MÔJ KOŠÍK
Môj košík je prázdny
 »   »   »   » 
Modern functions of ACTi cameras
 
IP CCTV equipment manufacturers are constantly looking for higher resolutions, higher numbers of transmitted frames and improvement of other parameters, often forgetting about the users, unable to fully utilize the improvements. Simply - better performance does not go hand in hand with additional features that allow the users for optimal configuration of cameras in order to maximize their potential in practice.
The company in opposition to the general trend is ACTi, developing new features that greatly enhance the potential of IP CCTV cameras. They include:
  • Event handler
  • GOP
  • CGI

Event Handler

Traditional CCTV cameras are passive devices - they can "see" but cannot "act". ACTi Event Handler transforms a set of ACTi IP cameras into the active partner of the security system. Event Handler is a software package that is built into the firmware of ACM camera series. What's important, the users of previously installed ACTi cameras of the series can download and install the new software for free. Some functions of the package are very innovative - not available in any other similar devices in the market!

What is in fact the Event Handler?
When something happens at the camera point: someone passes by, a door opens, a fire breaks out, or there is a change in lighting - these are the events (or triggers). For each event, the user may assign a rule that changes operating parameters of the video surveillance system, providing the desired response. Event Handler allows to set many rules.
Web Configurator window of the Event Handler
The main benefits of using Event Handler
Quick and intelligent responses
Event Handler provides rules and offers easy management of all events through a single user interface. Unlike some cameras from other manufacturers, when configuring a camera there is no need to move between multiple menu pages. With ACTi Event Handler, the user can select any event and any response on the same page. It is also possible that one event triggers several reactions.
Because all decisions are taken by the camera, there is no need to wait for responses from recording servers, and thus, in critical situations, the reactions are initiated immediately.
Automatic day/night switching
Most of available IP cameras have different profiles for day and night modes. A profile is a set of optimum picture settings for a specific environment and lighting conditions.
The cameras which use more than one profile have to ensure switching capability. Some manufacturers offer solutions involving manual switching, re-adjusting the settings, or selecting previously saved profiles (the procedures may be time-consuming). Some of the more sophisticated devices are able to switch between the saved profiles at regular intervals. However, because of the varying length of day, the times of profile switching should be regularly updated, which is inconvenient.
Variable motion detection settings
Properly functioning motion detection is a very important element of any security system. If a camera allows to configure only one profile, it is not possible to automatically change the detection area and/or sensitivity, for example, depending on time of day. As a result, it may cause loss of recording of important events or a lot of unnecessary material.
Automatic uploading and notification
In the past, all materials were stored on a central DVR. In the case of its failure, the data was lost. ACTi cameras allow to avoid such a problem - they can send images to a configured FTP server, notify users about events by email, or send URL commands. Even loss of connection to the main server can trigger recording on a remote FTP server.
Event-triggered PTZ control
PTZ cameras are used to observe larger areas. The problem arises when there is an interesting situation outside the current field of view. The solution is automatic PTZ control triggered by the event - the PTZ camera observing a larger area is zooming in on the spot with motion. Another example is focus on the place of an event (e.g. opening doors) while regular scanning of the whole area.
Hundreds of combinations
The presented potential of the Event Handler application would not be a breakthrough without the possibility of combining many functions. Every camera can support up to 10 rules.
Summary
The new functions of ACTi cameras introduce a new quality into CCTV industry. It is due to the fact that they are unique in the market as well as obtainable in the case of all ACM cameras installed in running CCTV systems. The ACM cameras provide the opportunity to access these features through firmware update.
The Event Handler flow chart

GOP

Group of Pictures (GOP) specifies some MPEG-4 / H.264 settings, i.e. the order in which intra- and inter-frames are arranged. It directly influences the bandwidth of the video stream, allowing to fully utilize the main feature of MPEG-4 compression, i.e. transmission of nothing but changes in the image.
GOP structure specifies the order in the group of successive frames within a coded video stream. The control decides on the number of I-frames in the group (I-frames are reference images representing fixed images in relevant moments that allow to reconstruct complete images). Other frames between I-frames (P and optionally B, D) transmit only information on the changes in the images. Therefore, control of the GOP is crucial to save bandwidth when monitoring still scenes, as the P frames carry less information.
GOP Length setting in Video Setting window
The GOP length specifies the number of P frames between I frames. GOP=1 means in fact MJPEG compression which forces the use of large network resources. For example, assumption of 5 fps and GOP=20 will result in I frame every four seconds. In the case of ACTi cameras GOP=0 means that the I-frame occurs once per second regardless of the frame rate.
GOP structure at 5 fps in various dynamic conditions
Because proper GOP length can significantly reduce the demand for bandwidth in the case of quasi-static images, it is worth to use this feature in conjunction with the previously described Event Handler. For example - a camera is directed into a corridor. GOP length can be set to 60 (this is the maximum value). Detection of motion in a specified area (a part of the image) can change the GOP length to 6. This means that any motion in the detection area will increase the number of I frames. When the motion ceases, the camera will receive the command to restore the GOP length to 60, saving the bandwidth again.

CGI commands

Each IP camera has a user interface, necessary for communication - usually by means of web browser or telnet commands. An interesting solution is the ability to use commands typed in the browser's address field. Without logging on to the camera, it enables the user to download all settings and even change them.
It is obvious that these commands can be entered on any web page using HTML. It allows the user to create own menu with only those options that are really needed. In addition, the commands may be a response to the events in the Event Handler, e.g. switching into night mode can lower the resolution of the camera.

http://LOGIN:PASSWORD@ADRESS_IP/cgi-bin/cmd/encoder?VIDEO_BITRATE=3M

http://LOGIN:PASSWORD@ADRESS_IP/cgi-bin/cmd/encoder?VIDEO_FPS_NUM=8

http://LOGIN:PASSWORD@ADRESS_IP/cgi-bin/cmd/encoder?VIDEO_RESOLUTION=1280x1024

A major limitation in the use of IP cameras is the need to install ActiveX(R) controls. This means necessity of employing Internet Explorer, which alone eliminates the users of operation systems other than Windows(R). The solution to this problem is CGI command:

http://LOGIN:PASSWORD@ADRESS_IP/cgi-bin/cmd/encoder?GET_STREAM

An image from ACTi camera in Mozilla Firefox browser

THE END