Optimal KDeint parameters - Your opinion wanted

[Maximus_G]

Hello, guys,

i'm ripping a DVD and facing a big problem. Using GKnot, encoded with default params and it showed me unsatisfactory results.

Please look at this:

1. Original frame with no deinterlacing (www.very.far.ru/mg/temp/72m_orig.jpg)

2. Frame using default kerneldeint threshold=10 (www.very.far.ru/mg/temp/72m_kernel_thr10.jpg)

3. Frame using kerneldeint threshold=23 (www.very.far.ru/mg/temp/72m_kernel_thr23.jpg)

As you see, in the original frame there are no "steps" on the man's forage cap (it is not moving or its motion does not produce these artifacts).
But when we use default deinterlacing, they appear.
And when we raise threshold, steps disappear, but really moving parts aren't deinterlaced.

What is the best way to overcome that?
Maybe there's a better deinterlacing technique?

[scharfis_brain]

oh-oh fieldblended Video.

this mostly occurs on standard converted (NTSC 2 PAL, or vice versa) Film.

If your source is PAL, try using restore24
If your source is NTSC,try using repal

Four first test, you may test unblend() and smartdecimate

or unblendpattern

[Maximus_G]

Thank you for the answer :)

I've tried it today, using repal (since the source is 29.97 720x480 NTSC).

The AVS script is:

mpeg2source("D:\Temp\VIDEO_TS\p.d2v")
crop(4,82,-12,-78)

DGBob(order=1)
repal()

And the result is here (http://www.very.far.ru/mg/temp/72m_tmp02.jpg).

What am i doing wrong?

[Mug Funky]

the only artefacts i see is chroma problems.

looks like you should put converttoyuy2(interlaced=true) before dgbob, then convert back to yv12 after - dgbob's getting the chroma mixed up.

[Maximus_G]

Originally posted by Mug Funky
the only artefacts i see is chroma problems.

They appear when i use dgbob filter (btw, converttoyuy2 and back doesn't change anything... :\), but the original problem can be seen here (http://www.very.far.ru/mg/temp/72m_tmp03.jpg).

Upper one is the original frame,
middle - default kerneldeinterlace,
lower - dgbob & repal.

[Maximus_G]

I've tried Decomb filter, unsuccessfully neither.

And after 2 days of continuous attempts, i just lowered the kerneldeint threshold value and put it into twoway deinterlacing mode, and it gave me a satisfactory result. Not good, but satisfactory.

And there still is one annoying artefact. Please look at it (http://www.very.far.ru/mg/temp/72m_tmp04.jpg). WHAT is it?

Looks like the filter throws away 2 lines, and replaces them with neighbour ones. It happens in every frame containing high-contrast objects disposed at an angle close to horison.

the script is simple: KernelDeInt(order=1,threshold=5,sharp=true,map=false,twoway=true)


P.S. It sad not to see some kind of a structured database of "hints and tips" explaining techniques of solving those typical problems.

[scharfis_brain]

kerneldeint uses (like its name says) a kernel for deinterlacing.
this kernel is 5 pixels high (2 above and 2 under the current pixel)

try to use

addborders(0,4,0,4)
kernelbob(5)
crop(0,4,0,-4)



btw. the articfacts you showed a post above are normal when doing deintlacing.

it is very hard to decide whether it is high detail or combing...
so either a little combing passes thru or that area is getting deinterlaced

[Maximus_G]

2 scharfis_brain:
Thank you for the explanation, it worked for me, at last :)

BTW, Google doesn't return any page in English for the query "avisynth kernelbob" - only German-language forums ;) So i used kerneldeint.

[scharfis_brain]

but kerneldeint instead of kernelbob in front of repal() would return garbarge.....

just search the forum for kernelbob...

[Maximus_G]

I decided not to convert it back to 24fps since repal and decomb produced a very jerky video - motion became twitched, and there were even duplicate frames. 90% of the video coinsided with the 3:2:3:2:2 guidance in Decomb, but still it couldn't produce a good result. So i just left it as it was... using kdeint only.

BUT now i've tried

crop(4,66,-12,-62)
kernelbob(5)
repal()

and it's very good!
Thank you so much :)