Extreme Rainbowing

[ZacharyGeorgeNN]

I copied over two VHS tapes that have some pretty bad rainbowing on them. Which avisynth script should I use to properly decimate these, and make them more watchable?

https://mega.nz/file/YVMGAIoQ#g7sU0iVFq7Dp_8qz30zF8ma-wD2O6YkMXkSC0oiwVM0
https://mega.nz/file/hEUSCRha#sm66D2Xig53UiyB8hh8tSZ7at5xXz1oe-dQLgYPaONM

[jagabo]

GrayScale()

[ZacharyGeorgeNN]

GrayScale()

They're both color films

[rrats]

Try using a different VCR or a TBC first.

[jagabo]

I agree with s-mp, a better vcr, and/or a better capture device, and/or a TBC will should be used to avoid the problem in the first place. I don't think there are any de-rainbow filters will fix the chroma in that video. That's why I suggested just converting everything to greyscale. You could try some quick dirty tricks like copying the chroma from other frames, or using motion interpolation of the chroma from the good frames surrounding the bad sections. But given the length of the bad sections and the amount of motion neither will work well. And it's a fair bit of work as you have to specify the sections manually.

Mpeg2Source("EYES_OF_THE_PANTHER.demuxed.d2v", CPU2="ooooxx", Info=3) 
TDecimate(chroma=false)

ReplaceChromaNext(2, 15) # copy chroma of frame 16 to frames 2 through 15
ReplaceChromaMC(21, 27) # interpolate chroma from frame 20 to 28
ReplaceChromaMC(73, 140)
ReplaceChromaMC(145, 152)
ReplaceChromaMC(181, 251)
ReplaceChromaMC(291, 371)
ReplaceChromaPrev(398, 424) # copy chroma of frame 397 to frames 398 through 424
ReplaceChromaNext(425, 450)
ReplaceChromaMC(520, 551)
ReplaceChromaPrev(615, 663)
ReplaceChromaNext(664, 677)
ReplaceChromaMC(724, 805)
ReplaceChromaMC(828, 914)

ColorYUV(gain_y=100, off_y=14)
Tweak(cont=1.4, bright=15, sat=1.7, coring=false)

StackHorizontal(src, last) # original on left, filtered on right
Trim(0,941)

You'll see many places where the chroma is not aligned properly. Of course, you can refine some of this by manually panning the chroma rather than just copying it, or otherwise tracking chroma. But that will be a lot of work.

[rrats]

I think I've seen this happening couple of times. Most likely a crappy capture card or TBC problem. Now the user would have to pray that the artefacts were created on the tape he's working with and weren't present in the previous generation