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

FFMPEG_UL ffmpeg at rgbaz.eu
Mon Sep 1 22:06:04 CEST 2014

Ok, here it is: Sample 29.970 fps file which I want to convert to 25fps: 
http://artnmedia.pl/damian/fps/sample-29.970fps.mp4 Damian Głodny 
<damian <at> artnmedia.pl> writes:
>>> I tried many ffmpeg filters like pullup, telecine, fieldmatch,
>>> decimate, but my output video always stuttering.
> Ok, that sample is "30" fps progressive. (I am going to use 30 for 29.97=30000/1001.)  It has 30 complete video frames per second. If you want to reduce it 25 fps
> 3) Magically turn the 6 frames of progressive video into 5 frames of progressive video showing the same scene evenly spaced out. Requires Magic(tm).

Your Magic might be called "optical flow".
It's technique where the movement of (all) pixels in the image is turned 
a vector. Once you have these vectors you can tell them for instance to 
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 

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

Maybe it will give you better results.


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