Multi-camera CCTV software for the Mac
Case Study – Housing Complex,
Area-Wide Surveillance System
Written by Jason Thomas of Thomas Security Industries
This public housing complex is located in Carbondale Illinois in the US, and is managed by the Jackson County Housing Authority. The area consists of two square blocks with a driveway through the center. This area has always been plagued by drug and gun activity. Recently, a serious crime became a catalyst for the Housing Authority to seek a vendor to install an area-wide video surveillance system. Our Company TSI specializes in municipal and public safety video surveillance, and we were chosen to design and install this system.
The purpose of the system is to protect the residents of this complex, who are often innocent victims of these crimes. This added level of safety will be achieved in three ways:
- By providing video evidence of perpetrations of drug and gun activity and by providing evidence that may lead to the arrest and subsequent conviction of said perpetrators.
- By giving the Carbondale Police Department real-time access to the system, so that they can monitor the area, especially during times of increased criminal activity, and thereby reduce their response time.
- By creating a deterrent to individuals who might venture into this area with the intention of committing a crime.
The entire area needed to be covered to the best possible extent, with as few dead spots as possible. PTZ cameras were not used for the simple reason that they often are pointed in the wrong direction when something you needed to capture happens in the other direction. In small and medium municipal surveillance, there often is not a dedicated person assigned to constantly monitor the cameras. For this reason, it is important to cover the area fully with as many fixed cameras as is feasible.
The system records constantly 24/7 in order to ensure that there are absolutely no missed events (events that occur far from a camera may be missed by motion-triggered recording). We record constantly at 15fps and SecuritySpy creates a new file every 10 minutes. This system holds more than 30 days of footage for all 20 camera views.
This plan shows the locations of cameras and cable runs throughout the housing complex (click to enlarge):
There is no wired internet connection at this location. Initially, connectivity was going to be achieved with a radio backhaul up to the Jackson County High Rise complex 1 kilometer away. However, line of sight was not achievable without a large and expensive tower, due to the elevation differences and the many old growth trees in Carbondale. Because of these limitations, we decided to locate the recording equipment on-site and provide connectivity via a cellular connection. There is no maintenance or common building at this complex, so we constructed a system in a box.
This System in a Box consists of a computer running NVR software, two 4TB hard drives, ethernet switches, a Cellular modem with external diversity antennas, and high power PoE injectors.
We chose the combination of the world's best small form factor computer, the Apple Mac mini, and the fantastic software SecuritySpy by Ben Software Ltd. This box contains a 6-core i5 Mac mini with 16 GB of RAM. The case of the Mac Mini is milled from a solid block of aluminum and provides excellent heat dissipation. We thermally bind the top of the Mac mini to the metal backplate of the enclosure, thereby turning the entire box into one big heat sink. Additionally, a thermostatically controlled fan pulls air through the enclosure during the hottest times of the year. We run Macs Fan Control to artificially increase the speed of the Mac's fan to a minimum of 80% speed. This helps to keeps the air inside the box moving, and also, Apple's system controlled fan speeds are too low because they sacrifice air movement for quietness. When a Mac Mini is properly installed as described above it is a very rugged computer. We have installations that have lasted 7 years outdoors, through the harshest winters and summers and continue to operate today.
We design and build custom aluminum brackets to hold the hardware:
The guts of the brain box. The computer is thermally bonded to this metal plate. The temperature sensor for the active ventilation is affixed to the plate. The plate is thermally bonded to the steel enclosure. Missing from this image is the external hard drive storage enclosure.
We utilize a very high power 90W Ultra PoE (Power over Ethernet) injector. Then one single Cat5e aerial cable carries all of the data and power for the entire system (most of it anyway). This single wire connects to a PoE-powered PoE switch. This switch has 1 incoming port and 4 outgoing PoE ports, each capable of providing a full 30 watts, or 15 watts each when all 4 ports are maxed out. This switch then connects to the other camera pods, either by an underground Cat5e, or further aerial cables. When the cable reaches the pod, it connects to yet another multi-port PoE repeater that then powers the cameras on that pod. The backbone of the system is 1GB ethernet throughout, and most of the cameras in this system are powered by one single ethernet wire! There is one camera pod location that was too difficult to get a wire to. For that pod, we used a Mimosa C5X radio link running on the licensed Public Safety band of 4.9ghz. That pod gets its power from the AC line that runs to the light on the same pole.
This is the brain box installed. Those two black things on top are LTE diversity antennas:
We chose Axis cameras for this installation. Axis has been the leader in IP video surveillance. This installation is funded by the US Federal Government and due to the NDAA, only non-Chinese cameras may be used. We build custom steel pods each sporting two Axis M2026-LE cameras. These have a 130° field of view. We used the Axis recessed mount to place as much of the camera workings up into the box as possible. We also employed the award-winning Axis P3717-PLE multi-sensor cameras. This is the best and most cost effective camera that Axis makes for this type of installation. The images are quite serviceable at the relatively modest resolution of 2MP, considering that compression and optics are the true weak link in most video streams. We found that the default settings were over compressed and under saturated. Once we fixed these two things, the images are very good. These "Spaceship" cameras have 4 individual cameras, each having a tiny varifocal optical zoom lens that is electronically adjustable from 3-6mm. This is very handy and allows the maximum pixels to be used for just the scene you are trying to capture. We used two of the cameras in wide mode and the other two zoomed in on important areas.
The Axis P3717-PLE and M2026-LE cameras:
We design and build custom camera enclosures. These boxes each house two Axis M2026-LE cameras. The majority of the camera body is recessed into the box. Byron is preparing these for installation.
This is one of the Axis P3717-PLE cameras and its radio backhaul:
Here are some screenshots from SecuritySpy, showing all 20 cameras (click to enlarge):