IP VIDEO WITH ANALOG CAMERAS Huntingdon PA

You don't have to scrap existing analog cameras and cabling to get many of the benefits of IP video. Replacing head-end equipment with video servers offers a path to update existing CCTV systems without replacing the significant investment in camera infrastructure.

Multiple-input video servers working with video management software can serve as a head-end replacement for matrix switches, VCRs and DVRs. Video servers provide a bridge between analog signals and IP networks. Video management software provides virtual matrix switching, digital recording and controlled access to remote video monitoring over LANs and the Internet.

This configuration has interest from many IT managers as an alternative to proprietary DVRs. By separating video capture, digitization and compression from video storage, commercial-off-the-shelf server and storage systems can be sourced and maintained through the normal channels of the IT department.

Disk-less, multi-channel video servers allow storage to reside in commercial off-the-shelf RAID disk arrays that can provide more scale, flexibility and reliability over DVRs. For example, a 16 camera system recording at 30 fps, 4CIF resolution with 15 days retention can require over 5 Terabytes — a level of storage that a DVR cannot support with internal disk drives.

At first glance the role of a video server seems straightforward: capture analog video, then digitize and compress the video before streaming the video over a network. Once on the network, the compressed video can be monitored by remote workstations and recorded by servers or network video recorders.

QUESTIONS TO START

Keep the following questions in mind as you consider the system requirements and compare video server products:

• How many cameras will be managed now and in the future?
• Will the system primarily be used for live video monitoring or recording?
• How many live monitors will the system support?
• Will video monitoring be done locally over a LAN or remotely over a WAN with data-rate limitations?
• Will the system support PTZ cameras?
• Is audio recording required?
• What are the IT department's requirements?

SELECTION PROCESS

A study of video server products from several leading manufacturers reveals differences in features, interoperability and performance.

• Number of Cameras — Video servers come in both single and multiple video input configurations. Multiple input servers can be found in single chassis form factors with a fixed number of video inputs or hot swappable "blade" architectures that can expand as the system grows.

  Many sites with large camera counts are constrained by the available space for head-end CCTV gear such as recorders and servers. A video server with a small footprint is highly desirable for these environments. Some video server products provide as many as 24 inputs in a 1U rack-mounted chassis.

• PTZ Control—the level of support for PTZ control varies significantly across products. Video server products from Axis have built-in control for over 25 PTZ manufacturers. Some video server products don't have any built-in PTZ support. These products require specific video management software packages to implement the PTZ control protocols over TCP/IP messages to the video server for pass-thru to the RS-485 data bus.
• Dual encoding—the ability to simultaneously provide two separately compressed video streams from a single camera input. This feature allows a camera to be recorded at one level of video quality, data rate and frame rate while being monitored at a different level of video quality. For example, dual encoding is useful to provide a video stream for remote monitoring over a low bit-rate WAN while using a higher bit-rate stream for higher quality video recording on the local area network.
• Motion Detection—On board motion detection can reduce the system performance requirements for computers running video management software by offloading this CPU-intensive task. Built-in motion detection can also reduce the load on the network by streaming video only on motion conditions.
• Configurable Compression—allows the video server compression to be tuned to balance the video quality, data rate and frame rate to meet the specific requirements for a given camera or surveillance scene. While MPEG-4 is standard compression, the implementation can vary from primary MPEG-4 codec compliant with the ISO compression standards to having to use proprietary implementations; all with extremely flexible configuration options.
• Software Support—The number of supporting video management software packages varies from manufacturer to manufacturer. Video management software can manage video recording, authorized access to video, PTZ control and system administration. Some manufacturers rely on software products to provide full-featured support of their video server while other manufacturers have more built-in functions. There is also a difference in the level of support from the open, third party packages.
• Video Streaming Performance—The number and quality of simultaneous video streams will vary by product. Systems that support multiple video monitors may need to deliver multiple video streams over the network for each camera input. Individual Unicast streams must be generated where multicasting is not available on the network. This places an additional performance load on the video server. Each video server product has a limit to the number of Unicast streams it can generate without impairing the quality of the video output.
• IT Friendliness—Video surveillance systems are increasingly part of the IT infrastructure and less likely to be standalone systems. Video servers and network cameras must conform to a set of accepted network standards and protocols to provide network security, network bandwidth management, user authentication management and system monitoring. Some important standards to consider are Quality of Service (QoS) for prioritizing network traffic, Secure Sockets Layer (SSL) to secure configuration changes, Simple Network Management Protocol (SNMP) to provide health status and Universal Plug and Play (UPnP) to automatically detect devices on a network.
• Advanced Features—Audio is an optional feature on most video server models. Some manufacturers are providing embedded video analytics, for example, analytics designed to detect camera tampering and sabotage.
• Video Quality—At the end of the day, the video server must produce reliable, quality video at a competitive data rate. The data rate requirements generally translate into the most significant cost component of the networked video system: storage. Most products can be configured to provide increased video quality at the expense of more storage and bandwidth.
• Price—Prices through distribution for multiple input video servers generally range from $165 to $250 per video input. Ultimately the best video server is the product that best fits your customers specific system requirements and budget.

TOM GALVIN of NetVideo Consulting (www.netvideoconsulting.com) is a network video specialist. NetVideo Consulting provides product evaluations, training programs and software tools to enable successful networked video solutions. Galvin recently published a competitive study of video management software and other IP video products.