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  • HD-SDI digital high-definition camera application analysis

        HD-SDI camera loggerheads traditional HD IP camera
        HD IP camera has all the advantages of the network camera has, of course, will be able to avoid the shortcomings with the network camera. The small-scale traditional CCTV video surveillance CCTV system to a local area network monitoring, and then pop up a wide range of remote network monitoring, network camera is undoubtedly the most with video networking conditions.
        As a network camera, which can be set via the TCP / IP protocol can access the IP address for the video network access through the LAN connection to the Internet, no matter anywhere in the world can access the Internet Unicom HD IP camera. But the problem is brought to the network exposed in the most front-end, may be met with illegal network intrusion user, network management security policy must do to avoid hacker attacks.
        HD IP camera due to the encoded video transmitted over the network, its own with coding function, while the standard H.264 compression technology with efficient MPEG4/AVC may be used relatively primitive, the bit rate of the video data encoded video data stream smaller than a hundredfold encoded video directly through the local SD / SDHC memory card to store the network access the video stream to the video store. The coding network pass will bring a significant delay, and video distortion stain blocks of color, clarity decline, the problem of lack of sharpness, each vendor programs and different network environment, network latency from 200ms to 1-2s video effects need enough bitrate to guarantee, which in turn requires a dedicated network bandwidth.
        Source video capture video parameters and functions for video surveillance - cameras are very important, because the scene objects, architectural, light changes, the need to re-adjust the video parameters or set some of the features its own access, HD IP camera network, as long as the network is smooth, the system administrator can access the camera, according to the current situation to re-configure the camera.
        With video surveillance, audio capture also monitored the event has a certain significance, monitoring the scene of some of the sound, the dialogue between characters in the scene, are likely to be important information, and HD IP camera through a simple audio capture, synchronization doing audio and video encoded audio data stream, encapsulated into video storage and network transmission of audio and video preview. Pickup audio capture equipment cost is very low, the bit rate of the audio stream is also very low, so there are many users still want to have a sound associated with real audio and video surveillance.
        Field of view of the camera lens at different focal lengths to watch and can watch different objects near and far, the surveillance industry may use motorized lens IP camera lens can be controlled through its RS-485 interface with PTZ can achieve real-time rotation focal length conversion.
        The new HD-SDI digital high-definition camera technology characteristics relative to traditional HD IP camera is very different:
        HD-SDI digital high-definition camera can only transmit video signals over coaxial cable can not be transmitted in Ethernet transmission distance is generally in the 100 meters, if you need more long-distance transmission, HD-SDI dedicated Optical, via fiber optic cable The transmission of video signals.
        HD-SDI video signal transmission to the original uncompressed digital video signal, not because of lack of clarity, reduced pigmentation blocks of color, sharpness of video compression. But the huge amount of data, the system unbearable encoding compression processing must be done to do more long-distance transmission of network, encoded video data is basically no difference with the HD IP camera for afterwards playback stored video, the two are basically the same .
        The beginning of the HD-SDI interface design only for one-way transmission of uncompressed video, the camera is generally was operated with little remote reverse camera; HD-SDI surveillance cameras only local operations, beginning installation debugging , or individually laying of control signal lines. Tie the PTZ and electric zoom lens to use, but also requires a separate laying of the signal line.
        Pure HD-SDI video transmission, surveillance cameras embarrassment quite difficult to meet the demand for sound quality, only transfer audio wiring alone, can not be integrated into the composite audio and video signal. The industry in the development of the audio data is embedded in the HD-SDI video signal technology, However, the major manufacturers of HD-SDI camera products almost no practical application.
        HD-SDI camera application and the current difficulties
        The demand for high-definition surveillance products, mainly from the user by source from two categories, one is the existing monitoring system needs to be upgraded to high-definition video surveillance, and the other is a new high-definition video surveillance system.
        Existing video surveillance systems, analog video surveillance vast majority of its earlier development, the use of a longer time, unable to play the role of monitoring should monitor performance has declined, there is a certain strength or the urgent needs of the users of the HD choose upgrading to high-definition video surveillance. From a convenience perspective, the only replacement equipment is the most convenient, HD-SDI camera and supporting HD-DVR is suitable only need to replace the camera and DVR video can easily upgrade,cost is lower than replace to the web camera and NVR and network rollout, at the same time to obtain a low-latency lossless video, unless, of course, very intensive user of network coverage, or the cost of wiring and switches will be more due to the number of points and had to be considered.
        New video surveillance system, the demand for HD IP camera with the development of recent years, the needs of users more and more use from the device configuration networking perspective, IP video camera to be superior, even without embedded -NVR hardware, you can use the existing computer or server to complete the monitoring and recording of the video preview. But from the system design to the implementation of the project will encounter bring high bit rate HD IP camera network bandwidth is too large and had to use more high-end switches, and the network is busy decoding computer performance preview is not smooth and delay problems. According to market feedback the troubles brought these issues to the user does not minority advantage of the HD-SDI camera reflected independent video signal transmission, 0.1 seconds of ultra-low-latency, high-definition lossless screen will let customers unique experience to enjoy the the SVA professional-grade equipment.
        For the description of the two customers and from the overall market situation, the HD-SDI camera´s main demand is dominated by high-end users and extreme users of high-quality delay requirements. Monitoring coverage may be small, and the overall system can be extremely complex.
        The overall application detailed in terms of the front-to-back, HD-SDI camera installation with analog cameras need to be installed on the front of the adjusted lens adjustment menu to configure parameters coaxial cable BNC connector plugged laying.
        Laying coaxial cable distance is generally less than 100 meters as well, if you need long-distance transmission, from the radio and television industry started using fiber optic cable to transmit HD-SDI Optical already mature, so with the fiber optic cable can be solved through a pair of optical transceiver; simultaneously Optical also RS-485 control signals support the transmission of audio signals, audio and remote control needs solved in one fell swoop.
        Audio and video signals transmitted by physical line to the back-end, users need both the local real-time preview, they need at the local video storage, video playback, supporting equipment will be used to HD DVR do the coding storage loop-through output to a high-definition monitor and other display devices; grading monitoring for large-scale monitoring network may need to be transferred to the farther, the decoder can stream HD DVR encoded by the network transmission, and then in the off-site decoding output; video wall display in order to switch to facilitate traditional analog matrix manufacturers now also launched the digital high-definition matrix. Nevertheless, the range of equipment for the entire video surveillance system is particularly complex, is encoded at the same time, playback and remote network monitoring, link and network HD cameras are no differences, no HD-SDI advantage. For such large-scale applications, the the surveillance industry leader two years ago to develop a comprehensive video platform products, HD-SDI monitoring of large-scale monitoring project almost a full set of supporting facilities function.
        The front-end video and audio signal directly to the the video integrated platform, internal video lossless exchange by HD DVI HDMI output on a large screen monitor, internal with some encoder board also large storage network video and audio encoding disk arrays, large-scale video storage capacity and security able to have double protection; integrated platform with some code division board can also access each video RS-485 control signals, decoding board can flow through the network to take other DVR, DVS and internet camera video stream to be decoded and output to the display device. Ordinary applications offsite cascade by laying more fiber optic cable transmission, but the integrated platform built of light cascade function, can save more dedicated fiber optic line, to do lossless video exchange after transmission through an integrated platform to the two three integrated platform. Applications supporting the whole HD-SDI camera is already very well equipped to meet the diverse needs of the user.
        HD-SDI camera applications in the face of comprehensive equipment can be resolved, but also to bring a lot of trouble. According to the feedback in the implementation of the project, the application issues include:
        Many businesses claim to HD-SDI camera can directly upgrade the analog control system, avoiding the problem of transmission distance, the actual user if the pre-wiring of poor quality, can not even use the a 75-3 low quality cable transmission distance up to 80 meters, even with 75 - 5 high-quality cable generally can only transmit 150 meters, if the user already has a analog camera transmission distance, repeater or Optical transmission, the cost will be significantly improved.
        HD-SDI camera most of the output interface only HD-SDI signal output, installation and commissioning, the adjustment of the lens is a very important part of the video picture quality, with traditional analog and network camera easy to watch the local screen, commissioning personnel must be equipped with HD -SDI digital input port on the monitor to adjust the lens, only some of the manufacturers of the products will provide analog video output interface to facilitate the installation and commissioning.
        Among the large-scale networking, network management system for the maintenance of the entire system has a very important role, and HD-SDI monitoring system does not have the special equipment network functionality also makes network management can not monitor the operational status of each device. Users also can not be adjusted based on the current needs of the device parameters.
        Taking into account the cost factors, except for a few large investment Safe City projects the construction of large-scale HD-SDI monitoring system, HD-SDI system mainly throughout the large system of independent system, as a the entire monitoring a large network node, by a coaxial cable to transmit video and audio signals, control signals and even power may make it more widely.
        The core technology HD-SDI camera sensor with conventional HD IP camera video signal output of the sensor to do the conversion, the difference, the main technical conversion processing. More existing programs can use FPGA and ASIC, mainly in image processing, addition SDI encoding conversion chip cost is relatively high, but also makes the cameras, HD DVR receiver end of the input and output video signal , Monitor, Optical cost is difficult to decline, the increase will make the chip cost down, reduce the cost of ancillary products, users will be more willing to accept future improvement and application of the technology of HD-SDI.