Cross The Bridge With Encoders
Over the last few years, “convergence” has become a buzzword that has been invoked thousands of times in nearly every corner of the security industry â€” so much so that upon hearing it, some people instinctively tune out whatever follows the word.
Buzzwords aside, there’s no denying that the day is coming when security systems and IT/IP systems operate seamlessly as one. Because that day probably won’t come for several years, the industry is in a state of flux. Analog cameras have long been the standard-bearer for video surveillance, but this move towards IP is pushing them to the side in favor of cameras that are capable of communicating with and transferring video across IP networks, which are becoming more and more ubiquitous.
As this shift towards IP occurs, where exactly does that leave those customers who have dozens â€” if not hundreds â€” of analog cameras a lready in place? Because analog and IP cameras communicate differently within security systems â€” and cannot communicate with each other â€” many believe that the migration from analog to IP is an all-or-nothing (and therefore very expensive) proposition. So it’s understandable why end users may resist a full-scale migration from analog to IP.
But if analog cameras could somehow communicate with an IP network, that all-or-nothing situation wouldn’t have to be the case. This is where video encoders come into the picture.
What Is It & What Does It Do?A video encoder is a device that is installed between an analog camera and an IP network. Its main function is to translate the analog video signal that comes into the encoder to a digital video signal (in MPEG-4, MJPEG or H.264) that then can be transmitted across the IP network and used with networked systems, servers and software.
Here’s a nuts and bolts look at how encoders work, courtesy of Miguel Lazatin, senior manager, marketing, for Sony Security Solutions Group, Park Ridge, N.J.: An encoder takes an analog NTSC composite signal via a BNC cable and de-modulates the signal to extract data (RGB). Since this NTSC signal is modulated, the color signal is on a color sub-carrier signal. The digital signal processor (DSP) feeds the RGB data into an image enhancement process and/or motion analytics. Then the DSP compresses the video and audio data, and converts it into network protocol such as TCP/IP or a variety of others. In a fraction of a second, the processing is completed and the data is transmitted over the network via a RJ45 connection.
As you may have guessed, these specifics are quite complicated and vary from manufacturer to manufacturer. So to put it in simpler terms, at its most basic level, think of an encoder as a bridge, that both physically and metaphorically spans the gap between analog and digital systems during the migration process.
Not surprisingly, encoders are almost exclusively used for customers who have existing analog cameras. They rarely, if ever, are used in Greenfield applications, says Fredrik Nilsson, general manager of Chelmsford, Mass.-based Axis Communications. When you look at the numbers, the market need for encoders is by no means niche. According Nilsson, IP cameras currently account for about 25 percent of the installed camera base. The remaining 75 percent are analog.
Meanwhile, says Ed Thompson chief technology officer for DVTel, Ridgefield Park, N.J., most manufacturers have focused the bulk of their energy and effort on IP. So as analog cameras reach the end of their lifecycles (approximately five to seven years), they will need to be replaced. And with the price of IP cameras becoming much more in line with analog, combined with the added functionality and analysis possible with digital, customers will most likely replace them with digital cameras.
These days, in particular, businesses are cost-conscious. They are reluctant to spend money on anything they don’t have a dire need for, so they are going to want to squeeze every last frame of video out of their existing analog infrastructures. The adoption of IP had been red-hot, but slowed down in 2009 as economic conditions worsened around the world, says Mark Wilson, vice president of marketing for Monmouth Junction, N.J.-based Infinova Systems.
So encoders provide an insurance policy for end users against what could amount to a massive outlay of cash they may not have on hand at the moment. By protecting end users’ investments in their legacy analog surveillance system, encoders allow them to continue to use their installed base of analog cameras, which, depending on the size of an organization, could number in the hundreds. This hybrid system, in which analog and IP cameras live together in harmony, allows customers to adopt a gradual migration policy.
The cost-effectiveness of being able to swap out analog cameras for IP cameras on an as-needed basis makes migration much more palatable for most customers.
But Thereâ€™s MoreIn addition to their basic function of converting analog video to digital video, encoders also provide end users with a number of other benefits.
For starters, says Bob Kramer, product manager, Panasonic System Networks Company of America, Secaucus, N.J., encoders can contribute to efficient use of bandwidth by allowing analog video to be compressed using standards such as MPEG-4 and H.264, which create small file sizes.
This digital signal not only makes storage more efficient, it also allows the video to be analyzed for motion detection, smart searches and other intelligent functions that are not possible in pure, unconverted analog video signals, Thompson says.
Perhaps the greatest potential that video encoders present is their ability to tie all video into a hosted storage service or solution. With increased security and archiving requirements, this is an area of the industry that is currently experiencing tremendous growth, Nilsson says. Currently, the only storage available on encoders is through a memory card, most often an SD card.
To accommodate greater storage, a video server is necessary. This is often an added cost â€” not to mention an added use of space â€” that customers are usually not prepared to take on. Instead, for a monthly fee based on their particular requirements, they can have their video stored (or simply backed up) at an off-site location. Transfer most often occurs at a predetermined interval (or in real time) via IP networks. This is a solution that is simply not available to any site that is using analog cameras exclusively.
Reality CheckWhile video encoders may seem like the perfect cure-all for the migration quandary many end users face, they are not without their share of drawbacks.
For starters, using encoders to bring analog cameras into a networked surveillance system doesn’t completely solve the riddle of how to balance the desire to move forward with migration with the important task of protecting investment in analog equipment. Sure, the cameras can now be used with the IP network, but the remaining analog equipment (DVRs, matrix switches, etc.) can’t. The final decision often becomes one of evaluating benefits versus consequences â€” the consequence being that analog equipment becomes expensive paperweights and door stops.
Naturally, when financial managers hear this, they are often resistant to approve the purchase and use of encoders until that legacy equipment has been fully depreciated for tax purposes, Wilson says. Therefore, each organization has to approach a decision on using encoders from an entirely unique standpoint and determine to determine the best fit.
A second issue revolves around controlling pan-tilt-zoom cameras remotely. With a fully analog system, when an operator wants to change the area that is being covered by the camera, there is virtually no lag between the command (say, with a joystick) and the movement of the image on their screen. That lag would have to be measured in nanoseconds.
But if video signals are sent through an encoder, it means any remote commands or controls have to go through that same device. This creates a lag â€” short, but noticeable without a nanosecond timer â€” between command and action. Naturally, this takes some getting used to, and most operators can do so quickly, but it can pose a challenge when attempting to follow the movements of an intruder in order to inform law enforcement of his or her location.
A third issue is video image quality. When you look at analog video on an analog monitor, the quality is quite good. If that video has been converted, it doesn’t look as good on an IP monitor, Wilson says.
However, newer models of encoders are equipped with the ability to improve and adjust image quality (color, brightness, contrast and de-interlacing of the video signal) to address end user complaints.
What To Look ForAs dealers, installers and integrators consider video encoders for their customers, there are a few main points they must consider in identifying the right fit.
Not surprisingly, image quality tops the list. As discussed above, this has been a complaint about video that’s been converted from analog to digital.
Performance is also a major consideration. When all of an encoder’s channels are engaged in converting video, the processor on the encoder has difficulty keeping up. As a result, there may be degradation in the video quality. Just how much degradation depends on the number of channels and the frame rate of the video, but often there are delays, artifacts appearing in the video and overall quality issues.
Other considerations include network functionality, scalability, on-board storage, interoperability and support for various video management systems. See related article on page 53 for a more complete list.
Peter de Konik, product line manager, video codecs/analytics, for The Netherlands-based Optelecom-NKF, cautions installers and integrators to set realistic expectations for customers with video encoders. All too often, customers expect the same (fictitious) functionality they see on TV shows like “CSI” and are disappointed that real-life solutions are not as robust. Digital video does improve those capabilities, de Konik says, but it is not the Holy Grail.
As with any technology, product or service, the main consideration installers and integrators must take into account is customer needs, Thompson says. Just as you wouldn’t use a sledgehammer to kill a fly, there’s no sense installing an expensive, top-of-the-line system for a customer who only wants to view video after an incident, and even then at only four frames per second.
A Glimpse Into The Crystal BallThe security industry is in a state of transition from all-analog to all-digital systems, which means analog is going to be with us for many years to come, Thompson says. He adds that the tipping point, where IP surpasses analog in the installed base, is coming soon because of the added functionality and more efficient storage options it offers.
As surveillance systems inevitably migrate towards IP technology, encoders allow installers and integrators to incorporate the benefits of network-based systems without the added cost of dismantling and rebuilding existing systems, Lazatin says. And given the number of analog cameras that have been and are still being installed, there should continue to be plenty of demand for solutions, such as video encoders, that tie those legacy cameras into the IP infrastructure. In short, this means there should be tremendous opportunities for installers and integrators in the coming years.
While the adoption of IP cameras and technologies virtually exploded a few years ago, 2009 saw a curtailing of customers’ enthusiasm, based on the economic climate. The next 18 months, Wilson says, will continue to see a mix of analog and IP cameras. Over the next five to seven years, he adds, there should be a gradual migration to IP. Where there are analog cameras, they will be working side-by-side with IP cameras across networks.
On the other hand, de Konik cautions against too much optimism for encoders’ future. He says that while encoders are going to be necessary for a while and will play a key role in the industry’s migration to digital/IP, encoders will one day be made obsolete by widespread installation of IP cameras.
Considerations in Evaluating Video EncodersImage quality: In response to complaints about the quality of converted video, some encoders are equipped with the ability to improve and adjust image quality (color, brightness, contrast and de-interlacing of the video signal).
Performance: Depending on your customers’ requirements, you may need to find a solution that can handle 30 frames per second for all channels, regardless of compression requirements. Some customers may also require multiple-stream capability on each channel.
Networking functionality: This consists of varying networking functions, including managing the IP address, video DHCP and networking security, such as 802.1X and the latest IP protocol, IPv6.
Codec specifications: M-JPEG, MPEG-4 and H.264 formats offer differences in image quality and file size, so it is important to determine a customer’s need for frame rate, storage, streaming and other factors before deciding on an encoder.
Compatibility: Some encoders are not compatible with other components within a surveillance system, so it’s important to determine product and/or brand compatibility. Does the encoder work properly with the various components of your surveillance system?
Scalability: Evaluate how many channels are needed in an encoder to account for future growth. Encoders are available with anywhere from one to 84 channels, and for larger installations, rack-based systems allow end users to mix and match different encoder blades.
On-board intelligence: Again, this depends on customer needs. Available intelligent features include video motion detection, tampering alarms and smart video search and analysis. With some encoders, it is also possible to download additional intelligence software or applications from partner companies.
On-board storage: SD cards are the most popular storage solution for encoders. Their relatively low cost-to-capacity price makes it possible to store anywhere from a few hours’ to a few days’ worth of compressed video.
Additional inputs: If edge devices, such as two-way audio and I/O ports are needed, it is important to ensure the encoder is equipped with the inputs to support them.
Support of video management systems: Determine how many (and which) VMS products the encoder supports. Also determine if the encoder’s compatibility with hosted video systems and solutions.