Member Discussion

Does IPVM Have A Storage Calculator? What Calculator Should I Use?


Have you considered creating a storage calculator that would use the specific camera model, retention time, resolution, codec, FPS, and bitrate to determine storage requirements? I am guessing there are slight differences in the VMS used as well on storage size?

Follow up question.... Is there already a calculator available that users on this site have found to be accurate and has the ability to a wide variety of camera models?

Good question.

We do not have a storage calculator because we believe providing accurate numbers (even as close as + or - 30%) is generally infeasible.

There is definitely differences in bandwidth across models. That's something that is rarely taken into account.

The bigger, impossible to solve, problem are differences across scenes, even for the same model. Even something as simple as zooming a camera in or out can double (or half) the bandwidth needed depending on what is being captured. See Advanced Camera Bandwidth Test Results for many examples of this.

Essentially, there's no abstract way to accurately determine the bitrate of a camera. Knowing the model and the general scene definitely helps but there's still real risk.

There's no storage calculator that I have seen that attempts this across multiple manufacturers. Axis does the best for their own cameras only (obviously) - see the Axis Design Tool.

In general, I recommend measuring the bit rate of your own cameras in your scenes. This takes some time but will provide far better results.

For more, see: How to Calculate Surveillance Storage / Bandwidth

Also, to get a feel about how vendor's trick / game this, see: Guaranteed Video Storage Calculation? Iomnis

Thanks for the detailed response John. Storage is an area in our industry where there is an element of art and science. I would agree that the calculators I've used in the past aren't any more accurate than +- 30%.

H.264 compression is so highly variable all of these calculation tools measure up to little more than 10% math, 20% gut feelings, and 70% wild guess. Any tool anyone generates is basically the dowsing rod of bandwidth/storage calculation. A given tool will give you different results than any other tool. I recommend finding one you feel is accurate, add some percentage of padding to it, and go from there. The manufacturers specific tool (e.g. Axis if using Axis cameras) is the best place to start.

"Any tool anyone generates is basically the dowsing rod of bandwidth/storage calculation."

That's funny...

Again, I recommend doing quick tests of the actual cameras in the actual places you plan to use them. It will radically increase the accuracy of one's calculations. Our Portable Power for Video Surveillance note explains ways to do this easily.

I agree, that's really the only mostly accurate way to do it. My point was just that I would take any calculation tools, even the ones Axis makes, with a grain of salt. Even they declare right in their training that the bad tradeoffs of H.264 or MPEG4 compression are difficulty estimating bandwidth utilization and processor utilization. Processor utilization is easier for us to test with Axis Virtual Camera.