View Full Version : 24p on DVD... question?


Taky Cheung
February 17th, 2012, 02:10 PM
Recently I start shooting 24p with DSLR. Now it's time to output to DVD. Correct me if I'm wrong. For my understanding, we can work with 24p footage on DVD by either method.

(1) Encode to MPEG-2 with 2-3 pulldown (hard telecine) added. The resulting footage is 29.97.

(2) Encode to 23.976fps MPEG-2. Author the DVD. During playback, depends on the capability of DVD player, some can insert the 2:3 pulldown on the fly. For those progressive DVD players connect to HDTV, it will play back the pure 24p.

Is it true?

Or (3) is all 24p DVD encoded like in (1), then the DVD player remove pulldowns on the fly?

Thanks

Garrett Low
February 18th, 2012, 08:27 PM
Hi Taky,

I believe that all DVD players have the ability to read 24p and if necessary insert pull down on the fly. I encode all my 24p footage when going to DVD as 24p and have my authoring software insert a flag that tells the player that is is 24p material and to insert 2:3 pull down if necessary. I have never tested if there is a difference if I hard encode the pull down. I just know that I have not had any problems from people when I encode the pull down as just a flag and the actual video is still 24p.

-Garrett

Taky Cheung
February 19th, 2012, 12:31 PM
Garrett, I think that's what it is. NTSC standard is 29.97. 24p or 23.976 fps are not. Thus, encoding program will insert the 2-3 pulldown flag to the stream to tell the DVD player or Authoring program it is a 29.97 stream.

Then for regular DVD player, it will play the 29.97 stream with the flag signal inserted. For progressive DVD player, it will play the 23.976 stream to progressive TV.

Peter Manojlovic
February 20th, 2012, 09:47 PM
Yes, almost all Hollywood authored DVD's are made with 23.987FPS encoding..
Flags are inserted to the headers, to tell the DVD player to playback for NTSC. There is actually no native 24 playback (if that's what you're getting at)...
Progressive DVD players will usually reconstruct the interlaced information and create a progressive frames.
Some authoring programs like to hard telecine your pristine footage, which is wrong IMHO.
I used to author, and use freeware like pulldown.exe to add the flags..

I believe Encore hard telecines your footage..

The nice thing about encoding 23.976FPS, is that A) the encoder gets to encode the frames, and not fields, B) you can allocate more free bits to this framerate, since it's 1/5th less in length, and C)encodes should go faster, since there's less frames to calculate..

Jason Garrett
December 2nd, 2012, 10:28 AM
Wish I had seen this before posting in the Adobe forums. I recently went through this. I’ve burned very few Blu-ray projects at all much less attempt to burn off a 24p project to DVD. I had an opportunity to pitch in to record a commemoration for a classmate at my high school and was hoping to do a decent job with it for the family and his kids to have a copy. I didn’t contemplate the prospect of making DVD’s with my video for those who might not have stepped up to Blu-ray yet – I know I only did in the last year so myself.

When I output the Blu-ray project in Encore to transcode to DVD as an afterthought it looked horrible! I’m not even sure what all it did to my video, but it was bad and my video isn’t really all that hot to begin with artistically; so, I at least like to see the technical quality shine.

I went back and encoded to DVD with native properties (24p) to the highest possible bitrates (20 minutes of video). Created a new Encore project and set to not transcode it and it looked pretty good on my Blu-ray player anyway. My older Progressive DVD player didn’t look quite as hot via component cables vs. hdmi on the new player. Still waiting to hear back if it played for the people I sent it out to.