Colors and objects are not in same place

[olfab]

Hi.
I just started working with Gordian Knot. Could solve all problems myself I ran into except this one: If you take a look at the attached picture you know what I mean.
http://img29.exs.cx/my.php?loc=img29&image=pic47.jpg
I guess it is an issue with the colorspace (YV12?) but I'm not sure and don't know how to solve it either.
Hope someone can help me.

Thanks, Oliver

[Asmodian]

Please post your avs (avisynth script).

[manono]

Hello and welcome to the forum-

It's not a colorspace issue. It could be a number of things, including a cropping problem, or deinterlacing, or perhaps something else. But as Asmodian says, we'll need a look at the .avs. When you post it, please leave off all the lines beginning with "#", since they don't do anything.

[olfab]

Here's my .avs file without the lines starting with #:

LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec3.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\undot.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\decomb.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\KernelDeInt.dll")
mpeg2source("C:\DVD\Projects\test01\test01.d2v")
crop(10,2,704,568)
KernelDeInt(order=1,sharp=true)
LanczosResize(544,400)
Undot()

Oliver

[manono]

Hi-

Either move the Crop below the KernelDeint line, like so:

LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec3.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\undot.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\decomb.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\KernelDeInt.dll")
mpeg2source("C:\DVD\Projects\test01\test01.d2v")
KernelDeInt(order=1,sharp=true)
crop(10,2,704,568)
LanczosResize(544,400)
Undot()

or crop the top and bottom by Mod 4 (in multiples of 4), like so:

LoadPlugin("C:\PROGRA~1\GORDIA~1\mpeg2dec3.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\undot.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\decomb.dll")
LoadPlugin("C:\PROGRA~1\GORDIA~1\KernelDeInt.dll")
mpeg2source("C:\DVD\Projects\test01\test01.d2v")
crop(10,4,704,568)
KernelDeInt(order=1,sharp=true)
LanczosResize(544,400)
Undot()

I recommend the first way. When deinterlacing in the YV12 colorspace (so it is sort of a colorspace problem after all), you have to crop vertically by multiples of 4. Please see this for more information:

http://www.avisynth.org/Crop

[olfab]

This works, thank you.

I understand how the second solution works. But why does the first one work. What is so important about the oder of these two lines?

Oliver

[manono]

Hi-

You cropped first and you didn't crop Mod 4. Take the upper crop. It was of two lines. But if you had read the link I posted above, and gone to the page to which it linked:

http://www.avisynth.org/DataStorageInAviSynth,

then you would have come across this:
4 pixels share the color data. These four pixels are a 2x2 matrix, i.e. two pairs on adjacent lines in the same field. As fields themselves are interleaved, this means that for fieldbased video line 1&3 share color data, as well as line 2&4.
So you need 2 lines from each field to get the complete color information. By cropping only 2 pixels from the top, you cut out lines 1 and 2, and left lines 3 and 4 of the 4 line set needed to convey all the color information. Remember, when interlaced, there are 2 different fields involved, and you need lines 1 and 3 from the top field to get the complete color information for it, and you need lines 2 and 4 to get the color info for the bottom field. Got it? Clear as mud?

Once you deinterlace, it becomes progressive, or frame based, and you're back to needing only 2 lines to convey the color information. And that's why it's safe to crop 2 pixels if the Crop is placed after the Deinterlace.

This isn't entirely your fault. I blame GKnot for not putting the crop after the deinterlace. Or maybe the developers give everyone too much credit for understanding all this esoteric mumbo-jumbo.

[olfab]

Once you deinterlace, it becomes progressive, or frame based, and you're back to needing only 2 lines to convey the color information. And that's why it's safe to crop 2 pixels if the Crop is placed after the Deinterlace.
Now I got it. Deinterlacing makes it progressive. I read the link but didn't see the connection.

Thanks again,
Oliver