What does 4K mean?
The name "4K resolution" refers to a horizontal resolution of approximately 4,000 pixels. It has been developed into a variety of standards. The DCI 4K resolution standard (4096 * 2160 pixels) is widely respected by the film and video production industry. Besides, UHDTV standard (3840 * 2160 pixels) is also popular which has twice the horizontal and vertical resolution of 1080p (as shown in the figure below)
What is TVL?
Generally speaking, the image on TV could be divided into many horizontal lines which are also called TV lines.A higher number of the horizontal lines means that a camera will be able to render images with more details.
What is Resolution?
Resolution is usually measured by the number of horizontal and vertical pixels. It can be expressed as number of horizontal point * number of vertical pixels. In a fixed plane, the higher resolution could provide better image.
What is ONVIF?
ONVIF is committed to providing and promoting open interfaces to the security industry for effective interoperability of IP-based physical security products.
What is H.264+
H.264+ technology is a kind of intelligent algorithm developed by Hikvision. It is a remarkable encoding technology which focuses on the features of the surveillance video and is optimized based on the H.264/AVC. H.264+ lowers the bitrate of the surveillance video greatly so as to save the system cost.
What is DVR/NVR?
DVR/NVR is a management device which realizes the function of centralized storage, local live view, search, playback and other functions.
The main difference between DVR and NVR is the function of encoding. DVR is an encoding unit, but NVR does not have this feature.
What are Stream and Bitrate?
After the video is compressed, a stream is generated.
Bitrate (bps): quantity of bit stream per second.
Bitrate type: Constant Bitrate (CBR), Variable Bitrate (VBR).
Stream type: video, audio, video & audio complex stream.
What is Main stream/Sub stream?
The main stream with high resolution and full frame rate can be used for main monitoring and recording.
The sub stream with lower resolution can be used for mobile monitoring.
Some devices support third stream which offers more flexible choices.
What is the maximum distance for PoE cable?
In case of using CAT5e cable, 100m (333ft) is the maximum distance between the two PoE devices.
What is the meaning of PoE indicator lights?
Usually one set of indicator lights includes a yellow light and a green light which are integrated with the Ethernet interface together(see picture below).
Yellow light means connection status. It will light once the device is connected.
Green light means data interaction status. The indicator Light begins to flash once data come in or go out. The bigger the data stream, the more frequently it flashes.
Note: In some cases the green light and yellow light may work together, and they all indicate data interaction status.
What could be some common interfaces?
Bayonet Nut Connector
One of the connectors used in coaxial-cable which could effectively block the signal interference.
It uses coaxial-cable to transmit composite analog signal (CVBS).Characteristic impedance is
Radio Corporation of
RCA is invented by the Radio Corporation of America and has become one of the standard
interfaces of audio signals and video signals. It could be used for analog video, analog audio,
digital audio and color component video transmission. When it is used for CVBS transmission,
coaxial-cable with the75Ω Characteristic impedance is always been adopted. However, BNC
interface which is more reliable is more frequently adopted in video surveillance project.
Standard Data Interface
It includes HD-SDI and SD-SDI
High Definition Multimedia
Audio & Video signal could both be transmitted compared to DVI. Transmit distance could reach
Video Graphics Array
VGA interface always comes with 15 cores of D-SUB. The disadvantage of VGA is that it is
proposed for analog display device such as CRT. When being adopted in digital display devices
such as LCD and TFTP, video signal requires D/A and A/D conversion which would influence the
image quality as well as the response speed
How to configure Zero-Channel?
Sometimes you need to get a remote view of many channels in real time from web browser or CMS (Client Management System) software, in order to decrease the bandwidth requirement, channel-zero encoding is supported as an option for you.
Enter the Live View Settings interface. Menu > Configuration > Live View
Select the Channel-Zero Encoding tab.
Check the checkbox after Enable Channel Zero Encoding.
Configure the Frame Rate, Max. Bitrate Mode and Max. Bitrate.
After you set the Channel-Zero encoding, you can get a view in the remote client or web browser of multi-channels in one screen.