The Digital Video Recording 关d Circuit TeleVision system or 硬盘录像机 CCTV system is rapidly becoming one of the most popular security and 监控文件 and monitoring tools in use today. Thanks to advancements in digital technology, not only is high-quality color 数字视频 possible, but its also economically priced, easy to install, and versatile in application. In addition, these systems are even able to 记录 clear videos in total darkness using infrared technology.
A 硬盘录像机 CCTV system is any system that 捕获s 数字视频图像 and 记录s them on some type of storage medium for later use. The difference between a 数字视频 记录ing system and an analog video 记录ing system is how the video image signal is created; however this lends itself to other differences such as how the video “footage”存储，如何传输以及有哪些类型和类型的图像可用。
让’s look at how an older analog video 记录ing system works, then we’ll compare it with the newer 数字视频 记录ing system. Both systems have a camera that “captures” the video images and a 记录er that stores those images for playback at a later time. Each system may also use monitors to display real-time (live) video as it is 捕获d.
无需太过专业，模拟数字摄像机就包含一个传感器芯片，称为电荷耦合器件或CCD或互补金属氧化物半导体或CMOS。这些传感器转换图像’s light energy, which is focused onto it by the 镜片, into electrical energy that can be measured and used to create a video image. The images are transferred from the camera to the video 记录er and monitor using a coaxial video transmission cable.
The analog video 记录er 记录s the audio and video as magnetic signals, usually on a magnetic tape. 什么 is actually happening is that the camera is taking several pictures per second but it appears to the human eye as smooth motion video. This is the same way its precursor, film video works.
Since analog video is stored as a magnetic pattern, each time the 记录ed video is played it has the potential for degrading the signal. In addition, time can also degrade the magnetic signal as the signal’s weaker points can fade. Analog video is stored on a variety of formats but the most popular magnetic video tape is VHS or BETA. The video 记录er either uses a video tape loop that re-records after reaching the end of the tape or individual video tapes that must be replaced when the 记录er reaches the end of the tape.
Digital video 记录ing systems 使用基本相同的技术来创建数字视频。有趣的一点是数字系统’s文件以照相机中的模拟信号开始，并且必须在离开照相机之前由照相机进行数字化。相机记录（随着数字图像的出现，“record”也与“capture”;意味着相机“captures”光图像）将光能成像并将其转换为电能。但是，数字摄像机的根本区别在于，摄像机还包含一个模数转换器，该转换器将模拟视频信号转换为一系列1和0，即数字数据。
硬盘录像机 CCTV系统已经变得如此流行，以至于它们如今已成为安全视频行业的标准，而不是例外。如果您想了解更多信息，请查看Security Camera King’s “央视学习中心。”