Red pixels in black/dark area's

[ViCroié]

Hey,

This bug is prolly not XviD related, though it occurs in all my XviD encodes.

Basically its a red blue or green (mostly red) pixel wich pops up in a black/dark area (as far as i noticed)

I made a screenshot of a it (trailer)

http://home.planet.nl/~donse113/error.PNG

I would like to know if anyone else ever had this problem or even seen it in an encoded XviD file and how to get rid of it :rolleyes: cuz it ruins all my encodes at the moment. I'm really clueless on this :confused:

I used: XviD decoder (version did not seem to matter), FFDshow did not make a difference, also changing colour space did not help... The way i encode the file seems to have no effect (i tried it all, XviD's version did not seem to matter), I used the newest MPC to play it but also WMP9 and vdub show it.

I encoded the file with the newest Vdubmod

(I'm using a P4 on XP)

Thx

[Manao]

What version of XviD did you use ? Have you the same issue with different version of XviD ? What were your XviD settings ? Why do you think it's not XviD related ?

Does the problem happen on a keyframe / pframe ? If so, do you see it on the following frames ?

Without those answers, my best bet is a hardware problem.

[CruNcher]

hmm looks more graphiccard related to me Memory/Core to hot ?
is the same problem ocouring in non Overlay surfaces also ?

[Manao]

I don't think it's related to the graphic card : zoom, you'll see a whole 16x16 block whose chroma completly went ajar. For me, it's as if DCT coefficients had been badly decoded.

[ViCroié]

Thx for the reply,

Well, the version did not matter, but this was 1.0.1 koepi

and i also thought it might be my GFX card... but i switched my Geforce for a Radeon, and it didnt resolve... and strangly when i dont use overlay it also happens :( (this picture was taken while redered in VMR9)

i think its encoded into the video, and not decoded wrong, like manao said the whole 16x16 block's chroma is encoded wrong.

and the frame was a B-frame

EDIT: they appear at encoding aswell as decoding (here is the sample video redpixel.avi (http://home.planet.nl/~donse113/redpixel.avi) )

[Soulhunter]

Originally posted by CruNcher
hmm looks more graphiccard related to me Memory/Core to hot ?
Also the first thing I considered, but...

Wouldn't this be visible @ the screen only then ???

Think a screenshot is made before passing the signal to the GC... :confused:


Bye

[ViCroié]

Did u download the AVI?

Cuz you prolly are able to see the pixel in the last second of that clip.

If ur able to see it, its not a decoding problem

I also tried turning off "Alow video overlays" when encoding with vdubmod, but it doesnt help

[malkion]

Loading it in Vdub, the dot is on frame 252.

How strange. This is on all your video encodes with Xvid only?

You should post all your encoding info, like the normal script u use.

The settings of Xvid, including matrix used, etc... heck, include your cpu info too.

edit: I just examined the avi with DivXDRFAnalyzer, can u try another sample encode, but disable packed bitstream.

[ViCroié]

Ok here it is,

My AVS script:

MPEG2Source("F:\TrailerVidz\trailer 1\Trailer1.d2v",idct=5)
LumaFilter()
Crop(6,78,-2,-74,align=true)
Undot()
LanczosResize(704,288)

My XviD settings:

Quantization Type: HVS-best
AQ, Qpel, B-frames (2,1.50,1.00), GMC, trellis quant (on)
VHQ4, Turbo

My CPU:

P4 2.4ghz

----

I made a new sample encode without packed bitsteam, settings i used:

Quantization Type: H.263
AQ, B-frames (2,1.50,1.00), trellis quant
VHQ1, Turbo

bluepixel.avi (http://home.planet.nl/~donse113/test5.avi)

http://home.planet.nl/~donse113/smaller.PNG

----

and, i mostly encode with XviD and RV9/10 and RV did not show it as far as i know, and it doesnt appear in every encode, but in a 5 min movie with allot of fading through black, it happens allot. But its still very random, sometimes i encode thesame movie with no problem at all.

[malkion]

I've never seen any avi's with a standard deviation that high before.

I dont rightly know what's causing these pixels to form. Perhaps one of our resident gurus can help.

For myself, I use any given matrix with b-frames, chroma optimizer enabled and chroma motion only. Never once have I used trellis, AQ, Qpel, Turbo or GMC. Old dev3api habits I suppose. Then again I never produce any strange encodes.

If it might interest you, why not just try a quick encode without all the extras, I noticed u have trellis, turbo and AQ in common between your 2 encodes.

Best wishes. (your settings actually look fine, and I think lotsa people have encoded with those settings without those colored dots)

[niamh]

hhmm, did anything happen right before this started? have you tried an older version of vdub? this is only in the final encoded file? i.e. nothing shows on the avs script loaded for preview? ( never know ) :) easier to ask questions than to answer this one ;)

[ViCroié]

@ malkion:
If it might interest you, why not just try a quick encode without all the extras, I noticed u have trellis, turbo and AQ in common between your 2 encodes.
thx for the advice, and well, thats also the reason i did not post my settings right away, because i tried all settings before i made this thread, also without all extra features.

@ niamh:
hhmm, did anything happen right before this started?
Well, it actually started some while ago. And XviD 1.0.1 wasnt even there at that time. But i ignored the problem, basically cuz i thought it really was my GFX card. And now that i changed my GFX card and the problem is still there, i really dont know what to do about it.
have you tried an older version of vdub?
I did use older versions of vdubmod and normal vdub with thesame results
this is only in the final encoded file?
yes its only in the final encoded file, if i play the AVS its not present

Also, nothing in my system is overclocked*
and i even formatted my HD and reinstalled Win XP, wich didnt help

[malkion]

one last observation, your crop settings arent multiples of 4.

[ViCroié]

Yes true, but it did not make a difference :/

ahhh well... i guess i allways have problems wich no1 else has :(

but thx for the advice

[gldblade]

But its still very random, sometimes i encode thesame movie with no problem at all. Something sporadic like that makes me think that it might be a memory problem. Its just a guess, but there's nothing to lose in checking it out. Try getting your memory tested, I know there are programs out there on the net, I'm don't have any in memory at the moment though.

The other thing that occurred to me is what if your filters are inserting random pixels into your source video. This is just a completely random guess, but once again no harm in checking, should take like 30 seconds.

[ViCroié]

Thanks allot, you might be right, cuz now that i think of it, i had 256mb memory and put another 512mb with it, and that could be about the time the bug started.

i still need to test it,
but thx

EDIT: SOLVED!!! thx allot, it was memory problem :D