does xvid tend to green colors?

[Omni]

i just made a comparision between a source-screenshot, xvid and divx5.
i noticed that the the colors from divx5 are really close to the source. but xvid tends to give the picture a very little bit more green.
i used xvid rc4 and the xvid decoder for my xvid version, and tried the divx5 version with the divx and xvid decoder. i'm just wondering if xvid encoder postprocessing causes this slight color deviration...it's not really much deviration from the source but the source and divx5 colors are a bit more brilliant. since xvid is the better encoder i'd really like to find a solution for this color deviration.

[ObiKenobi]

I doubt this has anything to do with the codec cause I've been using xvid for 2 years and have never noticed this problem. Can you post some screenshots so we can see this problem? This would make it easier to try to help you.

[Jackzeripper]

hello, the green color depend of color depth. I've had the same (but inverted) problem : DivX5 green (in 24 bit color depth) and XviD like DVD (12 bits)

You must stay at 12 bits of color depth (= "Fast Recompress" with VDubMod) ; 12 bits like the codec and like AviSynth 2.5x, and like ... DVDs :D

[Omni]

i can post some pictures tomorrow (i first have to clear my webspace)
i compared them and noticed that the same pixel has an about 5 higher green-saturation with xvid.

@Jackzeripper
if this is virtualdub related, then why is divx5 not affected?

i guess i'll just decrease the greenchannel about 5 notches. i already made some tests and the resulting image was nearly pefect to the source.

[ObiKenobi]

Well there has to be something else causing it since this is the first time I've ever heard this come up. But what are your xvid settings and your AVS script?

[Imperial Llama]

How are you comparing the two clips? If you are doing it by loading each one into a seperate instance of media player there will often be differences becuase the first clip loaded will be rendered using the video overlay where as the others won't. The overlay on some video cards (some old nVidia cards are known to have very poor overlays) looks different compared to when it's being rendered in software.

[stephanV]

Originally posted by Jackzeripper
[B]hello, the green color depend of color depth. I've had the same (but inverted) problem : DivX5 green (in 24 bit color depth) and XviD like DVD (12 bits)

DivX uses yv12 as internal colorspace too, right?

id be interested in the screenshots though :)

[Jackzeripper]

see here for screenshots => http://forum.ripp-it.com/viewtopic.php?t=1721&start=113

(must subscribe to read)


both codecs are yuv12 but if you encode with VDM in "Full Proc. mode" the codec receives 24 bits colordepth (and had green color).

[Sirber]

always use fast recompress mode, so there is no colorspace convertion.

[Omni]

colorspace conversion shouldn't be the problem. if divx has correct colors than the xvid gets the same colors as divx.


How are you comparing the two clips? If you are doing it by loading each one into a seperate instance of media player there will often be differences becuase the first clip loaded will be rendered using the video overlay where as the others won't. The overlay on some video cards (some old nVidia cards are known to have very poor overlays) looks different compared to when it's being rendered in software.


using vmr9 won't affect displaycolors on the 2. opened video but i also copared to screenshots taken when there was no other video stream opened.
i'm quite sure the problem is either in the xvid encoder or decoder because it's the only codec who shows a deviration.
wmv9, divx, vp6, rgb are all the same.
i'll post those screenshots later since i just got home and have to finish some u-works.

[Soulhunter]

Originally posted by Omni
i can post some pictures tomorrow (i first have to clear my webspace) Nah, upload them here... (http://www.imageshack.us/) ;)


Bye

[cweb]

Some things:
Try changing the resolution to true colour (32 bit) if it isn't yet.

There's an option too in the XviD decoder called COMPATIBILITY RENDERER.

I saw a PC today with this 'green problem' and enabling the above renderer solved it. So try it.

[Omni]

Source:
http://img7.imageshack.us/img7/6855/a1_source.png


Xvid:
http://img7.imageshack.us/img7/4523/a3_xvid.png


Divx5:
http://img7.imageshack.us/img7/618/a2_divx5.png


i tried other decoders (xvid,divx,ffdshow) made screenshots over zp and vdub but it was all the same. also noticable that divx5 colors devirate a bit from the source they are a bit more saturated which looks like divx5 enhances the color before encoding i guess.
i decoded the xvid and divx5 video via xvid-ds the source-screenshot was take from virtualdub....it looks the same if i output it to avi uncompressed.
i could post more screenshots but comparing the white spacesuit and the haircolor should be visible enough.


Some things:
Try changing the resolution to true colour (32 bit) if it isn't yet.

There's an option too in the XviD decoder called COMPATIBILITY RENDERER.

I saw a PC today with this 'green problem' and enabling the above renderer solved it. So try it.

nothing changed^^

[Jackzeripper]

weell, here are the shots

Xvid (12 bits - I got 12 bits in all compression modes it seems :confused: )
http://cinergon.free.fr/IMG/q1xvid.jpg

Divx 12 bits ("Fast Recompress")
http://cinergon.free.fr/IMG/q1divx12.jpg

Divx 24 bits ("Full Proc. Mode" de VDM)
http://cinergon.free.fr/IMG/q1divx.jpg




Xvid
http://cinergon.free.fr/IMG/q2xvid.jpg

divx 12 bits
http://cinergon.free.fr/IMG/q2divx12.jpg

divx 24 bits
http://cinergon.free.fr/IMG/q2divx.jpg

[Omni]

intresting...i'll make some tests using fast recompress, but since i need textsub for the karaoke i have to stick on my little color correction :)
i now wonder why in my case only xvid is affected and not divx.