TECHNOLOGY APPLICATION GUIDE

Video Surveillance - Compression

What is it?

With respect to video surveillance, compression is the reduction of data transmitted between devices. In analog surveillance, this compression occurs in DVRs. In network surveillance, this compression occurs in the network cameras and associated recording and viewing devices.

Compression Standard

Data Reduction Method

Benefits

MJPEG

Intraframe*

Minimal bandwidth variation regardless of motion

H.264 
(MPEG-4, AVC Advanced Video Coding)

Interframe**

Reduces bandwidth and storage by up to 80% compared to MJPEG

H.265
(High Efficiency Video Coding HEVC)

Interframe**

Reduces bandwidth and storage by up to 40% compared to H.264

* Intraframe: Compares frames of video and identifies if each particular pixel has changed. Uses more data by transmitting each pixel within the frame.

**Interframe: Where adjacent pixels are the same color, the software groups these pixels into blocks which allows less individual data to be transmitted for each pixel. Uses less data by transmitting groups of pixels within the frame.

Why is it important?

Each available compression method reduces bandwidth requirements in different ways and provides flexibility in designing a system to best fit the needs of the application. Accurately identifying the compression method required for a particular device makes sure the following happens:

  • The level of detail that needs to be reproduced is done accurately.
  • Data traffic on the network is at a manageable level.
  • Storage costs are controlled.
  • There is greater network stability.
  • Servers manage and process the data generated by the device. Servers also organize the storage locations within the available hardware.
Video Compression Diagram

In order to view a video with full image integrity, workstation video cards and processors need the ability to decode the chosen compression method.

Without compression of surveillance video, the data traffic generated would be extremely large and could overwhelm most networks, which dramatically increases storage needs and costs.

Video Infrastructure Considerations

Storage image

Storage

Video storage requirements may increase or decrease depending upon the compression chosen.

Workstations image

Workstations

Workstations require faster processors and more recent quality video cards when higher compression methods are chosen.

Switches image

Switches

Switches need the appropriate bandwidth between devices (cameras/encoders) as well as aggregated uplink bandwidth to servers.

Servers image

Servers

Servers will have reduced camera capacity when using multiple or more recent compression methods within the system. Both H.264 and H.265 compression algorithms require more processing capacity, limiting the functions that the server may be able to perform concurrently.

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Video Servers and Storage
Switches
Contact Anixter

Is your video infrastructure prepared to handle different compression algorithms? Contact an Anixter security expert or your local Anixter sales rep to determine the right solution for your needs.




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