Posts Tagged ‘Video Storage’

Hard Disc Drive Storage for CCTV Surveillance

Saturday, January 10th, 2009

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Veracity mentioned this article on their website in an email I received recently; it’s a good write-up on the use of hard disc drives in modern CCTV video storage. The article isn’t new but it provides a lot of useful information and we think it’s worth pointing it out to you:

The most obvious current trend in video surveillance is the slow evolution from analogue cameras to IP cameras. Industry vendors of recording systems appear to be divided into two camps : the sceptics, who are wondering when the IP video revolution is really going to take hold, and the informed, who know it is already here and are just getting on with it.

Although the IP video segment of the UK market is currently only around 15%, it is growing rapidly. In Europe, where analogue CCTV cameras are not so entrenched, the growth rate is even steeper.

One of the things that has held back IP video systems up to now is the lack of any real reason for users to switch, even for new installs. What would they have gained, bar a little increased flexibility ? Now, in 2007, the story is quite different : most well-designed IP cameras are progressive scan, at long last leaving behind the problematic interlaced image legacy of the broadcast TV standard. Further, and more importantly, mega-pixel cameras (with resolutions way beyond HD TV) are now here and affordable. At long last, mega-pixel cameras provide the compelling reason to switch to IP-based systems. The improvement in image quality offered by high-quality mega-pixel cameras in nothing short of dramatic, even breathtaking. Another problem which has held back adoption of IP cameras is the vast amount of legacy co-axial cabling installed in existing systems. However, several vendors are now offering Ethernet over-coax solutions, so this is no longer a barrier at all.

Well worth a read, to aid your understanding of the use of big HDDs, RAID storage and potentially high disk failure rates.

Gigabytes & Terabytes (and even Petabytes)

Monday, November 24th, 2008

Gigabytes is a term that we have all become familiar with, as the Hard Disc Drives (HDDs) in most Personal Computers (PCs) are now typically sized in the Gigabyte range.

A reasonably modern PC is likely to be supplied with a 250 or 500GB hard drive. A disc of such capacity is likely to be more than adequate for most standard PC usage.

Back in the days when Digital Video Recorders (DVRs) were a new technology the first units were typically supplied with a 40GB hard disc, that being the largest single drive capacity available at the time.

As with all things technological HDD sizes have developed greatly, and it is now quite simple to purchase a single HDD with a capacity of 1.5 Terabytes!

What’s a Terabyte? One Terabyte is equivalent to one thousand Gigabytes.

Therefore 1.5 TB = 1,500GB!

That’s a heck of a lot of storage capacity on a single drive.

Why do we need all of this capacity for IP CCTV recording solutions? If you are familiar with taking and manipulating digital still photographs you’ll be aware that a single high quality image file may be 1MB (MegaByte) in size. Bear in mind that with a network camera CCTV solution we will effectively be capturing many such images every second, from every camera, and you’ll begin to understand that we can very soon accumulate GigaBytes of storage.

The amount of storage available directly dictates how much video we can store. We can regulate this by either adjusting the file size of the images (using some form of video compression) or by adjusting the number of images per secnd that we capture (the frame rate or fps – frames per second).

The really big IP CCTV camera solutions (see our IP CCTV Facts page) are now using PetaBytes of storage.

  • 1 GigaByte = 1,000 MegaBytes (106)
  • 1 TeraByte = 1,000 GigaBytes (109)
  • 1 PetaByte (1015) = 1,000 TeraBytes (1012)
  • 1PB = 1,000,000,000,000,000 Bytes – that’s a lot of image storage!!!!