Video recorders are now equipped with both MPEG-4 and H.264 encoding; some industry experts see H.264 having greater uptake. The video surveillance industry has moved towards H.264 encoding to save on bandwidth and storage requirements, said Ken Maughan, PM of March Networks. “The differences between the specs depend on which profile the manufacturer has adopted and how the device is set up, as this affects the video quality, as well as how much compression is used,” said Mark Harraway, Country Manager of Controlware UK.
Data retention on existing products is affected by a number of factors, such as camera count, frame rate, recording schedules and the number of hard disk drives (HDDs) on the recorder. “Retention periods have not changed significantly over the past few years,” Maughan said. “However, the use of HD network cameras is pushing storage requirements to new heights to meet the basic retention periods used in the past. Larger drive capacities are helping to meet these requirements.”
Individuals preferring certain operating user interface can choose between Windows- and Linux-based systems, although preferences are subjective and the market does not seem to favor one or the other. “For camera recording, Linux is preferred, while for video management, setup and viewing, Windows works better for some users,” said Jay Yogeshwar, Director of Media and Entertainment, Hitachi Data Systems.
To maximize features, professionals tend to lean toward Windowsbased operating interface, as it is feature-rich. “For less sophisticated environment and to maximize ease-of-use, a Linux-based operating interface would be simpler to set up and operate with either a mouse, front panel or IR remote controls,” Kreutz said.
Linux is used for enhanced stability, virus protection and resource management compared to Windows, and comes at a fraction of the licensing cost, which makes it attractive to some buyers, Clark said.
The reliability of hard drives has been improving steadily over the years, as evidenced by three-year warranties offered by some vendors. A video recorder that has poorly managed heat dissipation will likely have more hard drive failures due to overheating, Maughan said.
Product design must account for thermal management. For some products, the ambient cooler now sits at the front, modifying the air flow design for proper cooling. “Heat control is important, as every 10-degree Fahrenheit difference cuts the hard drive life in half,” Kreutz said. “Proactive capabilities such as monitoring applications that alert on the increase of temperature are beneficial for users. Users are able to set criteria to better monitor storage conditions according to individual preferences.”
“Heat dissipation is an issue that is continuously addressed by manufacturers,” said Colt Yin, Director of the Support Department, Proware Technology. “Systems nowadays can be programmed with software for intelligent and automatic temperature control.”
Deciding between entry-level and high-end products goes hand-in-hand with how scalable the equipment is. The features and benefits, as well as the user's purposes, determine which products are suitable. “There is a good mix of entry-level and high-end products available on the market. Solutions based on high performance, scaling and availability provide maximum value for mid- to high-end systems,” Yogeshwar said.
“Entry-level storage devices are RAID-compliant, yet do not always have RAID support,” Kreutz said. “High-end products tend to have more embedded features, creating additional user benefits when utilizing the devices.”