SDI exploration in the field of security

In the current security market, the pace of digitization and high-definition video surveillance systems is accelerating. Although high-definition network products have a good performance, but they can not ignore its unsatisfactory places, such as delay, codec loss of video images , high bandwidth occupied by transmission, and system instability. In this regard, manufacturers and users are striving for better HD solutions. Under this demand, an exploration path for the introduction of broadcast standard SDI into security applications has been created, realizing real-time HD. Transport uncompressed, low-latency, and easy-to-install HD-SDI (high-definition digital uncompressed technology) solutions have sprung up.

HD-SDI advantage highlights

Undistorted reliable transmission. HD-SDI does not compress video data like IP systems and then transmits them in packets on the network. HD-SDI video transmits uncompressed signals in coaxial cable or optical cable, which is stable and reliable without distortion.

Easy to install, strong compatibility. In terms of the compatibility of the analog surveillance system, the original system can be upgraded and the HD-SDI mode can be recognized without further modification. This also creates more convenience for the transition from the traditional surveillance system to the HD-SDI system.

The HD image is consistent and there is no delay. The HD-SDI system does not undergo compression, packetization, and decoding during video generation and transmission. It does not produce delays in IP high-definition images. It is particularly appropriate in situations where emphasis is placed on real-time monitoring, such as casino and road traffic monitoring.

Provide more details, maintain the integrity and originality of the image, greatly improve the accuracy of intelligent analysis algorithms, and provide protection for intelligent video analysis IVS. The density of camera spots per unit area has dropped significantly, which has improved the utilization efficiency of the acquisition equipment.

In addition, HD-SDI has some advantages derived from the work characteristics. For example, in the transmission, video signal integrity and real-time performance can be well protected. Therefore, in face recognition, detail capture, etc. More advantages than high compression network monitoring equipment.

HD-SDI development still lacks

The protocol format is fixed. The HD-SDI standard defines the format and transmission protocol for video, audio, and ancillary data. In this protocol, video, audio, and auxiliary data all occupy a fixed position and bandwidth. This makes the transmission protocol not only have a single video format, but also have a large bandwidth occupied by the audio and auxiliary data that can be transmitted.

HD-SDI system equipment is expensive. Coaxial cable is usually used for short-distance transmission, but this cable is also required, must be a high-grade coaxial cable, BNC connectors also use high-grade. The repeater must be used for the medium and long distance, and the HD-SDI optical transceiver should be used farther away. This kind of digital optical transceiver is very expensive. If the back-end storage is directly stored without compression, the consumption of the hard disk will be very large, and if it is compressed, an expensive encoder will be added, so that the overall system cost will be very high, much higher than the network high-definition monitoring system. The HD-SDI monitoring core has fewer hardware manufacturers and higher chip costs, which also makes the entire system equipment cost more expensive.

The transmission method is not rich enough. HD-SDI currently uses only coaxial cables, optical transceivers, and optical fiber for transmission. Only TV stations use digital microwave transmission to transmit signals. This requires building a very high transmission tower. This is not true in monitoring systems. May be applied.

Backends and other accessories are not rich and use is limited. HD-SDI is similar in structure to previous analog monitoring systems and cannot be used in secondary development with other back-end applications.

On the other hand, in the competition with large-resolution monitoring equipment, the non-compressed standard HD-SDI technology also has obvious deficiencies. At present, for the monitoring system, how to transmit audio and video analog data to the data center more completely and truly is undoubtedly very important. However, for HD-SDI, if it is compressed, it will inevitably reduce the effect and real-time performance of data, and it is difficult to meet the intelligent work requirements. This is a contradiction in the development of HD-SDI technology toward intelligence. In short, HD-SDI has inherent advantages, but also has the disadvantages that cannot be ignored. With the continuous advancement and development of the monitoring market, it will go where it is and whether it can keep up with the pace of the market. It remains to be further verified.

High-speed into market trends

The general feeling of HD-SDI on the market today is that, in addition to the deep understanding of HD-SDI, the cost and cost of HD-SDI is higher than that of traditional analog products and IP products. There are many problems in the actual construction applications, such as the new features and new test methods of high-speed serial HD-SDI signals, the quality of coaxial cables is not very good, and the format of the front and rear devices is not on the number. Or do some propaganda and training work for the contractor and the user, so that they can better understand the characteristics of HD-SDI products and engineering application notes.

HD-SDI is still a new thing for engineering companies and users. There will always be problems in practical applications. For example, compatibility, number of front and rear devices, number of wires used in products, and how to install and operate And so on, although these problems are not entirely caused by the product itself, it may be due to improper operation by the project owner or the user. However, these require the company to carry out in-depth technical training and guidance for users.

Looking at the current video surveillance market, high-definition, networking, and intelligence can be regarded as the mainstream of market development. For HD-SDI monitoring equipment, it goes without saying that the degree of compliance with high-definition. However, if we talk about the efficiency of network and remote transmission, we cannot but admit that this is a difficult problem for HD-SDI. At present, the main means to implement network and ensure smooth network transmission is to compress data. But the uncompressible HD-SDI technology is bound to be bound by the huge transmission data. The low capability of remote monitoring and network integration also affects the improvement of the level of intelligence in HD-SDI equipment. In addition, the large amount of storage also makes many units afraid to deploy such monitoring equipment in large areas, I am afraid to be burdened by heavy storage pressures. Therefore, if we continue this "risk-up" development model, the future of HD-SDI is undoubtedly very difficult to succeed.