Video audio desynchronizes when interpolating 23.98fps

[DustyIdeas]

I'm using the latest version 1.41. When I interpolate this series, the audio progressively desynchronizes as I watch the movie. The desynchronization becomes severe, reaching up to 2 minutes by the end. Here's an example of the first 4 minutes of the show:

https://streamable.com/g5y8u1

As you can see, the video desynchronizes noticeably within just 3 minutes. Could you help me troubleshoot this issue or potentially fix it?

[chinobino]

I am also having this problem with 1.41.0 RC1. I have run it on short videos that are 5-6 mins and see the same desync, with the video appearing to lag behind the audio using RIFE (NCNN/VS) + RIFE 4.26.

[n00mkrad]

Can you provide your original files so I can reproduce the issue?

[DustyIdeas]

I've gotten rid of the original files. I was rendering all 7 seasons of "The 100" and found another torrent for season 7 that had a different frame rate. As far as I know, this frame rate doesn't have problems: "Frame Rate: 23.976 (24000/1001) FPS".

I think a solution would be to allow a lower fps definition. Instead of only about 5 extra 0s, it could be around 20, like this:

I wanted 3x, so for exactly 72 fps, the output would need to be exactly 3.0025020850708923 fps. But I tested that, and it still didn't work.

[chinobino]

The files I tested with are MPEG-2 in MPG container. The video is interlaced, and as Flowframes does not deinterlace I presume this is the cause of the desync.
I then tested with AVC in MP4 container and there was no desync.
Is it possible for Flowframes to deinterlace?