DVR vs NVR

[wax 0]

Hi! I'm new to cameras and this seems to be like a friendly community.

 

I was wondering what's the major differences? Someone told me that NVR uses more bandwidth then DVR. They also said the quality is better with DVR systems.

[FranciscoNET 0]

NVR = Network Video Recorder (Usually captures images through RJ-45 Ethernet based cameras)

DVR = Digital Video Recorder (Captures images through BNC connections routed through popularly RG59/6 coaxial cables)

 

If you plan to use Megapixel cameras, then you may need a Network Video Recorders because as far as I am concerned, DVR's highest resolution is of D1 at 720x480 DVD quality.

 

If you plan on using standard cameras up to 600TVL of resolution then you can go the DVR way as long as the DVR that you pick can record at D1 resolutions.

 

Going the Network Video Recorder way can present various problems, all depends on the quality of your router and switch hubs and even type of firewall(s) configurations in use at your home/enterprise. Some, if not all IP cameras (required for NVR's) optimizes their videos for internet transmissions, that way you can have images being recorded locally at your NVR and as well have another NVR at another remote location recording that same images, even have tertiary, etc backup NVR servers at other locations for redundancy and consistency in the event a thief steals your primary NVR you can still go to your secondary NVR to retrieve footage. The problem consists that since most IP cameras optimizes the images for internet transmissions, quality is lost, and compression has to be huge specially if its like a 3MP camera and is expected the upload to be less than, lets say 800kbps for compatibility of your cable ISP provider or DSL. If you plan to record locally, you may increase the bitrate of your IP cameras as locally your network speed runs at 100mpbs or 1024mpbs (if you have a gigabit network) for maximum offline quality storage, even though you will still be able to access real time remote images, but the remote images will be at reduced frames per second because of your possible ISP's upstream caps/limits. If you are under Verizon Fiber Optic ISP you wont have trouble receiving high quality mega pixel remote images as you will be under a 5mbps to 10mbps for upstream, so quality extremely fast ISP is critical if you plan to receive nigh quality NVR REMOTE images.

 

Now, as of the DVR, there is no limit on the bitrate you can choose to have your images recorded, you can be recording D1 resolutions at lets say 7 Frames Per Second at the highest bitrate and quality possible and stuff a chain of 4 TB of hard drives in your DVR and that should give you plenty of days of recordings. With some DVR's you also have the option of doing remote recording, all boils down to that DVR's software specific features and capabilities, but at least what get's recorded locally in the DVR is not images that were optimized for transmission over the internet insuring the highest quality of images locally on the DVR (as well as your optimized backup images at your remote location)

 

If you are on budget and still needs quality then go with the DVR at D1 and get 540 TVL Infrared CCD color cameras (or 600TVL CCD Black and White cameras/dual high intensity day/night vision)

 

But, if you are on EXTREME budget, you can compromise a little of your VGA quality and go for a QVGA (320x240) or CIF (252x288) DVR specially if your place is small QVGA or CIF recording qualities will suffice your needs and maximize the amount of days you can store videos.

 

So...

NVR = Extremely Expensive to Implement. On some software can go as far as charging you a premium per EACH camera you decide to add to NVR (not counting remote NVR's you might plan to use for redundancies can multiply that fee), not counting the high fees per hour you will need to pay your highly qualified technician to address and map your IP Addresses and ports and configure your firewalls accordingly for proper video accesses, etc, etc...

 

DVR at D1 = Expensive to Implement (you buy a 16CH DVR card, you get 16Channels of cameras you can enjoy at no additional costs. No need to hire a highly qualified technician, you can probably do it yourself)

 

DVR at QVGA or CIF = Cheapest to implement.

[Soundy 1]

Hmmm, that's a bit over-analytical, and WAY over-generalized.

 

Quite simply, "DVR" stands for Digital Video Recorder, which CAN include network cameras, and in fact, a system with ONLY network cameras is also a DVR; "NVR" is simply a more specific term to indicate that the system is network-only with no analog capture hardware. Typically, a system with analog AND network cameras is called a "hybrid DVR".

 

As far as cost, ANY of the three types of systems can be "extremely expensive" to implement; it really depends on a lot of different factors... hardware used, software used, cameras used... you could put together a dirt-cheap NVR with low-grade network cameras and cheap NVR software... you could assemble a VERY expensive analog-only DVR with high-end cameras, top-grade computer hardware, and highly sophisticated software.

[wax 0]

Man. That was a lot to take in.

 

 

 

Thanks for the replies though. I'm probably going to go with a DVR system since that's what so many vendors recommend I do. They generally say that DVR is just as good as NVR but it's cheaper

[Soundy 1]

Being strictly semantic, a NVR is a DVR... however, the important difference to remember is that you need a DVR if you have or plan to use standard analog cameras*, or an NVR if you're using network (IP) cameras (since the N stands for Network).

 

Don't worry about which costs more, worry about which will fulfill your needs, since TOTAL cost of a system needs to factor in the cameras as well - IP cameras in general cost more than analog cameras, but analog DVRs require some sort of capture hardware, whereas NVRs require only the proper software... in the view of a complete system of recorder AND cameras, the cost differences aren't that great.

 

*side note: analog cameras can also be used with an NVR with the use of a "video server" device, but that's something for a different discussion.

[woodyads 0]

Although some IP cameras will have poorer compression than others at the end of the day the encoder in a camera and the encoder in a DVR card both create a video file what ever that may be (AVI MPG or a proprietry file). This is where the compression is done to provide a digital file format for the hard drive not for the internet or network. An NVR encoder with a better codec will result in a better file than DVR with a poorer codec and vise versa.

[woodyads 0]

For me the big difference between DVR and NVR is working in an Enterprise environment, NVR makes much more sence. I can leverage off existing infrustructure, I have no Layer1 network (medium, fibre, coax, RF, etc) dependence as all security and addressing is done virtually. My servers don't have any video dependent hardware in them and I can put all or parts of my NVR in a virtual server. If hard disk capacity, speed or size becomes an issue I can move video streams to another archiver without having to recable, while the database can sit on any other server instance and the licence server can be on an entirely different instance.

 

Network wise it means I can beef up my network as I have synergies to increase the over all value. I can justify high end network hardware and if I decide to install dedicated switches I can join the two VLANs and Trunk the fibre for backhaul. There is so much flexibility available in an IP network. Analogue video medium is very limited.

 

In the server room I don't have any coax at all, this is a big plus. Just fibre and all on one protocol. Full IP means that security and addressing is in the IP packet where as Analogue Video has layer 1 addressing in other words physical. If you want to move your DVR to another room then you need to relay your cable. Furthur more my server room is 1km from my closest camera, I just want to put in one run of fibre anywhere (I use Fibreflow so I don't need to pull fibre see below) Coax I need conduit and pits. I can create a redundant loop with fibre and the IP protocol will look after it. Again with analogue routing addressing and security must be done at layer 1 in other words physical connection.

 

NVR is superior when connecting areas with wireless because it reduces RF management. All my cameras are on remote solar powered trailers so the Cameras come back to a switch on the trailer then are backhauled through wireless bridges, 2 independent mesh systems, to a point where they come back on fibre with a microwave redundant backhaul. While you could multiplex analogue and pass it over a radio link why would you bother when passing IP over wireless has instant synergies with other IP systems.

 

NVR has much better distributed points of failure than DVR as the encoders are all separated and the server services can be distributed virtually. If a DVR card fails you must take down the server. Where as if you have issues with a switch you can run up a switch along side and move the links acros.s If you have to work on an analogue trunk link you must take down that link. With IP if your running redundant backbone you can service fibre medium seamlessly.

 

The downside of NVR is you must have a solid holistic understanding of all IT functions to make the synergies work for you. And if you don't have high networking standards the synergies might not be there

 

**Fibreflow looks like very thick fibre but it has 3 to 50 hollow tubes in it each about the size of drinking straws. You direct bury it then you blow fibre through it. The advantage is you can go 1km without pits. Much better than laying conduit with pits ever 50m. It comes with upto about 50+ tubes. The stuff I use is 7 tubes and will take 12 core per tube. So you can blow more fibre through if you need it later.

 

Small comms trailer and externa camera stand

 

Large comms trailer. 5.5kw solar power over 4 redundant circuits, 4.6 tonne with 1.6tonne batteries, 15m air powered mast. Network 3 x fibre links, 2 x 5.8 Ghz, 3 x 2.4 Ghz, 2 mesh, 3 backhaul, Supports Cameras, 2 -Way radios, FM repeats, 3 meshes, 2 wireless bridges, 4 slope radars, Serial, Modbus, I Phones, Laptops, Digital IO, 120 heavy duty vehicles all over IP. Got 3 of these to move around when necessary. Cost about $200k each

[Soundy 1]

Large comms trailer. 5.5kw solar power over 4 redundant circuits, 4.6 tonne with 1.6tonne batteries, 15m air powered mast. Network 3 x fibre links, 2 x 5.8 Ghz, 3 x 2.4 Ghz, 2 mesh, 3 backhaul, Supports Cameras, 2 -Way radios, FM repeats, 3 meshes, 2 wireless bridges, 4 slope radars, Serial, Modbus, I Phones, Laptops, Digital IO, 120 heavy duty vehicles all over IP. Got 3 of these to move around when necessary. Cost about $200k each

 

That is some SEXY $#!+ right there! Wow!

[rory 0]

DVR is cheaper thats all u need to know

and we arent all blessed with a NASA style job like woody

 

BTW search is your friend;

http://www.cctvforum.com/viewtopic.php?t=14855

http://www.cctvforum.com/viewtopic.php?t=7210

[wax 0]

DVR is cheaper thats all u need to know

and we arent all blessed with a NASA style job like woody

 

BTW search is your friend;

http://www.cctvforum.com/viewtopic.php?t=14855

http://www.cctvforum.com/viewtopic.php?t=7210

 

Thanks.

[rory 0]

That is some SEXY $#!+ right there! Wow!

 

I just want to know why they spend so much money to look at dirt and rocks

(wonder if they can see anything at night)

[woodyads 0]

Hahahahahh, yep as I said synergies. We have 4 slope radars which are a wicked technology that scan the walls and set off alarms if they are going to come down. Typically we get about a months warning, so they set up critical monitoring, about 2 weeks to go they will bund off the area to catch rocks and divert traffic. 2 days to go they will close off that area. 2 hours they will stand on the edge and watch it go. 6 hours later they give the all clear, they cost about $1m each. Then we have Modular which is the Fleet Management system running off mesh at a cost of $4m. So its easy to justify $600k on comms trailers. Sticking cameras on them is just a bonus, but in saying that the site love the camera system. Unlike most security systems we get everyone using them, Trainers, Geo's, Geotechs, Dispatches, Managers and supervisors. We also use it to audit the Fleet management system and check the data comming from the vehicles matches the data collected by the system. Shovel dig rates, Clean up times, kick off times etc. Funnily enough we need those big trailers to supply enough power to make the cameras cost effective. My first attempt at a small trailer only had enough power for 2 cameras and was very inefficent. cost for the infrustucture was $25k per camera, not including the camera or NVR system, just comms and power. Now I have it down to around $5k per camera. plus got some wicked trailers out of them.

 

As for why look at dirt, it cost around $300m per year to dig that hole. Save 1% and we pay for all my systems in 3 years. Our group save around 10% of mining costs.