When you are purchasing a new security camera system, one of the first things to figure out is how to archive the HD video streaming from your cameras. NVRs and DVRs, cloud, embedded, VMS, analog cameras, analog HD video, network cameras…. I am tiring myself out just naming the different technology that is available.
We’ve been in the physical security industry for over 15 years and it seems like every year things get more complex. There was a time that only coax cable was installed between camera and recorder, but now with the technology changing at a rapid pace, it’s getting more difficult to design a solution for our clients. With IP systems gaining steam in the early 2000’s, mainly using network cable or ethernet cable to build a video surveillance network, it’s amazing that we are still buying boxes of coax cable for some sites.
So, what do these terms all mean and why are they important?
First, you need to understand how your surveillance cameras record. All recorders perform the same function, to store video, but the difference is in how the system is administered and managed.
DVR = Digital Video Recorder
DVR security systems came out in the early 2000’s and it was the replacement to the VCR. Prior to DVRs, cameras connected directly to a VCR, using coax cable, and tapes needed to be changed every 12-24 hours. If you wanted to keep video for longer, you would have to keep a bunch of tapes around and keep changing them.
The DVR, although still using coax cable to connect to the cameras, allowed you to record the camera’s digital signal onto a hard drive. When it was full, the recorder would just re-write over the oldest data, always leaving you with a set number of video storage (typically 20-30 days). DVRs are still around today, and the term is used very loosely, especially by people who have been in the industry for a while. They are purchased with a set number of camera inputs, for instance 16 channel, and when you reach the maximum you would need to purchase a new recorder. The maximum resolution was far from HD video, only allowing you to record in VGA 640×480 or 0.3 megapixel.
Digital Video Recorders process the video at the recorder, use analog cameras and is typically a wired system. With a high-speed internet connection, a simple ethernet cable would get the DVR to stream a digital signal over the internet so that you could see your cameras remotely. Analog cameras need to be directly plugged into the DVR via Coaxial cables and into a power supply via a low voltage power cable.
Windows based DVR vs Embedded DVR
When the first digital video recorders came out, it was basically a video capture card that allowed you to physically plug in a set number of cameras i.e. 16 channel DVR. The card was installed into a computer running Microsoft Windows, you would install the recording software, and voila you have what we refer to as a Windows based DVR.
Shortly after the invention of the DVR we started to see embedded DVRs. An embedded DVR looked very similar to a common household DVD player. A black box which had a set number of inputs on the back I.e. 16 channel or 32 channel DVR, etc., but they did not run on Windows. These recorders ran Linux which made them a simpler device and lacked the features of a Windows based DVR.
The main difference between the two was that embedded lacked the power required to have features beyond simple motion-based recording and video playback. Systems with large numbers of cameras (20+) would more often require a Windows based DVR. The image quality still did not change with a Windows or embedded DVR as HD video was just starting to hit the market and did not work on a DVR.
NVR = Network Video Recorder
This term started to appear in the early 2000’s as well but became the norm by 2008 and more so after 2010. The main purpose of an NVR is to record the digital signal of IP cameras over a network. Although the first IP camera was released in 1996, it wasn’t until 10-12 years later, with HD video becoming a huge benefit, that IP cameras started to take over. An IP camera no longer required you to run a coax cable directly to the recorder, you could use network cable or ethernet cable to get the IP camera plugged into a network switch.
Typically, software would sit on a dedicated Windows based computer (or server), the server would be connected to the same network with a network cable, and you could “find” the camera’s digital signal or stream using it’s IP address. When NVRs came out, you would need to purchase a camera license (or software license) for each camera that you wanted to record. The software is often referred to as a VMS or Video Management Software. NVR security systems encode and process the digital signal from the camera. Then it streams to the NVR recorder which is used for storage and remote viewing through an internet connection.
VMS = Video Management Software
The early NVRs almost always came equipped with a Video Management Software or VMS. VMS providers such as Milestone and Genetec, the pioneers in Video Management Software, focused mainly on developing their platform. VMSs were and still are, arguably, the most powerful and feature rich way to build a security camera system. If you want to record HD video more than 20 cameras at one site, with higher than 5MP resolution for each camera, you should strongly consider a Video Management Software.
A few advantages of a video management software are:
1. Greater variety of camera manufacturers to choose from to add to your system
2. Stronger integration with other building automation systems such as access control, alarm systems, etc.
3. More advanced search/save or live monitoring functionality, especially with large numbers of cameras
4. Advanced user management options
5. Strong fail-over & redundancy options
6. Network friendly tools to help you manage video traffic and control HD video bandwidth
The VMS providers spend a lot of money making sure their software is secure, up to date, and can record with the major security camera manufacturers. They also focus on integration with other security products and ensure their software is running smoothly. With a VMS you can expect better camera integration, faster and better compression/storage settings, and easier management settings.
Analog HD (AHD) Recorder
The arrival of IP cameras pretty much killed the analog video surveillance market. Just when everyone thought it was dead, manufacturers came out with analog HD video.
In simple terms, Analog HD refers to cameras that connect directly to the DVR using an analog signal (or a caox cable). You cannot put cameras on a network and record them, you must run a coax cable from the camera directly to the DVR. The DVR can be networked for remote viewing (if an internet connection is at the DVR), but unlike IP cameras which can sit anywhere on your network, analog HD cameras need to run cables back to the DVR. This was a huge benefit because now businesses could keep their existing analog infrastructure (coax cable, power supply, etc.) and just change the cameras to an HD video camera (upto 8MP now).
You still need to be careful with throughput on the DVR but do not need to move into an IP camera system, with an NVR, in order to get HD video. These systems tend to be slightly cheaper and are usually a perfect fit for smaller systems of upto 16 channel (even though larger systems are available).
The difference between all these systems come down to the cost, how the data is transmitted, and type of cameras. NVR security camera systems and VMS systems tend to have better picture quality, can handle higher HD video, and increased flexibility. However, they also tend to be quite a bit more expensive than comparable security camera systems.
For businesses looking for a relatively straightforward HD video surveillance system, a DVR will most likely be enough, especially if your property is already wired with coax cable from an existing setup. At the end of the day, the deciding factor will be based on the specific security needs of your property and how important it is to save money in the short run.
The video surveillance market has evolved significantly from the early days of VCRs to the emerging AI cloud era. Understanding each component of your video surveillance system is essential in evaluating security systems. To learn more about the other basic components of a video surveillance system click here.
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