Cropping messes up chroma

[mg262]

I know I am doing something stupid here, but I can't pin it down. This script:

LoadPLugin("DGDecode 140.dll")
MPEG2Source("b+s 140.d2v")
crop(0, 0, -4, 0)

In AVISynth 2.5.5 causes messed up chroma like this:

http://people.pwf.cam.ac.uk/mg262/posts/chroma bug.jpg

Cropping by mod 8 works fine. Someone please explain so I can beat my head against the wall...

here is the start of the d2v file just in case...

DGIndexProjectFile10
1
35 E:\dub\dvd\BS_1\VTS_01_PGC_03_1.VOB

Stream_Type=1
MPEG_Type=2
iDCT_Algorithm=3
YUVRGB_Scale=1
Luminance_Filter=0,0
Clipping=0,0,0,0
Aspect_Ratio=4:3
Picture_Size=720x576
Field_Operation=0
Frame_Rate=25000
Location=0,0,0,963FE

900 5 0 2048 3 1 90 b0 b0 a0 b0 b0 a0 b0 b0 a0 b0 b0 a0
900 5 0 489472 3 1 90 b0 b0 a0 b0 b0 a0 b0 b0 a0 b0 b0 a0

Edit: converttoyuy2() or converttorgb32() at the end fixes things... what is going on

summat similar...
http://forum.doom9.org/showthread.php?t=96044&highlight=crop+chroma

[Schlumpf]

IIRC this happens when Xvid is registered as decoder for YV12 Video and you feed with non-mod8 widths like in this case.
This topic was thoroughly discussed and a search should turn up some more answers.

[Guest]

@Schlumpf

Thanks for pointing that out. I'd never heard about that.

[mg262]

@Schlumpf -- thank you very much. I was searching in the wrong forums but have found the threads now.