problem with framerate conversion

[Bruno999]

Hello, I have a problem using Vapoursynth to convert 29.97fps videos to 59.94 fps. The original file lasts 5 minutes and after conversion it is 20% longer, it lasts 6 minutes. This does not happen on all the files, even if they come from the same camera. The video is slowed by 20%. The encoding codec is not for nothing I try x264, x265 is the same. The original file is 9000 frames, the output file makes 21577 frames whereas it should make 18000.
Here is the debug file.
Thanks for your help I have searched but I have not found...Please, read the 'Infos needed to fix&reproduce bugs,..'-sticky before you post about a problem.

[Selur]

That sounds strange. Since you didn't share much info on the matter, can you share the file you encode with me. (best upload it somewhere and send me a link via pm)

Cu Selur

[Selur]

Problem is related to the source filter.
For some reason LWLibavSource reports back 25fps not 29.976fps for the source.
-> disabling "Filtering->Vapoursynth->Misc->Prefer LibAvSource over FFmpegSource2" seems to fix the problem for me.

Cu Selur

Ps.: will do some additional testing over the next days, hoping to figure out why this really occurs and whether there is a way to detect such sources.

[Selur]

Small correction, problem is not LWLibavSource but LibavSMASHSource, so disabling:
"Filtering->Vapoursynth->misc->Prefer LibavLSMASHSource over LibavSource for mp4/mov" also fixes the problem.

Cu Selur

[Bruno999]

Problem resolved by disabling the option! thank you !