green screen after crop

[jk888]

Hi I am a newbie at Avisynth, recently I began to try cropping my video using AVSEdit. But seems whenever I do cropping, the output video turns green, when I decrease the cropping it goes away. Is there anyway around this?

I searched the forum, read through the FAQ and checked google, still not a single post about this green screen thing. I hope someone will enlighten me on this.

Here's the script I use:

LoadPlugin("F:\AviSynth 2.5\plugins\mpeg2dec3dg.dll")
LoadPlugin("F:\AviSynth 2.5\plugins\Decomb510.dll")
mpeg2source("F:\DVD3\test.d2v")
FieldDeinterlace(blend=false)
Crop(4,62,-4,-58)
LanczosResize(624,416)

[Wilbert]

If you open the cropped version in vdubmod/vdub it's also green? If so, check under file information what codec is used to decode it.

If some weird codec is used, check Q13 from the YV12 faq.

[jk888]

Yes when I open the cropped version in Virtualdub it is green, even after I encode the movie the output is also green. The decoder used in virtualdub is the Xvid decoder. When I watched the outputed video using ffdshow it's also green. It's as if the video itself became green after I cropped.

Is this an Avisynth feature to tell users that they cropped too much? Cause if it is I'd like to turn it off. Also I didn't overly crop the video, I just took off the black borders. Somebody please help!

[sh0dan]

Try using Decomb 5.1.1 (http://forum.doom9.org/showthread.php?s=&threadid=70579&highlight=decomb+5.1.1).

[krieger2005]

Hi,

I know the problem.
It seems that if the cropping is not devide-able through 4 (8) the output is green. I don't know when and why this happen (and does not tried the new decomb) but if you crop little bit more the scrren go... (As i can remember i thought, that this problem happen when changing color-space... while using different filter before).

Try when you correct -58 to -60 (and 62->64)... =>crop(4,64,-4,-62)

----- EDIT
I tried a little bit.... As i said is it a Colorspaceproble.... but nit of crop ;). Here the Source:

mpeg2source("D:\X\film.d2v").ConvertToYV12()
FieldDeinterlace(blend=false)
Crop(4,62,-4,-58)
return last

==> not a green output


mpeg2source("D:\VTS\Çèìíÿÿ âèøíÿ\D2V\film.d2v").ConvertToYV12()
FieldDeinterlace(blend=false)
Crop(4,62,-4,-58)
LanczosResize(624,416)
return last

==> Green Output


mpeg2source("D:\VTS\Çèìíÿÿ âèøíÿ\D2V\film.d2v").ConvertToYV12()
FieldDeinterlace(blend=false)
Crop(4,62,-4,-58)
ConvertToYUY2().LanczosResize(624,416)
return last

==> Not a green output

So you must convert to YUY2() before using LanczosResize... Maybe someone said the developer this problem (i don't know who he is)

[Wilbert]

Crop(4,64,-4,-60)

:)

[jk888]

-I tried the new decomb 5.1.1, and yes that works!
-Also tried adding the ConvertToYUY2() line to LanczosResize, and yes that worked as well!!

-croping to (4,64,-4,-60) didn't work, but that's not very convient anyways.

So now the question is, why does 2 methods work? What does it all mean? Should I use both methods on my script?

[mf]

actually, I've had this (http://mf.onthanet.com/forum/thread.php?threadid=9&boardid=4&styleid=1) happen to me when cropping non-mod4, and it annoys me pretty badly too. No decomb involved anywhere (not even mpeg2dec3-dg ;)), and converttorgb "fixes" the chroma. How very nice, if I'm only interested in an YV12-ONLY encoding chain. You'd say resizing to mod16 would fix the problem, but no.