How Do Network Cameras Remove Transmission Barriers in High-Definition Era

For video surveillance, image clarity is undoubtedly the most critical feature. The clearer the image, the more obvious the details, the better the viewing experience, and the higher the accuracy of application services such as intelligence. So image clarity is the eternal pursuit of video surveillance. The standard for measuring image sharpness is resolution, and the unit is pixel. The larger this value, the clearer the image. The so-called HD, SD, the difference is also reflected here. The dividing line between the two is megapixels or 720p, reaching megapixels or 720p is HD. Based on such standards, CIF and D1, which currently dominate the video surveillance market, are standard definition.

To achieve true high-definition surveillance, high-definition video must be fully supported in such areas as video source acquisition, video signal compression, video signal transmission, video browsing, and video file playback. For customers, HD only makes sense when it includes front-end, platform, storage, browsing, and display.

It can be seen that to achieve high-definition monitoring, HD must be considered from the entire monitoring system, and networking is the basis for the application of high-definition monitoring systems.

HD network cameras play a decisive role. We know that traditional SD monitoring is divided into analog, digital, and network types. The front end of the analog monitor is an analog camera, and the back end is a matrix. The digital surveillance front end is also an analog camera, and the back end is a DVR. There are two types of network monitoring front-ends, one is an analog camera + video encoder, one is a network camera, and the back end is a platform. In other words, in the era of SD surveillance, there are many types of analog cameras, network cameras, video encoders, and analog cameras at the front end.

The current high-definition video sensor is mainly CMOS. The CMOS sensor directly outputs the digital video signal. In the camera, the digital high-definition video signal is directly compressed and encoded by the DSP or ASIC, and then transmitted in a networked manner, and the HD signal is output directly from the camera. It is economical and more efficient.

HD surveillance problems HD network cameras have made a qualitative leap in image clarity, but they have also brought a series of real problems to HD surveillance systems:

The larger the resolution and the higher definition, the more the code stream will increase when the data is transmitted, increasing the network bandwidth pressure. The doubling of data traffic increases the recording capacity and puts pressure on network storage. The requirements for central control, management software, and hardware performance have multiplied. The workload for the management and post-mortem analysis of recorded video images will also exponentially increase.

High-definition video camera how to remove transmission barriers Network transmission has a popular type of promotion for monitoring, but also by the constraints of network bandwidth, transmission performance in large-scale long-distance projects, to the current basic megapixel HD 720P specifications, code The flow is about 2 times that of D1, and the bandwidth reaches about 4M. With the 1080P calculation, the bitstream is 5 times that of D1, and the bandwidth used is about 10M. Taking 100M Ethernet as an example, under the premise of ensuring smoothness, only HD video of about 5 channels can be actually carried at the same time. However, if the same video source has multiple users accessing, the occupied bandwidth will be greater. Switching to Gigabit Ethernet can take several dozens of ways. For small-scale high-definition monitoring systems, it can be effectively solved. For large projects, transmission performance will become a stumbling block.

In recent years, due to the rapid development of optical fiber communication technology, the cost of optical fiber transmission monitoring systems has also been greatly reduced, so the application of optical fibers and optical transceivers in monitoring systems is becoming more and more popular. At present, the author found that optical fiber has been widely used in home optical fiber and office access network, in the field of home intelligence, office automation, industrial control networks, automotive airborne and military communications networks and other fields. For high-definition video streams that require high transmission bandwidth and transmission distance, it is no longer a dream to realize high-definition monitoring in the era of optical fiber.