colors wrong after encoding

[bmnot]

hi. I'm currently having a problem with my encodings. on some dark scenes the background will go from light to dark and back, while it should be static. I haven't figured out yet, when exactly this occurs, as it seems to happen rather random and it is getting kind of annoying. (That's also the reason I'm not sure this is the right forum, as I don't know what causes this) the problem doesn't occur on the source file, so to solve this, I already tried to change:
- the player/decoder (mplayer and mpc with ffdshow-tryouts)
- the codec (h264 and xvid)
- the container (mkv and avi)
- the encoder (staxrip and gordian knot)
- the deinterlacing filter (yadif, field deinterlace(blend=false) and smartbob)
nothing worked. I've attached screenshots of the problem (you can see it best at the dark area on the left, which should be absolutely the same). I also uploaded a part of the source file to http://www.megaupload.com/?d=V398OMZL (13,3MB, 30 sec digital capture)
I hope someone can help with this and thank you in advance.

nudelbubu

[Dust Signs]

Hi,

is it possible that ITU-R BT.601 is part of your problem? ITU-R BT.601 limits the values of every plane (chroma and both lumas) to the range between 16 and 235 where 16 is black and 235 is white. It looks as if a conversion is performed, mapping the [16,235] range to [0,255]. How do you decode your source stream? Maybe the conversion is performed at that point. Just a thought... don't know if this is helpful for you

Greetings
Dust Signs

[bmnot]

I have been using:
- PVAStrumento 2.1.0.17 to demux the file
- Mpeg2Schnitt 0.9.0 to cut (that's where the uploaded file comes from)
- StaxRip 1.1.1.0 to do the rest (I'll include the StaxRip Log, that should list all used programs and filters)

thanks for the help so far
nudelbubu

as the attachment does not seem to be downloadable atm, I also uploaded it here:
http://wwdsl.ww.funpic.de/bubu/Alpha%20Centauri%20-%20081%20-%20Wo%20war%20der%20BigBang_StaxRip.log.txt

[Adub]

Hmm... it's interesting that there is no Colormatrix call in there. When converting between mpeg2 and h264, it is usually best to convert color matrices to the correct spec that h264 uses for (in this case) SD video.

I have never used staxrip, but if you can, edit your script to look like this:

MPEG2Source("E:\rip\ac_yadif\Alpha Centauri - 081 - Wo war der Big Bang.d2v", info=3)
Colormatrix(hints=true,interlaced=true)
LoadCplugin("C:\Programme\StaxRip_1.1.1.0\Settings\Applications\Yadif\yadif.dll") Yadif()
Crop(14,2,-10,-2)
BicubicResize(640,480,0,0.5)

[LoRd_MuldeR]

I really like that show - Alpha Centauri. It's funny how that guy gets into rage, when he explains astrophysical phenomenons. The best episode was the one when he smashed all those "the landing on the moon was a fake" theories to pieces :D

[bmnot]

Merlin7777: that didn't work, the output is still the same. thx anyway

LoRd_MuldeR: yeah, the show's great, that's why I've been recording it...

[Atak_Snajpera]

force hq-rgb32 in ffdshow

[bmnot]

you were talking about the "hq YV12 to RGB conversion" option in the output tab during playback, right? (Might have a slightly different name, as I'm using the german version)
If so, that didn't work either.

Is there anything I can check on the files to find out, what the problem is?

nudelbubu

[Atak_Snajpera]

I've encoded your sample and I see nothing wrong with colors! BTW. Did you uncheck all other options?
http://img413.imageshack.us/img413/7729/new1rw0.th.png (http://img413.imageshack.us/my.php?image=new1rw0.png)

[bmnot]

that solved the problem. \o/ you're my personal hero :D

It also works with mplayer now. All I had to do was switching the video output driver from DirectX to OpenGL (gl2)

thanks for all the help
nudelbubu

[Atak_Snajpera]

What graphic card do you have? Do you use Vista?

[bmnot]

graca is Geforce8800GTS512 and I'm running XP.
The reason for OpenGL to work on mplayer seems to be that it autoformats the colorspace to bgr24, while it stays yv12 with DirectX.