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Can Compressor 4 remove duplicate frames?

I have some videos which were converted to 30fps from a lower frame count. It was obviously a simple conversion that duplicated frames as needed.


The problem is, when I use these videos for slow motion, the duplicated frames cause the slow motion to "pause". In order to fix this, I have to remove the duplicated frames (obviously I don't care about sound, and I don't care about time sync). Once the duplicated frames are removed, the slow motion is nice and smooth.


In the past, I've always done this with very short clips, so I can do it manually. I open the video in QTP, advance one frame at a time, and when I see a duplicate, I delete it. Since there's always a pattern, depending on what the lower frame rate was, this can be done reasonably quickly, for very small clips. But it's obviously a tedious process.


I was wondering a few things:


1) Can Compressor 4 fix this issue for me? I've tried a few things in Compressor, but no help yet. I'm just a relative newbie, so that's not surprising.


2) Are there any other utilities that might help? Something that removes duplicate frames, for example?


3) These clips were already converted when I received them. However, in the future, when I convert a lower fps to 30fps for the purposes of doing slow motion, how should I do this in Compressor so as to have smooth slow motion at 30fps? Again, I don't care about audio.


I've done a few days worth of searching, but I still havent found the answers. Any help will be appreciated.


Thanks!


Dan

iMac (21.5-inch, Late 2012), OS X Mountain Lion (10.8.2)

Posted on Feb 3, 2013 8:21 AM

Reply
7 replies

Feb 3, 2013 3:47 PM in response to Dan Thomas (DAGWare)

Turn on Frame Controls and try Reverse Telecine (in the De-interlace box) on a test clip. Dependig on how they got to 30 (29.97?), it might get rid of the extra frame.


BTW, how much do you want to slow this down?


Compressor can do slo–mo (also in Frame Controls), but FCP (and Motion(does a pretty good job, depending on the content, and gives several options.


Russ

Feb 4, 2013 7:50 AM in response to Russ H

Thanks. I'll try that.


Generally, I want to slow them down to 1/4 speed. Depends on the clip, though.


Yes, I've been experimenting with the differences between doing it in FCP and Compressor. Sometimes FCP is fine, sometimes I need to use Compessor. I'm sure I'll learn as I go on.


Thanks for the help. I'll report back on whether this solves the issue or not.


Dan

Feb 4, 2013 5:25 PM in response to Dan Thomas (DAGWare)

The Reverse Telecine didn't remove the extra frames. Who knows - maybe the frames aren't exact duplicates, although for the most part, they look it to the naked eye, which I realize doesn't mean much.


Oh well, doing it by hand isn't the end of the world. I've probably spent more time trying to figure out an automatic method, than it would have taken to do it by hand. But of course, I'm sure I'm not the only one who's ever done that... 🙂


Thanks for trying. As I've been searching for help on other things, it's amazing how many times one of your posts helps. So you've helped me plenty, for which I thank you.


Dan

Jun 10, 2016 11:02 AM in response to Dan Thomas (DAGWare)

Had the same issue. Both Compressor Reverse Telecine (quick) and this (slower) has worked for me —

in Compressor set Rate Conversion to Best. Set Duration to 83.3333%.


It's important for the clip to start at the beginning of the non-duplicate frame sequence — 1 2 3 4 5 5 1 2 3 ...


I've found variations in films that have been converted to a different fps, apparently more than once. Some I've just had to convert manually.


Good luck.


Michael

loosethreadscinema.com

Jul 13, 2016 8:51 AM in response to Mei Mei Suuri

Pardon the error. My post should have read —


"It's important for the clip to start at the beginning (frame 1) of the sequence — 1 2 3 4 4 1 2 3 ..." (for 25 > 29.97 fps)

Trim the clip as required


Update:


Set Compressor frame controls to interlace > reverse telecine, duration to 100%.

Open the resulting clip in Cinema Tools and conform to 29.97.


Using the resulting shortened (hence, faster) sequence can best be returned to the original speed using Apple Motion with optical blending set at 83.33%. A slow process that eats available ram, but definitely produces the best results.


A dirtier but far faster method is frame blending. Compressor and FCP can do that.

Can Compressor 4 remove duplicate frames?

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