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Best Practice for Working with Mixed Frame Rates in PPRO?
Hi all, could someone please confirm best practices for working with mixed frame rates in Premiere Pro? Specifically two sets of footage that can be synced by audio, but were recorded at 29.97 and 23.976 frame rates, respectively?
The 29.97 footage will lose six frames if I’m working in a 23.976 Sequence, while the 23.976 footage will have duplicate frames–presumably from 3:2 pulldown. Neither is ideal, but I would think that losing frames from 29.97 is better than having duplicate frames from 3:2 pulldown. For this project, I’m transcoding the 29.97 files to 23.976 FPS and will then sync by audio waveform.
Should I anticipate any issues with this?
Thank you!
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9 Replies
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What frame rate do you need to deliver?
That’s the key here.Pat Horridge
Broadcast & Post Consultant, Trainer, Avid Certified Instructor
Free online Tutorials at VET digital media academy online https://vimeo.com/channels/752951
pat@vet.co.uk -
What Pat said. Your desired deliverable is what drives this decision.
System:
Dell Precision T7600 (x2)
Win 7 64-bit
32GB RAM
Adobe CC 2017.1 (as of 8/2017)
256GB SSD system drive
4 internal media drives RAID 5
Typically cutting short form from UHD MP4, HD MP4, and HD P2 MXF. -
23.976 and 29.97 are compatible. Nothing exotic needs to be done for audio sync. If the footage was true 24 FPS, you would have a pull-up/pull-down situation. 23.976 was invented to avoid that problem.
If this is for broadcast in the US, I’d edit in a 29.97 sequence. Premiere will add the pull down perfectly for the 23.976 footage. It’s very common and done all the time. Depending on the footage, 29.97 footage may have slightly odd look on fast motion or camera movement when converted to 23.976. In the US, people are more used to the look of 3:2 pull down (which does not exactly duplicate frames, but rather blends fields in a specific pattern).
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Thank you so much. Very helpful to know how audience-members consider 3:2 pull down vs frame loss of 29.97.
In your opinion, would the audio still look in sync if going from 29.97 to 23.976? In other words, is it more jarring to have duplicate frames while someone is talking (23.976 to 29.97), or lose every fourth frame when going from 29.97 to 23.976?
Being nit-picky here but trying to develop a best practice.
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Thank you Jon, John and Pat for responding.
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Going from 23.976 to 29.97 does not duplicate entire frames. That’s not how 3:2 pull down works. It’s not jarring at all. A high percentage of what you see on television in the USA is done that way. If you were not aware of it, that should tell something.
Converting 29.97 to 23.976 can produce visual artifacts, but it’s not just tossing out frames either. Frame blending and interpolation attempts to make it look as natural as possible, but with fast motion it may look a bit stuttery. Sound sync is hard to say with certainty but it may be fine.
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3:2 pull down (up) whatever creates an interlaced in between frame but if you aren’t American it can be noticeable. I do (teach) QC in the UK and I notice it as movement has an odd pulse to it. But its considered acceptable.
Pat Horridge
Broadcast & Post Consultant, Trainer, Avid Certified Instructor
Free online Tutorials at VET digital media academy online https://vimeo.com/channels/752951
pat@vet.co.uk -
[John Pale] “Going from 23.976 to 29.97 does not duplicate entire frames.”
23.98 (24p) to 29.97 progressive (30p)…progressive to progressive…will duplicate entire frames.
[John Pale] “That’s not how 3:2 pull down works.”
That’s only if you are going 23.98 to 29.97 interlaced (59.94i). I have many deliverables lately that want 30p…so they can stream it online, where interlacing is bad.
[John Pale] “Converting 29.97 to 23.976 can produce visual artifacts, but it’s not just tossing out frames either.”
By default, full frames are discarded. Unless you TELL it to blend the frames.
Shane
Little Frog Post
Read my blog, Little Frog in High Def -
Hadn’t considered 30p, as I’ve never delivered that in over 30 years in broadcast.
Good info, and a recent trend I wasn’t aware of.
Thanks.
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