Effect of low Maximum FPS

thelight · Post by **thelight** » Thu Oct 21, 2004 12:49 pm

Im trying to get 3 camera's to run at a resolution of 768x576 on a p4 2.0 with 640mb of ram. Ive found that running them constantly at this resolution at 25fps is really thrashing my system. Setting the camera's down to 10fps when idle/doing motion detect really gives the system a break and seems to be a workable solution to get all camera's running well on the system. One thing im not sure of though is the effect running them at 10fps is going to have on motion detection. Is it likely to limit its effectiveness very much or is it usually considered an ok compromise to make which wont harm the effectiveness of my camera's very much?

thanks.

lazyleopard · Post by **lazyleopard** » Thu Oct 21, 2004 2:07 pm

I run four cameras at present, and two of them are 567x768 colour ones. I have an Athalon 1800+ system with only 256Mb of memory, so I've had to curtail the frame rate even more than you're suggesting.

The limiting resource is sharable memory, as it really doesn't work if that starts swapping...

I find:

* Fast-moving activity may only trigger one or two frames. Really fast activity probably gets missed completely.

* The blend %age needs adjusting to try to avoid triggering on relatively gradual events. (I've not yet come up with a reasonable solution to avoiding triggering on light-level changes.)

Post by **zoneminder** » Thu Oct 21, 2004 10:04 pm

I think 10fps should still catch pretty much all events. If you want you can disable this maximum when alarms are detected so you get the full rate for an event.

The other thing I would suggest in any scenario is to go out and test your setup. Creep round after dark, stride up to your door, or set your cat or dog free in front of the camera. Really that's the only way you can be positive you've got your setup right.

Phil,