Convert 24 to 30 fps.

Ryan Patrick O'Hara

Ryan Patrick O'Hara

Veteran
What is the best way (if any) to get 24fps footage (23.98) to look like 30 fps footage (29.97).

5dmII, two camera shoot one camera was set incorrectly to 23.98. Both should have been 29.97.

Any help would be greatly appreciated.

Editing in FCP7

thanks

-Ryan
 
Motion blur? AE on render motion blur to match? Double the frames and convert down to 30? Stumped...
 
The only way I can think of is to telecine through Cinema Tools. The problem, however, is that you'll end up with interlaced frames. Though it will completely change the aesthetic of the project, it would be easier and cleaner to take the 30p footage and convert it to 24p.
 
Alex H. said:
The only way I can think of is to telecine through Cinema Tools. The problem, however, is that you'll end up with interlaced frames. Though it will completely change the aesthetic of the project, it would be easier and cleaner to take the 30p footage and convert it to 24p.
Click to expand...

Why would you end up with interlaced frames?

Cheers,
GB
 
RGBaker said:
Why would you end up with interlaced frames?

Cheers,
GB
Click to expand...

Telecine converts 24p (film) to 29.97 (60i) by adding a 3:2 pulldown. That adds interlaced frames by splitting progressive frames into fields and repeating some of the fields, and combining fields from two different frames to generate new frames. So every third and fourth frame of 3:2 pulldown is interlaced.
 
Alex H. said:
Telecine converts 24p (film) to 29.97 (60i) by adding a 3:2 pulldown. That adds interlaced frames by splitting progressive frames into fields and repeating some of the fields, and combining fields from two different frames to generate new frames. So every third and fourth frame of 3:2 pulldown is interlaced.
Click to expand...

Thank you for your detailed explanation. But I'm not sure where the foul occurs -- if the created third and fourth frame are interlaced, using the material from adjacent frames ... how is this problematic? We already understood that data would need to be created if we were going from 24 frames a second to 30 ..? It isn't as if you've lost anything in the frames that are not constructed from combining adjacent frames, and those constructed frames would have to be constructed one way or another ..? In fact, every movie ever telecined to DVD had the same process applied, no?

Cheers,
GB
 
Introducing interlacing is the wrong way to go about it. Telecine the progressive. Interlace after export. As I mentioned in my earlier post, if you drop the 23.98 progressive footage onto the 29.97 timeline everything stays progressive and pulldown is added. Export progressive. If you go to DVD or blueray the interlacing is done with compressor using your FCP 29.97 progressive as a master.
 
***** word of warning though *****
you can't do this with irregular frame sizes as you get a codec error in fcp, if you are working with 720p or 1080p you should be fine and fcp will recalculate pulldown on your clips as you cut them.

I had a weird one the other day where I added a 30p snapZpro screen capture at 1100 wide by 700 high of someone navigating a website to a 720p 29.97 timeline. I know FCP can recalculate the fps on clips as I edit but I was getting a codec error. I solved the problem by dumping the problem clip into mpegstreamclip and giving it the correct fps. Export then back onto my timeline maintaining the clips irregular size.
 
Ok, so that will get it in the same timeline, but it will still 'look' different right? What do those added frames FCP makes look like? Is it simply doubling existing frames, or creating blended frames?
 
Ryan Patrick O'Hara said:
That will have the 23.98 footage looks more like 29.97? Didn't know that. Does it create the missing frames by blending or something?
Click to expand...

Do you want 30p, or do you want 60i? They're totally different animals.

24p rarely makes a good conversion to 30p; you'll get jumpiness and ghosting.

If you want 24p to be converted to 60i, that's just a telecine -- insertion of 2:3 pulldown. However, it will still look like 24p -- it will not have the motion of 60i.

I'm not aware of any process in FCP or Cinema Tools which will take 24p footage and give it the motion of 60i. I know 120Hz/frame-repeating TVs somehow do this, but I don't think there's any way to do it in FCP.
 
Yeah, that's the trick. I want it to feel more like 29.97/30.

I figured if twixtor could make 24fps look like 60+fps look good under certain circumstances, there could be something that could make 23.98 look like 29.97. I understand one is slow motion and the other is a time base change, but the footage is a sit down interview. Nothing really moves much from what I recall. No action sequences or anything.

Thanks for the help!
 
If there isn't much motion, you're probably not going to see much difference between 24 fps and 30 fps. But then again, you might.

Though if there isn't much motion -- if it's all locked shots and talking heads -- then there probably isn't going to be THAT much of a problem with jitter and ghosting if you convert to 30p.
 
RGBaker said:
Thank you for your detailed explanation. But I'm not sure where the foul occurs -- if the created third and fourth frame are interlaced, using the material from adjacent frames ... how is this problematic? We already understood that data would need to be created if we were going from 24 frames a second to 30 ..? It isn't as if you've lost anything in the frames that are not constructed from combining adjacent frames, and those constructed frames would have to be constructed one way or another ..? In fact, every movie ever telecined to DVD had the same process applied, no?

Cheers,
GB
Click to expand...

DVD can support and play back 23.976 (24p) material, so it does not need to be telecined. Telecine was originally used to broadcast 24p film material on 60i television, and the interlaced frames that are created by the pulldown aren't noticeable on an interlaced monitor. However, those created frames take fields from two different frames, which will be obviously interlaced on a progressive monitor... especially with faster motion.
 
Alex H. said:
DVD can support and play back 23.976 (24p) material, so it does not need to be telecined. Telecine was originally used to broadcast 24p film material on 60i television, and the interlaced frames that are created by the pulldown aren't noticeable on an interlaced monitor. However, those created frames take fields from two different frames, which will be obviously interlaced on a progressive monitor... especially with faster motion.
Click to expand...

Hmm. I'm note sure I buy your limited definition of telecine -- 60i is but one option in the telecine choices. And yes, some players can look at a DVD and remove the telecine frame repeating, but in truth most don't. And to the best of my knowledge, an LCD (or Plasma or LED) HDTV doesn't actually use 'interlace' -- that's a CRT function. Convert a progressive source into interlace ... and you still have progressive playback, you've just increased the framerate and halved the frame resolution.

So I still don't follow your argument, though I appreciate your attempts to elucidate me. In truth I don't find interlace the evil it is often presented as, and now that my displays are all actually 1080p, it becomes a non-issue .. if you want that 60 fps look, shoot in 60 fps, or in 60i if your system can't do better. Most of the complaints on interlace involve freezing a pair of fields at once and worrying over the combing -- in use, the fields play back in sequence so what you really have is a reduced vertical resolution vs an increased temporal resolution.

Cheers,
GB
 
RGBaker said:
And yes, some players can look at a DVD and remove the telecine frame repeating, but in truth most don't.
Click to expand...

That's why you code it as 24p, not as 60i. There's no telecine to remove. There are only instructions for the player to insert pulldown/telecine if it has to.
 
David Jimerson said:
That's why you code it as 24p, not as 60i. There's no telecine to remove. There are only instructions for the player to insert pulldown/telecine if it has to.
Click to expand...

Respectfully, I think you have it backwards -- the DVD is encoded with pulldown (telecine) embedded, but a smart player can skip the pulldown instructions and play it back as 24p. Emphasis on smart player ...

But I believe you have to encode as 60i to make a legal DVD -- as you point out, that does no harm as reversing the telecine reconstructs it as 24p. Or 'dumb' players simply play the 60i encoded telecine file ... which is not as bad as you'd think, IMHO

Cheers,
GB
 
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