Any organisation running a video surveillance system has to decide how much video footage they will store. This is also commonly referred to as footage retention. Every organisation is different: some need 14 days and others up to 90 days. The most common duration storage by far is 30 days.
You may require fairly immediate recall of the footage because the incidences that they are checking for will be discovered quickly. Or it might take several weeks to discover the criminal action and you may need to store more video for investigators and/or law enforcement authorities to access. Every organisation is different but here are some basics rules for deciding how long you store video surveillance footage:
How long will it take you to know the video is needed? Think about two very different users of video surveillance: the bank and the car dealer. The car yard owner will notice very quickly if there’s been a theft, vandalism or damage to a vehicle. A bank, on the other hand, deals with frauds and identity-related crimes which may take longer to become evident because the crime itself has relied on a deception. Both of these systems need to give ready access to the footage to establish identities and to aid law enforcement in their investigations. But a car dealership may only need to keep two weeks’ worth of footage, while the bank may require storage that hold several months’ of video surveillance files. It’s worth getting this right.
How do you know how much storage is required to meet your needs? The short answer is you need to engage a security system integrator who knows how to design your system and calculate your needs based on your requirements. The calculation is complex and involves a number of factors including number of cameras, frame rates, resolution and compression format. Is there motion detection or analytics? There are tools to assist in determining the required storage, but it also relies on the correct system specification and then system configuration.
Many new video surveillance systems have what is called “fading long term memory”. This means that the frame rate can be reduced as the footage ages. A system may be set up to retain footage that is 1 – 7 days old at 12 frames per second, 7 – 30 days at 6 frames per second, and 30 days plus at say 1 frame per second. This type of set-up is suitable for an organisation where most incidents will be identified in the 1 – 7 day period, take the car yard example.
How much does it cost? It would be nice to live in a perfect world where the more you store, the cheaper it becomes. But it doesn’t really work like that: in order to store 30 days’ worth of continual video surveillance footage, you must invest in the hard drives, the servers and the video management software to manage and file and access the footage. It’s a question of system design and capacity. And the faster you want to retrieve it, the more you’ll have to spend on IT infrastructure. The best approach is to find a good security system integrator and have them tailor a solution.