FCPX, Compressor : converting 54 minute 29.97 fps to 24 fps??

Question

Level 1

112 points

FCPX, Compressor : converting 54 minute 29.97 fps to 24 fps??

I've got a 54 minute film shot in HD&4K at 29.97 fps. A number of IMAX theatres are interested in running it (even though it wasn't shot in IMAX). I sent the first theatre a ProRes 422 HQ to do a test on their specific screen. They are set up to do a basic DCP. But a basic DCP is 24 fps. So I found this: "Yes, Apple Compressor can conform 29.97 fps video to 24 fps smoothly using the reverse telecine feature, which automatically detects and adjusts for broken cadences during the frame rate conversion."

What do I want to do? Do I want to figure out how to make a DCP that runs 29.97? Do I want to use Compressor to conform the whole film to 24fps before making my DCP? The DCP they could do at the theatre if I send them a new ProRes422HQ, but at 24fps.

The film at 29.97 fps is very smooth, and looks 'cinematic' simply because of the way it was shot. What I don't want, is to end up with a jerky version. Which could quickly dampen the enthusiasm from the theatres.

I'm all ears for advice ...

MacBook Pro 16″, macOS 15.3

Posted on Apr 7, 2025 2:17 PM

Reply

Answer 1

Top-ranking reply

Meg The Dog

Level 6

13,796 points

Apr 7, 2025 6:44 PM in response to Ben Low

I haven't dealt with DCP for a long time so will only offer some comments to your post:

Ben Low wrote:

But a basic DCP is 24 fps.

My (limited) understanding is that DCP now supports standard non-fractional frame rates of 24,30 & 60 fps.

It might be better to convert your 29.97 to 30 fps if this is true.

I found this: "Yes, Apple Compressor can conform 29.97 fps video to 24 fps smoothly using the reverse telecine feature, which automatically detects and adjusts for broken cadences during the frame rate conversion."

I believe this is the function of Compressor that is/was used to remove the pull down that is apparent when 24fps film is telecined to 29.97 and extra fields are needed to fill out the 29.97 frames. The function (I believe) you are referring to made it possible to go the other way - reverse telecine - to recover the original 24fps from that 29.97 file by finding the cadence of the extra fields and removing them. Not sure this is useful for your purpose as your original is 29.97.

What do I want to do?

If it were me I would Google for the companies in your market that will create the DCP from your source file and see what they can do. I think they charge by the minute of program length.

They might also be able to offer guidance as to converting the sound into a suitable form for presentation in an IMAX auditorium.

Hopefully someone with more recent DCP experience will be able to advise.

MtD

Reply

Answer 2

Ben Low Author

Level 1

112 points

Apr 7, 2025 7:28 PM in response to Meg The Dog

Hey Meg The Dog,

Thank you most kindly. I know how IMAX does the DCP -- it costs a fortune plus more. I just downloaded Resolve, may just pay the bucks to get the Studio version, which does DCP's. I seem to remember doing this years ago.

I will also do as you suggest, and ask around. But, I've been thinking since I posted, even if it is 'cheap' it'll probably be more than the cost of the Studio Resolve. And I may be needing to do more versions. I also want to try some experiments, meaning some sample tests for a particual theatre, or theatres if I get lucky. And, ha ha ha... I just watched an IMAX film in a good IMAX theatre (and I know the producers spent a small fortune on the 5.1 mix -- because I audited the mix) ... so I saw this IMAX film back to back with a film shot in HD, mixed in stereo. And you know, don't tell anyone I said this, but the stereo version held up just fine. In fact, I didn't really sense much difference. And I spent 20 years in high end recording studios producing music, so I don't think this was naivety on my part (I could always be wrong of course).

The nice thing about doing the DCP's myself is I can try small chunks of the film at 29.97, 30, 24, and see which works the best in the given theatre. And try some modes tricks with the stero ... to give it as much spread and dynamic as possible.

I will post here what I find out over the next day or so. All the best ... and thank you again.

Reply

Answer 3

Ben Low Author

Level 1

112 points

Apr 7, 2025 7:36 PM in response to Ben Low

Ha. I just downloaded DCP-o-matic. Which also sounds very familiar. And I remember now that Resolve was a bit of a headache to figure out. And back then I switched over to, I think, DCP-o-matic, and it was loads easier.

Aha! Yes. I still had the manual on my MacBook Pro. DCP-o-matic.

Will report back.

Reply

Answer 4

Meg The Dog

Level 6

13,796 points

Apr 7, 2025 8:38 PM in response to Ben Low

Ok, good, hope it works out. I seem to remember that back in the day there were always difficulties if you were Mac based, but hopefully those days are behind us.

MtD

Reply

Answer 5

Apr 8, 2025 12:29 AM in response to Ben Low

Donald's favourite word is "TARIFF" whilst mine is "FREE".

Good to see your problem is resolved.

Reply

FCPX, Compressor : converting 54 minute 29.97 fps to 24 fps??

Similar questions