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Sudden pixelation

Posted: Wed Oct 26, 2011 6:35 am
by momcilosystem
Hi guys, I just installed Zoneminder on Fedora 14 box and it works very good.

I do have one problem. My monitors randomly pixelate and then just correct themselves after few minutes. It's not one camera that have this problem, it's both of them randomly and it triggers my modect.

I attached frame before pixelation and next one in which pixelation occurred. I also attached comparison image.

My kernel values are:
shmall = 4073421778
shmmax = 4073421778

I got this values by trial and error method :) I kept increasing value until both cameras worked at 704x576

Any help would be appreciated.

Re: Sudden pixelation

Posted: Wed Oct 26, 2011 8:39 am
by mastertheknife
What cameras are you using?

mastertheknife

Re: Sudden pixelation

Posted: Wed Oct 26, 2011 8:54 am
by momcilosystem
I am using two analog CCTV cams on GeoVision 250 card.

I don't think that cameras names are a known brand so I attached pictures of cam.

Thanks for your reply.

Re: Sudden pixelation

Posted: Mon Nov 07, 2011 12:11 am
by TucsonDirect
this is an interlacing problem

And it is most likely your capture card, there is nothing you can really do, IF your camera has a line lock (LL) setting try changing the settings to internal (INTL) or Line Lock (LL) i think this usually happens when the voltage changes on your power supply line, like when an A.C. unit starts up... (When using cameras that are AC)

Re: Sudden pixelation

Posted: Mon Nov 07, 2011 12:13 am
by TucsonDirect
just a side note you might want to get a camera that has back light compensation (BLC) for the location of your posted images


ETA:
Change these setttings on back of camera
AWB- ON
AGC- ON
EE>OVER TO AF(play with this one...
BLC ON

ground loops can also play a part in the problem if you are powering the camera from a cheap power supply