RECORDERS
DVR -
Traditional / Analog Digital Video Recorder
A
digital video recorder (DVR) is widely used video recorder for video
footage recording. Since DVRs have very mature technology and affordable
price, it’s one of major used security recorder in security & protection
industry. Traditional DVR receives the uncompressed video footage
from analogue cctv cameras, then recording to hard disc drivers (HDDs).
DVR has advantages of easy to install and offering cost effective
solution. Unfortunately, it has limited recording capabilities, the
maximum recording resolution is 480p (960x480) resolution. A DVR and
analogue cameras system is very suitable for small video surveillance
applications.
NVR - Network Video Recorder
Network
video recorder (NVR) is advanced video recorder which is designed to
record compressed video footage to hard disk drivers (HDD). The NVR can
receive the video/images or even audio through an Ethernet network
(cat5/cat6) from IP cameras. Typically, NVR can support high definition
recording including 1280x720 (720P) and 1920x1080 (1080P), some advanced
NVRs with capability to record 3 megapixel and 5 megapixel resolutions
for ultra HD video surveillance applications. Therefore, when compared
to a DVR and analogue cameras system, an NVR and IP cameras is more
expensive, however, it provides much higher resolution and superior
image qualities. Moreover, without extra audio cable, the NVR can do
two-way communication which can be used for audio broadcasting, as well
as performing remotely configuration to the IP cameras. You may find
some PoE NVRs which allows IP cameras receive power supply from NVR
through single Ethernet cable.
HD-SDI DVR
High Definition Serial Digital Interface (HD-SDI) is another standard
interface which complied with SMPTE 292M standard. The HD-SDI DVR can be
used as video footage recorder for HD-SDI cameras. With the compliance
of SMPTE (Society of Motion Picture and Television Engineers) 292M
standard, the camera can deliver uncompressed 720P or 1080P resolution
video over at least 100 meters using standard RG59 coaxial cable. Hence
the traditional CCTV system is using same standard coaxial cable for
video transmission, this allows user to upgrade their existing CCTV
systems with HD-SDI equipment without having to re-install cables.
However, the HD-SDI with its own standard, that means the HD-SDI DVR
doesn't support traditional analogue cctv cameras. Due to the hardware
limitations, only 4 channels and 8 channels HD-SDI DVRs are available in
the market, it’s hard to find the 16CH or even 32CH HD-SDI DVR.
HD-CVI DVR
HD-CVI is the abbreviation of High Definition Composite Video Interface,
which is in-house technology from Dahua. This is a new technology and
standard which provide another alternative for high definition video
surveillance. The HD-CVI technology can achieve 720P and 1080P analogue
video resolution which solved the resolution limit to analogue CCTV
security industry for many years. Currently, the highest resolution is
480p (960x480) for analogue CCTV cameras. Besides the high resolution,
the connection between HD-CVI cameras and HD-CVI DVRs can be up to 1600
feet away without visible degradation in video quality.
HVR - hybrid video recorder
A hybrid video
recorder (HVR) is another type of video recorder which is used to record
video from both analogue and digital formats. It can work with analogue
cctv cameras and IP cameras. Therefore it has both analogue BNC inputs
and RJ45 internet interface for working with IP cameras. HVR can bring
flexibility to your video surveillance systems, you can use your
existing analogue security cameras, at same time expanding your system
to IP system through using HVRs and IP cameras. That means you can keep
the standard quality system while expanding the system with mega pixel
resolution IP cameras.
Cameras types
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Box or
brick indoor camera
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bullet
in/out door camera
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dome
in/out door camera
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PTZ
Camera - Pan, Tilt, zoom
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Cameras optional features
Night Vision: These
night-vision cameras have the ability to see images in pitch black
conditions using IR LEDs.
Outdoor:
The key
to outdoor cameras is the housing itself, which must be impenetrable to
moisture, insects, dust and other elements
Varifocal: A
camera with a varifocal lens allows the operator to zoom in or out while
still maintaining focus on the image.
Wireless: Not all
wireless cameras are IP-based. Some wireless cameras can use alternative
modes of wireless transmission.
Vandal-proof:
Cameras are built to withstand vandalism and tampering attempts. These
rugged security cameras stand up to blows and other threats.
POE:
Power over Ethernet (PoE) enables power to be provided to the network
camera using the same cable as that used for network connection.
Build in DVR:
Video recording directly on internal SD memory card build into camera,
when main system is down recording continuous.
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