DVR DigitalVideoRecorder(数字硬盘录像机)，是目前视频监控行业最为常见并且最为理想的监控和记录视频资料的设备。
DVR是一套进行图像存储处理的计算机系统，具有对图像/语音进行长时间录像、录音、远程监视和控制的功能，DVR集合了录像机、画面分割器、云台镜头控制、报警控制、网络传输等五种功能于一身，用一台设备就能取代模拟监控系统一大堆设备的功能，而且在价格上也逐渐占有优势。此外DVR影像录制效果好、画面清晰，并可重复多次录制，能对存放影像进行回放检索。
DVR系统的硬件主要由CPU，内存，主板，显卡，视频采集卡，机箱，电源，硬盘，连接线缆等构成。
DVR DigitalVideoRecorder(DVR) is the most common and ideal device for monitoring and recording video data in video monitoring industry.
DVR is a set of computer system to deal with image storage, image/video voice for a long time, recording, remote monitoring and control functions, DVR set the VCR, image segmentation, yuntai camera control, alarm, control, network transmission, such as the five functions in one, with one device can replace the analog monitoring system of a lot of the function of the equipment, but also gradually have the advantage on price. In addition, DVR image recording effect is good, the picture is clear, and it can be repeatedly recorded, which can be used for playback retrieval of stored images.
The hardware of DVR system is mainly composed of CPU, memory, main board, video card, video acquisition card, cabinet, power source, hard disk, connection cable and so on.
目前市面上主流的DVR采用的压缩技术有MPEG-2、MPEG-4、H.264、M-JPEG，而MPEG-4、H.264是国内最常见的压缩方式;从压缩卡上分有软压缩和硬压缩两种，软压受到CPU的影响较大，多半做不到全实时显示和录像，故逐渐被硬压缩淘汰;从摄像机输入路数上分为1路、2路、4路、6路、9路、12路、16路、32路，甚至更多路数;总的来说，按系统结构可以分为两大类：基于PC架构的PC式DVR和脱离PC架构的嵌入式DVR。
数字硬盘录像机的设计从根本上取代了原来质量低下，高维修率的CCTV录像机，例如视频监控模拟录像机。DVR不仅仅革命性地扩展了CCTV视频监控系统的功能，并且所增加的功能使其远远优于以前使用的模拟录像机。
首先，最重要的是，DVR把高质量的图像资料记录在硬盘中，免除了不停地更换录像带的麻烦。其次，DVR的内置的多路复用器可以多路同时记录CCTV录像机的视频资料，降低了视频监控系统中所需的设备，显示出了强大的功能。这样，通过把安防摄像机的视频信息数字化并且基于MPEG-4进行压缩，DVR可以高效率地记录多路高质量的视频流。DVR也可能用其他方格式备份视频信息，如CD-RW/DVD-RW。USB驱动器，记忆卡或者其他存储卡等等。
因此，DVR不仅仅在普遍意义上增加了监控系统的部件和功能，而且，DVR软件已经极大地扩展了视频监控系统的设计，功能和效益。通过把数字报警信号输入和输出到硬盘录像机，几乎所有类型的安全系统组合都允许DVR作为主要的监测和控制设备嵌入。
At present, the mainstream DVR compression technologies in the market include mpeg-2, mpeg-4, h.264 and m-jpeg, while mpeg-4 and h.264 are the most common compression methods in China. There are two kinds of soft compression and hard compression from the compression card. The soft compression is greatly affected by the CPU. There are 1, 2, 4, 6, 9, 12, 16, 32 and even more routes from the input path of the camera. In general, the system structure can be divided into two categories: pc-based DVR and pc-based embedded DVR.
Digital hard disk video recorders (DVRS) are designed to replace the low-quality, high-maintenance CCTV models, such as video, which monitor analog video recorders. DVR not only revolutionizes the function of CCTV video monitoring system, but also makes it far superior to the analog video recorder used before.
First and foremost, the DVR records high-quality image data on the hard drive, eliminating the need to keep changing videos. Secondly, DVR's built-in multiplexer can simultaneously record video data of CCTV video recorder for multiple channels, which reduces the equipment required in video monitoring system and shows strong functions. In this way, by digitizing video information of security camera and compressing it based on mpeg-4, DVR can record multi-channel and high-quality video stream efficiently. The DVR may also back up video information in other formats, such as cd-rw/dvd-rw. USB drives, memory CARDS or other memory CARDS.
Therefore, DVR not only adds components and functions of the monitoring system in a general sense, but also greatly expands the design, functions and benefits of video monitoring system. Almost all types of security system combinations allow the DVR to be embedded as the primary monitoring and control device by inputting and outputting digital alarm signals into and out of the hard disk video recorder.
