An Introduction to VMS for CCTV
In Hartford, Connecticut, live surveillance cameras blanket the city, and ShotSpotter gunshot technology checks for gunfire, giving police a 24/7 visual of what’s happening on city blocks and streets. Data analysts within the police department monitor and review this surveillance activity from the Hartford Real-Time Crime and Data Intelligence Center where 30, 55-inch, 4K video monitors provide real-time views of the action and combine with data feeds from the ShotSpotter system, the dispatch system and social media mining tools. Analysts use the data to help officers with crimes in progress and to later analyze recordings as police investigate crimes.
This example provides a very sophisticated view of what is possible when open source, Windows-based video management system (VMS) is employed. Though not every application will be this advanced, VMS for CCTV is changing the way surveillance footage is collected and utilized in security applications. To fully benefit from VMS, however, it’s essential that users understand what it is and what it’s not, how it works, and where it works best.
What is VMS for CCTV?
VMS for CCTV enables users to record and view live video from multiple surveillance cameras. It can be either appliance- or Windows-based, depending on the manufacturer, and used with either IP cameras or analog cameras with an encoder. Appliance-based VMS typically utilizes a variant of a Linux operating system to function. Newer embedded appliances generally require a network drop and a web browser that communicates directly with the Linux-based software running on the appliance. VMS running on a Windows-based server, on the other hand, functions like other Microsoft-based tools. The Microsoft Windows Server runs the host application and communicates with either proprietary software or web-based client software over a client network.
Appliance vs Server
Whether appliance or server based, both VMS types typically operate on a Windows-based platform. “Ninety percent of the VMS on the market today run on Windows,” says Josh Sherer, senior field solution architect of video surveillance for CDW, a security integrator in the public safety space. “There are a handful of players that are Linux based, but even then, it’s still software running on an operating system. The appliance is just the specified server.”
The primary difference between the two is that an appliance-based system, even one with software on it, is essentially a system used to record and later review video. Such a system lacks advanced features, and will not integrate with other systems in play, such as a video analytics or access control systems. A server-based VMS, however, acts as a building block for a physical security camera system that can have video, access control, analytics, motion detection, trigger alarms and more built in.
Pros and Cons of VMS Types
Both applications have pros and cons. For instance, an appliance-based VMS for CCTV is very stable and requires little user intervention to maintain. Thus, an appliance-based system might work well in a client environment where few IT resources exist to maintain the VMS. However, the benefits of reduced set up, installation complexity and maintenance needs also come with a downside—appliances are generally proprietary and purpose built, rendering them less flexible, with fewer opportunities for customization, and making it difficult to integrate with third-party systems.
“If you are just looking for the ability to record with a few cameras and review the footage at a later date, do not plan to do any live monitoring or integrate with anything, then a basic video recorder and cameras might be a good solution,” Sherer says.
Windows-based servers, in contrast, require routine maintenance and management. For this reason, they tend to work best in scenarios where in-house IT resources are available to make sure the servers always operate properly.
However, these systems are more expandable and flexible than traditional appliance-based systems. Employees can control the VMS from anywhere on the network, and the software makes it possible for them to perform live monitoring as well as review captured footage for investigative and forensic purposes.
In addition, Windows-based server platforms do not limit the system to a specific hardware manufacturer; any server meeting minimum specifications set by the video platform manufacturer can be used. “That’s the beauty of [server-based] VMS,” says Sherer. “They are pretty much hardware agnostic. You can use whatever hardware you want, as long as it meets the performance requirements.”
VMS Servers Can Be Built to Spec
Windows-based servers can be built to spec and can offer much greater processing power than their appliance-based counterparts, a key benefit as video file sizes increase. Designing a server for a VMS is custom to each individual application. The process begins by creating a site design, then figuring out which cameras will go where, and the types of cameras and quantity. Finally, it considers the parameters of resolution, frames per second, retention and scene complexity to calculate processing power needs. “All of these things impact what is needed in the Windows server,” Sherer says. “You use this information to calculate processing power, needed network bandwidth, needed storage throughput and needed storage capacity.”
Video cards built into the servers can help process surveillance video from several cameras at a time. Nvidia video cards are most often used, but others also exist. Video cards are generally added to a server if the user plans to run video analytics. Adding video cards enables them to offload some video processing from the Central Processing Unit (CPU) to the Graphics Processing Unit (GPU).
GPUs are especially valuable in end-user workstations because they can speed up video viewing. For instance, if there is a video wall monitoring security footage coming from thousands of cameras in a large international airport, a GPU can speed the time it takes to process the video footage and put it on the screen. “You get the most use out of a GPU on the decode of compressed video,” Sherer says. “H.264 and H.265 have to be decompressed then put into a format that the computer can see to display it on a monitor. That’s a heavy load. Putting GPUs into a workstation speeds up this process.”
Open Platform vs Closed Platform
Open Platform Software allows third parties to integrate with the VMS through an application programming interface (API). This software is common in the security industry, as most mid- and enterprise-level platforms allow some integration with other systems.
Milestone Systems, for example, offers an open-platform VMS for CCTV that integrates well with different products from third-party manufacturers. Other VMS platforms do the same, but often limit integration opportunities to encourage end-users to select their proprietary ancillary products instead. “An open platform system, like Milestone’s, gives you the ability to select the best-of-breed product from different categories and integrate all of them into one system,” Sherer says. “You can pick an access control system from one company, an analytics suite from another, and you can actually take a product out of an existing system and replace it with something else without starting over completely.” Milestone video analytics partners write their software code to milestone’s open platform so security camera companies can incorporate multiple integrations into the IP security camera CCTV network.
However, there are cases where a company may want to select a more closed platform like Avigilon. Working with a single company for the entire system can simplify integration. “It really depends on what the customer is looking for,” says Sherer. “Open Platform Software gives you a lot of flexibility, but when products are not all from the same manufacturer, integration might not be seamless.” Avigilon Camera Systems use video software as a service (vsaas) to incorporate things like license plate reader cameras, facial recognition, and appearance search for commercial security camera systems in a proprietary, closed interface.
Connecting Security Cameras to VMS
Open source VMS for CCTV platforms also build drivers for thousands of cameras to offer full functionality inside the software. This is a more robust application than a simple ONVIF compatibility.
Sherer explains there are three ways a security camera can connect into VMS. The first is the universal RTSP system. This is basic integration where the user is getting a video stream and recording it. In between, is ONVIF, which is the standard most camera companies currently adhere to. An ONVIF driver incorporates the ability to control the security camera from within the VMS or recorder. The third method, which is the most preferred, is a direct driver that has been written toward the specific security camera provider and the VMS. This method allows the control of advanced camera functions within the VMS. For example, a company could put a region of interest into its system to keep track of people who are loitering or to build in an automatic alert if a car stops for too long in a given area.
But what happens if a company seeks to operate a surveillance system across multiple sites? In those situations, which VMS, appliance or server-based, makes the most sense?
That depends on how the system is managed. A basic appliance-based system will not allow for a unified platform in a multi-site application. It will be a group of systems operating independently where the end user can only be in one system at a time and is unable to view multiple sites at the same time. And that may be OK in some applications.
A server-based VMS enables a multi-site surveillance system to be centrally managed. The system might have servers in 10 cities but operate a centralized management server that controls all of them so that when the end-user logs in, he or she can see video footage from many different servers, seamlessly and at the same time. The user can log into a central management server in Chicago, for example, and talk to recorders in New York and Los Angeles.
“An old-school independent system is not easily managed across multiple sites,” says Sherer. “This is where a server-based VMS really shines. It makes life a lot easier when multiple sites are centrally managed.”