Mass Media & Technology

How did the Metropolitan Police digitise CCTV in 2005?

RI
Riaz
I might offer a prize to anybody who knows the answer to this question and can confirm it using official sources of information...

How did the Metropolitan Police digitise CCTV footage originating on a VHS tape back in 2005?

Did they use an electronic convertor or did they really point a digital video camera at an analogue monitor?

Despite repeated requests to the Metropolitan Police, they have not been forthcoming with an answer.
DO
dosxuk Yorkshire Look North (Yorkshire)
There's a multitude of methods. Capture cards for computers were widely and cheaply available in 2005.

Why do you ask? This sounds very much like a 'gotcha' type question (as in you know the answer and are trying to catch someone out).
RI
Riaz
Why do you ask? This sounds very much like a 'gotcha' type question (as in you know the answer and are trying to catch someone out).


It is a serious question. I have some CCTV footage and I'm interested in finding out the procedure for digitising it as it contains certain 'strange' features.
DK
DanielK STV Central Reporting Scotland
Riaz posted:
Why do you ask? This sounds very much like a 'gotcha' type question (as in you know the answer and are trying to catch someone out).


It is a serious question. I have some CCTV footage and I'm interested in finding out the procedure for digitising it as it contains certain 'strange' features.

Back in '05 they probably still ran on DVD, so a VHS to DVD convertor then make multiple copies of the DVD?
MW
Mike W London London
Riaz posted:
Why do you ask? This sounds very much like a 'gotcha' type question (as in you know the answer and are trying to catch someone out).


It is a serious question. I have some CCTV footage and I'm interested in finding out the procedure for digitising it as it contains certain 'strange' features.


The police in general had high end computers with capture cards for a variety of media, I’ll try and take a photo of legacy hardware if I get a chance today.

There was also a device with a vhs player and a photo printer on it.

These days with DVRs it’s all digital, even by 2005 most footage was digital. I was once sorting a room with the train and station footage from 7/7 (a full 24 hours worth of hard drives), it may have been the footage back then was recorded to DVR even with analogue cameras.
DO
dosxuk Yorkshire Look North (Yorkshire)
I think you'll be extremely unlikely to find out how your particular tape was digitised 15 years ago, or even if it's been pre or post processed. As I said, there were numerous methods available, probably almost as many as there was methods of recording CCTV onto VHS.
RI
Riaz
This is the CCTV footage



It was released to the public via the Metropolitan Police website on 2 May 2008 as the file terror41-05cctv-7july-luton.wmv but has since been removed and it has not knowingly been archived by any official body or the media.

The blurring of much of the background is deliberate (and has also obscured timestamps) but fast forwards to 3:56 for a clear section (a car park scene).

I have been semi-reliably informed that the CCTV installation at Luton station utilised a Tecton Miniplex multiplexer, which takes several video feeds and overlays the camera number and time stamp, then outputs a video signal to a recording device. The maximum number of camera inputs on a Miniplex is 17.

It is notable that the active area is surrounded by a black border and on the left hand and right hand outer edges are two grey columns. Is this a tell tale sign that an optical method was used then the border of the digitised footage, containing the outline of the cabinet of the CCTV monitor, was cropped in the digital domain?

The original analogue video recording almost certainly had a 4:3 aspect ratio but the aspect ratio in the digital video file is not 4:3 and the width of the active area is squashed. How did the digital video file most likely end up with an incorrect aspect ratio?

The CCTV footage has a vertical serial number 3 10 41071. This is clearest in the car park scenes. It appears to be subsequently added in the digital domain as the CCTV footage exhibits a certain degree of juddering with the camera number and the time date captions moving along with the rest of the image, but the position of the serial number remain fixed. Any ideas what the purpose of this serial number is?
MW
Mike W London London
The footage would have been edited in post production for an inquiry, the master would be intact and secured elsewhere for trial of there was one.

The full previous 24 hours and the 24 hours after were preserved. I can confirm that as I spent 3 days helping with cataloguing each exhibit for archiving. Luton was on a hard drive, as were the on board stuff which was never released, as was the KX Thameslink stuff.

The serial number looks like something put on by Tecton Nucleus, it’s a camera address - often they have this as well as a camera number as some places have more than one camera with the same number.

EDIT: It’s a HOLMES exhibit number, not a camera address.

The footage was collated and edited by British Transport Police’s digital video forensics centre in London, not the Met, and handed over to So13 as they were then for the investigation.
Last edited by Mike W on 3 May 2020 4:57pm
MW
Mike W London London
Also, it has been archived - it’s all been archived, it’s just not been released again and to get it out of the archive as it’s on a HDD would cost more than an FOI £450 limit.
DO
dosxuk Yorkshire Look North (Yorkshire)
Oh not this bloody conspiracy theory again Mad
MW
Mike W London London
One final input from me is these aren’t produced by video experts, often they’re civilians or cops who are trained up.
BA
Bail Moderator Meridian (South) South Today
That'll do methinks.

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