…from outer-space. I just walked in to find you here with that strange look upon your face…

Ah, there’s no song like a disco song!

The strange thing is that it’s almost as if I’ve never been away. It’s weird the way that happens.

For you (dear reader) who may have been wondering, I’m back in fighting form again, having had unspeakable and unthinkable things done to my eye. Much to my relief they were, however, successful, and I can see again enough to start griping about the state of the industry once more.

For reasons that make perfect sense to me (but nobody else) I returned to Ireland to have the necessary surgery performed and to recover. Principally this was because there was nobody to feel sorry for me here in Dubai, so I went home to be “looked after”. As a result, I am somewhat rounder than I was when I left, but we’ll gloss over that little point quite rapidly.

I’d hoped (because I’m always hopeful) that during recovery I’d be able to catch up on a number of work related projects that I’ve been unable to keep in my sights (no pun intended) for the last while. As it was, I couldn’t see anything for much of the time, or suffered from weird headaches when using the PC, so all my hopes came to very little, but I did manage to visit Ireland’s premiere security exhibition whilst there, to make sure that the industry was ticking along without me.

It may be…but not at the ISEC. The downturn was much in evidence – I’d have to say – with the country’s main distributors entirely absent from the show (and apologies to REW and Scott & O’Shea if you think I’m being harsh, but I do reckon Borsatec turn over more than you guys annually, so that’s who I’m talking about).

I was met with the blurred vision of a *horde* of Garda recruits fresh from Templemore leaving the venue as I went in. I say a *horde* because I can’t think of a better word. It looked like an outing from St Trinians (if the aforementioned educational establishment had begun accepting both boys and girls), with the accompanying bottles of red lemonade and bags of Tayto much in evidence (apologies to those of you who are not familiar with the staple diet of the culturally significant TJ and TJ, but it’s an Irish thing…and Irish police thing…).

Besides the fact that it was bitterly cold for the whole time I was in Ireland, I was also reminded where I was by the frequency of reported murders and shootings on the local news, and stories of Bernard McNamara and the varying number of armed bodyguards he currently employs to stave off the ever lengthening brigade of creditors currently baying for his blood (Polish mafia included, or so the potentially urban style myth informs me).

At least I was home for Paddy’s Day, and a decent pint…the doctor didn’t mention that I couldn’t drink, so I assumed that I’d be fine so long as I didn’t pour Guinness in my eye…

Bizarrely, there was an apparant gang-land assasination here in Dubai last night – but I suspect this is some strange space-time continuum effect resulting from my return, because it’s raining here too. So I’m assuming that the weather and the mob shootings have somehow temporarily followed me.

I have to mention the lightening here. It’s been quite amazing.

A couple of things that struck me from the Irish ISEC show while I’m thinking of them :

- there was a lot of IP video there. A lot more than usual, which is odd given the current environment, and I’m surprised there weren’t people there promoting alternative analogue solutions
- the visitor numbers seemed low, but there were a lot of small installers’ vans in the car park from outside of Dublin (I don’t think I saw a single 2009 registered vehicle, come to think of it, which is significantly unusual)
- bad planning from the Mobotix dealers. I know it was a small show, but they were pitched opposite one another showing the same cameras. Oops.
- Simmons Voss exhibiting their locking technology which I like. I got a flyer in the post from one of the Dublin locksmiths promoting it while I was home and saw another similar (though not very convincing) technology from another US supplier I’d never heard of. A real shame Abloy couldn’t get their Cliq technology to *really* work, because I think this is a very interesting opportunity area
- Saw a nice ANPR camera from ICRealTime embedded in a speedbump. Nice idea. I wonder how resilient it is? They had a lot of other flashy looking cameras on show, but they all felt flimsy I’m afraid
- Lots of training and certification bodies in evidence but no symbolic anti-PSA showing as I thought there could be, given the amount of actual PSA resentment there’s been in the press and on the web lately
- Interestingly, (but probably not entirely unexpectedly) the hot topics in Dubai are not the same hot topics in Dublin. Nobody making any fuss about IT/Security convergence, combined physical/logical access control. No significant biometric showing either. Like I say, this probably isn’t much of a surprise but I think it’s interesting that the show is beginning to take notice of the real world, because I’m fairly sure that you wouldn’t have a hope of selling those technologies in Dublin (in previous years I’ve seen plenty at the show that also wouldn’t sell in Dublin, but people still wasted their time and money presenting it).

So anyway, that’s about it for now. I’m really just getting my feet back under the table, and there’s a lot of stuff *on* the table that needs sorting out, but I’m really glad to be back, and looking forward to getting my teeth into it all again.

Calculating how much storage you need in your recording system is real easy – take the size of a frame, multiply it by the number of frames per second you’re recording at and the number of channels of video you’re recording, then just multiply that up by the seconds, minutes, hours and days you want to keep the footage for. Easy…

…or maybe not so easy.

Okay, so we know it’s maybe not *quite* that easy, but even so, I’m generally bemused by why people don’t do the basic math when they’re designing a system to work out how much storage they *could* need.

It particularly amazes me when I see specifications come from clients or consultants, and they say something like “…and the digital video recorder shall be provided with 500GB of hard disk drive providing 30 days of internal storage…”, and then I flick backwards and forwards through the pages and can’t find anywhere that tells me what frame rate, what resolution, what video quality, what compression algorithm or whether they’ll tolerate event/motion driven recording or continuous recording.

Inevitably the client gets his 500GB drive and he gets his 30 days of storage, but everything else is up for grabs.

I remember reading somewhere about a company that had built in the ability to degrade stored image quality over time in order to cram more data onto the disk. This came up again the other day over on www.ipvideomarket.info and I have to say again what a terrible idea I think this is. You (the system installer) have no control over which video is valuable and which is not, and the value of the video can change with time and circumstances – also beyond your control. When I consider the various murder investigations we’ve been involved in throughout Ireland over the past years, I remember a significant number where footage relating to the crime was not recovered until perhaps two weeks after the event. I can imagine the conversation we’d be having with the police (on behalf of the murder victim’s family) to explain why they can’t get an ID on a fuzzy-looking suspect because we “threw away” the resolution.

Dropping frames isn’t quite so bad, but it’s still impossible for the DVR to tell which frames are the useful ones and which aren’t if they’ve all got motion in them. I could maybe live with some sort of prioritisation scheme that defined areas of most interest and threw away less interesting frames after a while…but that’s still a risky thing to do.

All of these techniques are really just *tricks* to help one installer undercut the price of another installer with smoke and mirrors by cutting down the size of the drives. It’s no benefit to the client at all apart from maybe just getting a marginally lower price.

There’s nothing wrong with being inventive when it comes to compression as long as what comes out the end remains usable for the intended purpose. So by all means use H.264 if the jurisdiction you’re in doesn’t have a problem with the evidentiary quality of the video (some people only want to see M-JPEG for evidence because it’s effectively a sequence of stills rather than what the barristers might describe as “the concocted imaginings of some electronic contraption that bear absolutely no relationship to the events at the exact moment my client is alleged to have been at the scene”).

Motion based recording is a risk. I’ve seen so many issues where the storage calculations have been made for a site to get 30 days recording with – say – 30% motion, then a spider decides to set up house across the front of the camera housing, and suddenly you’ve actually got 100% motion – or the engineer sets up a motion mask to cut out passing traffic, and the next day it rains, so suddenly the camera can see car headlights reflected off what used to be a nice empty black asphalt car park.

I’m not aware of cases where anyone has maliciously caused motion in front of cameras in order to eat up storage and thereby destroy video evidence, but I wouldn’t rule the possibility out.

On some of our large sites where the impact of a small percentage of cameras generating too much footage can be quite significant, we’re having to factor in the time of an engineer connecting to site remotely maybe once a week just to check for *hungry* cameras, often then adjusting motion masks to account for seasonal changes. This is in addition to the continual preventative maintenance that keeps the cameras clean and insect-free.

We used a few machines from a company called ICRealTime a while ago. They make life extremely simple by basically just selling machines that record live, full resolution for one month. Period. No frame rate settings, no video quality adjustments and no motion masks. So, that’s the end of problems with spiders and rain. They were nice easy machines to use too, I don’t think we had problems with them in the field and they recorded at 4CIF unlike a lot of similarly priced middle-of-the-road embedded machines for about the same price that were 2CIF or worse.

Really, you want to be as pessimistic as possible when you’re doing the storage calcs, but when you’re price constrained that can be a problem – and on big systems with big RAID arrays a 10-20% reduction in storage converts into big money.

Interestingly, every halving of frame rate halves the amount of storage you need at the same quality. But the *significance* of that halving in frame rate isn’t a linear thing. The difference between 25 and 12.5fps (PAL) is huge, whereas the difference between 2 and 1fps is negligible, really. So rather than *guessing* your activity levels (and getting it wrong because a spider gets in the way), why not just reduce the frame rate (if you can) and record continually instead of on motion?