At present, there are three development directions of DVR technology, namely, intelligent, integrated and networked. To predict the development trend of embedded DVR technology, we must first understand the main technology solutions used in embedded DVR. Most of the technology solutions used in embedded DVR in the market are composed of four important parts, namely: embedded software/hardware technology; Hard drive management technology; Algorithmic technology; Network technology.
Embedded DVR core devices are similar to PCs, are high-performance CPU, compatibility standards are different, different functions, with the further development of chip technology, MIPSDSP or ARMDSP technology will be more suitable for embedded DVR.
Operating system: The operating system used in embedded DVR on the market is divided into three main categories: the first category is the manufacturer's own development of simple RTOS; The second category is commercialized dedicated embedded operating systems, such as VXWORKS/WinCE; The third category is the LINUX operating system with open source code. RTOS is the simplest and most efficient, but its scalability is relatively poor, complex functions are difficult to achieve; The second type of operating system has very good system characteristics, but its scalability is not very good, many function extensions rely on third parties, and the license fee is relatively high; The third type of LINUX operating system adopts an open architecture and modular design, can be tailored for the application, removes unnecessary functions unrelated to monitoring, and, LINUX supports multi-person, multi-work, only requires very little hardware support, such a system, more efficient, lower chance of error. Its reliability has been verified, can be used in mission-critical and situational multi-application operating system, the Internet uses web servers, are 24 hours continuous operation, the vast majority of which are using LINUX operating system.
He is also a system specifically for network applications, so it supports a lot of network protocols, supported by related software, can implement WWW, FTP, DNS, DHCP, E-mail and other services. And its kernel code is completely exposed and can be developed and changed at will. This feature has enabled more than 10 million people around the world to use Linux, and the functionality and integrity of Linux has grown as many vendors have invested in developing core programs, developing related software, and hardware peripheral drivers. Therefore, the use of LINUX operating system is also the trend.
2, hard disk management technology
Embedded DVR hard disk management system is divided into two categories, one is the same FAT format management system as the PC, the second is the embedded DVR manufacturer developed, suitable for storing media data flow of the hard disk management system. The advantage of the former is that it can take advantage of off-the-shelf PC technology without the need to invest in research and development costs. However, this system can not manage large packets, can only be subcontracted, a complete video, divided into several small packages, so easy to produce the phenomenon of dropping frames between packages and packages; At the same time, the hard disk head needs to read and write data and file index frequently, the head beats frequently, for the DVR system of continuous reading and writing hard disk ten to twenty-four hours a day, it is very easy to cause hard disk failure; If the hard disk is full, the whole file needs to be deleted, but the newly recorded file is different from the old file size, which will generate a lot of debris space on the hard disk, affecting the use of the hard disk and system efficiency; In addition, fat file system used as video recorder video data management there are two risks, one is that if the file distribution table is damaged, most of the video material will be lost, and the other is the system suddenly power failure or human damage, the current video data can not be saved.
The second approach would fundamentally fix the above problem.
Algorithmic/network technology
Therefore, from the development direction of embedded DVR hard disk operating system, the second way of long-term stable recording can greatly improve the reliability of hard disk recorders.
But the special file system needs professional companies with considerable development of hard disk file system capabilities and experience, at present only a few manufacturers have this technology. Such as Zhejiang Dahua production of all embedded DVR are self-developed file management system, but also the use of hard disk sleep technology, extending the life of the hard disk. In the future, if we want to gain a foothold in embedded DVR, we must also incorporate dedicated file management into the research and development agenda.
3, algorithmic technology
In the algorithm, the mature application of MPEG-IV and the expansion of H264 application will become a trend. The growing number of developers of MPEG-IV products makes it more and more mature. H264 has become mainstream because it is more in line with the requirements of network transmission.
In the future, in order to make embedded DVR more widely applicable, the unification of various algorithms will be the trend of future development, but this unification is not based on the domestic standards of which enterprises, need a wide range of government functions and DVR industry chain of various types of enterprises widely involved.
4, network technology
The new generation of embedded DVRs already has the same network characteristics as PC, and the future development of network technology will enable embedded DVRs to meet the requirements of image transmission in different network environments. Embedded DVR network technology is developing in two directions: First, the development of high-quality network video recorders to meet the needs of security monitoring under the conditions of special network technology, its technical requirements are real-time, clear, reliable, flexible networking, decentralized storage, multi-level management, the ultimate development goal is to replace the analog fiber optic cable under the conditions of image transmission market; The second network technology is the network transmission solution under the condition of public network, because of the poor transmission conditions of public network, so in order to maximize the QoS in the transmission of images on the public network, a variety of new network and image compression transmission technology, such as streaming media technology.
In summary, with the development of network technology, identification technology, microelectronics technology, codec technology, operating system technology, etc., embedded DVR will make the development of intelligent, integrated, wireless, high-definition, personalized, interactive, in the future more open up automatic tracking, specific target tracking, specific target identification, ingestion, processing and other functions.
The development of civil high-definition video system will affect the development direction of embedded DVR technology. Due to the huge civil high-definition video market, broad prospects, large companies at home and abroad are investing in human and material resources here, in order to look forward to a breakthrough, if in the near future, high-definition video system widely popular, its technology and standards will also be used by video surveillance systems, into digital monitoring systems of fact. DVR manufacturers are closely monitoring the development of high-definition video and are constantly exploring the possibility of applying their technology to security surveillance.
