[FFmpeg-user] How to change video fps from 29.970 to 25?

Damian Głodny damian at artnmedia.pl
Tue Sep 2 08:21:59 CEST 2014

Hi, Arno. Thank you for advice, I will check it. I also found some information about converting videos from 29.970 to 23.976:


In document above you can find some techniques to convert your videos. There are methods for conversion from 29.970 to 23.976 called: 
   - 3:2 Pulldown Removal,
   - 2:3:3:2 Pulldown Removal
   - Duplicate Frame Removal (bad)

Is it possible to use them in FFMPEG? 

If I can convert from 29.970 to 23.976 than I can easily convert 23.976 to 25.

Arno wrote:


Your Magic might be called "optical flow".
It's technique where the movement of (all) pixels in the image is turned into a vector. Once you have these vectors you can tell them for instance to take move slower or faster. This generates very smooth speed changes.
There's a huge lot of other things you can do once you have this information.

There's an open source project that seems to work with ffmpeg here:

I haven't tried this one myself. I have used commercial versions of the algorithms.

Maybe it will give you better results.


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