Using ffmpeg to change framerate

Question

I am trying to convert a video clip (MP4, yuv420p) from 30 fps to 24 fps. The number of frames is correct so my output should change from 20 minutes at 30fps to 25 minutes a

Answer 1

You may consider using fps filter. It won't change the video playback speed:

ffmpeg -i  -filter:v fps=fps=30 

Worked nice for reducing fps from 59.6 to 30.