Properly reduce 30 & 29.97 fps to 23.976 fps

[kalemvar1]

Hello all

Recently I came across a video from a known tv series in 30 fps. It’s progressive no interlaced. Is there a script / command line with avisynth to reduce fps to 23.976 fps (where it should be) ? WITHOUT reducing the duration of the video ? Same question with a video at 29.97 fps, progressif too (and not a live event)

I’ve search the forum a bit, I found many posts but no clear answer.

Thanks

Kalemvar1

[Luke M]

I'm not familiar with avisynth, but this is called decimation; you should be able to find an answer by searching for decimation or decimate. Here's how to do it with ffmpeg:

ffmpeg -i input.mkv -vf decimate -acodec copy -scodec copy -map 0 output.mkv

(Note: this performs a re-encode. I don't know of any tool that can do this without re-encoding).

If the source were interlaced (like a DVD), then it would be called inverse telecine (IVTC).

[jagabo]

AviSynth, if it doesn't have blending artifacts:

WhateverSource("filename.ext")
TDecimate()

The default in TDecimate() is to remove one frame out of every five. It will preferentially remove duplicate (or near duplicate) frames. That will reduce 30p to 24p, 29.97p to 23.976p.