the zoneminder experience

kylep · Post by **kylep** » Thu Feb 15, 2007 6:10 am

Hi! First off, I'm brand new. I'm getting components to build my third cctv system, and will be trying zoneminder for the first time.

I used an pentium-3 800 coppermine system running a wave-p (chinese brand) ether-9404 120 fps with 4 conexant chips, with motion detect on all 4 cameras, running thier own dvr software. CPU was taxed, but it ran!

When I browse the forums for zoneminder, i see so much discussion about low framerates and motion detection. i see that it is common to set camera speeds to 5 fps or 1 fps to untax the system to allow for motion detection - this seems very odd. will i be disapointed, or am i missing something? I've wondered what the system requirements are for this. I've also wonder how this compares to active webcam, perhaps there's another thread.

Thanks for your help.

Post by **Flasheart** » Thu Feb 15, 2007 8:25 am

I'm curious - why would you need 120fps per camera, do you have some special circumstances? Or is that 120 per card, so 30fps/camera?

ZM will work at whatever speeds your hardware can support, of course - what I think you're "missing" is that tweaking fps discussions are normally about IP cameras which take more resources so need more fine tuning on busy boxes, not analogues as you'll be using, so if that's concerning you - ignore it.

30fps is very doable, 4 cameras shouldn't tax your 3800 if it has enough ram.

jameswilson · Post by **jameswilson** » Thu Feb 15, 2007 11:17 am

also zm is jpeg based (better quality) where as most other cheapo stuff is mpeg based (higher framerate lower quality)

to get 100 fps accross all your cameras you will need a high spec machine. But as i have said many times before this is security recording and 5 fps is more than enough but you will never need more than 12 fps. Its not sky or video conference its security

kylep · Post by **kylep** » Thu Feb 15, 2007 3:09 pm

The framerate was 120fps / card, and with 4 cameras was 30 fps per analog card, mpeg based dvr software. Thanks for the clue about the ip cameras, which i'm not into right now, i'm into the analog cameras.

The 30fps was for the coolness factor, and a swift hand of an employee at a cash register.

High spec machine can mean many things to many people. Since i'm new, and am interested in comparing zoneminder to my old system, what would it take to run 4 camera's at 30fps with motion detect, copuled to bluecherry's popular PV-149 board (4 port 120fps total), a p4 2.0 Ghz? I havn't yet purchased the cpu and would like to get it right. Thanks for your opinion.

jameswilson · Post by **jameswilson** » Thu Feb 15, 2007 4:33 pm

i would suggest a 2.8 gig p4, but it depends on many factors, if you drop all the motion detection off, and record at cif then probably, but as i said before 12.5 fps is the most you will ever need. I nenver set mine above 8 fps

wkulecz · Post by **wkulecz** » Thu Mar 15, 2007 1:24 pm

Unless the capture card has on-board compression, I suspect you'll run out of PCI bandwidth before running out of CPU. 640x480 30fps 8-bit video is ~9MB/sec, seems low compared to the PCI 132MB/s burst rate, but sustained rates much above 25MB/s are very tough to obtain when you factor in disk usage which forces bus arbitration delays.

Dropping resolution to 320x240 cuts the data rate 4X but IMHO for security you are better off with 640x480 and 7.5 fps for the same 4X reduction -- I mean you know something was stolen or some evil done, but if the image quality isn't good enough to ID the perp, its been a wasted effort.

--wally.