Progressive audio/video desync when exporting WMV (29.970 fps) source — video timestamps generated at 30 fps

[PeggyzZZ]

Describe the bug

WMV (VC-1, 29.970 fps / 30000-1001) source exported by Jasna has progressive A/V desync in the output MP4: in sync at the start, drifting to ~7 s by the end of a ~2 h file.

ffprobe shows the output video track is shorter than the audio track (video 7185.06 s vs audio 7192.36 s, same frame count as source). Looks like the video timestamps are generated at 30.000 fps instead of the source's 29.970 fps, so the video plays ~0.1% fast.

To Reproduce

Input: SSNI-476.wmv, exported with Jasna's default config profile.

SSNI-476.wmv.MediaInfo.xml

SSNI-476.mp4.MediaInfo.xml

Desktop:

• OS: Windows 11 Pro
• Jasna Version: v0.10.0
• GUI or CLI? GUI
• GPU: RTX 5070 Ti
• Nvidia Driver version: 610.88
• CPU: i5-13600KF

[shawhu]

I can confirm this.
what I do is this, for now, I just rewrite the pts. didn't touch the actual video data track, and it seems to fix the problem for me.

ffmpeg -i input.mp4 -c copy -bsf:v "setts=pts=PTS*1.001" fixed_video.mp4