ZoneMinder Forums

Hi,

I've just set up ZoneMinder (0.9.15) on Suse 8.2 and it all appers to be working apart from a problem with extreme image brightness fluctuations from frame to frame (viewed using Mozilla 1.4). The vieo card is a GrandTec Video Capture card (4-channel device using the BT878 chipset) and the image looks stable when checked with KWinTV. However, the flucuations are so extreme in ZM that it is virtually impossible to define meaningful monitors and zones. Any thoughts?

Cheers,

Norman

PS - Very impressed with the software otherwise!

Hi Norman,

I've seen this from time to time on one of my cameras. I'm not really sure what is causing it but a restart or reboot usually sorts it out. It seems to be some sort of extreme fluctuation in the brightness control in the driver to me. I don't _think_ it's anything to do with ZM but I could be wrong.

What version of the bttv driver have you got and do you get the problem all the time?

Phil,

thats hardware problem.
iam sure you have some of this.
1) connect a camera, monitor and the grabber together without a video spliter "no a simple coaxial T".. this generate 3 resistences of 75 ohms. you need a spliter to do that, or you will see this problem/
2) you have some channels of the grabbers open like monitor, modec etc etc. you have to set up this to none o disable that port is there is not camera conetect or if you dont want to do that you have to put a 75ohm terminator...
3) some of your cameras dont have 75ohms resitences..

this problem will affect all the cannels of the grabber..

Phillip, Fernando,

Thanks for your comments and suggestions. The bttv details are -

Linux video capture interface: v1.00
i2c-core.o: i2c core module version 2.7.0 (20021208)
i2c-algo-bit.o: i2c bit algorithm module version 2.7.0 (20021208)
bttv: driver version 0.7.105 loaded
bttv: using 4 buffers with 2080k (8320k total) for capture
bttv: Host bridge is Intel Corp. 440BX/ZX/DX - 82443BX/ZX/DX Host bridge
bttv: Host bridge needs ETBF enabled.
bttv: Bt8xx card found (0).
PCI: Found IRQ 10 for device 00:12.0
PCI: Sharing IRQ 10 with 00:12.1
bttv0: Bt878 (rev 17) at 00:12.0, irq: 10, latency: 64, mmio: 0xe8109000
bttv0: subsystem: 3f3f:ff3f (UNKNOWN)
please mail id, board name and the correct card= insmod option to kraxel@bytesex.org
bttv0: using: BT878(GrandTec Multi Capture ) [card=77,insmod option]
bttv0: enabling ETBF (430FX/VP3 compatibilty)
i2c-algo-bit.o: Adapter: bt848 #0 scl: 1 sda: 0 -- testing...
i2c-algo-bit.o: bt848 #0 seems to be busy.
bttv0: using tuner=-1
bttv0: PLL: 28636363 => 35468950 .. ok
bttv0: registered device video0
bttv0: registered device vbi0

I will check out the hardware aspects at the weekend when I have time (and manage to get 75ohm terminators).

Cheers,

Norman