The Digital Video Recorder
Many people are under the misconception that building a DVR is simply taking a PC, inserting a video capture
card and adding some off- the- shelf software. This explains the hundreds of companies that have hung up a sign,
taken out some ads and begun working out of basements and garages, holding themselves out to be DVR manufacturers
and security specialists.
The reality is, a true DVR (Digital Video Recorder) meant for security is a sophisticated system composed of
hardware components, software programs and sub-assemblies with built-in checks and balances. It all must work in
unison to create a robust and reliable piece of equipment, designed for mission critical applications.
Analog systems
The cctv surveillance that many people are used to is the elderly analog technology. This was made up of a
camera that transferred a video picture to a video recorder and the images were stored on video tape. This
technology is largely redundant in the commercial context.
Integrated stand alone systems
These are digital recorders that do not rely on a computer platform to function. They look very similar to a
household vcr unit. They come preloaded with hardware and software and are designed to be almost plug and play.
They can be cumbersome to use as they do not use a keyboard but rather a built in function control usually on the
faceplate. Ideally suited to simple applications that do not require any kind of complex functionality - they do
offer a cctv system that is easy to install provided you do not require long recording times, remote viewing or
system flexibility. This is a generalisation as performance specs differ from supplier to supplier - but as most do
not offer any serious cost advantage and limited functionality they are not popular. I believe this will change
over time as the technology becomes more sophisticated and I will keep this updated as necessary.
PC Based - digital
This is where the real confusion sets in.
Digital video recorders come in all shapes and sizes much like anything else. Just because the hardware or unit
has the title of DVR does not automatically infer any degree of usability. And just like in footwear - where an
athletic shoe may be suitable for one application - and totally inappropriate for another - so to in the DVR world.
DVR's are all simply not alike.
For the purposes of this website resource, we will concentrate on the DVR applications best suited to the
commercial and industrial world where a certain base level of performance must be attained.
The DVR is a complex and sophisticated construct of hardware and software that is built by a dedicated team of
software and hardware engineers, programmers and system designers, plus support personnel. This is not a
product you will see truly manufactured by the local IT guy. It's no different than buying a car. There are
R100,000 economy Hyundai's, R600,000 luxury Mercedes and everything in between. It all depends on your needs and
requirements - both can drive and get you from point “A” to point “B.” But a R600,000 Mercedes won't carry your
cattle to auction - a R50,000 bakkie would be better suited.
The selection of a suitable DVR system then, depends on the circumstances in which it will perform and tasks it
will be expected to consistently perform, the level of operator interaction and competence - and the list
continues. It is for this reason that we strongly recommend a comprehensive needs audit on all our proposed
projects before we recommend any particular solution.
The DVR is a single component in the entire CCTV system. It is simply the part of the hardware/software that
works with video capture and translation. It requires the resources that surround it to make this possible. Digital
video recording is a process intensive multitasking application and can tax the most robust of systems if not
configured properly.
The DVR is composed of a CPU/motherboard, ram memory, vga capability, and a hard drive just as a normal
computer. The DVR card is installed via a pci slot. Windows XP Pro or Windows 2000 are the recommended
operating systems. In a competitive environment many are tempted to compromise on the quality of some of these
components - settling for a lower quality component and therefore a cheaper option. All too often this translates
into unreliable system - causing anguish for all concerned.
Along with processing power you require robust related parts and assemblies equally. The famous saying is “you
are only as fast as your slowest component.” If the system is not beefed up from end-to-end, in each and every
aspect of hardware and software, it does you no good. If it's under powered it is eventually going to break. Using
the car analogy, if you buy a light weight truck it may be a fine vehicle, as a light-weight truck, but try loading
it up with 10,000 kg of cargo and drive it up and down hills daily. Don't expect a long life out of the
transmission or engine. It's not that it's a poor product, rather that's not what it was designed to do. This
principle holds true with virtually any product.
This is one of the reasons for the disparity in DVR pricing. It's what's under the hood that you pay for, but
unfortunately without a Consumer's Guide to DVR's, it's difficult at best, for the user to ascertain the
difference, until it's too late. You can buy a blender for the home for R125.00 but it is not the same as the
R1250.00 one at the local bar. One is a consumer product the other commercial.
This is even more true in computer technology. Light-weight technology crashes under pressure - and when relying
on Video Surveillance it is not practical to have light-weight and unstable technology.
Components become even more of an issue as you get into the large systems. So “Caveat Emptor” – let the buyer
beware – all DVR's are not alike. Some have the nerve to build them out of R3299 PC's and call them Server Grade
Enterprise Equipment. As far as the system doing what you need it to do, without a lot of experience with DVR's,
this becomes a difficult task. The entry-level products will fail to mention many things that their system will not
do. Often the buyer doesn't realize it until:
• It doesn't work with certain cameras
• Too many simultaneous users freeze the system
• The quality of the recorded video is poor and unstable
• The recording and display speeds were not as you were told
• The number of days of storage are far from what you were promised
• Certain functions only work under certain conditions which renders such other functions inoperable
• You just bought a second system from the same company and it doesn't work with the old one because
the software is no longer compatible
• The distributor I bought it from no longer carries that product line so you can't get help
• There is no one in this country to support the product There is no shortage of potential shortcomings of a
substandard system or supplies. That is if you can get it to work in the first place for any extended period of
time.
In our knowledge database, we have identified dozens of different core items that can go awry with DVR
construction, and hardware and software conflicts. The biggest concern always remains reliability. Many of the
entry-level systems, are not meant for mission critical security. Remember in its most crude form, you can go to
PCShoponthecorner, buy a PC Cam, video capture card and PC and you've built yourself a DVR. But these are not the
right components for security and of course there is the issue of software.
Another good analogy in somewhat relevant terms is the ability to video conference. You can accomplish this with
MSN or Aol for R299.00 with a USB camera and microphone, so why do companies spend thousands of rand on
conferencing solutions?
Answer - for the exact same reasons discussed here in. At the heart of any DVR is the video capture card,
there are substandard consumer–type economy cards and industrial-type products. Most video capture board
manufacturers do just that, manufacture “the board”. You know that green thing you see that has a bunch of neat
looking colourful soldered components.
In reality, these companies are assembly plants. This is no different than much of the consumer electronics
industry, where virtually all companies create products assembled from other company's components. So what is it
then that makes the difference, between a top notch product and a substandard one.
First and foremost - quality control. Care in how they are assembled, and the right combination of parts to
achieve the best performance. In speaking with distributors who offer" economy cards" they experienced as much as a
20-30% reject rate. That was just the board, forget about that number when you factor in the software problems.
We only work with DVR components designed and manufactured to the highest specifications and with proven track
records of reliability.
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