Thursday, September 28, 2006

Scripting, scripting everywhere!

In the light of the vector graphics vulnerability in IE6/Outlook and all the other nasties that can arrive into your PC via scripting I've been running NoScript under Firefox - It is excellent - by default it stops any active (i.e. Java, Javascript, Activescript, AJAX etc) content from executing in your browser. You then have the choice of white-listing a site or only temporarily allowing it. Most sites look broken when you first enter them, but I take the view that I'd rather choose who I allow scripting for. Your also never quite sure if a site has a load of iFrames back to dodgy sites and then there are all the add banners to consider. Have a look at this site - they clearly refer to MANY other sites with active content!
Now I have just one bit of Javascript on this blog - it allows you to launch the webcams in a buttonless window - but if you have scripting turned off it merely launches in a new browser window.

Friday, September 22, 2006

Vulnerability in Vector Markup Language Could Allow Remote Code Execution

Even if you have a fully patched XP/SP2/IE6 machine you are vulnerable to this exploit that uses a bug in Microsoft's vector graphic rendering engine - apparently Ad and warez sites are seizing on this bug exponentially and all it needs is for you to visit a site (or have an email show itself in the Outlook preview pane) that has one of these specially crafted images for you to get infected.

As ever, the fewer bits of nonesense in your browser the better, so de-register the faulty DLL for a worry-free life!

regsvr32 -u "%CommonProgramFiles%\Microsoft Shared\VGX\vgx.dll

The more I think about it the less likely it is that you're reading this with IE - tech savy people use Firefox!

Have I mentioned noScript?

Wednesday, September 20, 2006

Enigma lecture at the IET

Last night I went to a superb lecture at my institute on the German Enigma machine and how they went about cracking it's encrypted messages at Bletchley Park. Dr Mark Baldwin - the lecturer - had brought along his working four-rota machine and gave a demo. The quality of construction was excellent with that sixty year old example still working perfectly. Although I had a vague idea of how it worked he explained in great details the mechanical and wiring details. Having recently re-listened to Steve Gibson's excellent encryption series on Security Now! (episodes 30 to 37) I now see that the Enigma was a good example of how to do encryption. The Germans avoided security by obscurity - the allies had many working Enigmas and had figured out the wiring of all the rota sets before the war even started. The power of he system is in the size of the key-space and it was sloppy practises that allowed the allies to crack the system. Repeated use of sweetheart's names etc. as well as non-random sequences of keys allowed the size of the key-space to be radically reduced and in a symmetric stream cypher these are bad ideas!
Dr Mark Baldwin's Enigma site is here.

Tuesday, September 19, 2006

Rowan and Sophie in Nova Scotia

Our good friends Rowan and Sophie are working in Canada for the next three months - Sophie is a lawyer and Rowan is a database guy for the treasury and this picture is from when they got married a couple of years ago (Sophie looking like the young Audrey Hepburn, I think you'll agree).

Anyhow - they are on a working holiday, check out their blog as the scenery looks stunning and I would love to be spinning llama wool rather than what I'm doing today!

Friday, September 15, 2006

HD at the 1992 Barcelona Olympics

A while ago I remembered the first HD job I was involved with in 1994 - I came across this interesting PDF showing that there was full HD coverage of the 1992 games and even delivery to many (possible!) viewers using the HD-Mac transmission standard. I did monkey around with C/D/D2 Mac at the time and was amazed when I read the spec for HDMac - it allowed up to 1250 line signals that could be switched on the fly - frame to frame - so that when a 720 line (for example) fifty-fields interlaced sports programme went to the slow-mo it could up-res to >2k but at a lower frame rate (typ. 12.5 fps).
But, the really clever feature was that this was all compatible with the SD standard D2 Mac signal (the one which the origional BSB system used before Sky bought them out and reverted all broadcasts to PAL). So a broadcaster could send the 36Mhz signal at whatever resolution/framerate he wanted and be assured that all viewers could watch it. The page on Wikipedia is a good starting point.

Thursday, September 14, 2006

It's happened to me!

Sunday, September 10, 2006

IBA Tech Report from 1970

After writing about the new Tek WFM7100 last Friday I came across this brilliant document - it is the Chief Engineer's report to the IBA board and contains lots of info about the state of broadcast technology thirty-five years ago. There is a description of how they were upgrading the ITV network for colour and how the use of twin-lense telecines were taking off - Mk.1 Cintels I'm assuming - the Mk.2 was either a jump-scan or "digi-scan" depending on vintage (we had a few of those in TV news at the Beeb - I was quite a dab-hand at repairing the memory boards). Automated measurement using Vax PDP-series mini-computers is examined as well and serves as another parallel with the Tek. This picture shows how they did screen-grabs back then - using a polaroid camera mount!
Anyhow - give it a read - I was gratified to see how much of it tied in with what I learnt at BBC Evesham in the late eighties. It is a big 12-meg PDF but worth the download.

Saturday, September 09, 2006

Gilbert's Fridge

When I first started at the Beeb in the late eighties there was a superb kids TV show called Gilbert's Fridge - Gilbert was an alien who (for no explained reason) was a South London car dealer. He was voiced by Phil Cornwall who has gone on to much bigger things. Although it was a children's programme all the BBC engineers I worked with thought it was superb and there were always VHS copies floating around the workshop. Imagine my delight when I found the complete series on UK Nova - here is a two minute DivX clip so you can see for yourself.

It's also on YouTube.

Friday, September 08, 2006

Tektronix WFM7100

I've just my hands our new Tek WFM7100 demo unit and after one quick firmware update (to v. 1.23, fact fans!) I've been monkeying about with it ('cause I'll be demo'ing it post IBC). First thoughts are that it's very sluggish - screen update on waveforms is fine but navigation is slow. It feels like i's running on top of something (Windows Embedded?!) and that seems to be born out by the fact that when you hit it over the Java interface the menu on the front panel screen remains with the last selection you made and the remote display changes as per selections you make on the browser - almost like a remote desktop.
Anyhow - feature wise it is pretty much a WVR7100 with some nice extras. The biggest step is the screen grab facilities. In the same way that video or audio 'events' (gamut, level etc.) can be placed in the log, close the GPI, honk an SNMP alarm or just indicate on the front panel you can now have an error condition dump a screen-grab to a USB thumb drive. Now you can imagine exporting the XML log with still-frames of the offending video - excellent for monitoring the state of a cable head-end (for example). Another addition is having a picture o/p SVGA as well as the instrement's display out. We often install the WVR series rasterisers into machines rooms and DA the feed to several places (including for the operator in the machine area) - but since this has a built-in insterment display it would be advantageous to have just the picture (on a 15¨ TFT panel) thus avoiding the cost of an HD monitor.
Unlike glass-tubed traditional 'scopes (and even some other rasterised models - specifically the Videoteks) the 7100 generates the graticules in the same digital space where the HD/SDi stream is demultiplex'ed - the upshot of this is that they are ultimately accurate - something no other 'scope can lay claim to (unless they've just been calibrated!). Having spent time doing a head-to-head with the other manufacturers (Videotek, Omnitek and Hamlet) I conclude that the only reason folks don't buy Tek is the price. In terms of accuracy, ease of use and feature set the Tectonix are way out in front. Their automated QC features are pretty impressive and make delivery reports very easy to prepare.

Wednesday, September 06, 2006

The comma is on its way out....

Wired is a fashion magazine for people who like to imagine they know something about technology. Every five years or so I read it and my prejudices have always been confirmed! It appeals to people who have money to buy-into a digital lifesyle (sic.) but have little understanding of any underlying IT.
Anyhow - in this month's issue I spotted this Nathan Barley style quote:
Commas are a kind of channel noise. You’re not getting to the verb fast enough. Why make us wait? The comma is on its way out. Use small words.
- Bart Kosko, Polymath (apparently).

Tuesday, September 05, 2006

Friday, September 01, 2006

Nobody's Cool

It's a bit emo for my tastes, but this tune has been running around my head since I saw one of the students at my eldest boy's school do this at their last music evening.
nobody's cool, we're all the same, you're not a player, life's not a game
don't you think it's time we left high school behind
you're not a stud, you're not the man, you're not a pimp, and i'm not a fan
your misogyny is just a plea for l-u-v

the only thing i've seen that's cool in my life is a mom who loves her child and a man who loves his wife

your two tattoos don't make you tough, please quit the act i've seen enough
you say you're different but you all end up the same
just be yourself, don't fake the geek, don't say you're random or a freak
dude you're not punk rock, we're all just human beings

the only thing i've seen that's cool in my life is a dad who loves his kids and a man loved by his wife

nobody's cool, put down your nose, i don't care where you bought your clothes
can't you see it's time we left high school behind
cause it's plain to see we're all just human beings