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Derek Taylor and Barry Gilchrist gave us two interesting presentations on CCTV. Firstly, Derek showed us
what to expect from a commercial package followed by Barry’s home brew Raspberry Pi system.

Security cameras come in all shapes and sizes to cover all requirements from home security to large site
security with numerous advanced features.

There are two types of system to consider – Analogue or Digital.

The main difference between analogue CCTV and digital (IP) CCTV is the method by which video is rec-
orded and delivered. Analog cameras record images and then send the signal over a coaxial cable to a DVR
(Digital Video Recorder). The DVR converts the video from analogue to digital signals, compresses the
file, and stores it on a hard drive. Monitors need to be hooked up to the DVR to view the video, or the DVR
can be connected to a router and modem to broadcast it over the internet through an internal network.

Digital security cameras on IP-based CCTV systems, on the other hand, record the images digitally to begin
with. Then, they can receive and send data over a computer network rather than going through a DVR first.
This method overcomes the boxy setup with multiple ports in favour of an NVR, which is typically a sim-
ple software program that can be run on a device dedicated solely to operating the NVR or on a complete
system.