If we look back about ten years ago, the
graphic compression card was dominating the CCTV industry. In a typical CCTV
system, it always had graphics card with PC computer, and all the coax cables
were wired back to the graphic card. We almost can’t find this kind of
application today. People use dedicated DVR/NVR instead of graphics card and PC-based
DVR. The operation of dedicated DVR/NVR is simple as set-top box, barely
require no technical skill to operate. However, the PC-based VMS (video
management software) is still having strong market share. Both VMS and
dedicated DVR/NVR can accomplish part of job which is similar, but they are not
the same.
Recording-Playback-Live
Recording and playback footage, providing the live for real time monitoring is the basic function for all video surveillance system. Both VMS software and dedicated DVR/NVR can get these job down. The dedicated DVR/NVR is more effective with these functions. Single dedicated NVR can handle 128-channel 1080p IP cameras. If we employ VMS software, it could take several powerful PC computers working together to build the system. Plus license fee for cameras and windows OS, the total cost could be triple up. However, the VMS is more versatile than dedicated DVR/NVR, most of the dedicated don't even have quick playback which is the standard function in VMS software.
System Scale
The VMS is more suitable for middle or
large security system. It is center-server (CS) software structure. All the IP
cameras connect to a center server, and the core functions, such as recording,
video regeneration, are processing at the center server. The operator can
access the server with client software. It is easier to deploy distribution
structure to manage and record over thousands cameras with VMS software. The
dedicated DVR/NVR system requires each camera link to itself for recording and
display. Those DVR/NVRs doesn't communicate with each other. Somehow it is more
similar as many independent severs sitting on the desk. The operator needs to
access each of the servers to search the footage. One of the solution is we can
use NVR switch to manage multi NVRs on single station. It still doesn't put
dedicated DVR/NVR to communicate with each other, but it improves the
operator's accessing speed to each dedicated DVR/NVR unit.
Video Analysis
Video analysis is the weakness part for embedded DVR/NVR this moment. It is easy for VMS to perform the video analysis as long as PC server is powerful enough. Most dedicated NVR are still after cost-effective this moment, try to connect as much IP cameras as possible with maximize the CPU resource usage. I believe people will focus on video analysis in next step, especially the machine learning become mature. Training the NVR to classify the object could be a possible concept. For example, giving the NVR over millions different pictures of dogs, when the NVR receive a new pictures, it can tell it is a dog from otherwise. The direct way could just purchase the modeling feature from the supplier. What NVR need to do is grab the pixel from the image and compare with those existed feature.
H.265 or H.264
Dedicated NVR is leading this part now.
Most of the VMS software is still doesn't support H.265 compression. If you
connect an IP camera and set to H.265, normally, you see no video stream on the
VMS. I don't think it is because H.265 is too complicated, it is only because
H.265 is eating too much CPU resource and the conventional CPU still doesn't
support hardware decoding.
System Maintained
Technically, both systems have similar
reliability. The dedicated NVR always employs embedded Linux, the system
firmware is burnt to the ROM on board, and the user can not modify the core
system. Most of the VMS is PC-based system, it require operation system such as
the windows. Yes, we can put SSD and lock the OS driver, basically, it is
similar as embedded PC, but still the general operation system is taking much
CPU power for other features NVR doesn't require, running those services could
generate more system maintained.
VMS delivers versatile functionalities, but it needs high cost and more maintenance. The dedicated NVR is simple, cost effective, and limited to basic surveillance purpose. We are seeing more and more function is adding to embedded NVR, such as dedicated NVR with LPR, fisheye VR. There are just not new for the VMS.
3 Komentar
Thanks for sharing an nice informative about the dedicated NVR and PC based VMS with us...
BalasDo you know the market share of NVR vs. VMS?
BalasGrateeful for sharing this
Balas