luminance varies itself.. causes event

[m_kane]

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.

[m_kane]

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??

[bb99]

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.

[m_kane]

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..

[bb99]

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

[m_kane]

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?

[S-cape]

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.