Application Analysis of HD Network Camera Network Transmission
Guide: China Security Surveillance has been pursuing to provide users with higher definition images. After several years of market gestation, especially through the technical preparations and application inspections of various manufacturers, HD surveillance has become an unstoppable trend in China's security, and related product technologies and application systems are becoming more and more mature. Tapping the door is about to break out.
China Security Surveillance has been pursuing to provide users with higher definition images. After several years of market gestation, especially through the technical preparations and application inspections of various manufacturers, HD surveillance has become an unstoppable trend in China's security, and related product technologies and application systems are becoming more and more mature. Tapping the door is about to break out.
As a system project covering the front-end, transmission, management center, and back-end links, high-definition monitoring is bound to be networked due to the transmission distance, flexibility, and deployment costs of the monitoring system. HD cameras, as front-end devices for high-definition monitoring, will also be networked. At present, high-definition cameras only have some applications in some industrial fields. In the conventional surveillance market, high-definition cameras have not been fully promoted. The reason is that the core obstacle is the network transmission barriers.
Second, crack the network transmission obstacles of HD cameras
For high-definition cameras to be used on a large scale, in addition to passively expecting network operators to make some adjustments, we also need to take the initiative to take some alternative solutions to alleviate the contradiction of insufficient network bandwidth of high-definition cameras.
2.1 Adopting advanced video compression standards
Actively adopt advanced video compression standards to ensure the best image quality with the least amount of data. At the same time, through the combination of image coding technology and intelligent technology, the use of local coding can reduce the need for high-definition image transmission to a considerable extent. Network bandwidth. At present, there are three main compression formats: JPEG, MPEG-4, and H.264. JPEG is a single-frame picture compression. The single picture has the best effect, but it takes up a lot of network bandwidth resources. MPEG-4 and H.264 are continuous compression between frames. Among them, H.264, the most popular compression format, has the highest compression efficiency. H.264 compressed video data requires less bandwidth during network transmission.
2.2 Provide dual stream support
While realizing high-definition local recording, the use of dual-stream technology can take into account the reduction of bandwidth used for remote transmission and ensure better local image quality. In the remote monitoring environment, the HD camera can provide a high bit rate stream for local HD storage, such as 720P / 1080P encoding, and a low bit rate stream for network transmission, such as QCIF / CIF encoding. Remote network transmission. According to the network bandwidth, the stream format can be flexibly selected to achieve local high-definition storage, while the back-end low-stream network transmission. It can ensure the stable operation of the transmission system when the network resources available to users are limited.
2.3 Improve the added value of intelligent technology
Intelligent technology can improve the monitoring efficiency. The value it can bring is more than that. Through encoding and intelligent analysis, the HD network camera with embedded intelligent analysis module can grab valuable information from the source and then transfer it to the background. Can reduce the transmission pressure and truly achieve effective transmission. The high-definition camera can analyze and judge the collected images and transmit the alarm signal to the back-end system, which is different from the way that the conventional intelligent technology transmits the image to the back-end system and then analyzes and alarms by software. The previous method requires too much bandwidth and storage space, and due to the loss of the image signal during transmission, false alarms are prone to occur. Since all the signal processing of the HD camera is inside the front camera, the signal is the most complete, so the accuracy of the alarm is greatly improved, and the bandwidth can be reduced.
2.4 Improve front-end caching technology
Reasonably designed front-end caching technology to ensure that device images are not lost. HD cameras have limited data storage capabilities and rely on communication transmission and back-end storage devices. We can prevent data loss during communication failures by designing a reasonable front-end caching mechanism. For example, when designing a high-definition camera system, you can choose on-board memory or other storage devices and support offline work. In the case of an abnormal network interruption, data can be temporarily stored locally, and then returned to the server after the network recovers. You can also use network management technology to implement front-end caching when the network is temporarily interrupted, and automatically upload the recording data after the network is restored to ensure the integrity of the recording.
2.5 Develop and adhere to industry standards
It is necessary for the manufacturers in the monitoring market to unite and formulate some common norms to seek common ground while keeping minor differences. At present, the emergence of standardization organizations such as Onvif and PSIA makes people see the hope of standardization of video products and systems. The era of "plug and play" for video surveillance is believed to be not far off.
Network surveillance cameras represent the future of surveillance cameras. At this stage, the application of high-speed network transmission technology represented by optical transmission systems in our country is becoming increasingly popular. Ultra-high-speed backbone networks spanning a large geographical area and high-speed networks in local areas have become normal facilities, and high-definition images of large streams are transmitted through the network Real-time transmission has become possible, and there is still room for downward adjustments in tariffs. These have opened up a broad space for development of high-definition surveillance.
This article is edited by World Security Technology Center. World Security focuses on the development and manufacture of security surveillance cameras. Shiyou is a leading surveillance camera brand. Network high-definition cameras, lightning protection cameras, and dot-matrix cameras are the flagship products of Shiyou. For more details, please visit the Shiyou camera product page.