18, 2003 7:05 pm

What the fuck did you just say?

IVTC = Inverse Telecine

Inverse Telecine = the process of taking a telecined 30fps video stream and restoring the progressive frames and then deleting the duplicates to get 24fps

3:2 pulldown = Telecine

Telecine = the process of taking a progressive 24fps video stream and telecining it up to 30fps, making two fields per every second, and adding 6 duplicate frames per second.

Now...restate your question.

DJ_Izumi · Post by **DJ_Izumi** » Thu Dec 18, 2003 7:06 pm

If 3:2 Pulldown flags interlace the video to bring up it's framerate, why can't the flags simply be stripped away?

trythil · Post by **trythil** » Thu Dec 18, 2003 7:09 pm

The pulldown flags are ignored when you rip a progressive-frame DVD. A couple of examples: the Buena Vista re-releases of Ghibli films are progressively encoded, as is the Final Fantasy movie.

It's just that a lot of anime DVDs aren't progressively encoded with the 3:2 pulldown flag set. Sometimes you can't do it -- like maybe the source will have been produced at 29.97fps interlaced, like with a TV show generated on computers -- but in many other cases, you can.

I don't know enough about the way anime gets licensed to really say why more US distributors don't do this, especially for material transferred from film. My guess is that obtaining the original film master is a bit on the expensive side, but...again, just a guess.

By the way, it's IVTC, not IVCT.

zalas · Post by **zalas** » Sat Dec 20, 2003 2:33 am

Some studios also post process in 29.97 fps, so there IS no 23.976 version of the material. Things like full metal panic have the original animation done in 23.976, bumped up to 29.97 and then had their effects applied at 29.97.