transcode Variable Frame Rate (VFR) AVC video to Constant Frame rate (CFR)

[hydra3333]

Is there a reliable way of using ffmpeg to transcode Variable Frame Rate (VFR) AVC video to Constant Frame rate (CFR) ?
If so can you please show an example commandline ? I have an nvidia gpu, if that's of any use with cuda or something.

I recently bought a Samsung S8+ mobile phone. ALL videos recorded by the S8/S8+ cameras are h.264 8-bit progressive VFR .mp4 in various resolutions and colour spaces and profile levels as outlined in the attached pdf.

The video editing software I use (VideoReDo) and apparently most if not all others only handle CFR, hence the query.

[Selur]

Is there a reliable way of using ffmpeg to transcode Variable Frame Rate (VFR) AVC video to Constant Frame rate (CFR) ?

Keeping it simple:

ffmpeg -hwaccel cuvid -c:v h264_cuvid -i input -c:v h264_nvenc -preset slow -r X output.mkv

should create Xfps cfr output by duplicating or dropping frames to archive the target frame rate, so replacing X with a frame rate >= the max frame rate for each video should work.
(alternative to duplicating the frames one could use minterpolate for motion interpolation based frame creation)
You might also adjust the nvenc settings depending on your speed, quality and color format needs,...

[hydra3333]

Thank you. That looks easy.

I'll look into minterpolate as well then.

I reckon I should probably look over on the doom9 forum to see if they also have a motion compensated conversion solution in vapoursynth.
Unfortunately great tools like DG's set don't handle VFR input, so I'll need to look into an alternative vapoursynth input method if there's a vapoursynth related approach around.