Strange artefact on a PAL DVD (cartoon)

[pila13]

Hello, i was asked, encode old cartoon, and everything fine, except of strange artefact what i yet never saw, i almost never encode PAL, and not sure what is this and how deal with it.
At first i thought it's dotcrawl, but tcomb / checkmate didn't react on this artefact, after this i try run qtgmc with medium preset....But it's make everything even worth, well here it is →

No filters -

http://a.pomf.se/1/eheljg.PNG

qtgmc -

http://a.pomf.se/1/ejjuwz.PNG

And short clip -
http://www41.zippyshare.com/v/88776550/file.html
＿＿＿＿＿＿＿＿＿＿＿＿＿＿

I'm quit frustrated about this bug, and i appreciate any tip, help, advice what can help solve this problem.

Thank you.
- Cheers.

[Guest]

Hello, pila13. It looks like interference. Try an FFT denoiser, such as defreq or fft3dfilter.

[pila13]

Thank you i will try defreq. I usually use dfttest... never got into fft3d.

[Guest]

I think fft3d is pretty old and defreq is the more used one. But hopefully some Avisynth gurus will help better than I can.

[pila13]

I tested defreq, and wow, this is pretty hard =)
I wan able get right frequency, and still doesn't seems like it's actually helps, i'm not even sure that this artefact is interference =(
FanFilter, if something, could not even run it, eh... i'm bloody scrub at avs, all hope on gurus ^^;
Thank you neuron, i was able at last get some kind of idea what is this.

[Guest]

Hmm, you should get some improvement. I will have a go at it, but remember I probably have less experience with it than you. Waiting for others...

[pila13]

I do receive very very small improvement, i can't understand why this interference happening after qtgmc, if i don't use it, this "noise" look like very very bad DC.
Haha, i'm pretty sure, you neuron, have much more experience with it than me ^^

[Guest]

Looking more closely, it does appear to be dot crawl and not interference.

Let's try some more dot crawl filters.

[pila13]

Oh wow, really ? Because i try my main checkmate(tthr2=0) to prevent artefacts on a fast moving objects. And tcomb().
Now i try some new DC filters ^^

[LemMotlow]

Chroma Sampling Error. Common on many DVD's and playback devices since pre-2000. https://www.google.com/#q=chroma+upsampling+error+sample+images

[pila13]

Oh my ! Thank you , i right away will search filter for dealing with this. DC filters didn't help at all.....
Sad to say, but doesn't seems like. But, any way, thank you for help.
Seems like img hosting on what uploaded pictures in down, so here new one -
I'm having trouble with this artefact -http://i.imgur.com/pvSqGRh.png
But using this DC script -

DeCrow
DeCrawl()
DeDot(luma2d=20, lumaT=20, chromaT1=0, chromaT2=255)


QTGMC( Preset="medium" ).SelectEven()

function DeCrow(clip source)
{
out1=source.checkmate(tthr2=0)
out2=source.checkmate(tthr2=0)
return out2.mergechroma(out1)
}

I have this result -
http://i.imgur.com/dyWa16T.png

But picture loosing quit alot of details, i want keep some kind of details in rip, if it's possible....

[Guest]

Chroma Sampling Error. I'm not sure about that. It isn't showing the characteristic vertical spatial frequency you would expect, and you still see the artifacts without chroma upsampling. Still looks like classic dot crawl to me. We're talking about the checkerboarding around the red digits at frame 44, right? Or are we looking at different things?

[LemMotlow]

I know what you mean, neuron2. The checkerboard looks like a mix of CUE and dot crawl IMO. The worst effect shown here is inconsistent on every frame. At first I was going by posted images, but looking at the downloaded clip I see more than just this problem. There's a lot of jitter, frame hop, line twitter, etc. Looks like it came from tape with no line tbc. I don't know why QTGMC is being used on video that's progressive with pulldown. At least that's what I see in the clip. Motion is really jerky, with or without IVTC. Is this sample clip processed and re-encoded, or is it the original source the O.P. works with? I think maybe we need more history about this video.

[Guest]

I agree with everything you said, LemMotlow. There also seems to be some interference as well.

Some such terrible sources are arguably not worth spending much time on, but some may view it as an interesting challenge.

What DVD is that, pila13?

[pila13]

No, french dvd. dvdbox, if be more specific. Fun thing that clip what i add from DVD3 (ep2), and first episode on dvd3 fine, but rest horrible. Prev. dvd 1-2 was fine, normal PAL, with some DC and rainbow....
I did used qtgm, since thought it's PAL, but when notice source progressive - tfm. Seems like this title have MUCH more problems than i thought at first....

[Guest]

What is the title of the DVD set?

[pila13]

Biker Mice From Mars (Les Motards de l'Espace)

[pila13]

So...no more ideas how deal with this title ? ；ω；

[LemMotlow]

I'm looking at dot crawl mixed with a kind of cross-hatch -- you see the latter most noticeably in saturated colors and along edges, plus halos and edge ghosting. And some oddities, like uneven horizontal motion, often some effects that look like dropped frames, projector hop, etc. In the unprocessed d2v sample posted earlier, it seems to me that in the sequence starting in frame 241, some frames are out of sequence. Starting in frame 1411, the downward pan shows jitter and twitter in horizontal lines, followed by a panning shot from left to right that has jerky motion. For the cross-hatching and edge artifacts I used this code:

TComb()
assumetff()
TFM(order=1).TDecimate()
Stab()
Spline16Resize(360,576)
DeHalo_Alpha().MergeChroma(aWarpSharp2(depth=30))
Spline36Resize(720,576)
LimitedSharpenFaster()
Crop(8,2,-14,0).AddBorders(12,2,10,0)

...and got this improved but imperfect result (top = original, filtered = bottom):
http://forum.doom9.org/attachment.php?attachmentid=14248&stc=1&d=1403406149

Stab() helped calm the frame hopping and Crop/AddBorders smoothed the resulting border twitches. You could try additional blur/resharpen or smoothers like TemporalSoften, but it's far too easy to make this video look denuded and plastic with a ton of plugins. If more smoothers, I'd advise finishing off by adding fine grain or random noise -- or you'll see banding after re-encoding. And there would still be the weird motion, some macroblocks, and other problems.

[pila13]

Thank You very much ! It's works like a charm, i will little tweak it, for example change LimitedSharpenFaster() on lsfmod() and maybe super light dfttest >:3

[Guest]

+1. Great work, LemMotlow!