Possible Problem with Input 2:3 Pulldown VOBs and MKVs

[shijan]

Things where slightly adjusted in dev. versions when you fixed DVD importer, but i guess some mistakes remained somewhere. This is only guess, so correct me if i am wrong. Here is example of same VOB source:

VOB Mediainfo:
Frame rate 23.976 (24000/1001) FPS
Scan type Progressive
Scan order 2:3 Pulldown

VOB opened in Hybrid:
telecine
29.970/CFR
Image looks normal if i apply Deinterlace->TIVTC or VIVTC

VOB muxed with MKVToolNix GUI to MKV Mediainfo:
Frame rate mode Variable
Frame rate 23.976 FPS
Scan type Progressive
Scan order 2:3 Pulldown
(VTS_01_1-TEST3 example muxed by MKVToolNix to 24.811. Have no idea why)

VOB muxed with MKVToolNix GUI to MKV and opened in Hybrid:
progressive
23.976/VFR
If i set input as progressive, i can see 2 interlaced frames and 3 progressive frames pattern.
If i apply Deinterlace->TIVTC or VIVTC output framerate changes to incorrect 19.1808 fps.
Image looks normal and framerate remains unchanged only if i apply Frame->Misc->TFM or VFM

So the questions are rather complex:
Why Hybrid reads 2:3 Pulldown MKV files in this way?
Is it normal to use Frame->Misc->TFM or VFM in this situation?
Why MKVToolNix changes files metadata like this?
Where came from those strange framerates in some muxed files? Corrupted VOB or maybe a bug in MKVToolNix?

Maybe for situations like these it make sense somehow add an option for Hybrid to manually set input framerate and scan type independently before deinterlacer?
Or somehow else adjust things?

Here is a folder with VOBs and muxed MKVs if it helps: https://drive.google.com/drive/folders/1...sp=sharing