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Audio Synch 24fps vs 23.98fps
Hi Forum
Here is an interesting dilemma that someone may have insight on:
We are doing graphic 3d animation out of Maya at 24 fps.
Set up custom sequence in Final Cut to take the image sequence in as prores either converted with Compressor or After Effects (seems the fastest for setup of image sequence conversions). It is Custom 24fps 1280×720 audio at 48k. This is checked against the HD preset that says 24 but is actually 23.98 HD standard.
We edit, output to self contained Quicktime file to give to the ProTools guys. They do their magic.
They send back to us at 24fps and it doesn’t synch. We have them convert to 23.98 it doesn’t synch. I import and convert to 24 one time in after effects and it synchs….one time but we think “hey this is a klugh but hey it works – this is our pipeline and we’ll figure out what the problem is later”
Later comes. We are in the final hours of delivery. We get the files back. Nothing synchs. We convert in AE. Still doesn’t synch. We double check all the settings. All are running at 24. We try converting everything to 23.98 – still no go. I sit with my head in my hands. I look at everything again. Try it all again. It must be me. Still no. Exhausted I open Quicktime player. I add track in quicktime player and it synchs perfectly. We save and output – make the deadline.
So…Anyone have any insight on the synch issues in FCP? If quicktime player can do it in 30 seconds why does it seem uncontrollable in FCP?
Thanks
David -
11 Replies
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[David Miller] “We are doing graphic 3d animation out of Maya at 24 fps. “
PLEASE Call it 24.0 and 23.98-
23.98 fps ( 23.976) is accepted as 24fps materials in North America and Japan.My question is WTF are you doing?
Why are you going thru all of this hassle when Maya can generate the output file at any frame rate necessary why are you fighting everything. Pick a frame rate and stick to it, 23.98 allows for realtime playback on NTSC based editors, but a professional system should be able to handle the content at 24.0 without issue (Some BMD cards do not allow for 24.0 workflows)
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsCheck out
https://www.aja.com/kiprotour/Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php -
Hey Gary
Thanks for taking this on and responding to the post.
We did choose to have everything at 24.0fps. But when the protools sessions came back to us they were out of synch even though they swore up and down (and I visually confirmed it) that they were working at 24.0fps.
We aren’t using any cards like the Aja or Black Magic for processing. In retrospect it would have been better to make it 23.98 although that option was not available in Protools – only 23.976. It was these differences that made us decide to set the foundation at 24 and keep it all uniform.
The crazy thing is that Quicktime Pro Player sees it at 24.0 and everything is in synch. I bring the same file into FCP and it is out of synch in the 24.0fps sequence. I try to set up a new sequence with the preset of HD – Prores which defaults to 23.98fps, import the footage, tell the sequence to not conform to the 24.0fps of the clip so that it stays native to the preset, import the audio and it’s still out of synch.
So why QT Pro Player can do it and I can’t in FCP?
best
david -
[David Miller] ” In retrospect it would have been better to make it 23.98 although that option was not available in Protools – only 23.976. It was these differences that made us decide to set the foundation at 24 and keep it all uniform. “
But that makes no sense.
23.98 and 23.976 are considered the same frame rate in every editor I know of.[David Miller] “The crazy thing is that Quicktime Pro Player sees it at 24.0”
no it just tells you that is it, without hardware there is no proofing to make sure, you cannot just guess at these things there is a reason that hardware is used and by thinking that you can do high level projects without basic hardware is an incorrect assumption on your part.
gary adcock
Studio37
HD & Film Consultation
Post and Production WorkflowsCheck out
https://www.aja.com/kiprotour/Inside look at the IoHD
https://library.creativecow.net/articles/adcock_gary/AJAIOHD.php -
Got it. So why on the same hardware can I get something in synch in one simple program – QT Pro Player and not with FCP given that the base hardware foundation is exactly the same? One works, the other doesn’t.
The other thing that you might be able to point me to then is which hardware I can genlock to a blackburst generator so that everything is working from the same clock. Is that an Aja board or BlackMagic boardor do I have to go back to Media 100 or Avid to get this kind of “basic hardware” to use on a project where sound has to be in sync with picture?
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PLEASE
STOP USING THE TERM 23.98.
It does not make sense for those who want to do math.
23.976 is a better term, it avoids confusion.
(although not accurate enough to do decent math.)And i do agree, why not start working in 23.976 from the start and keep it that way.
Bouke
https://www.videotoolshed.com/
smart tools for video pro’s -
I use this term because that is how it is listed in the presets for Final Cut Pro. It states: Use this preset when editing with Apple ProRes 422 (HQ) 1289x720p 23.98 fps material with audio set to 48 kHz.
In fact in the custom box it does not allow for the option of 23.976 but only 23.98, 24, 25 etc.
Could this be the problem of why the protools session cannot conform to the synch that the quicktime player can handle?
thanks
david -
To add to the confusion, ProTools has different timing for 23.976 and 24. If one side is thinking 24 means 23.976 (probably the norm) and the other side thinks 24 mean 24, then sync will be off.
John
MacPro 8-core 2.8GHz 8 GB RAM OS 10.5.5 QT7.5.5 Kona 3 Dual Cinema 23 ATI Radeon HD 3870, 24″ TV-Logic Monitor, ATTO ExpressSAS R380 RAID Adapter, PDE enclosure with 8-drive 6TB RAID 5
FCS 2 (FCP 6.0.5, Comp 3.0.5, DVDSP 4.2.1, Color 1.0.3)Pro Tools HD w SYNC IO, Yamaha DM1000, Millennia Media HV-3C, Neumann U87, Schoeps Mk41 mics, Genelec Monitors, PrimaLT ISDN
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so I understand that I should have set up the project at 23.976 (which on the interface doesn’t exist). I understand that I should take a lot of flack from the pros here. Next time I’ll set the project up differently than what I did. 24 was a nice even integer and it seemed to make sense. No .98’s or .976’s. But this is what I got and I was hoping there was some underlying knowledge on the internal structures of FCP that would, at the very least, be revealed. My fault.
What I don’t understand is why I can get it to work if I bring it into QT Pro player or render it in an AE project at 24fps but I cannot get it to sync in Final Cut. Why can two other programs read it properly, and the core program cannot, when it clearly states that it is set to those properties?
I don’t want to get banned from Creative Cow. I just really want to know how Final Cut handles sync issues.
david
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David,
I am having a similar issue on the night before my project is due. Imagine that.
Here is my set-up. I’m trying to layback in FCP 6.0.6 audio from pro-tools. My FCP project has always been 23.976 (aka 23.98)
I sent my audio guy omf files weeks ago, I got them back today laid them in my on-line sequence at the same frame rate and the sync drift is occurring. Here are some interesting facts.I made aiff reference mixdown files from my off-line audio mix and re-imported them into my on-line seq and everything syncs fine. No Pro-tools round trip.
My reference quicktime with timecode that I sent to Pro-tools syncs with everything perfectly in my audio guys system.
The problem is deffinetly in how FCP is reading the 23.976 (aka 23.98) wav or aiff (tried them both.)
I have been reading many posts tonight on all different forums with no good solution offered. Some say FCP is trying to re-time the file by adding frames (or pulldown) because it doesn’t know what fps it actually is. It would be great if anyone at apple would be willing to try and recreate this problem.My last resort has been to digitize my project (90min) from FCP via Kona 3 HDSDI to my Avid Symphony at 1080 23.98psf and then layback the audio files in Avid. It syncs up perfectly. I realize not everyone has that option but It has worked for me. I love FCP and Apple, but I believe this looks and feels like a big bug.
Does anyone know if this problem is still happening in FCP 7.0?
Kent Esmeier
Senior Editor / Colorist
grootersproductions.com -
Hey Kent
This is a rascal of a problem and even if you do everything right it’s still not clear when it will show up. The only way that I have found to solve this problem quickly is to open after effects and set your project up for the correct frame rate. Render only the audio at that frame rate with the correct sampling rate. Then open quicktime player pro and add the track to your exported movie. Then you can re-import into FCP, dump the video track if you want in a sequence and then you can use your audio which will be in sync. Any other way and I couldn’t get FCP to work no matter how I mixed up the various combinations. I have had to do this in both 6 and 7 for this project. I know there must be ways to set this up in the beginning but here is at least one bit for a real world solution when you’re in the thick of it.
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