by Oliver Vellacott*
This article aims to clarify some of these questions and establish the most important factors that need to be taken into account when choosing an IP-based digital CCTV system.
The myth of standards
Many people in the industry believe that so-called "open" or "multi-vendor" IP video systems achieve interoperability thanks to the use of open market standards. This is a myth. There are certain aspects of IP video that are based on standards. One of them is video compression. MPEG-2, MPEG-4, H.263, H.264 and jpeg2000, all ratified standards that are widely used in the IP CCTV market. These formats only apply to digital compression and decompression of analog video, but not to live streaming of digital video.
IP video systems require real-time digital video transmission over a network, and for this a transmission control protocol is needed. These protocols are transmitted using the Ethernet IP network standard, allowing IP video to coexist with other network traffic, such as computer overview. There are many transmitters on the market that use standard video compression but rely on proprietary streaming protocols. The least standard element of the system is the transmission control protocol; however, this is precisely the element that allows the realization of many of the advanced features of IP video systems.
The protocol contains certain basic commands that allow you to start and end a video recording, send an alarm or turn a camera, for example. Each manufacturer uses its own protocols and without them the system does not work. If video analytics is also added to an IP system, the complexity of the protocol will increase dramatically. With analog video systems there is a similar problem, since the video transmission is standard but the controls of the matrix and those of the rotation, inclination and zoom of the cameras are proprietary.
The truth about "open" systems is that video management software has to connect with the equipment of each of the different vendors using different proprietary protocols, which is obviously not a standards-based solution.
A single supplier or multiple suppliers?
All IP CCTV systems have three basic components: streaming hardware, recording hardware, and video management software. Some manufacturers have opted for the "one-stop solution" approach and have a single vendor. All software and hardware is designed, tested and sold as a single, comprehensive system. While other manufacturers have chosen the "open" approach and have multiple suppliers. Thus, a single video management software application can communicate with equipment (transmitters, IP cameras, etc.) from various manufacturers. This approach has many advantages:
•The ability to obtain equipment from multiple manufacturers
•Lower pricing of hardware components
•Independent software vendors often sell their product to a wider market, and the user can benefit from this investment and the resulting features
•The user is not limited by a single hardware manufacturer's plan (e.g. their development plans or preference for a particular application)
•The ability to modernize existing IP video systems with new third-party hardware
•The ability to choose the most suitable manufacturer for a specific application (e.g. a particular type of IP camera that may be more suitable)
Although the multi-vendor approach in principle seems like the most sensible solution and in fact is often the appropriate one, it also has disadvantages.
Multi-vendor systems: they are obtained from a single source
Multi-vendor systems often assume that video management software is purchased from an independent software vendor and that it can communicate with equipment from different manufacturers of transmitters or IP cameras. The hardware is "open" but the user can only use a single software manufacturer. Therefore, not all the solution comes from the same source, only the video management software does. This shouldn't be a problem, but the independent software vendor has very little control over the hardware of the multiple vendors that are used. For this reason, due to the absence of real standards, these systems are not as capable of using an optimal performance system as single-vendor systems, which control the entire solution from start to finish.
Limited interoperability
There is an opinion that using software applications from multiple vendors will allow the user to get the transmission hardware from any manufacturer easily and economically. However, there are many restrictions on multi-vendor systems that make it difficult to freely combine equipment from different manufacturers. The system always has the quality of its worst performing component (the lowest common denominator), which can lead to a reduction in overall functionality. In reality, many IP video systems based on multi-vendor solutions only use hardware from one manufacturer to lessen these restrictions, so they end up becoming two-vendor systems.
Many IP CCTV systems require communication between different hardware, for example, the flow from the transmitter to the hardware decoder, an important element in the so-called "virtual matrix", which is what gives IP video systems their flexibility and expandability. No type of software will allow the integration of these two components, so a fundamental component of a "virtual array" IP (the link between any point) is invalidated.
They can be more expensive
As far as development is concerned, the most expensive component of an IP CLOSED-circuit TV system is video management software, but often the true cost does not come to light. By using an independent software vendor, the user is tying themselves to the most expensive component of the system. In addition, the price increases even more, because the control protocols of the equipment of many suppliers have to be incorporated into a single software application. This is why multi-vendor support costs a lot, and the customer has to pay for supporting hardware that they don't use.
More complex support issues
Video management software has to connect with several different technologies, and this extra complication can affect the reliability of the system and highlight support issues. Multi-vendor systems rely on strong strategic alliances between many different companies to maintain comprehensive support. But, if something goes wrong, who will the user blame? Who will be responsible for the revision of the firmware that should be used in an IP camera, when a new version of the video management software comes out? With a comprehensive solution from a single vendor, the responsibility for performance certainly lies with one point, and the user only needs to complain once.
Integration and choice in single-vendor systems
With a single-vendor solution, all components of IP video are sourced from a single manufacturer, limiting user options. However, the truth is that there are still many components that can be chosen from different suppliers. IP video systems often use a combination of analog cameras connected to transmission modules, rather than dedicated IP cameras, which is the same as at home with televisions and digital set-top boxes for home use. In this case, the user can choose cameras from any manufacturer based on their price, specifications or brand. Similarly, many manufacturers make it possible for their network video recorder software to work in any computer configuration, allowing the user to choose any solution, from low-cost computing equipment to a multiple RAID server. IP video systems also offer multiple connections to third-party equipment such as monitors, keyboards and controllers, thus expanding the possibilities of choice.
Another very common mistake is to believe that integration with third-party equipment is easier to achieve with multi-vendor IP video systems, as single-vendor systems are considered "closed." This is absolutely false. In many cases it is easier to obtain the integration of IP video with other types of system, such as intrusion alarm systems and access control, with the solutions of a single provider. This is because the control of the different components and software of the system is in the hands of a single company and this ensures that the integration is totally perfect.
Analogy with the world of computing
The division between a single provider and multiple providers that occurs in the IP video market in a way reflects what is happening in the world of computer interconnections.
Small organizations tend to use different network equipment manufacturers, and change their selection continuously based primarily on pricing.
On the other hand, larger organizations typically use end-to-end teams from Cisco, HP, etc. because this gives them much higher total performance and a lower total ownership price. The same goes for IP video: larger users are opting for a single provider for the same reasons.
Video Analytics Integration
IP-based video management systems offer the ideal platform to fully integrate adequate analytics into the system, which would make such analytics a fundamental and integral part of its operation. The most prominent IP video solutions can use analytics that can be run in two fundamental modes: live (to detect events as they occur) and after processing (to test various scenarios in the recorded images).
As is evident, the ideal place to place live analytics is the camera, since this is the only solution truly capable of modernizing and also does not consume network bandwidth. Real-time central processing will eventually lose momentum, while each camera may have its specific processing. For example, a camera that has its own comprehensive analytics can monitor image activity and transmit only specific events, for example, a person moving in the opposite direction at an airport security checkpoint.
The ideal place to place the analytics after processing is, of course, a central server within the video management software, to be able to investigate the recorded video many times according to different parameters. With video management software, both systems can perform these analytical functions of past events. However, with multi-vendor systems, implementing real-time analytics in the camera is very difficult, due to the extra complication of the numerous control protocols that connect to the video management software.
Conclusion
At first glance, the "open" solution from multiple vendors seems the best approach when choosing a CCTV system, as the user has more options and the opportunity not to be limited to a single manufacturer. However, if we compare it carefully, we see that a comprehensive solution from a single vendor also has many advantages: it is potentially more robust, offers more features, is easier to support and, in many cases, is more economical.
Of course, the single-vendor vs. multi-vendor debate will continue, but it's interesting that most major companies in the IP video industry offer single-vendor systems, which are capable of higher performance. The biggest proponents of multi-vendor systems are always, of course, independent video management software vendors.
* Oliver Vellacott founded IndigoVision in 1994. He was previously a production manager with product experience for smart cameras. Oliver studied piano at the Guildhall School of Music before obtaining a Bachelor of Software Engineering (Imperial College, London) and a PhD in Electrical Engineering (University of Edinburgh).
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