"Intelligent" conversion 30fps -> ~ 25fps.

[rgr]

Hi.

I have a video downloaded from YT at 30fps.
But the original one was recorded with a different framerate, because every 5 frames, two consecutive frames are the same (but I don't know if this is the case in the whole material) ..
Anyone have an idea to make a movie with the original framerate (probably 25fps or 23.976fps) from such a movie?
It would be enough for me to convert the material with detecting and deleting these frames.

[rgr]

I guess I found a pattern:

The sequence of 6 frames looks like this:
012x345
(where x is duplicate frame # 2)

It comes out that the original is 25fps, and the one downloaded from YT is 30fps.
And how to convert it efficiently?
(I have VirtualDub, Vegas, ffmpeg ...)

[jagabo]

ffmpeg -i input.ext -vf decimate=6 output.ext

[rgr]

ffmpeg -i input.ext -vf decimate=6 output.ext

And it automatically detects which frame is duplicated?
I can see that this is how it works.
How simple and effective! Whoever came up with this function is a genius

[jagabo]

Yes, out of every group of N frames it discards one duplicate frame.