Development of video processing technology in the

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The development of video processing technology in security system

in the late 1990s, with the development and popularization of computer technology, image processing technology and network technology, a wave of digital monitoring rose

new development of video processing chips

with the annual growth of China's digital video surveillance market by more than 30% and the growth of other fields in recent years, the video processing chip market has also been growing. The demand of the security monitoring industry has gradually become clear, and chip manufacturers have begun to pay attention to and actively promote the potential market of video monitoring. Video surveillance has become a new profit competition for chip manufacturers outside the fields of industrial automation, consumer electronics, computers and so on. The development of video surveillance industry has attracted more and more chip manufacturers to join. The monitoring industry will become an important application field of video processing chips

in 2004, American SPI company was established especially for video surveillance applications, and began to promote in the Chinese market in 2006. When it comes to why SPI is specifically targeted at the field of video surveillance, Huang Shihua, project manager of Magellan (general agent of SPI China in the United States) Technology Co., Ltd., believes that compared with the fields of set-top boxes and computers, the application of security market tends to be mature, and the demand is quite obvious. As long as the product performs well, it will be able to seize the market. At present, American SPI companies are taking advantage of the strength of Chinese agents to cultivate their own customers from some small and medium-sized customers. According to Chen Shiming, senior system marketing director of NXP Asia Pacific, at least 25 manufacturers are competing in the chip market. It can be predicted that with the increase of predators, the competition will be more intense in the future. The foam granulation unit is to crush and plasticize foam, draw strips and cut granules

following the promotion and application of Philips PNX1300 chip in China in 1999, Ti launched the general digital media processor TMS320DM642 in 2003, officially entering the field of digital video surveillance in China. Around 2004, Hisilicon, as the world's first semiconductor company to launch h.264soc monitoring dedicated chip, entered everyone's vision after more than three years of research and development. At almost the same time, Taiwan's Shengmai technology parent company (Zhiyuan) began to integrate armcore, compatible with fa526cpu, mpeg4/mjpegcodec and a number of peripheral IPS, creating a video codec chip SOC tailored for digital monitoring

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with the continuous investment of telecom operators in the security monitoring market, network monitoring began to ferment in 2007. Lai Rongxing, director of Taiwan Shengmai technology products market planning department, predicted that the growth rate of DVS, IPcamera, NVR and other network monitoring equipment will double in the future, Thus, chip manufacturers will be more attracted to increase investment in the video security market

dual coding technology and range array

looking back, the development of digital hard disk video recorder (DVR) has been many years. Generally speaking, it has developed rapidly, and various new technologies, new products and new concepts emerge in endlessly, but the video definition and video cost are always the two important factors in the monitoring system. Video definition is closely related to image quality, resolution, code rate, frame structure and other video coding parameters, and video cost is closely related to compression efficiency. In order to achieve high image quality, it is bound to increase video cost. On the contrary, to reduce video cost, it is bound to affect image quality. In the specific application, how to give consideration to these two factors? To this end, Hikvision has proposed and implemented the technology of "dynamically adjusting coding parameters"

"dynamic adjustment of coding parameters" refers to the adjustment of coding parameters without starting or stopping recording (without switching recording files), which takes effect at the same time. In specific applications, for static or general monitoring scenes, adjust the corresponding coding parameters to keep the video at a very low code rate. When the image changes or an alarm occurs, you can adjust the corresponding coding parameters to achieve high-quality video. The parameters that can be dynamically modified include: resolution, video quality, code rate control, frame rate control and frame structure

because the above parameters can be dynamically modified, the continuous image can be maintained without frequent file switching, which not only meets the requirements of high image quality at critical moments, but also saves hard disk space

joint monitoring is another important demand after the completion of the digital transformation of the banking system, especially for the unattended off-line ATM machine, joint monitoring is an important means of efficient operation and maintenance. The monitoring center can not only understand the status of DVR in real time, but also view the on-site images with alarm in real time, which changes the current situation of post-processing simply through video compounding to a certain extent

for the financial industry, the video clarity test project is relatively simple, and the clarity should be guaranteed. In this case, the video data is large, and the network resources are limited, so the network bandwidth has become the bottleneck of video data transmission. To solve this problem, Hikvision has proposed and implemented dual coding technology

the image quality, resolution, frame rate, code rate and other video parameters of the output code stream can be set independently. The two generated code streams can meet different application requirements, such as the main code stream for video recording and the sub code stream for network transmission. With the expansion of the application field of video monitoring and the development of coding technology, the realization of multi coding technology will become possible. Such multiple code streams can meet the needs of different transmission channels and applications, such as Gigabit, VPN, ADSL, wireless network and other transmission channels, as well as important users and general users, which can transmit video data with different code rates and image quality

for the traditional CCTV monitoring center, the matrix is a very important device, which mainly completes the functions of video switching, PTZ control and so on. At the same time, it can also program and set the switching rules. The number of video switching channels depends on the switching ability of the matrix host backplane, and the switching is realized through circuits. Hikvision has proposed and implemented digital matrix for digital monitoring, which is implemented on two platforms

for a single DVR, it is actually a video switching matrix based on data bus. For PC DVR, the number of input video channels is the number of video and audio compression cards. One channel of video can be switched and output to the graphics card. By adding a decoding card, you can also switch multiple videos to the decoding output channel (the number of output channels depends on the number of decoding cards). The total number of channels that can be switched mainly depends on the bandwidth of the bus. In addition, switching rules and PTZ control can be easily set through PC platform. For embedded DVR, the number of video input channels is the number of video input channels of DVR. Generally, there is at least one output channel. Some DVRs output two or four channels. Similarly, switching rules can be set through DVR and PTZ control can be carried out

for a monitoring system based on IP network, the front-end video input, IP network equipment, back-end decoding equipment and control equipment together form a digital matrix based on IP exchange

the number of video input channels depends on the number of front-end video coding channels that the control end can access, and the number of video output channels depends on the number of decoding servers and the number of decoding output channels of each server, as well as the bandwidth of the IP network. The switching rules are set by the console, which can conveniently control PTZ at the same time

compared with the traditional analog matrix, the digital matrix has strong flexibility in the setting of switching rules, the friendliness of switching interface, and the processing of switching pictures. At the same time, the scalability of the number of switching channels is more convenient and the cost is lower. For example, in terms of the processing of switching pictures, the picture segmentation line can be realized on the DSP platform without picture splitter, and the video output can be carried out in the unit of window. In short, digital matrix has more development potential

HD video codec

after nearly 10 years of development, the coding ability of the chip has been greatly improved. Before, to achieve 1080i image quality, 10 chips were needed to encode, but now only two or three chips are enough

in combination with market demand, the pursuit of better image quality is a very reasonable and eternal requirement of users. With the advent of intelligent monitoring era, in order to meet the requirements of video image analysis and processing of the monitoring system, such as license plate recognition, face recognition, etc., higher requirements are put forward for image quality, such as high-definition format in the past two years. This poses a greater challenge to the encoding and decoding ability of the chip

"for our front-end chip manufacturers, the most important thing is to improve the definition of video images. Originally, our product resolution can only reach about 400 lines. Tw2864 uses 10 bit ADC and enhanced 4H adaptive comb filter to make the image definition up to 450 lines or more, and can obtain better image quality, rich color quality and image sensitivity." Techwell Cheng Liming said

on the other hand, the continuous upgrading of compression algorithm also changes the image quality. With the development of the mainstream compression format in the market to H.264 or even more advanced algorithm format, it has become the pursuit of chip manufacturers to continuously improve the compression ratio and optimize the algorithm. "In terms of computation, MPEG-4 is four times more complex than JPEG, and H.264 is more than three times more complex than mpeg4. In addition to the basic requirements of decoder compatibility and encoder compression quality, high-speed system architecture, memory bandwidth, efficient DMA controller, and even multi-core parallel processing are the key to the excellent SOC performance."

judging from the products launched by the mainstream chip manufacturers in the current market, most of them support HD formats. For example, ADV202 and 212 products of ADI can support HD formats. Ti's dm355 can support MPEG4 real-time coding at 720p, with a bit rate of 4mbp to 8mbps, and can be used as the core processor of HD video camera or HD video server. It is understood that Ti can support H.264 real-time coding chip under 720p, which will also be launched soon. The birth of high-definition coding chip will enable video monitoring products to obtain higher image quality under a lower bitstream

in recent years, China's security monitoring market has developed rapidly and attracted the attention of the world. DVR products, as the mainstream products in the domestic monitoring industry, have been leading the trend for 5 or 6 years. Under the guidance of digital monitoring technology, the domestic monitoring market has experienced explosive growth, with an annual growth rate of more than 40% in terms of DVR alone. With the development of the market in the direction of vertical deepening, the networking, intelligence and platform trend of digital monitoring products has become increasingly obvious. (end)

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