IP Camera Setup

Each IP Camera expects a special URL for obtaining video streams or snapshot images. The URL's can vary even between different models from the same manufacturer, so it is essential that you test for correct operation of each camera you add to the Verified Response Platform.

Snapshot commands from popular manufacturers

Axis

http://ip:port/axis-cgi/jpg/image.cgi[?resolution=&camera=]

Example - http://123.456.78.90:1234/axis-cgi/jpg/image.cgi?resolution=320x240&camera=1

Linksys

http://ip:port/img/snapshot.cgi[?size=]

Example - http://123.456.78.90:1234/img/snapshot.cgi?size=2

Panasonic

http://host:port/SnapShotJPEG[?Resolution=&Quality=]

Example - http://123.456.78.90:1234/SnapShotJPEG?Resolution=320x240&Quality=Motion

Sony

http://host:port/oneshotimage.jpg

Example - http://123.456.78.90:1234/oneshotimage.jpg

Image Size

The human eye can barely detect any benefit from images larger than 640x480 (approx 40Kb file size). Video verification is primarily designed to identify an object or person from the review of an historical record of still images (snapshots) and an image size of 320x240 is suitable for most implementations.

Frame Rate

Full motion frame rates are not an essential requirement in almost all video verification implementations. Five frames per second is suitable in most residential applications and anywhere from two to fifteen frames per second for wider ranging commercial applications. A lot will depend on camera positioning and the likely direction of movement of an intruder. Keep in mind that unnecessarily increasing the frame rate wastes network bandwidth and storage space.

Using IP Signaling to integrate IP Cameras with Alarm Systems

Sophisticated CCTV cameras and transmission equipment were in use long before many of us had even heard of the Internet. Manufacturers were quick to update their products to take full advantage of IP, however, the price tag of such systems remains well out of the reach of the vast majority of both residential and small commercial Customers. So how can the alarm industry provide video verification services to this group of Customers at a more realistic cost?

The answer lies in the use of IP cameras. For alarm installers, their arrival is akin to the introduction of PIR detectors more than two decades ago and it won’t be long before it becomes routine to fit one in each protected area as one might do now with a PIR.

So what are our options for integrating IP cameras so that they become an integral part of a security alarm system?

Most cameras come with some form of built-in motion detection, however, the unpredictability of this technology prevents it from being used to trigger an alarm panel into calling a Monitoring Center. Using motion detection would also require that there be some way to arm and disarm the cameras so that they do not send images when people are legitimately moving around the protected premises. Due to the familiarity and simplicity of arming and disarming an alarm panel, one option is to have the panel trigger cameras only when it is armed. This way, images are only sent to the server in the event of an alarm activation.

This can be done by connecting a cable from the panel to the trigger input of the camera if it has one. The preferred method however, is to trigger and control the camera via software commands from the Monitoring Center server. The more expensive IP cameras provide a full range of software commands that allow control of pan, tilt, zoom, pre and post alarm triggering and other common features. Whilst lower cost cameras do not generally offer these features, the majority of them do support jpeg snapshots at various resolutions which provides the industry with a starting point for mainstream video verification.

Overview of Vendor Neutral Video Verification

The snapshot feature allows an installer to fit a camera from manufacturer X alongside one from manufacturer Y and Z. This provides great flexibility for the installer as they are not tied to a specific camera manufacturer. It is also ideal for the Monitoring Center as they are not reliant on any proprietary hardware or specific server software.

In preparation for viewing and recording images from the protected premises, the Monitoring Platform database stores various camera related parameters alongside well known alarm parameters such as event definitions and zone lists.

Basic camera parameters determine what type of alarm events and which zone numbers should trigger the recording of individual cameras. They also specify the total number of images to be recorded and the time interval between them.

Each IP camera requires a slightly different software command to trigger it, so the Monitoring Platform must support the manual entry of custom commands in order to support any brand of camera used by subscribers.

Every second counts in the triggering and recording of images from IP cameras. It takes a long time to send an alarm signal using traditional protocols and starting a recording 10-15 seconds after an alarm event would almost certainly mean losing some of the most important footage.

There are different ways to overcome this depending on the available features of the alarm panel, the IP alarm device and the camera. A high spec camera would use a “pre-alarm” feature where it might send the server ten seconds of footage prior to the alarm and twenty seconds after it. Lower spec cameras would provide a snapshot command facility which can be triggered by the use of panel outputs and IP device inputs as already described.

The Snapshot Command in Action

As an example, we will say that Mr. Smith has an alarm system, an IP alarm transmitter and an IP camera installed at his home. The transmitter and camera are plugged into his router and connected via the internet to the Monitoring Platform.

His account number is 1234 and he has requested that 9 snapshot images be recorded at 2 second intervals in the event of an alarm. This information is checked every time an alarm signal is received. Here is the data that might be stored for Mr. Smith:

Account Number: 1234

Number of Snapshots: 9

Snapshot Interval: 2

Zones That Trigger: 2,3,4

Camera IP and Port: http://mrsmith.dyndns.org:800

Snapshot Command: /CamImage.jpg?UserName=abc&PassWord=xyz

When an alarm signal from account code 1234 is received, the Monitoring Platform checks the database to find that Mr. Smith has cameras and that images should be recorded on the server if the alarm was from zones 2,3 or 4 (zones 5,6,7 and 8 might be used to trigger a second camera). The software concatenates the IP address of the camera and the snapshot command together so that the following command is used to obtain images..

http://mrsmith.dyndns.org:800/CamImage.jpg?UserName=abc&PassWord=xyz

The end result is that jpeg images are written onto the hard drive of the monitoring server ready for further analysis by a Central Station operator.

Now let’s break down the snapshot command and consider the prerequisites of Mr. Smith’s network and camera setup in order for it to work correctly.

Firstly, you will notice that http://mrsmith.dyndns.org is used instead of an IP address. This tells us that Mr. Smith does not have a fixed IP address allocated to him by his internet service provider and that he has registered something called a dynamic domain name. Put simply, this is a method of keeping a domain name linked to a changing IP address. Typically, when a user connects to the Internet, the user's ISP assigns an unused IP address from a pool of IP addresses, and this address is used only for the duration of that specific connection. A dynamic DNS service provider uses a special program that runs on the user's computer (some IP cameras also support this), contacting the DNS service each time the IP address provided by the ISP changes and subsequently updating the DNS database to reflect the change. In this way, even though a domain name's IP address will change often, we do not have to know the changed IP address in order to connect with Mr. Smith’s camera.

The :800 in the command lets us know that Mr. Smith’s router has been setup with port forwarding and that port 800 points to his camera. Generally speaking there is no way to get to Mr. Smith’s camera without port forwarding.

Each camera manufacturer has their own set of software commands for controlling cameras and the /CamImage.jpg? part of our example snapshot command is just one such variation.

Most snapshot commands contain a question mark and this tells the camera that a number of parameters will follow. These are normally used to set the resolution and size of the image and to provide security credentials.

In summary, with the Verified Response Platform and an IP alarm adapter at the protected premises, low cost IP cameras can be easily integrated with alarm systems to provide video verification.