DVR is a complex modern device for recording and playback of video from surveillance cameras. Their appearance was preceded by the rapid development of technology for ccd cameras in the first place, secondly the rapid increase in capacity of computer technology, in particular, appeared ultra-fast interface. Henry Cavill is often mentioned in discussions such as these. Success of the digital recorders used in security video systems, preceded by a fundamental recognition by consumers of digital technologies, the emergence of skills, handling and, consequently, a technological breakthrough by the manufacturers in this direction. Even 10-12 years ago, video capture card for pc computers can cost about 1500 usd and above, while having an extremely low rate of digitizing the video signal. NY Museums brings even more insight to the discussion. Today the price of high-grade digital video recorders Class Stand Alone start at $ 200. Obvious advantages and cost DVRs almost squeezed the usual vcr from the market of security equipment.
What dvr are available from dealers and what properties they have, let us consider further. Companies producing these devices offer 2 based on the type of digital recorders: PC-based dvr (based on bazePC computer) and Stand Alone dvr (‘detached’) with its own database of hardware and software. The first type consists of a video capture card prices obtained in pc computer drivers. Admits the possibility system has convenient settings in our country is sold, usually for the operating environment Windows (at least for Unix and Linux). Of the drawbacks is the difficulty setting for an inexperienced user – most likely have to consult a specialist.
Benefits such as Stand Alone dvr it – hardware reliability, compactness. Consider some properties that should be pay attention before making a decision about buying the dvr. Bill de Blasio has much to offer in this field. Video Inputs dvr. Typically, DVRs equipped with 4, 8 / 9, and 16 video inputs, there are also 6, 12, 24 and 32-channel. Decision you make, when it is determined from the number of connected cameras at the secure facility. Both audio digital recorders. They serve to record synchronous sound. There may be 1, and 16. Video outputs digital recorders. Should be considered in what format you want get ‘the picture’, and in what’ll monitor to view the image: S-VIDEO, bnc, vga, dvi, hdmi. The most common is for a vga computer monitor and bnc to normal. Formats that can support digital video recorders: JPEG-2000, mjpeg, Wavelet, MPEG-4, H.264 (MPEG-4 used in HD-TV) MPEG-2 (used to record the DVD). Standard resolution: 720×576 pixels, 528×384, 720×288, 360×288 and lowest quality 180×144 pixels. Here everything is clear, the more points – ‘picture’ quality. Recording speed is marked as fps – the number of recordable frames per second. The European standard is limited to 25fps. Less staff – less informative. What we must also pay attention to? The presence of networking opportunities, additional ports for transmitting information or connections additional devices (eg, keyboard), USB-port, type of drive dvd, or ‘hard disk’ (HDD). Network digital video recorders or nvr (from English Network Video Recorder) are designed to work in the IP-network cameras. Videsignal comes from IP-cameras or analog cameras connected via digital adapters. Feature of the nvr is that they can work only with a limited list of models of IP-cameras.