[Question] FPS in Davinci Resolve not matching source

Hi, I am a new convert to Davinci Resolve (Version 17 Build 39), coming from Premiere Pro. This is my first project and I am loving it, but something does not make sense to me. I have a 2+ hour clip that is 23.976026 FPS (FFMPEG and VLC confirm this). When I import it, Davinci Resolve warns me that “The selected clips have a different frame rate to the project…”, my project is set to 23.976 FPS. If I select “Don’t Change”, the audio track wanders out of sync by a few seconds by the end of the clip. If I select “Change” my project is reconfigured as 24 FPS but the audio is in sync throughout.

I have tried the same h264 video stream with and without the audio stream by importing the audio separately. I have imported the audio as AAC and PCM. I have also tried .mov and .mp4 containers. All with the same result.

Why does Davinci Resolve seem to think this video clip is 24 FPS? I could continue on with a 24 FPS project but I would like to understand why this is happening. I would also prefer to retain the original FPS for the final output.

Thanks in advance,
Brandon

[Peter Chamberlain]

Where is the source clip from?
it could be a variable frame rate clip as 23.976026 seems odd

It might work if you right click the clip in the bin and change the clip attributes to force 23.976 rate on the clip.

I bet it's VFR since you wrote "stream". VFR means trouble.

Thank you for your kind responses.

Unfortunately, I don’t have the original video straight out of the camera. It was delivered to me having been transcoded and I don’t know what settings were used in the process. Obviously not ideal.

Using FFMPEG vfrdet seems to indicate that it is VFR (I always thought that VFR was some exotic thing I would never deal with ) anyone know of any other way to confirm that it is VFR? As I said in my original post, if I let DaVinci Resolve handle the video like 24 FPS then my audio remained in sync until the end…am I just incredibly lucky or does it do its best to handle VFR? I don’t know if there could be any noticeable frame rate conversion artifacts in the final product if I take this route.

I could reencode it again to CFR as I have seen suggested elsewhere on the forum.

Any other suggestions for how to deal with VFR video in DaVinci Resolve?

Thanks again for helping a newbie out,
Brandon