ZoneMinder Forums

Hi to Everybody.
I built surveillance system using centos 6 and zoneminder 1.24.4. My goal was to integrate it with mythtv dvr-system.

I have four composite cameras connected to pico card. Everything works fine, except I am getting lots of false alarms caused by brightness changes.

I don't know what happens, but I see brightness changes in picture, and it happens in all cameras at same time. I think pico card somehow "adjusts" brightness, but how?

Brightness changes looks just like if there is some kind of sensor and automatic gain control. First I thought that cameras do it, but it really happens in all cameras at same time. And then I have four events recorded at same second..

I have tried to define max alarm pixels in zones, but it still triggers alarm. I also have tried bttv options in modprobe/bttv.conf.
I think there is two options that could affect:

chroma_agc 444 0-1 0 (No) Enables the AGC of chroma signal
adc_crush 444 0-1 1 (Yes) Enables the luminance ADC crush

I tried disable both, but did not see any changes.
Is my card bad? It is cheap ebay card, so I don't expect much from it.

Ok,

I think that my one-chip pico card is the problem. If I have only one camera connected, there is just stable picture without problems. But after second one is connected, I have all kind of problems. Jumping picture and wondering brightness.

I have tried all possible bttv options and zoneminder settings for interlacing, etc, but no help.

I think I must get four chip card. It seems that they are hard to get, particularly to Finland.
I searched ebay, and there is four chip cards, but none of them ships to FInland.

Can anyone recommend card that has four chips, works, and is available to Europe??

For your original problem: set multi buffers to off and set capture per frame to a value of 2. All cameras on a single chip must be set up exactly the same. For the purchase problem check with bluecherry.net; I'll bet they will help.

Thanks for your reply. I have tested those settings, but they do not help. I have exactly same settings for all cameras.

Biggest problem is jumping picture. It jumps one frame up and down in all cameras. I have tried all interlace settings etc. Mostly, when I unload and load bttv module, and restart zoneminder, it stays stable for a while (1-2hours) and then starts jumping. Jumping is annoying, because it confuses motion detection, no matter what I try to set.

I'll try bluecherry..

Add a heat sink to the 878 chip. Heat causes exactly what you're discribing.

There is heat sink, but small one.

I have almost given up with this card, because using four cameras it is so slow, even if I could get it to work.

I found this card on ebay:

320858510897 (ebay item number)

It uses philips 7134 chips. Does anybody have that card in use? I found some mentions on forum that picture quality may be poor.. any experiences?

Hi M_Kane
Any luck with that 7134 card? I just bought a generic 7134 16 input card and 4 cameras. Trying to set it up without much success over the past 3 or 4 days.