Video Encoders – Enabling Video Surveillance over IP without replacing Analog Cameras

This article gives an idea about how the video encoders help use existing analog cameras and analog (coaxial) cables and still migrate to an IP platform for Video Surveillance. We also discuss the features supported by such video encoders.

Video surveillance has traditionally been handled through analog video cameras, analog coaxial cable network and a DVR/recording-playback central device with monitors to view the output. But of late, IP surveillance systems (IP Cameras, IP Cat 5E/6 network cables and computer servers/video management software’s) have started to become more popular due to many advantages of IP Video surveillance.

But since many companies/organizations have huge investments on the existing analog surveillance cameras and also on the analog coaxial cable network. To change to an IP Video surveillance system means to discard all these analog components. Not many are aware of Video Encoders which can be used (as a temporary measure, if required) to migrate to IP Video surveillance by retaining the investments on the existing analog cameras and the analog network.

What is a Video Encoder?

Video Encoders (also called video servers) connect to analog cameras via coaxial cables at one end and an IP network via RJ-45 jacks and Cat5E/6 cables at the other end. They are introduced (possibly near the analog cameras) to convert the analog video produced by the analog CCTV cameras into digital video streams that are sent over the IP network. So, it basically helps to build an IP based video surveillance systems (with many of its advantages) by retaining the existing analog CCTV cameras and coaxial cables (to a certain extant). Video encoders support a single camera as well as multiple cameras, based on the model. The cost advantage of not having to replace all the analog cameras with IP cameras is the primary goal of introducing such an intermediate device but the compatibility of the existing cameras etc. needs to be checked with the vendors before investing in them, but many types of analog cameras (like fixed, PTZ, dome etc.) can be connected to the video encoder. Such video encoders can support a lot of features of IP video surveillance using analog cameras and a short list is given below.

Salient Features supported by Video Encoders:

¤ The analog cameras can be controlled from remote location over the IP network and the video encoders.

¤ Certain video encoders support PoE (Power Over Ethernet) standard which lets them to be powered via the Cat5E/6 cables which carry power along with data. So, a separate power cable may not be required.

¤ Video encoders introduce intelligence into the surveillance by enabling features like video motion detection and a few even support audio detection. This is useful when playing back the video images where only the scenes where some motion was detected could be looked at. Or, recording of the video can be limited to only those scenes where some motion or sound is detected.

¤ They enable alarms to be generated based on certain events (like cutting off the cables to the cameras etc.). These alarms could be simple email alerts, starting video recording etc. and also complex actions like activating a siren/closing doors automatically etc. Such actions can be possible by connecting external sensors and relays through the I/O connections present in the video encoders.

¤ The video encoders support high frame rates (like 25/30 fps) and multiple resolutions like CIF, 4CIF etc. They also support more than one compression formats simultaneously – like MPEG4, H.264 etc.

¤ Some of them correct the aspect ratios obtained by the analog capture to suit the viewing on a PC screen.

¤ Video encoders can provide multiple video streams simultaneously and each stream can be configured with different compression formats, resolution and frame rates.

¤ Based on the vendor, video encoders support video management softwares which allow for central control of recording, monitoring, playback and management capabilities.

¤ Once the video is converted in to the IP format, many IP network security systems like encryption, authentication (802.1x etc) are supported by video encoders.

¤ Some video encoders also support network QoS reservation parameters for optimum quality of video playback.

excITingIP.com

In case you have any questions, you can contact us using the contact form or leave a comment below. You can also subscribe with your email address (on the right side of this site) to get notified (title and summary) when a new article is published on this site.