Video signal spatial redundancy and temporal redundancy is large,to eliminate this redundancy,lower the threshold video applications to enhance the user’s sensory experiences,humans expanded tireless research and exploration.And because the codec algorithm complexity, in order to ensure the versatility of the encoded image, relevant international organizations based on the latest research results video codec developed a series of image coding standard, mainly ITU-T(ITU) standard H-series images (H.261/263/264/265) and the Moving Picture Experts Group MPEG family of standards (MPEG1/2/4). In the 21st century, the rise of the Internet, network convergence trend to strengthen other reasons, the two organizations gradual integration of the standard technique. It is a video codec standard push toward digital video surveillance, networking and business to promote high-definition video surveillance, ultra high-definition era.Through video codec technology innovation development process, we can understand the development process of video surveillance. Uncompressed video era,a low-resolution video images need hundreds of megabytes of bandwidth to digital media storage and network transmission simply unrealistic, that era video surveillance can only exist in analog form.With MPEG-1/MPEG-2/MPEG-4 standard introduction video size to get the number of times the compression, so that the video recording using digital media as possible, but due to high bandwidth video transmission still used, the network transmission is not yet reality. In recent years, with the introduction of H.264 standard video compression to obtain hundreds of times, which makes video content network transmission is possible, and with the demands for higher image quality, required to achieve 720P/1080P resolution video image , H.264 codec technology for high definition network surveillance era. Human pursuit of quality of the video image is endless, and in August 2012, H.265 video codec standard ITU draft officially approved organizations, sounded the clarion ultra high-definition era, it will lower the cost of technology achieve higher compression ratio (compared with H.264 compression rate increased by 30 ~ 50%) and better image quality (up to 7680X4320 resolution images), along with the increasing maturity of the industry chain H.265, video surveillance transition to ultra- HD era will be just around the corner.
In the IP network camera, the subject through the lens into the ip network camera through the sensor of the light into electrical signals that can be processed, and then through the ISP function check of image processing modules, and finally by encoding video compression module, Output video compression stream. Compressed bit stream for transmission over the network, from the background of the video management system (VMS) or a network video recorder (NVR) for image storage and management. Need to play on the wall, the first through the decoder to decode the TV on the wall and then realize image display. It can be seen in the video surveillance video streams plays a vital role in determining the quality of the video surveillance system, cost and efficiency and so on. Current video surveillance mainstream codec standards H.264 and MPEG-4, and around which these coding standards built up a mature industry chain environment. The higher the price the more viable technology, no doubt, H.264 is the current cost-effective codec technology, there are authoritative statistics, 80% of the video chip supports the H.264 standard. However, video surveillance, after entering the Internet age, especially in the current safe city big networking context, H.264 limitations also been highlighted.
First, customers do not want to bring high stream high construction costs. With the popularity of high definition in the field of digital video surveillance customers want to enjoy high-definition image quality, while GM 1080P video images, often takes 6 ~ 10M bandwidth, which gives the network construction and system construction cost pressures brought. As Huawei video compression technology based on their own accumulation, depending on the shooting scene, the use of more efficient compression algorithm, using the same quality case, 30% lower than the industry code stream, this technique is the construction of large-scale projects very meaningful; secondly customers have been satisfied with HD, hoping to bring in business decision making ultra-high definition high accuracy. With the popularity of video surveillance applications, especially as transport and safe city and other areas, the traditional 1080P image quality has failed to meet the needs of customers, customers want to get super clear picture more precise management of the business, while at the same time bring the cost required upgrade is acceptable. Customer demand has been the driving force of technological progress, in the face to keep the high-definition video applications, high frame rate, high compression ratio direction of the trend, HEVC (H.265) protocol standard is in this context came into . Here we look ahead to the next H.265 to bring the value of video surveillance.
First, a higher compression ratio will reduce the construction cost of end to end. The benefits of the network, the ip camera can be infinitely far away, and according to the construction industry model of network video surveillance, storage and network devices occupy 35 to 40% of construction investment, construction of video surveillance has become a top priority, how to maximize efficient use of transmission bandwidth and storage space, a fundamental solution to flow from the hand of video compression code, using H.265 video compression technology, H.264 increased by 30 to 50%, according to estimates potential savings of up to 20% of the investment, is very impressive. Second, higher resolution, more accurate business judgment. In the field of digital consumer, 1080P video has become mainstream; 1080P video surveillance is becoming popular among the customers but also some made 4Kx2K, 8Kx4K digital video needs. Ultra-high-definition images, you can get a larger field of view, sharper images, more accurate business decisions based. On the other hand, restricted the development of an intelligent analysis of the reasons is the image is not clear enough lead to misjudgment analysis, using a higher image quality analysis results easier to obtain an accurate set. H.265 standard is based on the H.264 standard developed, combined with H.264 video applications in the mainstream H.265 protocol can be expected in the future the majority of prospects. And H.264/AVC compared to the same PSNR can save about 40% lower bit rate, in the same subjective quality, to save on average 50% higher than H.264/AVC bit rate, is the H.264/AVC half of the definition of the sequence and above 720P saving rate is particularly significant.
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