DVD movies, telecine, and 24p

[balkandvb]

I got a question ...

Has telecine been performed in all NTSC DVD movies or is it true 24p? Im asking because once i converted a small clip from a 3ivx 4.5 file to a quicktime DV file and I checked the "telecine" and it turned out like crap. So id like to know what is really "true" 24p.

[guns1inger]

The framerate for film is 24 fps, and film is, of course, progressive. Most film transfers done by studios will be true conversions, with 2:3 pulldown applied for playback on non-progressive TVs.

[balkandvb]

2:3 pulldown? I thought to go from 24p film to 60i NTSC , 3:2 pulldown is needed. And 3:2 pulldown is also called "telecine" while 2:3 pulldown is also called inverse telecine am I right?

[balkandvb]

Never mind.. i read this on the site:

2:3 pulldown
The process of converting 24-frame-per-second film to video by repeating one film frame as three fields, then the next film frame as two fields



3:2 pulldown
An uncommon variation of 2-3 pulldown, where the first film frame is repeated for 3 fields instead of two. Most people mean 2:3 pulldown when they say 3:2 pulldown.

[guns1inger]

Apologies - typo. Doesn't change the fact that most major studio transfers are 24p, and will playback that way on a progressive set through a progressive capable player.

[balkandvb]

no you were right, it wasn't a typo. Basically i read that 2:3 pulldown is the proper way to represent the telecine process and 3:2 is basically the same thing except its wrong. People mistake telecine for saying its 3:2 instead of 2:3.

Inverse telecine is referred to as 2:3 correction.

I tested inverse telecine method by capturing a ppv movie clip to my DV camcorder, and then captured it on my computer. I then took the raw DV file which had interlacing artifacts and was 29.97fps.. and performed inverse telecine (IVTC) and the interlacing artifacts disappeared while returning to the original frame rate of 24 and progressive.

[guns1inger]

Can you post some before and after stills ?
This sounds interesting.

[balkandvb]

well its kinda hard with stills but here is an example of the interlacing artifacts. I captured Dish Network's DVB MPEG-2 satellite stream from their PPV channel directly to my MiniDV camera using and S-video cable. Basically the movie that was being broadcast has already had a 2:3 pulldown performed (telecine) and is ready to playback on a NTSC TV. i then captured it into my camcorder and transfered it to the computer. Now in order to get the 29.97 fps, interlaced dv file to its original 24 frames/sec, and progessive form, and Inverse telecine was performed by me using Cleaner 6 for OS X. The end result looked fantastic. (5 frames under here)

[balkandvb]

these frames are actually the original, already telecined footage to show how 24p was squeezed to 60i. I did not put frames up for the inverse telecine.. which simply had no interlacing artifacts and was true 24p.

[Baldrick]

Please try post in correct forum, this is no DVD Authoring. Moving you.

[balkandvb]

hells if i know what the "correct" forum is.. there is too many.

[edDV]

Your frame 3 and 4 clearly show the mixed field 1 field 2 from opposite frames. The greater the motion the more obvious the field tear. It's not a bad thing if the DVD player is your target. A good progressive DVD player will remove 3:2 (2:3) and create the progressive 24fps and then convert that to 60 frames per second 480p.

2:3 3:2 terminology may be commom in some circles but in the TV industry 3:2 is used for both. "Reverse 3:2" is also used refering to removal of 3:2.

So many ways to say the same thing.

One of the best written summaries of how 24fps material is encoded to DVD and how a progressive DVD player works is here. Enjoy.

WHAT THE HECK IS 3:2 PULLDOWN? by Dan Ramer
http://www.dvdfile.com/news/special_report/production_a_z/3_2_pulldown.htm