HD cameras have the same lens requirements as discussed earlier, but the bandwidth and storage consumption is more reasonable than that of their megapixel brethren. The megapixel camera discussed earlier had an average bit rate of between 40 and 56Mb/s. A HD camera using H.264 compression running at 30fps would have an average bit rate of between 5 and 10 Mb/s depending on the scene. The storage consumption is higher than standard definition cameras but is about one-third of the megapixel cameras. Plus, the HD cameras will look good on your 60-inch plasma in the operations center.
The number one problem I've seen over the years with video surveillance systems is a lack of recorded video for one reason or another. Anything from time synchronization to network outages can affect your system.
Several years ago, I went on a service call to pull video evidence from a location where a murder had taken place. Upon arrival, I found that the video system in question had not recorded a frame of video in more than four months due to internal hard drive failures. That means no one had looked at or checked the video system in more than four months.
Video systems are 24/7 systems that are continuously writing massive amounts of data, and they need periodic system checks. Checks on a weekly basis should include:
- Live playback: Check video feeds, camera power, and network status if working with IP cameras
- Short-term playback: Check the functionality of network video recorders, DVRs, or iSCSI recording services
- Long-term playback: Check the functionality of any DAS SCSI or NAS iSCSI subsystems to ensure retention time requirements are being met.
"I need all the video from this incident in the next hour." It's a request you might hear on the CSI: Crime Scene Investigation television show, and this should be a reasonable request when dealing with small events in a specific period. Post motion detection has been a common feature in video surveillance systems for years, and with video content analysis readily available in better systems, searching metadata after the fact is now a reality if the features are enabled beforehand.
Misconceptions create problems when you are dealing with large systems and looking for the needle in the haystack. In 2001, I worked for a manufacturer that at the time had its CCTV system in the Washington Dulles International Airport and the Pentagon. After the 9/11 attacks, I was part of a team that had the laborious task of reviewing all the video from the airport with several federal agents looking over our shoulders. Did you notice I said all the video? That's every frame from over 300 cameras with 30 days of retention time. The task took three weeks of 15-hour days.
So, what is the answer?
Education, education, education. Educating your customers goes a long way, and an educated customer will likely settle on a nice blend of standard definition and high definition cameras with a sprinkling of megapixel where needed, as long as it suits their storage budget and gets the job done the right way. Educating your customer on proper system checks assists law enforcement with the ability to retrieve video when there is an incident.
The Federal Bureau of Investigation (FBI) has been leading the charge with an educational campaign that it put in place several years ago. In 2010, it released a training video, "FBI: Caught on Camera," which can be viewed on the FBI's website. This video covers camera placement, compression and native formats, among other topics. Don't hesitate to share this with your customers.
And, remember, a nonfunctional or poorly configured video surveillance system is as useful as no system at all. It won't help anyone, not even Criminal Minds' tech-whiz Penelope Garcia.
About the author: David Brent is a technical information engineer for IT systems at Bosch Security Systems, Inc. He has extensive knowledge of video surveillance systems and holds a number of IT and networking certifications. He can be reached at firstname.lastname@example.org.