Guest Echo Posted September 28, 2004 Posted September 28, 2004 Software compression DVR card is a hardware-based circuit board which is designed on several video capture chipsets, cooperates with peripheral circuits and components to complete the function of video capturing. The appearances of cards from different manufacturers do not vary much from each other. This is because manufacturers have to design the circuit according to the model circuit information provided by the chipsets.Video capturing function of software compression DVR card is realized by video capture chipsets such as Fusion 878A, and video compression is realized by software and operation of CPU. Because of difficulties in developing software compression method, there are not many products on the present market, and the main cards are Pico 2000 from Canada, Ether8000 series from Shenzhen Wave-particle Intelligent Technology Co., Ltd., PICASO and KODICOM from Korea. Besides, there are pirated PICO, PICASO, KODICOM etc which are renamed by some dishonest companies. Also, due to difficulties in research and development of software compression cards, only companies with strong R&D strength are able to develop them. So software compression programs are of high technology content. If they are properly used, capability and stability of the software are not worse than those of hardware compression. Below is a brief introduction to the main original software compression DVR cards in market. Hardware compression DVR card realizes video capture and compression by chipsets in DVR board. Its main difference to software compression is that, in hardware compression DVR card, video compression algorithm is written into DSP chipset on the board. DSP does the compression work of CPU, thus reduces CPU's burden. When DVR card is connected to multi-cameras and you need a real time recording with low CPU frequency, you can use hareware compression DVR card if your harddisk space is big enough. Hardware compression cards do not take too much CPU resource, so most of them adopts great-rate compression mode and have high viewing resolution (but they do not adopt high recording resolution, so video definition of recorded files are not better than software compression cards). But this causes new problems, such as great data amount, high harddisk usage, and short save time for video files etc. At the same time it brings pressure to network transmission. Thus hardware compression DVR card is not suitable for remote control from multi-channels. Furthermore, DSP chipset used in hardware compression is not designed scientifically as CPU. Its heat emittance is very high, sometimes up to 80 centigrade. When four cards are plugged in one computer system to form 16 channels real time, the computer is easy to crash in summer when the heat dispersion condition is not good. So this aspect has to be taken into consideration if hardware compression DVR systems are to be installed in hot areas. Hardware compression card has an unconquered defect, that is its cost is too high and its price is hard to drop. Some cards don't have advanced software encryption technology, and have to realize encryption by plugging expensive USB interface encryption dog. This not only adds to hardware cost of DVR card, but also reflects that the card manufacturer is not strong in research and development strength. For the reason of expensive cost, hardware compression cards are mainly used in higher-end locations, medium or low-end client locations like resident sites, medium and small-sized hotels, factories and workshops are difficult to popularized. By the above comprehensive compare between the two kinds of cards, we know they both have advantages and disadvantages. So users must choose a proper card according to their installation location and other factors. For example, if you need 16 channels real time recording without remote control, you can choose hardware compression DVR card. If the surveillance channels is less than 8 real time, then software compression is equal to hardware compression card. If you need remote control of multi-cameras, you can choose near real time (6.5-8 fps) MPEG-4 software compression cards. This kind of cards have splendid network effect, support long recording time, and are almost real time to flesh eyes.
Guest Echo Posted September 28, 2004 Posted September 28, 2004 Oh, I didn't expect there will be a cute dog running in the article. I meant ENCRYPTION dog, haha
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