On 02/24/2011 08:25 PM Chuck Munro wrote:

....

From experience I can attest to the fact that PAL/NTSC CCTV cameras are significantly inferior to modern digital security cameras. I have used devices from Axis, who appear to be the largest and most diverse manufacturer (www.axis.com) but they're not the cheapest. As an aside, Axis cameras run embedded Linux.

I read that. I would imagine that a lot of digital cameras-- in fact, a lot of digital devices-- employ Linux in their firmware. If I were writing code for an ARM processor, that's what I'd do. Why reinvent the wheel? You'd think under the GPL they'd be required to divulge the firmware code. And there should be a way to hack into these. But now I'm going way OT.

The newer Ethernet-enabled cameras can use POE (power over Ethernet) but you'll need either a power supply that you insert somewhere along the cable run, or a POE-enabled switch which supplies power to its Ethernet ports. Several brands are available.

Wikipedia has an article on PoE and there's other docs on the web about it. It's nice because you don't have to wire in 110V (or 220V in non-US countries) for every camera... cat5/7 is a lot easier to snake through walls and install generally than is Romex.

Using POE makes a lot of sense and saves a lot of trouble, but make sure your Ethernet cable installation is of high quality.

I found there's a couple PoE standards. One requires only cat5. The newer one-- which delivers higher wattages-- needs cat7. The higher-grade cat7 would be the way to go... if in a couple years you decide to upgrade the camera to one which needs more power, you won't have to re-snake the better cable.

Open-source software such as ZoneMinder works with cameras from several manufacturers, and runs on CentOS. I personally haven't tried it, but I understand it works well.

Their website has a fairly good delineation of its features... and screenshots which give you a good feel for what it's like to use it. I didn't know about Zoneminder, so thanks for that tip.

According to that website Zoneminder comes in a variety of install routes, one of which is RPMs (yea!). None in my list of yum repos, however, has it. That's okay. I still remember how to upgrade without yum.

Chuck

Thanks for the info!

On Thursday, February 24, 2011 08:25:35 pm Chuck Munro wrote:

Open-source software such as ZoneMinder works with cameras from several manufacturers, and runs on CentOS. I personally haven't tried it, but I understand it works well.

I'm running a zoneminder instance on CentOS 5 under VMware ESX now; there are a few caveats.

First, I didn't find RPM's for ZoneMinder for CentOS for the current version of ZoneMinder. For F12, F13, and F14 they're out there, but niether EPEL/RPMfusion nor RPMforge has them that I could find; but I didn't look in any testing repos, just the production stable ones. Even ATrpms doesn't package ZoneMinder for C5.

So I built from source. This has some odd dependencies, for a specific version of libraries needed. It builds ok, but it does take some work to do. I'm tempted to take the Fedora source RPM and try it, one day when I have time to do that, as it will likely need some patching (but I'm not sure of that, since I haven't tried it).

Once built and the database configured and the schema loaded, it works fine. However, if you're using a lot of IP cameras and a high frame rate, you need a lot of CPU power. If you set the frame rate to 1 frame per second the CPU utilization with eight or nine cameras isn't too bad; trying to do 5-10 frames per second takes nearly 100% of a dual vCPU VMware ESX instance on our Dell PE6950's (four 2.8GHz dual-core Opterons).

ZM can take all kinds of video inputs; it can even 'chain' to another zoneminder instance as if the other zm instance was an IP camera. So you could build a multichannel NTSC or PAL video capture box for cheap CCTV cameras (monochrome CCTV cams with C or CS-mount interchangeable lenses can be had for way less than $100 each), and then chain that to another zoneminder.