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View Full Version : IVTC MPEG2 chroma correctly in VirtualDub?


tygerbug
5th November 2023, 20:13
http://orangecow.org/shared/bananahands.png

I am working from a DVD MPEG-2 file (29.97i) and IVTCing it in VirtualDub to 24p Lagarith.

Clearly the chroma is not IVTCing in the correct way here. I have tried various options under "Decode Format" and "Compression" and it does not seem to have an effect.

I used to know how to handle this problem on Mac. Ideally I would like to handle this problem entirely in VirtualDub (on PC). (I could add some AviSynth filters although that would not be my preferred solution.)

As I recall, the Mac solution was to use MPEG Streamclip, decode to ProRes and select "reinterlace chroma." The PC equivalent of this has no good/ uncompressed options and is an extra step I'd rather not go through. (Even if it would fix this, and is what I'm experimenting with at the moment.)

There were also command-line ffmpeg options.

I am having better but still a bit smeary results by "Using conversion: YUV422 -> YUV420." ("Configure" hasn't had much effect on this.)

poisondeathray
6th November 2023, 04:14
Assuming your source is ok, the vdub IVTC filter works in 4:2:2 . You would need to convert 4:2:0 to 4:2:2 in a an interlace aware manner first , instead of progressive chroma upsampling resulting in artifacts

JPDSR has an AutoYUY2 vdub filter that can do that. Set to interlaced and apply prior to IVTC
https://github.com/jpsdr/Filtres_JPSDR