Video2X Qt6 6.4.0 desync audio problem

[alien337]

Bug
Win 11
After upscale video there is a problem with audio desynchronization I can not say exactly how much but about 0.3
seconds.

This can be seen in the video I attached (test.Upscale.mp4).

Also in the program logs I get the following message
[warning] Estimating the total number of frames using duration * fps

Settings
My settings can be seen in the attached screenshots Screen1.jpg and Screen2.jpg

FFMPEG INFO
In ffmpeg, I saw that the videos have different durations and upscale video has a bitrate lower than the original.

ffmpeg -i test.mp4
Duration: 00:00:15.12, start: 0.000000, bitrate: 9492 kb/s Stream #0:0[0x1](eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/unknown/unknown, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 9356 kb/s, 23.98 fps, 23.98 tbr, 16k tbn (default)

ffmpeg -i test.Upscale.mp4
Duration: 00:00:15.01, start: 0.000000, bitrate: 6814 kb/s Stream #0:0[0x1](und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709/unknown/unknown, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 6508 kb/s, 23.98 fps, 23.98 tbr, 16k tbn (default)

I cleared all the metadata because I thought it was the problem, it didn't work

Also the file type does not affect the solution mkv and mp4 have the same problem

[alien337]

For some reason I can't pin the videos, so here's a repository of them.
https://github.com/alien337/Bug

[alien337]

add another example in repo

ffmpeg -i test2.mkv
Duration: 00:00:15.25, start: 0.000000, bitrate: 4615 kb/s Stream #0:0(rus): Video: h264 (High), yuv420p(tv, bt709, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn (default)

ffmpeg -i test2.Upscale.mkv
Duration: 00:00:15.01, start: 0.000000, bitrate: 9798 kb/s Stream #0:0: Video: h264 (High), yuv420p(tv, bt709, progressive), 3840x2160 [SAR 1:1 DAR 16:9], 23.98 fps, 23.98 tbr, 1k tbn

[alien337]

It seems the problem was the way I cropped the video using ffmpeg

By using ffmpeg you must specify the -ss and -to parameter before -i

But, maybe my mistake will somehow help improve your project

[alien337]

The problem still exists
I get a warning in the logs all the time
[warning] Estimating the total number of frames using duration * fps

[alien337]

I have added new files to the repository test.Waifu.RealESR.libx265.mkv and test2.Waifu.RealESR.libx265.mkv (test.mkv and test2.mkv upscaled with Waifu2x extension GUI) and they play fine, there's no desynchronization with the sound.

I also tested the previous version 6.3.1. Same problem.