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How to convert 50p (25p) to 23.976 with Dupe Frames?
#1
So I have two different HDTV broadcast from PAL land and I'm have a devil of a time trying to convert them to standard 23.976.

Normally, I'd use assumfps in AVisynth for converting 25p to 23p but both of these are a little different. Mediainfo says both files are 25p but when I go frame by frame in MPC or VLC each frame seems duplicated. So it seems it is really 50p sped up to 25p?

Regardless I've tried everything I can think of to slowdown and delete. Actually the slowdown is easy, its the de-dupping that is hard. I tried T/decimate but seem to have not hit on the right formulation. Running slowdown in eac3to (or changing it in mkvmerge or tsmuxer) result in dup frames but at the right speed. Placing the files in Premiere de-duppes it but dumps good frames with bad.

So any idea from the fanres brain trust?
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#2
It happened to me, too; what I did in avisynth was:

Code:
selecteven #or selectodd, it's the same
assumefps(24000,1001)
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#3
Thanks spoRv that might just be it, I'll try it out and let you know.
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#4
What resolution are the caps? I think 720 supports 50p, not sure about 1080.
You may gain something from averaging the two frames depending on how well it's compressed, likewise from ditching a noticeably worse compressed frame
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#5
(2021-08-12, 08:41 PM)zoidberg Wrote: What resolution are the caps? I think 720 supports 50p, not sure about 1080.

1080 for sure. Technically it is 25p so not violating standards but its a crappy way of achieving that.

(2021-08-12, 08:41 PM)zoidberg Wrote: You may gain something from averaging the two frames depending on how well it's compressed, likewise from ditching a noticeably worse compressed frame

You know that's not a bad idea. Hadn't considered that. There is some bad compression I'm working on that might be unfixable but if I have a "spare frame". Have to see if the frames are unique.
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#6
What movie is this? Usually, 25fps material (if it's cleanly progressive and not hard interlaced/field blended) in a 50i container would first get deinterlaced and resampled to 25p, then a slowdown is applied to bring it to 23.976. Sometimes, 25fps progressive material can be a 23.976 source without any speedup, but results in dupe frames.

If this source is indeed 23.97 in a 25/50i container, one method that could work is bring the file into the Handbrake and output to 23.976. The latest versions of Handbrake find and remove dupes (if the frame rate is say 25 in a 23.97 file and you output back to 25), but it's not 100% perfect and won't work on field blended stuff or a file that is 29.97. Second option would be a a linear editing program and edit the dupe frames manually there.
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#7
Got it figured out, thanks everyone for the help.
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