对DVR来说，它的发展除了光学技术、激光技术、微电子技术、细微加工技术、计算机与自动控制技术、压缩技术的进步带来存储技术在记录密度、容 量、数据传输率等等关键技术的巨大突破外，完全依赖于通讯和信息网络技术的快速发展。从模拟到数字，从硬压缩到软压缩，从一芯一路到一芯多路，从PC到嵌 入式DVR，各领**。但不管技术如何发展变化，技术方向与产品特色化是关键所在。
For DVRS, it besides optical technology, laser technology, the development of microelectronics technology, fine processing technology, computer automatic control technology, compression technology progress and storage technology in the recording density, capacity, data rate and so on key technology breakthrough, depends entirely on the rapid development of communication and information network technology. From analog to digital, from hard to soft compression, from one core to one core, from PC to embedded DVR, each leads **. But no matter how the technology develops and changes, the technical direction and product specialization are the key.
DVR技术三形态
一、市场的特定需求推动技术升级
DVR技术链首先是芯片，其次是视音频压缩算法技术，三是软件集成技术。目前DVR芯片国内还没有企业能够开发。
随着金融、交通、公安监控市场需求的增加，很多用户希望能够实现稳定的实时传输监控。但ASIC方案的压缩算法是由芯片商直接提供，而且已经固 化好，对板卡生产商来说没有二次开发的平台，而当时一些芯片开发商并不知道中国市场的这些特定需求。这些二次开发商迫切需要一种新的芯片平台，加入自己的 压缩算法开发出适应国内市场需求的DVR。时隔不久，这些芯片厂商推出了DSP解决方案，而DSP和ASIC两种方案最根本的区别在于，ASIC方案中压 缩算法是由芯片制造商固化好的，DSP方案中压缩算法是由板卡制造商提供的，对下游整机制造商来说技术升级方便。
同时，DSP方案给板卡开发商也无形之中设置了一个较高的门槛，必须有自己的压缩算法技术。压缩板卡的关键技术包括视频压缩算法、网络技术及智能化技术，尤为视频压缩算法最为关键。
DVR technology three forms
First, specific market demands drive technology upgrading
DVR technology chain is first chip, second video and audio compression algorithm technology, third software integration technology. At present, no domestic enterprises have been able to develop DVR chips.
With the increasing demand of financial, traffic and public security monitoring market, many users hope to achieve stable real-time transmission monitoring. But ASIC solution of compression algorithm is provided directly by the chip makers, and has solid good, no secondary development platform for the board manufacturer, at a time when some chip developers do not know the specific market demand in China. These secondary developers urgently need a new chip platform to add their own compression algorithms to develop DVRS to meet the needs of the domestic market. Shortly after, the chip maker introduced DSP solution, and DSP and ASIC two plans of the most fundamental difference is that ASIC solution medium pressure is good by the chip maker curing shrinkage algorithm, DSP program in the compression algorithm is provided by the board manufacturers, technology upgrade convenient for downstream machine manufacturers.
At the same time, the DSP scheme has also set a high threshold for the board card developers, so they must have their own compression algorithm technology. The key technologies of compression board card include video compression algorithm, network technology and intelligent technology, especially video compression algorithm.
二、嵌入式技术成为主流
2001年，当国内企业的数字硬盘录像机还刚刚起步时，韩国POSDATA和IDIS率先将采用MPEG-4视频压缩技术的POS-WATCH 嵌入式DVR产品带入中国市场。以其前沿的技术优势，优良的产品质量，完善的售后服务一直占领韩国和日本的大部分市场份额，也征服了国内大部分数字监控录 像机市场。从2002年开始，已经有国内企业试做嵌入式DVR产品，现在无论是采用软压缩还是硬压缩技术，毫无疑问嵌入式DVR已经成为市场主流产品。
但是，DVR产品在中国市场的消费者绝大多数都是政府部门和金融等重点单位，他们的需求并不像国外的消费者一样仅仅是录像存储功能，是需要实时 传输和查看，而韩国的DVR产品并不具备这些功能，曾经一度颇受欢迎的产品并没有得到大规模的应用，国内市场仍然处于观望状态。随着海康威视、成都德加 拉、浙江大华、浙江大立、北京汉邦、武汉恒亿、深圳图敏、广州金鹏等国内DVR板卡研发企业，利用TI、飞利浦等芯片平台加上自己的压缩算法等核心技术， 批量生产出清晰、稳定又能实时传输和查看的视音频压缩板卡。从此，采用此技术的DVR产品在中国内地遍地开花，并在短短两三年间已经发展为成熟产品并得到 广泛应用。到2005年，韩国、台湾的DVR产品在国内市场已经没有了太大声音。
Embedded technology has become the mainstream
POSDATA and IDIS of South Korea took the lead in introducing POS-WATCH embedded DVR products using mpeg-4 video compression technology into the Chinese market in 2001, when the digital hard disk video recorders of domestic enterprises were still in their infancy. With its cutting-edge technology advantages, excellent product quality, perfect after-sales service has been occupied most of the market share, South Korea and Japan also conquered most of domestic digital surveillance camera market. Since 2002, some domestic enterprises have tried to make embedded DVR products. Now, whether using soft compression or hard compression technology, there is no doubt that embedded DVR has become the mainstream product in the market.
DVR products in China market, however, the vast majority of consumers are government departments and the financial and other key units, their demand is not just like foreign consumer video storage capabilities, is the need for real-time transmission and view, while South Korea's DVR products do not have these functions, once a popular product has not been widespread application, the domestic market is still in a state of wait-and-see. With hikvision, chengdu degas, zhejiang dahua, zhejiang, Beijing hanbang figure min, wuhan, shenzhen, guangzhou jinpeng domestic DVR boards such as research and development enterprise, the use of TI, philips and other chip platform, combined with their own core technology such as compression algorithm, batch can produce clear, stable and real-time transmission and check the audio compression board. Since then, DVR products using this technology have blossomed all over the mainland of China and have developed into mature products and been widely used in just two or three years. By 2005, DVR products from South Korea and Taiwan had become less popular in the domestic market.
三、软硬压缩的技术之争
由于2001-2004年期间，CPU速度比较慢，而且价格相对比较昂贵，软压缩DVR受CPU性能影响，无法满足大路数全实时监控需求。针对 软压缩卡存在的问题,2002年,国内有一批厂家开始研究通过DSP芯片技术代替CPU运算压缩视频，降低了电脑CPU资源的消耗，解决电脑配置偏低导致 PC式数字硬盘录象机无法做到大路数全实时的监控要求,称为硬压缩技术，这种监控卡称为硬压卡;这批厂家的主要代表就是杭州的海康威视、武汉恒亿、北京汉 邦。在此期间，由于政府工程中对大路数全实时监控市场需求较大，硬压缩DVR所具有大优势得到了充分发挥，那一期间国内硬压缩DVR产业得到了迅速的发展 与壮大。软压缩技术DVR基本处于灭绝的边缘。一是软压缩技术主要是来自韩国和台湾，在压缩算法方面，采用的是MJPEG和MPEGII格式，这种格式导 致硬盘存储占用空间比较大，一般在350M-500M，而DSP硬压缩采用的是H.264压缩算法，占用空间比较小，一般在50M-150M;所以用硬压 缩卡就更省硬盘;二是电脑配置在2004年以前，CPU太低，导致超过8路以上用软压缩卡基本都不是很稳定，CPU占用率很高;而且虽说硬压卡成本高，软 压卡价格便宜，但从整机成本来看，软压卡的整机就没有任何价格优势了;三是一些做盗版软压缩DVR的公司技术服务不到位，且盗版公司销售的是国外过时的旧 版软压缩DVR卡,使得原本稳定的软压缩DVR卡因使用不当导致不稳定。在加上舆论的宣导，误导消费者，使得软压缩发展更为艰难。
软压缩还是硬压缩?这是DVR在发展过程中形成的两大阵营。持软压缩观点的人认为：计算机运算速度会越来越快，处理视频的能力会越来越 强，DVR路数也随之增加，从开始的1路到4路逐步增加，同样能达到硬件压缩的要求，而且成本相对较低，况且，视频压缩算法不断更新，周期很快，可以用最 快的速度升级。持硬压缩的观点的人认为：采用专业的视频芯片，占用计算机资源少，能处理大路数视频。
Third, the technical competition of hard and soft compression
Due to the slow CPU speed and relatively expensive price during 2001-2004, the soft-compression DVR is affected by CPU performance and cannot meet the demand of full-real-time monitoring of large Numbers. Aiming at the problems of soft compression card, in 2002, a group of domestic manufacturers to research by compressed video DSP chip technology to replace the CPU operation, reduces the consumption of computer CPU resources, solve the computer configuration is low in PC digital hard disk video recorder can't do big ways on the real-time monitoring requirements, called hard compression technology, the monitoring card called hard pressure; The main representatives of these manufacturers are hangzhou haikangwei vision, wuhan hengyi and Beijing hanbang. During this time, because the government project of big because all the real-time monitoring of the market demand is bigger, hard compression DVR has big advantage got into full play, the domestic hardware compression during DVR industry got rapid development and expansion. DVR, a soft compression technology, is on the verge of extinction. Is a soft compression technology are mainly from South Korea and Taiwan, in terms of compression algorithm, adopts MJPEG and MPEGII format, causing this format the hard disk storage take up the space is larger, is in commonly 350 m - 500 - m, and DSP hardware compression using h. 264 compression algorithm, the relatively small footprint, generally in the 50 m to 150 m; So it's much cheaper to use a hard drive card; Second, the computer configuration before 2004, the CPU is too low, resulting in more than 8 channels of soft compression CARDS are not very stable, high CPU occupancy rate; And although the cost of hard pressure card is high, the price of soft pressure card is cheap, but from the cost of the whole machine, the whole machine of soft pressure card has no price advantage. 3 it is to do some pirated soft compression DVRS company technical service does not reach the designated position, and the company sales of piracy is the old version of foreign outdated soft compression DVR card, make originally stable soft compression DVRS paid use undeserved cause instability. In addition to the propaganda of public opinion, misleading consumers, making the development of soft compression more difficult.
Soft compression or hard compression? These are the two main camps of DVR's development. Soft compression view people think: computing speed will be faster and faster, the ability to deal with video will be more and more strong, DVR because also will increase, from 1 to 4 road began to gradually increase, also can meet the requirements of hardware compression, and the cost is relatively low, and constantly updated video compression algorithms, cycle quickly, can use the most fast speed upgrade. According to the viewpoint of hard compression, professional video chip can take up less computer resources and deal with video.
软压缩DVR和硬压缩DVR较量了一段时间，通过产品在市场的洗礼，2001年-2002年上半年，依托银行的拉动，行业对大路数实时性和长时 间稳定性的要求，致使基于MPEG1视频芯片DVR逐渐占据了上风，基于BT878芯片软压缩产品逐步退出高端市场，主要面向诸如小区监控等非金融行业。 软压企业陷入进退两难的境地，有没有一种方式，既保留了软压缩的灵活性特点，又集成了硬压缩稳定占用计算机资源少的特点呢?答案是肯定的，随着全球芯片业 向SOC系统解决方案的推进，DSP芯片得到了长足的发展，人们考虑把视频算法往DSP上移植，用DSP完成视频的编***，这样就实现了在芯片基础上的软 应用。同时，MPEG4算法不是象MPEG1和MPEG2那样形成了一个固定的标准，并得到了大家的一致认可和广泛的应用。MPEG4算法只是提供了一个 标准框架，是一个持续不断发展的算法，性能的好坏取决于各自的优化能力。MPEG4的专业芯片因市场定位和技术的不确定性，迟迟不能推出，但是MPEG4 算法的优异表现得到了大家的一致认可。国内MPEG4算法的原型基本都是来源于DIVX和XVID的开放源码，在此基础上进行优化和封装，将MPEG4算 法移植到DSP芯片，两者的完美结合，使MPEG4算法除了在软件应用以外，在芯片层得到了大范围的应用。2002年，国内基于PHLIPLS公司 Trimedia1300的MPEG4板卡得到了成功的应用，在压缩比、清晰度、网络传输性能上得到了很大的提升，MPEG4算法的DVR成为主流，逐步取代了MPEG1 算法的DVR，DSP板卡方案一统天下。PHLIPLS公司DSP板卡虽然赢得头筹，但随后被TI公司迎头赶上，TMS642的成功推出，使DSP板卡形 成PHLIPLS和TI两大阵营，随着DSP处理器性能的不断提高，DVR对图像的清晰度、存储空间和网络带宽的要求也越来越高，视频算法也得到了进一步 发展。H.264是国际标准化组织(ISO)和国际电信联盟(ITU)共同提出的继MPEG4之后的新一代数字视频压缩格式，称为MPEG4Part10(MPEG4AVC)或H.264(JVT)。视频算法和DSP性能的提高，使DVR不再只满足CIF格式，开始向D1发展，单个DSP不再只处理一路视频，开始处理 4路、八路或者更高路数的视频，板卡竞争向大路数和高清晰度发展。
Soft compression DVRS and hard compression DVRS battle for a time, through the baptism of the products in the market, in the first half of 2001-2002, relying on Banks, industry in big ways on real-time and long time stability requirement, cause based on DVR gradually prevailed, MPEG1 video chip based on soft compression BT878 chip products gradually withdraw from the high-end market, such as residential area mainly monitor the non-financial industries. Soft pressure enterprises are caught in a dilemma. Is there a way to preserve the flexible features of soft compression and integrate the features of hard compression and stable use of less computer resources? The answer is yes, with the global chip industry solution to the SOC system, DSP chips got rapid development, people consider transplant video algorithm on the DSP, using DSP to complete video encoding * * *, thus realize the soft application based on the chip. At the same time, MPEG4 algorithm does not form a fixed standard like MPEG1 and MPEG2, and has been widely recognized and applied. The MPEG4 algorithm only provides a standard framework, which is a continuously developing algorithm. The performance of MPEG4 algorithm depends on their respective optimization ability. The professional chip of MPEG4 has been delayed due to the uncertainty of market positioning and technology, but the excellent performance of MPEG4 algorithm has been unanimously recognized. Domestic MPEG4 algorithm is the prototype of the basic it is derived from the DIVX and XVID, open source, on the basis of optimization and encapsulation, MPEG4 calculate method transplanted to DSP chip, the perfect combination of both, make the MPEG4 algorithm except in software application, a wide range of applications in the chip layer. In 2002, based on domestic PHLIPLS company Trimedia1300 MPEG4 interface card has been successfully used, on the compression ratio, resolution, network transmission performance got the very big promotion, DVR to become the mainstream of MPEG4 algorithm, gradually replaced the DVR MPEG1 algorithm, DSP board scheme of unify the whole country. PHLIPLS company DSP board, although won the top, then catch up by TI company, TMS642 successfully, make the shape into PHLIPLS and TI DSP interface card two camps, with the constant improvement of the DSP processor performance, DVR image clarity, storage space and network bandwidth demands more and more is also high, video algorithm also got further development. H.264 is a new generation digital video compression format proposed by the international organization for standardization (ISO) and the international telecommunication union (ITU) after MPEG4, called MPEG4Part10(MPEG4AVC) or h.264 (JVT). Video, the improvement of the performance of the algorithm and DSP makes DVR no longer meet the CIF format, just began to develop in the D1, no longer deal only with a single DSP video, all the way to handle 4 road, no. Or higher because of video, competition to the imlet and high-definition development board.
2004年下半年，深圳天敏科技、深圳龙安视科技、深圳波粒智能、深圳豪威等等几家软压卡生产厂商经过几年的技术攻坚，在编码算法和图画质方面 都有了划时代的突破，把H.264的压缩算法运用到软压缩卡上，自主开发基于PHILIPSSAA7130新一代9比特高画质DVR卡。正是此卡的推出， 改变了中国软压缩DVR产业不利局面。2005年下半年后，电脑CPU性能猛增，价格猛跌，300多元的CPU就能满足软压缩DVR卡压缩16路基本实时 的高画质无马赛克视频。2006年Intel9系列主板开始普及，这种新型主板不仅比原先8系列主板的性能大大提升，同时也改善了软压缩DVR性能;另外 9系列主板的PCI-E，克服了软压缩数据流量瓶颈，更可喜的是经过测试，双核CPU使得软压缩DVR的处理性能翻了一倍。随着很快就要到来双核CPU的 普及，CPU的发展越来越快，以及其他种种有利因素的出现，中国软压缩DVR得到了迅速发展与壮大。
同时由于硬压缩卡在技术上和生产成本上都没有优势可言，2006年以来，整体销量开始下滑，到2008年，硬压卡的月销量占所有监控板卡总量不 到20%，新一代PCI-E软压缩DVR将采用专用的压缩算法，处理性能比标准的MPEG-4提高一倍，同时采用双核CPU，率先实现软压缩DVR卡做到 16路D1录像。
嵌入式CPU+硬压缩图像处理专业芯片，即大家常说的硬压缩方式。由于硬压缩图像处理芯片开发难度高，升级能力差，技术革新周期太长，而且成本 上没有任何优势，所以现在采用硬压缩板卡做嵌入式DVR企业大大减少;嵌入式CPU+DSP芯片，即软压缩方式。使用这种方案使嵌入式DVR成本相对比较 低廉，而且修改产品应用软件比硬件压缩模式要容易得多，非常合适变化莫测的安防市场的需要。目前国内90%以上的厂家是软压缩模式的嵌入式DVR，但采用 的芯片组不一样，产品稳定性可靠性层次不一，不同厂家的产品相互难以兼容，产品的标准化很难统一，这确实是一个问题。
Long An moons in the second half of 2004, shenzhen science and technology, shenzhen science and technology, shenzhen, shenzhen wave particle intelligence, Howe, and so on several soft press card manufacturers, after years of technology, and in the coding algorithm and picture quality has the epoch-making breakthrough, the h. 264 compression algorithm applied to the soft compression card, independent development based on new generation PHILIPSSAA7130 9 bits high-definition DVR card. It is the introduction of this card that has changed the adverse situation of China's soft compression DVR industry. After the second half of 2005, the performance of computer CPU has soared, and the price has plummeted. More than 300 cpus can satisfy the basic real-time high quality non-mosaic video of DVR card compression 16 channels. In 2006, Intel9 series motherboards became popular. The new motherboards not only greatly improved the performance of the original 8 series motherboards, but also improved the performance of the soft-compression DVR. In addition, pci-e of 9 series motherboards has overcome the bottleneck of soft compression data flow. What's more, after testing, dual-core CPU has doubled the processing performance of soft compression DVR. With the advent of dual-core cpus, the development of cpus is getting faster and faster, as well as the emergence of various other favorable factors, China's soft-compression DVR has been rapidly developing and expanding.
At the same time as the hard compression card in technology and production cost advantages, since 2006, the overall sales began to decline, by 2008, the press hard card monthly sales accounted for 20% of total monitoring interface card not to a new generation of PCI - E soft compression DVRS will use special compression algorithms, processing performance than the standard mpeg-4 double dual-core CPU at the same time, take the lead to achieve the soft compression DVRS do 16 road D1 video card.
Embedded CPU+ hard compression image processing professional chip, known as hard compression. Due to the hard compressed image processing chip development difficulty is high, poor ability to upgrade, technical innovation cycle is too long, and don't have any advantage on the cost, so now the embedded DVR hard compression boards do enterprise greatly reduced; Embedded CPU+DSP chip, that is, soft compression mode. Using this approach makes embedded DVR relatively cheap, and it is much easier to modify product applications than hardware compression, which is well suited to the changing security market. Now more than 90% of the domestic manufacturers are soft compression mode of embedded DVR, but USES the chipset is not the same, product stability reliability level is differ, the product of different manufacturer is difficult to compatible with each other, the standardization of products it is difficult to unify, this is really a problem.
