Recording at the edge

A new wave of excitement in the video surveillance industry is cresting-the move to storing or embedding images inside the camera, also known as edge recording.

There's a sigh of relief from some, especially end-users, who can see that this type of decentralized storage, embedding images on a flash memory card inside the camera-may relieve some of the pressure of constantly storing to and accessing the network or even a DVR. It also may foster the proliferation of cameras in more applications-smaller specifications and installations where one camera can offer a total solution of viewing, recording and storing images.

It's all coming in part from innovation in the consumer market, fostered by the move to HD and higher megapixel cameras, according to James Marcella, director of Technical Services, Axis Communications, Chelmsford, Mass.

"Consumer electronics is influencing security technology," he said. "Chip size is shrinking and at the same time, increasing the amount of storage on the card. We expect some 50 times more performance at the edge within the next 10 years." Marcella was a recent speaker at the AMAG Engineering Symposium. He said that in the past, storage was at best a hindrance to video surveillance; now it's becoming a driver of technology. Last year, the Secure Digital Association released a new standard for SD memory cards called Secure Digital Extended Capacity or (SDXC). The standard increases the existing capacity of SD cards from 32GB to a possible 2TB of storage in a card that can be as small as a thumbnail in the mini-SD version.

Milestones Systems, Beaverton, Ore., recently announced plans for its video management system platform to support data transfers from SD cards. That support is in progress for 2010 releases of XProtect(tm) and its hardware support Device Packs. Smart Client 5.0 is their newest interface for the video management system that provides a more user-friendly way to find, view, manage and transfer the necessary recorded video from the camera for viewing or storage.

According to Christian Bohn, head of product management for Milestone Systems, when the quality of the SD cards change with the move to the SDXC, the technology will allow data to be stored much longer.

Bohn said the initial intent for edge recording was to provide a backup to video. The other was to be able to record at the camera when a network switch needed replacement or other maintenance became necessary.

"There are some shortcomings to edge-based recording from a security perspective," he added. "It probably will not attract installations with high security needs that must preserve evidence or data. We still believe there should be a central server archive database for video recording and there's a danger to not having that."

According to Doug Shubert, president and CTO of Access Gate Servers, Orlando, Fla., cameras with analytics built in may also foster more edge recording, as they store a lot of load and can do that especially well with H.264 compression on the server heads.

Embedded Storage Not Cut and Dry

Edge recording is hot right now, but here are other considerations:

- Determining the number of times data can be written to a card before it fails, especially with super-write intensive operations such as video. Current estimates are that a 2TB memory card will support at least 5,000 rewrites.
- Potential costs are still unknown, since SDXC cards have not yet hit the market.
- Preserving evidence when the camera fails.