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Recommendations for Digital Security Systems?
An Anonymous Coward asks: "My company has an ailing analog security
system, (you know the types: 16 position multi-plexer etc, 24hour VHS
tape, and so on). We're in the market for a 21st century solution,
and was hunting around for a computer/hard drive solution, being able
to store up to 8 weeks of video, from 8am to 10pm, 7 days a week at
multiple frame rates (up to 30, but we'll settle for 3 to 5 frames
per second, with motion detection...) and preferably at a resolution
where you can tell if that's a nose on the persons face or not!"
It's a reasonable enough question. Just for fun, how difficult would
it be to build such a system using consumer-level-off-the-shelf
parts?
"Some of the ones we're looking at have in the order of 480gb of storage. Windows or Linux based, it does not matter, but the ability to schedule recordings, export the pictures (water-marking for possible criminal and court proceedings...), backup options to dat/cd-r/dvd-r, always on, ability to view previous footage AND record live from multiple camera's (8/16 or better), possible remote network access, motion recording, and ability to use both digital or analog cameras (significant previous investment in these, would like to re-use the colour newer models...) and newer digital higher resolution camera's are some of the features I would like. Any ideas from the very knowledgeable Slashdot crew?"
One problem that you have to watch out for with digital security systems is random glitches. Sure, it doesn't happen too often, but when it does it can be a real hassle.
At the company I work for, our security system one day decided to change all the codes, so nobody could get in or out of the building. It turns out that something triggered a complet reset, erasing everything and restoring the default settings.
It's funny now, we all laugh about it, but craving a smoke while locked inside can be very stressful. I don't know how many times I was tempted to break a window and escape....
-Space for rent
we wanted to catch a change-stealing thief. We bought a buch of alaris weecams off of eBay ($25 and under) and set them up. We didn't bother with motion sensors. The images didn't take up a lot of drive space and the software (webcam32) we used created AVI files for the time lapse. It worked well too - the bonehead looked at one of the cameras up close after he cleaned out a drawer. We had taped over the little light showing it was on and had the monitors off on the PCs. Nice picture. You could probably do it more advanced on the fly (add cameras and drive space as needed) for under capital expense (our company requires God to sign if anything is over $500).
"If you are on fire you can just stop, drop, and roll. If you fall into Lava you are just dead." - my 5yr old daughter
I had my camera and cable modem up for a day when I caught this image
the story is here
---- join dshield.org Distributed Intrusion Detec
I'm not sure how hard it would be to put something like that together yourself, but I can offer one suggestion in case you decide to try.
National Control Devices has been offering a video switcher for a few years now that will handle up to video 16 inputs, for only $150. It looks really impressive. I've been considering getting one for ages, just to play around with. It's controllable through an RS232 serial port.
This was asked a while ago ..
I'm sure the consensus that I felt was expressed will be the same: go analog.
"I can't give you a brain, so I'll give you a diploma" - The Great Oz (blatently stolen sig)
I'm actually thinking of wiring my house for security too. This is what I'm looking at:
- A bunch of motion sensors, installed at all entry points (actually, pointing to the entry point), including windows and fireplace.
- A few micro camera, pointing to those entry points (I can save a few cameras, if I figure out how to control the head of the camera from the computer)
- An old computer (P166) with a large HD.
- A few cron tasks to activate the system, when we are not at home, or activate only certain areas while we are sleeping.
- Motion sensor signals are sent to the computer for processing.
- Cameras are controlled by computer remotely.
- In order to save disk space, the cameras are activated and start taking video, only when a motion signal is received by the computer. Cameras are turned off 3 hours after last motion signal.
I'm also considering to have 802.11b on my palm, so I can remotely de/activate the system.
I haven't done the total cost estimate yet. But a motion sensor cost around $29, an 80GB HD around $250. Camera's price varies, depends on whether you want b/w or color. I think the wiring part is going to be the most expensive, as I'm no electician.
If you are securing a room that people rarely enter, MPEG compression will see one frame as very similar to the previous frame, and record very little information for the frame.
Also, a feature you may not have thought of, if an alarm is triggered, the recording should go into overdrive, and record high resolution colour at 30fps. There's no excuse for the grainy out-of-focus stop-start security camera images we see on the news!
Once more unto the breach, dear friends, once more, Or close the wall up with our American dead!
It seems that since Sept. 11, the issue of security systems in offices has become a pretty hot topic. The place where I work is now looking into some pretty neat digital systems.
Like traditional systems, these systems pretty much record 24/7 whatever is going on. However, most of this data is useless. Unlike in traditional systems, all the data is not stored. The system can analyze when there was motion and then save what happened 10 minutes before and 10 minutes after motion occurred. At the end of the day, you are storing much less data that happens to be much more usable.
While I'm not a fan of their advertising practices, I am a fan of the hardware. And there is a Linux driver for the CM11A controller. X10 will allow you to integrate motion sensor events with camera control for /very/ short money - 3 cameras, receiver, x10 receiver, etc. for about $140.
My boss recently asked me about implementing a video security system, and this is the way we're going.
I recall either 8 or 16 cameras per rack-mounted machine, but I imagine they've gotten bigger / better / faster in the last five years. A higher number of simultaneous inputs reduces the frame rates, so we chose the maximum number of inputs that could give us the frame rates we desired (3.5 frames/sec, I think.)
They have digital tape jukeboxes parked next to the racks, and even our largest site keeps at least 90 days of video.
They provide client software that allows us to remotely access the video stream via our internal network, and they modified their system to include a SQL database of a journal of the accompanying financial transactions being performed. They identify each computer with a camera, and upon request deliver this journal synchronized with the video stream. We also have some public safety cameras feeding the system that are not tied to the transaction system.
It's elegant for the investigators, who are non-techies. They have search capabilities on that data, and can speed right to the relevant transactions. They can also simply click a button and burn a CD with the selected video stream and it even comes with the required digitally-signed proprietary viewer.
Another thing it has that you maybe haven't yet considered is that their company has experts who will testify in court on our behalf that their system is valid, and that the images haven't been tampered with. We have used their imagery as evidence in many successful prosecutions. IANAL, but having a built-in Trusted Third Party strikes me as a strong benefit.
So, with a wonderful system like this, what are the drawbacks? Money, plain and simple. You have to be willing to invest money (and people) to get a top notch system, but the cost-avoidance was definitely worth it for us.
Oh, and before anyone goes off about Big Brother, you should know that the transactions we are recording are financial in nature, and cash is involved. The computers are ours, and the users know they are being recorded. Just that knowledge provides a huge fraud deterrent. We honestly much prefer deterring theft up front than prosecuting our own employees after the fact. And armed with this system, we have no problem prosecuting thieves.
Disclaimer: I do not have any financial investment in Loronix, I am just a very satisfied customer.
John