[FFmpeg-user] Detelecine: I got the right result from the wrong command?

[Mark Filipak]

On 28/05/2025 21.27, Alex Xu wrote:
> I got those "unnecessary" args from
> https://trac.ffmpeg.org/wiki/Encode/YouTube They aren't important.
> 
> I think you might be mistaking CRF for CFR (constant frame rate).

Nope.

> CRF is a
> measure of compression, it shouldn't drop and duplicate frames. frames.
> https://trac.ffmpeg.org/wiki/Encode/H.264#a1.ChooseaCRFvalue

Crf is essentially undocumented in both FFmpeg and x264. I think it means constant rate factor -- a 
factor? what kind of factor? a factor in what?. I reckon frame 173 was 'late' and so, was dropped. 
Then frame 174 was repeated to maintain 'crf=18' (whatever that is). I think crf is for streaming, 
not transcoding, of which detelecine is part.