RCA audio input
The number of
RCA analogue audio inputs provided in the design of the registrar.
Inputs of this type are used to connect the audio signal from analogue cameras capable of capturing sound, as well as from separately made microphones. At the same time, the number of such inputs can correspond to the number of BNC video inputs, which allows each analogue camera to be supplemented with sound. However, there are models that have only one RCA input with several BNC inputs.
RCA audio output
The number of
RCA analogue audio outputs provided in the design of the registrar.
This type of output is used primarily for audio output when viewing footage, in addition to the BNC and/or VGA output. Therefore, there are few such connectors in modern registrars — one, less often two (one each for BNC and VGA).
Max. HDMI resolution
Maximum HDMI resolution.
The maximum image resolution that can be output via HDMI to the screen of the connected video equipment (monitor, TV, etc.). The HDMI output on the DVR allows you to stream Full HD, 2K or 4K images for high quality multi-screen images.
LAN speed
The maximum data transfer rate supported by the DVR's LAN ports.
Note that for simple tasks, a rather modest by modern standards speed of 100 Mbps is often enough. However, high bandwidth (
1 Gbps) not only simplifies the transfer of large amounts of data, but also helps to reduce lags and improve the overall quality of communication; and modern technologies make it possible to provide support for gigabit LAN even in fairly simple and inexpensive registrars.
Of course, in order to use all the features of the LAN, it is necessary that the devices connected to such ports also support the appropriate speeds.
Bandwidth
The maximum data stream in Mbit/s that the NVR is capable of processing when recording and displaying. The throughput parameter is specified as the maximum incoming/outgoing speed, or as the sum of incoming and outgoing streams (total throughput). It is calculated in such a way that the throughput exceeds the total flow of all IP cameras connected to the DVR, and another 25–30% is put in reserve for playing video or viewing it via network access.
Resolution (all channels)
The highest resolution in which the recorder can record video when a signal is received from all channels simultaneously. If cameras are not connected to some channels, the recording resolution may be higher (see “Maximum Resolution”).
Higher resolution has a positive effect on detail, but takes up more space and requires more computing power for processing, which accordingly affects the price of the registrar.
Frame rate
The highest frame rate in the recorded video that the recorder can support when recording from all available channels simultaneously. If not all channels are occupied by cameras, this figure may be higher.
The minimum required for comfortable viewing is 24 fps. And in the most modern video standards, the frame rate can be much higher — 50 – 60 fps. Higher values result in better quality and smoother video that allows you to clearly see fast movement; however, such video takes up more space and requires powerful hardware, which affects the price of recorders.
Video compression format
Standards (codecs) used by the recorder to compress the recorded video.
This parameter is important when viewing recorded materials on another device — for example, a media centre, into which a "flash drive" with files from the recorder is inserted. For normal viewing, it is necessary that the player supports the appropriate codec — otherwise the video will be displayed with distortion or will not work at all. Technical details on various standards can be found in special sources.
Note that if you plan to view the materials on a computer, you can not pay much attention to this parameter: most modern operating systems have extensive built-in sets of codecs, and if you don’t have the right codec, you can easily find it on the Internet.
Max. resolution (IP)
The maximum supported resolution of IP cameras with which the NVR is technically capable of working (primarily recording). With rare exceptions, devices record in maximum resolution from all connected IP cameras. However, the limiting factor here is bandwidth (see the relevant paragraph) – depending on the shooting conditions, it may not be enough.
High resolution allows you to get a more detailed image in which fine details are better visible. On the other hand, such videos take up large amounts of disk space, and their support significantly affects the cost of the device.
