How many hours worth of surveillance will a Mpeg4 Digital Video Recorder with a 250GB hard drive hold?

Question

I am purchasing a CCTV system for work. Awaiting answers to my inquireies made directly to various company sales reps. In the mean time I would like to see what those of you experienced with CCTV can tell me. I have seen systems with hard drives smaller than the one I am looking at claim to hold 3 weeks worth of 24/7 video. I do not know what kind of resolution this would be at. Basically I am wondering if a 250GB hard drive will give me adequate resolution (for identifying faces from under 10 feet) and at the same time, a few weeks worth of storage before I have to write over the drive, or back up the video on cdrom. Come on Holsbrook..what ya got for me? :)

Answer 1

Another issue is what standard of evidence you need - does it need to stand up in court or do you just need enough to convince someone you know what they're up to?  A lot of CCTV systems in the UK aren't good enough to be used in court.  If you're in the UK, make sure you understand the Data Protection Act - it applies to video surveillance systems.

Answer 2

This is kind of hard to answer because there are a lot of factors like frame rate, number of cameras, compression codec, resolution, continuous record vs. motion record, etc.

I've only worked with professional systems and we needed several terrabytes of mass storage for a 10-14 day lookback, but that was also with 16 cameras.

Answer 3

go to www.techcctv.com or give them a call they can help

Answer 4

This website has a good guide on information that you may require. From what I can see you would only be able to record at about 3 or 4 fps at 640x480 with high sharpness for about 4 weeks.

http://www.boundlesssecurity.com/storage...

Answer 5

All of the other posters ahead of me are correct. My practical experience:

The security DVR in my home system is set to take a still every 4 seconds. There are four cameras pointed at different places. The DVR has a 200 gig drive (and can use up to 250 gig, I just did not get it at the time). The DVR has a feature that can detect motion in the camcorder's visual field - and you can specify the motion detection area. When motion is detected in the specified area, the DVR starts recording that camera's video feed at real-time. All four cameras can be recording in real-time simultaneously.

Admittedly, the areas covered are not that busy, so the 200 gig typically takes a little over 30 days to fill. Then, it is first-in/first out over-writing. The image resolution of the cameras will be just as important as the compression employed by the image storage firmware in the DVR... but at 10 feet, you should have little trouble identifying faces... this presumes a good angle on the camera (closer to horizontal is best).

http://shop2.outpost.com/product/5080315...

(I use.)

http://shop2.outpost.com/product/5315908...

(I use, but am planning to replace.)

http://shop2.outpost.com/product/5080295...

(I am planning to get.)

Other considerations:

1) You might not need night vision.

2) CAT5 twisted pair cable works great - COAX for runs under 100 feet or not near fluorescent lighting or AC power is not necessary.

3) Get a good sized battery back-up. If there is a power outage, don't leave your system without power. You can use a big UPS that would normally power a computer for power back-up. Provide power to the cameras and the DVR - and at least one flat-screen monitor.

4) Secure - as in BIG BOLTS and strong straps - the DVR to something or have it in a locked (strong), well ventilated place (shelf, rack, whatever). Best to hide it. It would be a bummer to go through all this only to have the bad people just take the DVR (and hence, your evidence).

5) Consider having a small flatpanel monitor visible to show you really have a video surveillance system - and put "Alert" signs up, too. This *could* be a different system - so that bad people just figure out where the video cams cannot see and do bad stuff there... The "other system" would cover THOSE areas.