Affordable Long-Term Video Storage

07/02/2010 | By Michael Fickes

New video technologies call for security policies that extend the period of time that surveillance video is stored

New video technologies call for security policies that extend the period of time that surveillance video is stored.

You probably wouldn’t expect storing surveillance video to present a security risk. However, thanks to emerging video storage technology, it does. Here’s what the technology can do and why you may want to alter your surveillance video storage policies to save surveillance video for longer periods of time.

High Definition and Insufficient Storage Space
Today’s workhorse high-definition video surveillance cameras compose each video frame with 1.3 million pixels, about three times as many pixels as required by the previous generation of standard definition cameras. Those extra pixels create a highly detailed image.  The problem is the additional resolution also requires about three times the amount of disk drive storage space as standard definition images.

While prices have come down for high resolution cameras and disk drives, a building security manager will need disk drives capable of storing three times the amount of digital data to keep the same number of video hours on file as with the older cameras. In other words, what you save when buying lower cost cameras and disk drives will go right back into the cost of tripling the amount of disk drives space necessary to save the same number of video hours.

Addressing Data Storage
An efficient new video data storage format called H.264 addresses disk drive spaces.

The conventional video storage format for standard definition video, MJPG, will store 24 hours of video from a 1.3 megapixel camera at 30 frames per second (the full frame rate for video) in 237.3 gigabytes. If a building has 10 cameras, that’s 2.4 terabytes of data per day.

The H.264 format slashes those space requirements dramatically, according to Mark Wilson, vice president of marketing with Infinova, a Monmouth, N.J.-based video surveillance camera manufacturer. When storing data on H.264 disk drives, says Wilson, a 1.3-megapixel camera running 30 frames per second will fill 34.6 gigabytes of storage space per day. Video from 10 cameras will take up 346 gigabytes per day.

In other words, H.264 will store three times as much video information as was produced by old standard definition cameras in about one-seventh of the space required by the MJPG format.

Add to that today’s new compression technologies. Recently developed disk drive and software combinations can also significantly reduce disk drive space requirements. A company called TimeSight Systems, Inc., in Mt. Laurel, N.J., is marketing a storage system that compresses video data and reduces video frame rates as stored video ages.

Is it smart to degrade the quality of stored security video? Yes — not because it makes the images hard to interpret but because the high-resolution video can be compressed — degraded — quite a bit without compromising its usefulness as evidence for the kinds of issues that might arise after a week or two.

“After a few days, you will know if someone broke into your building and, say, stole some laptops,” says Scott Carter, founder and vice president of business development with TimeSight. “During the first week or so then, you will need high quality video capable of identifying strangers walking through common areas or breaking into the building.”

After that, continues Carter, it isn’t as important to identify people appearing in the video as it is to confirm whether or not an incident occurred. For instance, if someone claims to have slipped and fallen on a certain date, at a certain time, in a certain place in your building, compressed video will verify – or dismiss – the claim.

That’s important considering that 46 of 50 states have given slip and fall victims two years or more to file claims. While many slip and fall claims are legitimate, some are not. It is reasonable to suspect that some fraudulent claims will be made close to the statutory limit, in the hopes that no video will have been saved to disprove the claim.

Up until now, storing three months of video has been an effective strategy. Storing 24 hours of video per day from multiple cameras for two years or more, however, has always been prohibitively expensive for building owners — even when the video has been compressed using available techniques.

“Office building security departments that use video surveillance cameras today typically do not store video for more than three months or 90 days,” says Jonathan Lusher of I3 Security Services, a commercial security consulting firm based in Kerrville, Texas. “Ninety days has always been a logical period of time. It is fairly easy to afford. You will usually learn about most problems for which you might need a clip of video. So that has made a reasonable policy.”

But today’s H.264 storage format, according to Carter, combined with the new compression technologies have made it affordable to save video for years instead of months at a cost close to what building owners have been paying to store 30 to 60 days of video.

If 90 days has been a logical cut off point for storing video because the cost of storing video for 90 days is reasonable, then a system that charges less than that for two years of video storage and can virtually eliminate fraudulent slip and fall claims is certainly worth considering.

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