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How to remove duplicate frames for a 25 fps file converted from 24 fps native edited master
I’m having a hard time figuring out how to remove the extra 1 frame on a 25 fps broadcast master converted from a 24 fps edited master. Is it at all possible in FCP X or Compressor? The interlaced 29.97 reverse telecine is possible, but never done it on a 25 fps master reverse telecine to a 24 fps native.
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8 Replies
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Can you slow it down? If sync audio is important, slow down with a pitch correction. Obviously duration will change. The only other way is Compressor and interpolate the frames using optical flow; however, you will likely see some artifacts.
– Oliver
Oliver Peters – oliverpeters.com
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I tried to slow it down. But it failed qc due to the presence of duplicate frames. It looks like a consistence duplicate frame pattern. I see an extra frame is added onto the 25 frames throughout the entire content. The only way to pass qc on this is to remove the extra single frame that added when you put a 24 fps content into a 25 fps sequence. In essence, it’s a reverse telecine process that worked from 23.976 -> 29.97 fps 3:2 pull down. But it appears there is no such thing as a reverse telecine for 24->25 fps. Compressor would typically allow the option to Reverse Telecine if it sees a 29.97 fps interlaced file.
If there’s any 3rd party utility that will remove the extra duplicate frame on every second (25 frames/sec). This will get the content back to its native 24 fps frame rate and pass qc.
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Export as image sequence, find the pattern, write a little Automator/AppleScript and convert back to 24 using Compressor.
Spherico
https://www.spherico.com/filmtools\”He who fights with monsters should be careful lest he thereby
become a monster. And if thou gaze long into an abyss, the abyss will
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I use JES Deinterlacer for this kind of thing.
It’s dependent on the old QuickTime framework, and works beautifully (for now). Unfortunately, the dev has passed and the site taken down, so I’m not sure where you’d find a clean copy unless I were to post one here. Last release is v3.8.5a5, weighs in at 7.7MB.
Doug Metz
Dalton+Anode
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[Sam Lee] “how to remove the extra 1 frame on a 25 fps broadcast master converted from a 24 fps edited master. Is it at all possible in FCP X or Compressor? “
In FCPX when you add 24 fps material to a 25 fps timeline, the frame count will be the same but the 25 fps version will have less “wall clock” running time. IOW the default conform algorithm is run the 24 fps material slightly faster.
In Adobe Premiere and maybe other NLEs, when you do that, it duplicates each 24th frame to maintain the original running time. This manifests as a motion cadence “hitch” about once per second and (in your case) is causing the material to fail QC.
Apple Motion won’t let you do reverse telecine in this situation — that option is greyed out.
It is theoretically possible to delete the extra frames in FCPX using a similar procedure to that mentioned here. I played around with it and it seems like it might work but I don’t have time to complete the R&D:
https://www.lafcpug.org/phorum/read.php?1,288135,288142
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There is some hope to the manual method with the LACPUG forum. But it’s looking very tedious and open to processing errors by not deleting all of the 5th duplicate frame. Was hoping for a commercial app that will solve this. I have a handful of these (15-20 hours) from time to time.
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If you’re willing to post a sample file, I’d be happy to run it through the app to test efficacy.
JES Deinterlacer is a freeware app, and I have the last version complete with all documentation. Does anyone know if there is reason not to post it here? I am confident it will handle this task with ease. Of course, it will cease to function when QT7 does, probably with macOS 10.15
Doug Metz
Dalton+Anode
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I thought I have answered this in another forum?
Quicktime can do so, just open and transcode with a different frame rate.
One gotcha, you need to start on the right frame. (A few tests and you’re there.)If you want batch, and a commercial app, my QT change can do this.
(But I’m sure the free ones will also work for this.)Bouke
http://www.videotoolshed.com
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