Talking about HD video surveillance and its future

Talking about "HD" video surveillance and its future development trend

since the concept of "HD" has become popular in the video surveillance industry in recent years, more and more manufacturers have opened or preserved fresh food packaging and began to launch "HD" products. Through the wide variety of "HD products" on the market, we find that many products have different understanding of the indicators of "HD" and their performance effects are also very different. So, what is the concept of "HD" in the video surveillance industry? What is the real "HD"? In this paper, we discuss briefly

what is HD

what is HD? Let's take a look at the definition of HD in digital TV technology

digital TV is mainly divided into standard definition TV and high definition TV. Standard definition TV (SDTV) refers to a digital TV system with image quality equivalent to the current conventional analog color TV system, such as pal, with a definition of about 500 TV lines and a code rate of about 5mbps; High definition television (HDTV) refers to a digital TV system with horizontal definition and vertical definition about twice that of the current analog color TV system, and an aspect ratio of 16:9. The definition is about 800 TV lines or more, and the code rate is about 20MBps

ITU in itu-rbt In the 1201 proposal, several standards for ultra-high definition image (HRI) are proposed. The basic element is that the minimum resolution of the image is 1920x108, and 1billion euros will be provided within 10 years. HRI is divided into four levels, including hri0, hri1, hri2 and hri3, with resolutions of 1920x1080, 3840x2160, 5760x3240 and 7580x4320 respectively

according to the above definition, corresponding to video monitoring, analog-to-digital hybrid monitoring using analog cameras can reach up to standard definition. For example, through digital processing, the highest resolution brings confidence to extruder enterprises, with a resolution of 4cif or D1, about 400000 pixels, and a definition between 300 and 500 lines; For IP monitoring with a network camera, if you want to reach the definition of 800 TV lines, the resolution of the network camera should at least reach the standard of 1280x720, about 900000 pixels, which is more than twice that of analog-to-digital hybrid monitoring; If the network camera with 2million pixels is used, the requirements of ultra-high definition image will be met. The network camera with an aspect ratio of 16:9 has a corresponding resolution of 1920x1080, and the network camera with an aspect ratio of 4:3 has a corresponding resolution of 1600x1200

high definition monitoring

high definition network camera provides the source of video monitoring. It has carried out high-definition coding and IP packaging of video, and carried high-definition images through the IP network, which can realize high-definition monitoring, video recording and other monitoring functions

at the sending end, the network camera integrates image acquisition, video compression coding, communication control and transmission interfaces, and the video data is output through the IP network

in the image acquisition part, CCD and CMOS sensors are designed for different needs. CMOS has certain advantages in high pixels, and CCD has better adaptability to the monitoring scene. In the part of video compression and coding, different compression algorithms and algorithm implementation schemes determine the quality and coding efficiency of high-definition images. In the communication control part, the adaptability and security of the network, the packaging format and transmission function of the code stream depend on the planning and design of the monitoring system. In the transmission interface part, different network access methods, such as wireless and wired, can be well supported; In addition, some network cameras also integrate other interfaces required for monitoring, such as alarm, control, intercom and other interfaces

at the receiving end, it is decoded and output to high-definition display devices, such as LCD, and the high-definition image is recorded through the recording device

due to the large code stream of high-definition images, which is generally above 3mbps, image recording is an important part of realizing high-definition video recording. To record high-definition video camera images, we can adopt the following methods:

PC NVR

embedded NVR

hybrid DVR

no matter which method is adopted, the following requirements should be met, such as:

to ensure the storage cycle of video recording, sufficient storage space is required

ensure the effectiveness of multi-channel concurrent recording, that is, there should be no bottleneck in the recording process

convenient and fast retrieval and playback efficiency

it has a circular coverage mode, and the efficiency of recording and retrieval should be guaranteed after multiple coverage

reliability and cost performance should meet the requirements of monitoring business

pc-nvr uses pc-dvr development technology to carry out secondary development through SDK provided by HD network camera, and storage technology can adopt DAS, NAS, IPSAN, etc

both embedded NVR and hybrid DVR come from embedded DVR technology. Embedded NVR and hybrid DVR integrate network storage, retrieval and playback, video switching and other monitoring functions. If the hybrid DVR or NVR needs to support HD monitoring, the following conditions must be met at least:

support the access of HD network camera

with HD decoding and decoding output interface (such as VGA)

have enough storage space or expand storage interface

for example, Hikvision ds-2cd862, 852 and other series of high-definition network cameras adopt CCD and CMOS sensors respectively, and support 1280x720 and 1600x1200 high-definition coding respectively, which can achieve up to 5 times D1 effect display, and the code rate is adjustable between 2m-8mbps. On the back end, the ds-9000 series hybrid DVR, the first in China, can access up to 8 channels of HD. In the next five years, the market value of global functional composite materials will grow to $43.35 billion. The video recording and decoding resolution support 1280x720, and the display resolution support 1280x1024.. It supports 8 SATA slots, and the built-in storage capacity can be configured. If it is equipped with 8 1TB hard disks and 3mbps code rate, the average storage cycle of each channel is about 780 hours

outlook

"let's see more clearly" is the goal of HD monitoring. Different industries and different occasions have different requirements for image clarity. For example, in busy downtown areas, it is very important to see a person's facial features and vehicle license plates clearly; In the halls of high-rise buildings, crowded and noisy entrances and exits, entrances and exits of parking garages, highways, stadiums and other occasions, HD monitoring can greatly improve the application value of the system