Monday, April 30, 2007

UVW Series Error Codes

Always getting asked these - and I can never remember them as well as I could those for the BVW-75P

Wednesday, April 25, 2007

Optical link hacking

I saw this article on The Register and thought it was worth commenting on. Basically they've found that you can bend a fibre and get enough signal out of the bend to reconstruct the data stream. I can only imagine that this has been tried on mono-mode cable only (mono-mode transceivers are a lot more robust when it comes to dB loss). If you've ever ended-off a fibre you know how fragile the glass is - having to open up a loose-tube cable, scrape off the coloured ident paint, attach an optical coupler and bend the fibre just enough to get leakage but not have it break would be a real feat! I know in military applications they de-tune the sender to the point where the receiver has less than 3dBs of tolerance - any mucking about with the cable makes the link fall over and an engineer investigates. That's why the MOD ban UDP traffic on their fibre networks - they know the 3-way TCP handshake requires a link that hasn't been interfered with.
I started thinking about whether you could try this with multi-mode fibre - it's a lot thicker (62.5 microns as opposed to typ. 9 microns) and so physically is a lot easier to manipulate. However, after spending last weekend measuring the response of multi-mode cables that had been only mildly abused I realised that where you can tolerate 10dBs of loss on a mono-mode fibre (even at 10 gigabits per sec) you rapidly run into trouble at even half that data-rate with multi-mode fibre.
So I think I'll consign this story to the category of you might be able to do it in the lab but the practicalities are too troublesome.

Sunday, April 22, 2007

How things change

I was working over the weekend at a facility that has a fibre infrastructure that looks like it was done by people who lack opposable thumbs! They want an assessment of how easy it will be for them to move up to a four gig Avid Unity. Anyhow - while there I spotted this BKSTS poster about film formats - I was tickled by the how assured the authors were of film's future as an origination format.
Film is the ideal origination format for HDTV

Which I suppose was true up to a couple of years ago if resolution was your only concern - film has poor motion rendition compared to video but it does have more detail.
The day before I was having a coffee with my good chum Dan Sassen - chief engineer at Envy. He told me an interesting thing - apparently Arri UK have just taken delivery of seven extra D20 digital cameras to service the requirements of the European film production community - they now have fourteen of those cameras for hire. Fantastic you might think - digital cinematography takes another leap forward - clearly the demand to shoot at 4k has doubled in the last year or so. However - compare this to the number of pre-orders for the Red camera - 11,000 (in case you were wondering!) and I think film as an acquisition medium will die even quicker than I thought.
It seems HD is the ideal acquisition format for film!

Friday, April 20, 2007

Real Alternative

I love the BBC listen again feature on all their radio websites.

I hate Real Player in it's various incarnations.

This is the solution - and it works!

Thursday, April 19, 2007

Clarke on Channel 9

Dr Sneath visits James Clarke, one of the program managers on the Expression team to see an amazing end-to-end demo that shows the power of Expression Media Encoder and Silverlight working together.

I used to work with him!

Wednesday, April 18, 2007

Burn-in on Sony LMD-230 series HD TFT monitor

It's not a great image (and I had to crank down the gamma to get it even visible) but what you can see here is the residual burn-in of colour bars on a Sony LMD-232 high-definition monitor. I would not have believed it until I saw it at the facility I was working at today. This monitor is two years old and I don't know if this kind of distortion is correctable. It must be the TFT panel itself - there is no way the backlight could take on the effect of bars. You can just see a yellow bar (where the blue bar would be) and where the green-magenta transition is you can see a magenta-green line. I do remember Martin Euredjian from eCinema Systems telling me that if you switch liquid crystal faster than the 15mS recommended by the manufacturer you run into trouble - the transistors become lazy and loose the ability to switch back entirely. This looks like what I saw on this Sony display.
While on the subject I thought I quote Martin on another of his TFT pet hates - grey-grey response times for monitors;
...this brings me to a topic that is being greatly abused by several monitor (and panel) manufacturers. To clarify, "monitor" means a finished product that an end user would purchase. In contrast to this, "panel" means the raw LCD element use by monitor manufacturers in fabricating their product.
This business of pixel response time has to do with how quickly the pixel is able to fully turn on (white) and then off (black).
If you were clicking out Morse code with a flashlight, you couldn't go any faster than the time it took for the light bulb to go from full off to full on and then full off again. For example, an LED flashlight can do this significantly faster than a conventional filament bulb flashlight.
In the context of LCDs, the only response time number that is of any relevance to film/video applications is a measurement taken from black to black. In other words, start with a black display and flash it to full white, returning to black. This is the only number you want a display manufacturer to quote you for response time.
Marketing guys have been known to bend things --a lot sometimes-- and so, it should come as no surprise that some are quoting response times that are simply not achievable within today's constraints. The latest one I heard during NAB is 6 milliseconds. I had people coming to the booth saying "how come yours couldn't do 6 milliseconds, "x" are saying that theirs do".
The critical question here was "Is it from black to black?". When asked, the answer was a resounding "no". People are taking measurements from some level of grey to another level of grey and quoting this as the display response time. You might as well be quoting the time it takes the average person to sneeze, because it would be just as irrelevant. Be aware of this and don't fall prey to contrived marketing.
Best-of-class response time today is somewhere around 15 milliseconds for all LCD's manufactured anywhere in the world. Why? Because there is only ONE liquid crystal fluid manufacturer that supplies fluid to the makers of ALL the good panels. The response time is largely a function of what the fluid can do. Today, the fastest fluid available can do about 15 milliseconds. Remember that and smile as a sales guy quotes you 2 millisecond response time. It might happen.

If you're interested you can read some of the other things he has to say on the cinematography mailing list.
If you're new to TFT displays for television and want a very good overview of how they work check out

Tuesday, April 17, 2007

Bye bye Windows server, hello Linux!

Just a quick post to say that the Windows server (that has required a lot of maintenance AFAIC) that has sat in the cupboard under my stairs for the last six years has been pensioned off and from now on this blog (as well as several other sites I look after) will be hosted on my little embedded Linux box (running a 2.4 kernal compile of BusyBox).
It was a relatively painless switch-over with only one site falling foul of a path that contained upper-case letters that I didn't notice.
Now I can hold my head up in the company of other geeks!

Sunday, April 15, 2007

My standard recruitment questions for engineers

A DigiBeta machine has an 8-Field lock switch – why is this an anomaly on such a VTR and what does the switch do?

This question would really sort out the sheep from the goats! This shows if they know anything about PAL and how VTRs lock their servos. If they can give a credible explanation that uses the phrase “vertical interval sub-carrier (VISC)” and they appreciate that the VTR can re-encode the PAL o/p with the same phase of sub-carrier that was used to decode it then give them the job there and then!

0dBu = 4PPM = -18dBfs

What do these expressions mean and why is this equation significant?

Do they know anything about audio measurements and how analogue and digital levels relate? If they can explain the terms dBu and dBfs then all the better.
What is the significance of balanced audio and why shouldn’t you plug unbalanced equipment into a balanced distribution?

Kind of important – if they mention “common mode rejection” in relation to balanced audio hire them! If they don’t know about the risks of unbalancing a whole facility then worry!

Hub, Switch, Router.

What are the differences and similarities between these gadgets? How would you use each?

The whole world runs on packet switched networks – do they know anything about it?

A line-drive amplifier has a gain of 20dBs on zero level – how big a power supply would such an amp need?

Do they know that 0dBu is 0.773v? Do they know that 20dBs is approx a ten-fold increase in power? If they can do the calculation don’t let them escape!
What is the significance of technical and domestic (“cooking”) mains – why shouldn’t equipment powered by one distribution be connected to equipment powered by the other?

Do they appreciate earth distribution and the danger of putting mains hum over every feed in a facility?

On a Unity server what is the difference between ‘Allocation Groups’ and ‘Workspaces’?

Any Unity configuring experience (or more importantly have they taken an interest in an installation they may have had to look after?)
What is a Media Database and why would you ‘trash’ it. What other things might you ‘trash’?

Have they had to provide tech support to editors?

Wednesday, April 11, 2007

Good to see....

...that this venerable blog is blocked in China! Thanks to Kev for alerting me to this - you can check to see if your website is considered too subversive for Chinese people to read.

Tuesday, April 10, 2007

Overpriced Apple stuff & unreliability

Wow - lovely bank holiday weekend but things went wrong! The battery on my MacBook died (just vanished - not seen under Vista or OS-X) - and guess what, a trip to the Apple Store revealed that it will take 'till Friday for a genius to see me (they drink the Kool Aid!) - in the meantime it's just shy of a hundred quid for a replacement battery. On the subject of the Genius Bar - How can someone in their mid-twenties be an expert in anything? Anyhow - I seemed to remember it being the same price for a replacement DC power supply. In fact, looking around I saw an Apple branded rucksack for a hundred quid, the cheapest iPod, and Joe found a set of headphones for (yes!), a ton. The Apple Store is like the Pound Store for wealthy people; ¨yes, ladies and gents, everything a hundred pounds (or multiples thereof)¨.
Also - my Belkin Skype handset stopped working and the good folks at Broadband Buyer did the usual reseller step-backwards and refused to be of any help further than giving me Belkin US's tech support number.
Then, after tidying out one of our attics and putting down a rug etc. so the kids can do Warhammer up there I fell out of the loft! I need a hot bath....

Monday, April 09, 2007

Growing up an army brat

I grew up on military bases and in embassies and there were a few things that I thought were normal - chocolate from army composite ration packs which was just a slab of dairy milk with the NATO stock number on it. One other thing was that my Dad (who'd done the MI6 photography training) would often borrow a work OM1 and snap family pictures and then they'd get processed in the embassy lab. So, here is a picture of me, on a sledge, with an MI6 reference number and the word restricted on it! Have I just broken the official secrets act?!

Sunday, April 08, 2007


I love Weebl & Bob and CSI does it for me as well. Watch this very funny combo.

Friday, April 06, 2007

Kumala, kumala, kumala VISTA!

After trying to carve out a half-day to repave my Macbook with Vista I eventually got the chance. So, I threw in a new 160gig drive, re-loaded Tiger and used BootCamp v1.2 (which now comes with all the Vista drivers) and installed the copy of Vista Ultimate that James Clarke sent me straight from Microsoft!
Given that I have really enjoyed using this little MacBook for the last six months - it's been the fastest PC I've ever had for work purposes - I was interested to see how well Vista would run. I haven't been disappointed - I shall review my experiences with Vista soon, but here are a few thoughts about BootCamp 1.2 as it applies to the v.1 MacBook (white, dirty-white!);
  • Although BootCamp includes a proper keyboard layout it doesn't install it as default. Go to the Language Bar and install it as the primary keyboard layout.

  • The mouse-pad is a load more usable - including a very neat right-click feature and two-finger scrolling (as under OS-X)

  • The remote works with MediaPlayer - very good, I now need to retrieve that unused gadget from the depths of my rucksack!

  • The eyesight camera works (even thought the release notes say it won't).