From 2007 to 2008, the network camera market continued at home and abroad, "rattling in the goals," gradually "eating away" the encoder market share. In particular, safe city, the Beijing Olympic Games and Shanghai World Expo as the current network camera boost the development of force, makes the network camera application market in China, the number of multiples is beginning to show the geometric growth of the network cameras are currently more than 100% growth rate. Industry was widely predicted that after the next two to three years marketing, network cameras, video surveillance market, will become the mainstream, we also believe that Network cameras will monitor the next few years will gradually become a mainstream product areas. In the digital and network era of the concept of the impact of simulation technology, how do we use digital and networked video surveillance of thinking to understand the products, in particular, is a network camera?

  Encoders and network cameras camera solutions in the comparison of
  Encoder camera solution uses a simulation technique, namely, analog camera + analog transmission line. The working principle is that analog video signal through the analog transmission line, passed on the encoder, and then to digital, encoding, network transmission, storage.
  But we all know, analog camera output signal is CVBS video signal format, due to the N / P system of strict norms, CVBS signal to support a maximum resolution of D1, that is P or N system under the new system 704x576 under 704x480, that is CVBS only a maximum of 36 million per pixel and this pixel resolution is interlaced.
  When the image quality requirements higher, such as megapixels, or the progressive image (CMOS outputs are progressive image), the standard CVBS signal transmission can not be achieved. Of course, can also be specifically designed for high-resolution images of dedicated transmission lines, but such lines need to adopt Gigabit coaxial or fiber can be realized, it is clear that the high cost of manufacturers or users can not accept. Therefore, the encoder of this camera solution, it is difficult to design a high-resolution products.
  Another problem with analog transmission line is: an analog signal big losses in the transmission process, with the transmission distance increases, signal to noise ratio increased dramatically, making the rapid decline in image quality, and the transmission process due to the introduction of a lot of noise , which makes the video compression encoder more difficult, but also makes the video bit rate will increase exponentially, thereby making the low-bandwidth network under the transmission more difficult, but also makes the video hard disk storage space requirements increase, that is analog transmission not only makes the image quality and easy to drop and have to make transmission and storage costs.
In addition, there is an analog transmission line question is: safe! As we all know, CVBS signal format is an open standard, video information is transmitted over coaxial cable, there is no encryption and authentication mechanisms. Long as we know the location of video cables, any person means by grafting to watch and switching video. Members who have read a number of large European and American films, such as "The Italian Job", "emergency landing" and other movie scenes, the perpetrators of those ways is through grafting to switch video signals in order to avoid video surveillance video surveillance personnel.
  That is analog video signal transmission lines can not guarantee security.
  On the contrary, the network camera uses because it is a solution embedded camera, camera photographic images of the device does not require access to long-distance transmission, direct transmission to the coding module, which has evaded the N / P specification constraints to avoid the CVBS signal restrictions on the issue of image resolution, meaning that network cameras can provide high-quality, low bit rate image, the image resolution to support more than megapixels can also support the progressive image. In addition, network cameras, video signal can be securely encrypted, which ensures the security of the transmission process, thus can effectively prevent unauthorized users of the eavesdropping and tampering.