Monday, December 20, 2010

Monitoring in 5.1

Nice article that Colin Birch (@InformedSauce on Twitter) mentioned this morning - I PDF'ed it as the online reader that Broadcast Engineering World use is clumsy. Click the link in the title of this entry.

Wednesday, December 15, 2010

Rio / Sonic Blue / Dell Digital audio receiver

I picked up these on eBay for a fiver a go! They are tiny little Linux boxes that stream audio from a nominated PC on your network. The original Rio/Dell software is very 2002 and although adequate offers no integration with iTunes or Windows Media Player. When you power the box it shouts out a BootP request (that's an old protocol I haven't had to deal with since Phillips/Thompson routers of the mid-90s!) and that starts the download process of a tarball that has the Linux kernel to run the box. Once that's loaded it grabs an IP address via DHCP (from the same client software that serviced the BootP request - I guess not many people had home-routers when this was a product!) and you can then stream your MP3s to it. It has a nice display, IR remote and the audio output quality is good.
However, since it's demise it's become a target for home-brewers and hackers and there is a new kernel that makes it look like a Squeeze Player - the standard that Logitech have used for all of their home entertainment products. This makes it quite an interesting gadget as a network music/streamed radio player and it didn't take me very long to get it working with my Windows 7 media center. Using Logitech's server mean it integrates brilliantly with iTunes and you get access to all the BBC's iPlayer and streamed radio.

Once you've got Squeezebox running you can use it to stream to WinAmp, your iPhone or even another instance of iTunes (rather perversely!).

So, here are the bits you need;
Rio's v. 1.04beta which was the last release. It's the only one that works with Windows 7 and it doesn't have all the instabilities previous releases had with 10 vs 100BaseT ethernet (this was the early noughties after all!).
SlimRIO is the tar-ball with the new kernel to make the box behave like a Logitech Squeeze player.
Squeezebox is the server that makes it all work nicely.
Finally you'll probably need a copy of the LAME encoder so that the server can transcode AAC, RealMedia etc into MP3 streams for live radio - lame.exe - it needs to go in;
\Program Files\Squeezebox\server\bin

Thursday, November 25, 2010

Video and high-speed networks - article in Broadcast Engineering Magazine

What an up-market magazine Broadcast Engineering is! Well, when they publish my stuff.
You can snag a PDF of the print version from my DropBox; BroadcastEngineering_Article_Nov2010.pdf

Thursday, November 18, 2010

You know you're getting old when.....

OB Trucks you built are knocking about on the 2nd hand market!

They've also used the photos I took back in 2001! The same thing happened when I took a load of pictures of the same truck being lifted in to Fame Academy in 2002. Loads of people used these images and I never got as much as a thank you.

Wednesday, November 10, 2010

High Dynamic Range video

We all know about high dynamic range (HDR) imagery due, in part, to the examples you can find on Flickr. This image I nicked from Wikipedia shows how three bracketed shots are combined into a composite image where you have all the details in both the blacks and whites that couldn't be captured in a single image.

So how could you achieve this with moving images? Have an ultra high frame rate camera where you can capture three frames sequentially with a rotating set of ND filters? Maybe, but the focus and effect are somewhat spoiled by rapid moving parts of the image. The guys at Soviet Montage have a system where they use a beam-splitter to feed the same image into two 5D Mk2s (one of which has 24dBs of attenuation - that's four stops for non-video people!).

HDR Video Demonstration Using Two Canon 5D mark II's from Soviet Montage on Vimeo.

I think it looks very engaging. Kind of like a moving old-master. For my money this is much more engaging than 3D on TV with none of the problems that 3D at home have.

Thursday, October 28, 2010

Most memorable gigs I've ever been to

  • Level 42, Birmingham Dome, 1983
  • Bruce Springsteen and the E-Street Band, Wembley Stadium June 1985
  • Billy Bragg, Wolverhampton Civic Hall, May 1986
  • Eden Burning, Brixton Academy, August 1994
  • Kevin Prosch, The Forum, April 1996
  • The Vigilantes of Love, The Borderline, June 1999
  • Counting Crows, Wembley Arena, September 2003
  • Julie Lee, The Borderline, August 2005
  • All Star United, The Half Moon, Putney, November 2007
  • Martin Joseph, Union Chapel, September 2008

Wednesday, October 13, 2010

Babbage's Analytical Engine

In December 1837, the British mathematician Charles Babbage published a paper describing a mechanical computer that is now known as the Analytical Engine. Anyone intimate with the details of electronic computers will instantly recognize the components of Babbage's machine. Although Babbage was designing with brass and iron, his Engine has a central processing unit (which he called the mill) and a large amount of expandable memory (which he called the store). The operation of the Engine is controlled by program stored on punched cards, and punched cards can also be used to input data.
John Graham Cummings is trying to get together the money and team necessary to actually build an Analytical Engine - aside from it being the coolest Steam Punk project ever it will give a real insight into how computation is independent of physical arrangements (we won't always be running our computers on silicon) AND it is possible for someone to be literally a century ahead of the curve. Remember - this machine was Turing-complete and so can be considered in the same category as modern computers.
As an aside the Science Museum made a Difference Engine in the early nineties using only materials and techniques that would have been available to Babbage and it worked well. The difference engine is not a Turing-machine, it was used to automate the production of printed log tables but is equally as impressive.
If you want to hear John talking about the project then he is on this week's TwiT and is jolly interesting.

Monday, October 11, 2010

Replacing the DVD drive in an XBox360

Microsoft realised after the original XBox that folks would find ways around the games' DRM and so in the case of the 360 they make it as hard as possible to use anything other than the stock optical drive that came with the machine. Every motherboard and DVD drive pair each have half of an AES key pair and so if you install another drive it'll play video DVDs but not games. They hoped this would stop people sticking in non-stock drives that could (for example) read home-burned disks. However, the hacking scene around XBox is extensive and so in pretty short-order there were hacker tools to read the drive's key and then flash it into a replacement drive.
Microsoft got wise to this pretty quickly and the summer 2008 update to XBox requires not only the key halves to work together but the drive ID strings to match. So - if you had a machine with an Hitachi drive and replaced it with a BenQ drive (for example), even if you extracted the key from the Hitachi and re-flashed the BenQ the XBox's OS would now query the drive ID and stop it working if that came back wrong.
Hackers are clever people and since v4.5 of Firmware Toolbox it's been possible to include the old drive's ID in the firmware for the new drive. This is what they refer to as 'spoofing'. It turns out that the drive ID is just that - a string that has no bearing on the drive's operation. So - your BenQ drive can now report it's an Hitachi 79 with this key and the XBox is happy.
Well, it's spy vs spy and the rumor is that the next update to XBox will include routines to test the ballistics and responses of the DVD drive to ensure it's the model it claims it is...!

So - if you have an XBox with a DVD drive that is on the way out (and it's almost always the laser) then you have three options which may/may not work;
  1. Open the machine, remove the DVD drive, open it and clean the lens with some IPA or some such. Seems to work for lots of people.
  2. Buy an identical model DVD drive on eBay (there are plenty of all four kinds for sale sub £20 from broken machines or around £30 for brand new ones). Then swap the controller cards between the drives. This means you have the old electronics but new mechanics/optics.
  3. Extract your old drive and using the right tools read-out the key and drive IDs, save them and then write them into a replacement drive (which can be another brand and model). This is potentially the most risky as anyone who has flashed firmware into any device will tell you. Browsing the forums reveals many folks complaining about having bricked their newly acquired drives. Also - if the XBox detects what you've done you'll be kicked off XBox-Live (both your machine and your account).
Anyway, if you're any kind of engineer and have any experience opening up equipment the first two are trivial. If you choose the third way (Mr Blair!) then it's worth giving some guidelines.
Whichever way you proceed you'll need to open the thing up and it's mostly held together with fragile plastic clips, and so here is the best tear-down instructions I have found.
Also remember - the XBox DVD drives have a standard SATA connector but a proprietary power connector. For all these tests I left the drive in the XBox (which powered the drive) and I used a long SATA cable to go to the eSATA port on the back of the PC. Now then - the XBox has a class-two (double-insulated) design and so the internal metalwork is floating at some undefined DC voltage. I suggest an earthing lead from the XBox's internal chassis to the PC's metalwork.

Extracting that precious key from the broken DVD drive
  1. Connect the "Original/Broken DVD drive" to your PC via SATA or USB-SATA adaptor.
  2. Place the DVD drive into MODE B with SLAX - SLAX is a live Linux CD that allows you to issue SATA commands directly. A good tutorial is here
  3. Please Note: Once you have the drive in MODE B you will notice it will take 3 presses on the eject button to close the drive.
  4. With the Original/Broken drive now in MODE B restart your PC and make sure that the new drive has been identified by Windows. Once the new hardware has been found and installed it will be shown in the my computer/explorer area on your PC as a additional DVD drive.
  5. Insert a DVD Movie or an XBOX 360 game into the "Original/Broken DVD drive". Even if the laser is nearly dead it may read a DVD movie just fine so try it.
  6. Open Firmware Toolbox (at least v. and choose 'Tools -> Direct Drive Dump (GDR ONLY)
  7. On the next screen choose 'RAW DUMP' and save the file as "original.bin". If you have problems with 'RAW DUMP' try 'CLASSIC DUMP', eg. c:/xbox360/hitachi0047/606HG324277-may2006/original.bin
  8. Make sure you can identify the backup firmware in future by placing it in a directory that matches the serial number which is located on the sticker of the DVD drive. This will make it much easier to identify in the future.
Replacement Xbox 360 DVD Drive
  1. Connect the replacement DVD drive to your PC via SATA connection.
  2. Place the DVD drive into MODE B with SLAX
  3. Please Note: Once you have the drive in MODE B you will notice it will take 3 presses on the eject button to close the drive.
  4. With the replacement drive now in MODE B restart your PC and make sure that the new drive has been identified by Windows. Once the new hardware has been found and installed it will be shown in the my computer/explorer area on your PC as a additional DVD drive.
  5. Insert a DVD Movie or an XBOX 360 game into the Replacement DVD drive.
  6. Open Firmware Toolbox and choose 'Tools -> Direct Drive Dump (GDR ONLY)
  7. On the next screen choose 'RAW DUMP' and save the file as "original.bin". If you have problems with 'RAW DUMP' try 'CLASSIC DUMP'. eg. c:/xbox360/hitachi0046/606HG324240-may2006/original.bin
  8. Make sure you can identify the backup firmware in future by placing it in a directory that matches the serial number which is located on the sticker of the DVD drive. This will make it much easier to identify in the future.
  9. When the firmware is backed up it will ask you if you want to open it. Choose"yes". Now select "Tools->Spoof Firmware" from the Firmware Toolbox 4.5 menus.
  10. Choose the version that you would like the fw to report back as. Leave all other options as they are.
  11. Please note: - Spoofing a drive as itself has the effect of UNSPOOFING it
  12. Now Click "APPLY SPOOF"
  13. Choose "Tools->Smart Hack Patcher", a window warning will appear, choose OK.
  14. Choose the output file name, I suggest calling it "final.bin" and save it at the same location as the original. The ruleset option should be automatically selected for you so leave it alone. eg. c:/xbox360/hitachi0046/606HG324240-may2006/final.bin
  15. Push the "Generate File" button, if everything goes fine the file will be generated almost instantly
  16. Once the file has been generated it will ask you if you want to open it. Choose "Yes". The Main Window will show the generated file (final.bin). You will notice that the spoofed information is shown in bold.
Original/Broken Firmware Key
  1. Open the old original/broken DVD drive firmware which you backed up in step 1. Choose the Browse for file button "..." to load the original/broken DVD firmware.
  2. With the old broken DVD firmware now loaded you will notice the "Key Information @" area in the center of the 360 Firmware Toolbox application.
  3. Highlight the entire key and copy it by right clicking your mouse and selecting copy or press Ctrl + C so you can paste it into our new replacement drive.
  4. Open the replacement DVD drive firmware named "final.bin" which you created in step 2. Choose the Browse for file button "..." to load the firmware.
  5. Paste the Key into the "Key Information
  6. Click on "Replace Key" and it will update the firmware with the new key you have just pasted.
Check Firmware Differences

Before flashing the drive I suggest re-opening the old firmware from step 1. Then open the final.bin firmware you just created in step 3 and make sure keys and other information match just to be safe. If you're happy that your keys etc match then move onto flashing the drive.
  1. Choose "Tools->Direct Drive Flash->Differential Flash Patch". Make sure the DVD drive you want to flash is selected
  2. Click the "Read Drive and Detect Differences" button, after a few seconds the sectors list below the button should be populated.
  3. It will now ask you if you would like to keep the keys from the drive.. Choose 'No'.
  4. Click the "Start Flashing" button and choose the flash mode.. I suggest using the 0047 flasher for 47 drives etc etc..
  5. After a few seconds the flashing is complete.
Replace the DVD drive into the XBox and test - you don't need to re-build the case and re-attach the hard drive.

SLAX Linux live CD
Firmware Toolbox

Thursday, October 07, 2010

The end of universal benefits?

I watched Mr Cameron's speech yesterday with some interest. I had thought for a while that child benefit for all was strange (although Sarah and I have come to depend on it over the last few years) and I'm surprised higher rate tax payers have received it for as long as they have. They should have avoided the debacle over the aggregated salary issue, but there you go.
Anyway - it got me wondering about other universal benefits which could (presumably) be cut for those folks who make too much (or contribute to the system too much?!);
  • Healthcare - why should people who make enough to pay 40% of it back into the system expect to receive free hospital treatment?
  • Education - This is an area where a gradual erosion of support for teachers and head-teacher's rights to run their schools they way they want to has caused a defacto segregation. Those who can afford it and value education end up paying for it. Presumably by means-testing state-provided education you could free up loads of money.
All of this breaks the fundamental aspect of the welfare state that says we're all in this together - you contribute as you can and you're provided for as you have a need. For this reason the government shouldn't be looking for ways to take low-earning workers out of the tax system. The danger of building a welfare state where some provide (and are still told they need to 'shoulder their part of the cuts') and some take is that eventually the providers wind up voting for government that stops spending their taxes on things that don't benefit them - as in the US.
It may not be the case that cutting one universal benefit will lead to the others becoming means tested but the UK may have crossed the Rubicon.

Thursday, September 16, 2010

Even leaving Virgin Media was painful!

I got my Talk Talk line run in yesterday and now have a nice aDSL2 connection and new 'phone line. I've ranted about Virgin in the past, but in a nutshell they are expensive (because I don't use the TV service), unreliable (it's gone down for days at a time) and their tech support is awful.
So - I called them to discontinue and start the number-port process and got the following torrent of lies!
  1. "You won't get more than two megabits per second out of Talk Talk" - well I ran several times yesterday and averages 22mBits/sec - faster than my Virgin cable.
  2. "We can arrange for you to never have to talk to a foreigner again" - honestly, they said this before I'd told them how poor I thought their tech support was. This is implied racism; I don't mind talking to someone from India (they tend to be more polite and better informed than someone from Blighty - that's just because they're probably a graduate on decent money in India and not a minimum wage worker in a UK call centre).
  3. "Talk Talk won't let you bring a number with you" - well they were kind of right here - the dirty little secret Virgin don't tell you is that they don't have number-porting agreements with other service providers (unlike the rest of the industry who follow OfCom's recommendations) - so you can take a number to Virgin but never away from them.

So - I'm pleased to be rid of them and their trail of lies and broken promises! Take some time to read my other entries on them before you sign up to an expensive, unreliable service.

Wednesday, September 15, 2010

Things at IBC 2010 that tickled my fancy

Dolby PRM-4020 Monitor - five years ago I went to see a demo of a monitor by Brightside Technology and was amazed to see such dynamic range on an LCD display. However - to get that degree of black detail they had to drive the whites at many hundreds of Cd/m2 which pretty much knocked it out of the water as a grading display. Given that most TV graders like to run their monitor at 80Cd/m2 and film guys even colder at typ. 60Cd/m2 it is a miracle that Dolby (who acquired the technology) have managed to tame it and without sacrificing dynamic range. I sat watching film & video cameras sourced material on this for maybe half an hour and was blown away how good it looked. However - as I often say it isn't about how 'good' it looks, rather how faithful it is to standards. In the case of film it's the only monitor you can buy that conforms to the P3 colour space (as specified in the DCI specs). 709 (for HD tele) is a subset and when it's being fed with video I couldn't find fault. Although the source the same LG domestic panels as other manufacturers they have the advantage of the whole modulated LED panel/correction matrix that allows them to 'zero' each monitor at the factory so that inconsistencies in the backlight and panel are got rid of. They also have a funky calibration procedure that involved covering the monitor's front with a (supplied) blanket and the software then drives all parts of the backlight and an internal set of sensors measures the illumination so track any changes in the LEDs. This means the panel should be good for 50,000 hours (unlike the 10,000 for others).
This is a very high-end product that will only be bought by people who have £30k to spend (the kind of folks to used to buy BVM-D series CRTs) - let's hope some of the innovations make it into the sub £10k broadcast LCD panels that declare themselves as 'grade-1'!

Evertz - router and monitoring technology, XLink is a system that now lives in the backplane of Quartz (they're keeping the brand) routers and exposes all of the inputs for upstream use in the their facilities monitoring multi-display products. Very cool - it means you can deploy big panels in your MCR / switching centre and have them driven directly off the matrix without having to sacrifice any i/o on the router itself.

Omneon - Media Asset Server etc

Tuesday, August 24, 2010

A year with the iPhone - what apps?

I thought I'd re-visit a post from a bit more than a year ago with what apps have stood the test of time on my iPhone. IOS 4 on the 3G was a no-no, I went back to 3.1.3 quite quickly and was pleased to have done so. Despite all the LifeHacker tips I couldn't get v.4 on a 3G to run acceptably fast. I'm looking forward to our upgrade to the 4 in a couple of months though.
  • Memory Stick - file manager & WiFi NAS utility – it’s how I’m managing my cable schedules etc
  • Dropbox is the best thing for file sync - half the reason I carry a device is for this!
  • Undercover - GPS tracker for lost/stolen iPhones - Ungainly, and without multitasking I think it is pointless. It seems like Apple are starting the include this functionality.
  • London Tube - the official one
  • Solitaire - probably the thing I used most on the Windows smartphone!
  • VNC light
  • Remote - the Apple iTunes one
  • SpawnLite - fun OpenGL demo - Meant the kids just left fingerprints all over screen all the time!
  • Wikipanion - makes Wikipedia a lot more usable on the small screen
  • Classics - a dozen books with a nice reader app Even though Apple took this app for the iPad I've not got used to reading for more than a few minutes on the iPhone's little screen.
  • Guitar Tuner - works really well – AEDGBE! Doesn't work as well as a real guitar tuner (which is always in my guitar case!)
  • Holy Bible - I like to read the scriptures and this one does it well
  • Skype
  • Independent newspaper - really free! I've started reading the paper every day again.
  • iCar Radio Lite - best radio app, I listen to Radio 4 over 3G all the time.
  • TWiT streaming app - all Leo, all the time - excellent!
Aside from these here are my home screens so you can see for yourself;

Tuesday, August 17, 2010

Some notes on monitor calibration

Root6 offers a calibration service primarily for CRT-based grade-1 broadcast monitors as many people who are serious about colour accuracy still regards a CRT as the gold standard. By default we work to the BBC standard with a white point at 80 Cd/m2 and a colour temperature of 6504K (AKA “illuminant D”) although we are aware that facilities that grade for film will set their monitors slightly dimmer (in the 60-70 Cd/m2) for better Delta-E performance.

  1. Source material – we will bring test footage on videotape as this is still the lingua franca – if you don’t have a DigiBeta or HDCam playback deck then let us know.
  2. We won’t make your monitor look ‘great’ rather we will make it correct – compliant with the standard. The whole point of accurate monitoring is to produce an honest display to shows good pictures only when the pictures are good. Remember – the person in the QC suite at the broadcaster/mastering facility will be looking at a calibrated monitor, not a ‘great’ monitor.
  3. Hardware faults – calibration won’t fix a monitor that needs a trip to a workshop. If you crank the contrast knob and the pictures ‘blooms’ (changes size slightly) then your EHT regulation is poor. There are a few other faults that get progressively worse as a tube ages and you can’t calibrate-out these faults.
  4. White levels – we often arrive in edit suites and find the whites set at twice what they should be (typ. 150 Cd/m2) because the room isn’t set up for grading and has too much ambient light. This is sub-optimal because at those light levels your eyes aren’t seeing any black detail and your monitor is likely out of its linear range and the fidelity in the whites is compromised. Remember, in grading brighter isn’t better!
  5. Black levels – ambient lighting affects black levels noticeably. Please think about the lighting in your room so that we can set accurate blacks for the same environment you’ll be working in. We’ll show you how to re-set your blacks if you need to brighten-up the room (for a client viewing, for example).
  6. LCDs, Plasma, projectors and other display types – We are often asked to match a projector to the grading CRT monitor which is fine but domestic LCDs and Plasma televisions are an order of magnitude brighter than grading levels and should be treated as client content monitors only.
  7. Broadcast LCD monitors – The colour of newer ‘grade-1’ broadcast LCD monitors is governed by the colour of the backlight and as such doesn’t vary for the first 20-30,000 hours of use and generally leave the factory set correctly. Again, we can match these to the grading CRT but metameristic differences mean that we won’t set up an LCD in isolation.
  8. Computer monitors – These are designed for displaying computer GUIs at much higher light levels than you would grade at – typically 200-300 Cd/m2 and so a correctly calibrated broadcast monitor next to an Apple Cinema display will look milky and dim. You couldn’t grade accurately off the Cinema Display that shows your FCP playback and so wanting to make your broadcast monitor match it is ultimately futile. Always treat your NLE’s playback display as content only, it isn’t colour or light-level accurate.

Saturday, July 31, 2010

Internet security - when should you pay?

People often ask me about what security software I use. I'm of the opinion that you want solutions you don't have to think too much about. OpenDNS fits that bill entirely but here are some other thoughts;
  1. Firewall - ten years ago before Windows XP and when your broadband connection was probably via a USB modem (and you had an internet-facing, routable IP address) it made a lot of sense to have a software firewall - Zone Alarm or somesuch. Since XP SP2 (when the Windows firewall is on by default) and hardware NAT routers there is no good reason to spend money on yet another firewall. Your NAT router acts as a very effective hardware firewall because any packets that aren't a direct response from outgoing connections (from one of the machines on your network) are ignored. You could quite happily run Windows (or Mac or Linux) behind a NAT router with no firewall.

  2. Web filtering software - Cybersitter etc. You may well want to filter your incoming traffic but having a piece of software on every machine is not the way to do it. By far the best solution is to use a DNS filter - every DNS lookup that your router sends out goes not to your ISP's server but to OpenDNS who (based on their database and your settings) will return null DNS entries for sites you might not want accessed. I've been using it for a year and it's excellent - nothing needs to be done to new machines as the router has the IP addresses for OpenDNS in it's settings. OpenDNS also blocks all known phishing and malware sites and since they have a worldwide userbase of tens of thousands they are more likely to block new threats before you try and go to them.

  3. Web filtering pt.2 - NoScript is an excellent plugin for Firefox that stops active content from running on pages. It's a bit of a pain when you first install it as you're constantly clicking on the settings icon and allowing a domain (BBC iPlayer isn't much use without Flash!). But after a while you get used to it an the sites you visit often where you need active content soon outnumber those that you visit occasionally (and you may not want them to run JavaScript, Flash, ActiveX etc - common vectors of infection).

  4. Antivirus - Microsoft Security Essentials sneaked out earlier this year with little fanfare but has been getting excellent crits with detection scores near the top of the test tables. Definitely better than Norton, Panda, and AVG. It integrates well with XP through Windows 7 and I found it to be very unobtrusive. It's what I'm using on all my Windows machines.
  5. Spybot etc AntiMalware - Windows now has the Malicious Software Removal tool - MRT.exe (you can run it from Start>Run whenever you like). It updates itself silently on patch Tuesday and is as effective as anything else at removing malware. It's free and unless you've deselected it from Windows update any machine running Win 2K or later has it.
So there it is - not paying for security, far from being the cheapskate option is, I think, the best policy. Have you sat down to use a machine that had a full-up Norton or McAfee install and realised how cumbersome and slow this computer (which five years ago would have been considered workstation-class) now is. The firewall is fighting the Windows firewall, the antivirus is popping up reminders to renew the subscription ('cause you only got 90 days with Dell!) and you can't access files on your server for some reason.

The dirty little secret the anti-virus industry never mention is that once your machine has been compromised they can't be sure they've rid you of whatever nastiness crawled in. Root Kits and other techniques mean it is nigh on impossible to ever trust a PC that has been virus infected. You need to reformat the hard drive and re-install Windows. It's not hard and you'll find your machines feels like new again as you will have lost the detritus that Windows picks up along the way.

Thursday, July 29, 2010

Colour calibration probes for less than a grand?

I'm often asked if the kind of colour calibration gadgets you can pick up on Tottenham Court Road are of any use in setting up monitors for film or TV grading – I’ve played around with a couple of those sub-£1k colour probes and although they are OK for getting your monitor in the ballpark for print-prep they aren’t suitable for film and TV usage for the following reasons;

  • Luminance level – Computer displays tend to sit white at 200Cd/m2 or even higher so the probe must be able to work over that range. The white level we use in TV is 80Cd/m2 and some film guys prefer 60Cd/m2 (delta-E increases a luminance goes down). This means the probe which (at best) is a ten bit (but probably eight bits) is operating over a fraction of it’s range when used for setting up a monitor for TV grading which means it’s now only a five or six bit probe. There is no way on earth it can measure better than the ½ GND that you need for calibrating for TV & Film.
  • Metamerism – Photometers (of which this is one) rely on the relative metameristic performance of the display – CRTs are different from LCDs in this respect. That’s why our £5k photometer (Phillips PM5639 in case you’re asked) says on page one of the manual “...only for CRTs, not for LCDs” – I’ve sat a CRT next to an LCD and had quite different colours on both displays and the probe says they’re the same – it’s a limitation of photometers but the Huey claims to be able to do both CRTs and LCDs – not sure how it gets around this as it’s not a calibration issue, it’s physics baby! You need a spectroradiometer to be able to accurately measure both kinds of displays and they start at £15k!
  • Colour space – computers monitors tend to be set up for RGB working and not for the colour-space we use in TV (rec 709) with a white point at 6500k.
So I think these things are worse than useless – they give you a false sense of security for no actual worth.

Friday, July 23, 2010

How to serve your Wiki off DropBox

Firstly I wanted to mention how powerful DropBox is - I've tried a few cloud-based storage solutions (Humyo, SkyDrive etc) and this is the one that works more reliably than all of the others. You install the client on your Windows/iPhone/Mac/Linux box and you have a folder that synchronizes with every other authenticated instance of that account. You always have access to your documents and the iPhone app is superb. Even if you only have a web browser you can download what you need. It sits in the background and trickles stuff up to their data centre without you realising.
A really powerful feature is that there is a public folder which if you drop files into you can right-click and get a URL you can email to someone.

Something else I find very interesting is the one-file compact Wikis that you see - the best one I've found is TiddlyWiki which is superb for small collaborative projects.

By placing the index.html file (which includes everything you need for the Wiki - style sheets, database, everything!) in your public folder and getting the URL (which you could make easier with TinyURL or stick it on your domain in a frameset).

See for an example. Of course it's only editable by about four machines, but that's part of the strength of it.

Thursday, July 22, 2010

Back from a job - a few thoughts on DVI, HDMI & audio

Having just got back from a slightly unusual build (all HDMI capture off games machines for a 24-7 HD channel on Sky) I had a few observations that might save you some head-scratching;
  • DVI extenders; I normally recommend extending DVI and HDMI over fibre; twisted pair copper isn't really up to it. It works most of the time so long as patch cords and wallboxes are avoided and you can't realistically do that in edit suites. Anyhow - on this job we discovered we needed to extend and extra DVI into a couple of the edit rooms after cables were run and we'd used up all our fibres on the edit machine's GUI displays. So - with a spare cat6 we gave it a try. The model we used had an eq tweak on the receiver with an LED that lit when the signal was tuned. Only it didn't! Turned out the lit LED meant 'sub-optimal'! Hmm - OK when I discovered!
  • HDMI vs DVI and interlaced 1080 video - the Samsung domestic panels that we were using for the time-line display wouldn't work with 1080i video over DVI, only 1080P (at whatever fancy framerate you wanted - 23.976P, 24P etc). Turns out that model only does DVI progressive. Changes the cable from the extender to feed the monitor's HDMI port and it's all good.
  • AJA k-box's unbalanced audio outputs aren't buffered. We had a set of PPMs that were loading the signal earths (but not enough to effect the accuracy of the meters) but it was enough to load the unbalanced outputs which fed the speakers - cut the screen on the XLRs behind the PPMs and it's all good.
On the subject of HDMI and DVI it should be stressed that from a signal point of view the TDMS data lanes are the same in each - you can use DVI extenders to carry HDCP and audio data which aren't part of the spec, it's only the equipment at each end that generates/won't recognise those things.

Friday, July 09, 2010

Tektronix and audio loudness measurement

I just had a rather splendid lunchtime presentation from Tek regarding the new firmware for WFM & WVR-series test sets. EBU rec 1770 has been around for some years but a couple of things have stopped it's widespread adoption.
  • It's integration time for short-period measuring is three seconds - Channel Four (who previously were the only UK broadcaster who got shirty about perceived loudness) always specified a Chromatek meter which used a four second rolling window.
  • It's long been understood that most archive material fails 1770 in it's original state but the inclusion of a silence gate mitigates this.
It seems like whole industry is tip-toeing around the dirty little secret that commercials producers mix audio with a very limited dynamic range so as to make them more punchy. It's in their interest (and the broadcasters who make their living out of them) to not embrace this. It's why my Mum complains to me about how loud the ad breaks are. The EBU should stop pretending this is about programmes, it's about commercials and the sooner they enforce loudness limits the better!
We got to have a play with the new Tek firmware and they have done an excellent job of interpreting the LUFS scale. They make it very easy for an operator to see where a programme is and if the Dolby DialNorm (dialogue) and Dynamic Range figures match what is measures.
More when I've got a copy to put into my WFM 7120.

Tuesday, June 29, 2010

Reducing electricity usage

Sarah got me one of these gadgets for Christmas and it's been a real boon. It is a clamp meter that monitors your current draw in your house's 100A feed from the street and wirelessly sends it to a monitor that lives in the kitchen. It keeps tracks of rolling averages and the best display is the one that shows instant power draw as well as a previous week's average daily consumption (in kW-hours).
Now then, at Christmas we were averaging just short of twenty kWh per day and I started on a mission to reduce this;
  • Cut the number of computers! The kitchen Mac and the Windows machine that runs MediaPortal went and a single machine (with dual DVI o/p's and dual soundcards) replaced them - it also has much better power management.
  • 'phone chargers on a timeswitch. Those wall-warts are around 50% efficient (put your hand on one even when it's not charging a 'phone).
  • All incandescent bulbs replaced with compact florescents.
  • Intelligent mains switch - this gadget powers off the TV, XBox, Wii etc when you sleep the TV. I might get a couple more for other parts of the house.
So, I've managed to reduce my consumption from 19.8kWh to 16.9kWh (as of yesterday) - that's around a tenner a month.
My next step is to replace the 50w halogens in the bathroom and kitchen with 4w LED bulbs.

Wednesday, June 16, 2010

Root6 training

I've just finished a couple of days of running four of the half-day courses I've been developing. You can get my lecture notes;

Audio 101 for runners and trainee assistants.
Video 101 for runners and trainee assistants.
QC for Television using Tektronix WFM/WVR series test set.
TCP/IP for broadcast engineers.

Monday, June 07, 2010

2010 update for Optical cabling specification for fibre‐channel SANs

Root6 has supplied many thousands of terabytes of fibre‐channel storage over the last decade and has much experience in the area of bespoke optical cabling. We are often asked to audit existing installations and the following notes are our recommendations for customers who want to provide their own cabling and not make use of our Systems Integration services.

  1. Grade of cable ‐ All current models of film and video SANs make use of multimode connection. OM3 cable is increasingly the preferred grade (50 micron laser-optimised glass as opposed to OM1 & 2’s 62.5 micron VCSEL‐optimised glass in accordance with ISO‐11801) and since current configurations are 4 gigabit (moving to 8 gigabit) more attention needs to paid to circuit loss than 1 gigabit (the standard when OM1 was introduced). Mixing OM1 and OM3 should be avoided because of the 2.5dBs of loss when going between dissimilar core sizes (62.5 vs 50 microns). In the case of an existing OM1 installation thought should be given to staying with that standard or migrating to the newer OM3.
  2. Bandwidth ‐ Whereas 1 gigabit traffic will tolerate up to 8dBs of loss we are now dealing with SANs that demand at least two octaves more bandwidth and so best practise says that we now expect no more than 3dBs of loss on a SAN circuit.
  3. Style of cable ‐ Although tight‐buffered cable is easy to install it is never optimal for long runs. For interconnection between equipment within a cabinet it is appropriate and between cabinets if run in protection – Copex etc. For inter‐area runs a loose‐tube cable is the best solution as it is an order of magnitude more robust and although has an slightly larger install‐time cost has a much lower TCO.
  4. Connectors ‐ All contemporary host‐bus adaptors and fibre‐switches terminate runs in the LC connector. If existing cables are terminated in legacy SC or ST connectors they should either be re‐terminated or re‐run as adaptors introduce signal loss. SC or ST patch panels are fine so long as run‐out cables are SC‐LC (to equipment) as appropriate.
  5. Testing – We will ascertain if circuits are suitable for proposed SAN deployment by illuminating them with a calibrated laser tester (850nM wavelength, ‐19dB(m) signal) and measuring circuit loss – these results will be provided to the customer.

Friday, June 04, 2010

Requirements for Electrical Supply for Systems Integration projects

If we are obliged to power equipment sited in a machine room and/or edit suites we ask that the customer’s project manager and electrician read and sign these notes to ensure a proper configuration for the mains supply. The difference between an optimal arrangement of mains power and one that merely satisfies the requirements of safety legislation will be the difference between a smooth-running facility and one that is bedeviled by hum on signals and corrupt data streams. Attention to detail initially will save money and result in a robust system.
  1. Circuit breakers - Our requirement is that the customer’s electrician provides a separate spur connection for each bay and all feeds are provided via a D-rated 16A MCB. We recommend the area is protected by an Earth Leakage Breaker. For the edit rooms an MCB-protected 16A mains feed terminated in a Commando connector is required. Since most equipment used in modern television production represents inductive loads C-rates breakers found in domestic and office premises will results in unnecessary supply interruptions.
  2. It is important that the customer’s electrician runs the earths for the edit rooms back to the same earth bus-bar as the mains feeds to the bays thus creating a technical supply for all production/editing equipment.
  3. The practice of tying the domestic ‘cooking’ earth to the technical earth should be avoided as a quick and cheap way of unifying the earths between the edit suites and machine room. Although this satisfies the requirement of a safety-earth it means that the technical earth is now united with the dirty earth.
  4. Be aware that new projects that start after June 2008 have to conform to 17th Edition of the IEE regs (BS7671:2008). These notes are meant as additions to legal requirements and should be included in Root6’s Scope Of Works submission.
  5. Testing- we will regard demarcation of responsibility for the machine room cabinets and edit suite desks as being at the 16A Commando connector – we will provide a standard set of tests results (earth continuity, Insulation, run-current, leakage, and flash-test) from that point for every circuit. We ask that the electrical contractor provided us with a copy of his test results as detailed in IEE.17th.ed and Part-P.

Tuesday, May 25, 2010

DVI, HDMI and Display Port

It's been more than a month since I blogged! It's not that I've been mega-busy at work rather life has been hectic with a couple of disappointments thrown in that have kept my thoughts occupied. Still - engineering goes on!

So - a few weeks ago I went to an excellent training day with Lightware Engineering who make DVI and HDMI extenders and matrices. They really are excellent chaps who know their stuff - the link (above) is to the PDF of the presentation they gave.

Here are a few notes;

The difference between single and dual-link DVI

DVI has been around for some years now - the difference in resolution and data rates between single and dual-link is shown above. The four pins that sometimes surround the larger 'blade' pin are the R,G,B and sync signals that carry the analogue version - but this isn't supported by all graphics cards and/or monitors. Most graphics cards 'mute' the analogue pins if the DVI handshake has taken place. The difference between digital-only and analogue/digital-DVI is shown with the suffix D or I (for 'integrated').

Evolution of DVI to HDMI v1.4

Key interchange for HDCP

Display Port

I shall finish this off later!

Monday, April 19, 2010

Blackmagic Videohub & RS422

I've talked about BlackMagic's router range - the VideoHub before but never installed one of the larger 72x144 models.
They are very thin! Where you'd expect the cables to terminate at the back of the bay these have to be long enough to terminate at the front of the cabinet.

Here are a few notes relating to it - it's amazing that you can buy a 3G-capable HD-SDi router (with RS422) for around ten grand. To do the same with Probel et al would be north of £50k. However - there are a few things you lose with your budget router.

  • Remotes control - although in the past I've mentioned how the VideoHub can't do the TX/RX crossover that all 'proper' matrices do (i.e. they know how to handle controlled/controlling devices) they have introduced this in v.4.3 of the control software (that runs on a USB-attached Mac or PC - can can even re-share control over a network so you can run the same control applet on your Avid/FCP workstation). In v.4.2 you had to declare what a device was - either a 'deck' (a controlled device) or a 'workstation' (a controller). This falls down when you think about doing two-machine front panel editing between two VTs - the recorder becomes the controller and so you have to go into the labels menu and temporarily declare that VT a 'workstation'. The reverse is true if you want to run your Avid in VTR-emulate mode (when the timeline can be controller like a piece of video tape). We thought 4.3 was the answer to all our RS422-payers but it doesn't work that well - and when it gets it wrong you have to keep making and breaking the route in the hope that it gets it right. So - we're sticking with v.4.2 (BlackMagic s/ware archive in the title link).
  • Touchscreen - our customer wanted a touchscreen to control the software which works quite well - I'd recommend at least a 19" 1280x1024 res screen as a 17" is fiddly.
Of course - in a non-TX environment these things may not matter. It really is a very good deal!

Thursday, April 15, 2010

Why did late 60's/early 70's rock singers have two mics taped together?

I've been enjoying "Guitar Heroes at the BBC" on BBC4 where they compile clips from Whistle Test, Rock goes to College, TOTP etc. I've always wondered why rock singers from a period of only a few years would have two mics taped together. By the time I was paying attention in the late 70's the practice seemed to have stopped so I suppose it was a technical development that made the change.
I asked the question on Twitter and Facebook and got great rock'n'roll answers; " they could take it to 11", "early form of stereo recording" etc. In fact when I went back over my old BBC notes I had been told why they did it but only a few weeks out of university I don't think I understood common mode rejection!

Ronnie Van Zant of Lynyrd Skynyrd c.1973 - two mics!

So - having re-read my notes and had a trawl around the web (my word, there is some awful rot spoken by people who know very little!) here are the two reasons (and I'll list them based on the technology that fixed the problem), they both rely on the fact that the two mics are wired anti-phase to each other and the assumption is the singer sings predominately into only one of them (doesn't matter which).

1. pre-compressor/limiters you needed a way of loosing some of the induced stage and line noise - this does it.
2. pre-parametric eq - you needed a way to reject howl-round and this does it.

So - you mix the anti-phase feeds in two channels on the desk and all noise/feedback etc gets canceled and the voice (predominantly coming down one feed) remains. Interestingly another technique to gate a mic is to have either an optical detector on the mic stand or a pressure mat in front of the mic which mutes the channel when nobody is near the microphone.

Monday, April 12, 2010

My blog is blocked in UAE!

Fantastic - China as well - I'm kinda glad they don't want my kind of radical engineering ideas been seen there! Thanks to my good pal Tim Taylor (who's working out there at the moment).

Tuesday, April 06, 2010

I'm going to leave Virgin Media (and so should you)

I've been with Virgin Media since they were Blue Yonder and then NTL and have consistently upgraded as faster cable connections arrive. I like lots of bandwidth because sometimes I need to download large files quickly but I find that for Skype, iPlayer and the plethora of other bandwidth hungry apps you can never have a big enough pipe.
Several times over the last couple of weeks my connection has slowed to a crawl. This screengrab from my 'phone is typical - unusable for anything other than email or IM. Eventually I called tech support (which is often a painful affair!) to be told that I'd fallen foul of the traffic management cap. All the details are in the title link. Bear in mind I never signed up for this - they introduced it without fanfare last summer and the details are show in the table below;

So let's take the slot between 16:00 and 21:00 - if you pull more than 3.5gigs across your connection you trigger the cap and they slow you for five hours. "Hang on, who downloads three and a half gigs of an evening?" you ask - but it's not the downloads that get you. We're talking about an 18,000 second slot which (do the calculation yourself) means that if you run your connection at two megabits per sec (it's actually a tad less) you fall foul of the cap - ten percent of what you pay for (on my twenty-meg connection) will give them the excuse to slow you down.
So - in a household of teenagers it is by no means unusual for more than one person to be watching the iPlayer (Sarah and I on the TV using the Wii, the boys of their computers) - so that's 2 or 3 x 800kBits per sec, maybe a bit of Skype (around 400 kBits per sec) and add to that a download or two and you've fallen foul - and over recent nights I have every evening!
Part of the problem has been the dodgy DVB-T tuner in my PVR - I've been downloading BBC shows in HD rather than recording them!

Virgin's response is one of fairness - why should some people hog all the bandwidth? The implication is that their network (the only one that is 100% fibre-to-the-cabinets as their adverts remind us) isn't up to delivering the bandwidth we have been sold. This is bogus because when I raised this with them their response was to try and up-sell me to the fifty-meg package which has no restrictions! It's a marketing strategy. I bet when they launch their 100meg connection the fifty meg one will suddenly have limits introduced to 'maintain a fair usage model'.

Monday, March 15, 2010

Again - DRM penalises legitimate users only

Sarah works at Barnet Library on Saturdays and returned very excited this weekend as they've just introduced electronic loan of audio books and eBooks - fantastic you might think. Just download the book to your machine and then portable device and you save a visit to the library. Understandably they want DRM so that it mirrors the same service the library currently offers (you do have to return a physical book or CD after all).
So, Sarah installed the software on the media machine (which has a 10" 800x600 screen in the kitchen for iPlayer/iTunes etc and a second feed to the living room HD TV for Media Centre/Player - two sound cards mean you can be watching an HD recording in the living room and listening to/watching iPlayer in the kitchen). After she'd downloaded a book and tried to play it locally (which is entirely within the allowed behavior);

Quite why you need a hi-res screen for listening to an audio book is another matter. "No matter" I thought - I've got an old iPod kicking about, lets transfer it to that (again, OK in the EULA) and listen to it that way. Click the transfer button and you're in for an eight hour wait while it transcodes the WMA files to AAC. Also - it finds the iPod about one time in five (iTunes sees it every time) and so the chance of it working and you getting more than just a sample of chapters is remote. I did think about pulling out an old Windows Mobile 'phone but at that point I just torrented the book and it's good to go. You try and do the right thing but they make it impossible.

This all begs the question why public money has been spent on this very sub-optimal solution? If you don't want people to listen to these things then don't make them download'able - don't have an audio/eBook service. They will no doubt say that they can't make it easy as people can pirate/pass on the files. However - the OverDrive Media Console allows you to burn regular Red Book audio CDs - so they have NO trouble exposing the data un-DRM'ed! I despair. It reminded me of a time that I bought a couple of episodes of CSI from Channel Five's VOD service - they'd only play on the laptop I downloaded them on and not my media machine connected to the tele. Again - within half an hour I'd scored them off bittorrent (and in HD!)

Thursday, March 11, 2010

JVC monitor calibration software

Whilst at Channel Five recently I got to play with JVC's new monitor calibration software - it's for their DTV-series LCD panels and works using one of those little USB colourimeters (it supports several of the £150-gadget Tottenham Court Road specials). You use a DVI o/p from a PC to feed the monitor and hang the USB detector on the panel and via an RS232-USB connector the software models the monitor and uploads a 1D-LUT that makes the panel conform to a flat D6500 colour-space. Just the job for TV use.
There are a few caveats I can see;

  • The JVC monitors don't switch in a different colour matrix when you go between 601 and 709 working (i.e. SD and HD signal) - the monitor assumes you'll be wanting reliable colour at HD and any SD work is just for content. Previous posts on this here.
  • You calibrate the greys and whites using DVI (hence an RGB source) which only exacerbates my first point.
  • Those little USB gagdets are a couple of hundred quid against a proper colourimetry probe which is a few thousand and a photo-spectrometer which is many thousand. Given how sensitive your eye is (particularly in the blacks) I'm not sure I'd place a lot of faith in something you'd buy in the high street.
  • The software seems to do all it's modeling at 120Cd/m-sq - much hotter than you'd set the monitor for TV use and maybe twice as bright as if you were setting up a film grading display. This isn't as bad as HP's DreamColour range which start at 300Cd/m-sq!
Aside from those quibbles it looked quite good. I like the idea of being able to keep the LUTs for all your monitors and the fact that the software is looking to bring the display into compliance rather than "making it look good"(!)

Tuesday, March 02, 2010

Some more notes on Return Loss

After my poor attempt at an explanation yesterday here is a page from Fluke's manual - much more concise.

Monday, March 01, 2010

Cause of return loss in cat5e cable

One of our biggest suppliers asked us to test a sample of cat5e cable - we tried a couple of different RJ45 ends on the cable - a non-name one and Tyco. We ran the same 1000BaseT test on all six cores for both connector types and if you look you'll see that cores 2 & 4 consistently fail on return loss.
I initially thought it must be down to badly terminated ends but the DTX makes a distinction between return loss over the length of the cable and return loss at the remote end (how on earth it works that put is anyone's guess!) - generic RL is therefore all the reflections along the whole length of the cable that impede the transmitter's ability to send a strong signal.

Now then - it's the brown pair in every case - that suggests that the brown pair is sub spec. We didn't test to an ISO standard (because the cable isn't marked with one) so we used a generic gigabit Ethernet test which is a bit more tolerant.

I have to say I think the cable has a manufacturing fault in the brown pair.

With that in mind we stripped out some of the brown pair from core 2 (bad) and core 5 (good) and you can see the twist in the bad pair is much more variable than the twist ratio in the good pair.

So - it seems like the brown pair in cores 2 and 4 is inconsistently twisted compared to the brown in the other cores.

Thursday, February 11, 2010

Understanding HD & 3G-SDI Video In HD

I'm giving a talk at Broadcast Video Expo next week on HD infrastructure (10Gig Ethernet, OM3 fibre & 3G Video) and I was pleased to see several manufacturers are doing similair. The link is to Tektronix's 3G poster - all good stuff.

Wednesday, February 10, 2010

All your paywalls are belong to us!

I subscribe to Broadcast (our industry's magazine) Tweet feed. Most of the tweets point to subscriber-only content which is annoying. I use a great site 'Be The Bot';

Have you ever been googleing something, and you see exactly what you need in the preview, but when you click the link it doesnt show you what you want to see? This is because the owners of the site are trying to trick you into buying something, or registering. It's a common tactic on the internet. When Google visits the site, it gives something called a "Header". This header tells the site who the visitor is. Google's header is "Googlebot". The programmers of the site check to see if the header says "Googlebot", and if it does, it opens up all of its content for only googles eyes.
Now, all we have to do is trick the site's headers, into thinking that we ARE google. That's what this site does. See the How to use box to the right for instructions on usage

It would appear that Broadcast don't even bother to do that - if you cut'n'paste the headline into Google and click the article you can read it all - it's the HREF tag they must be checking.

Tuesday, February 09, 2010

Cory Doctorow is a genius!

Aside from him being an insightful writer and having some very intelligent things to say on the whole DRM/copyright/copyleft debate he seems to be a nice chap - my eldest boy, Joe, had him sign his copy of Makers at a recent book signing and he had the time to talk and be interested in a nervous sixteen year-old.

Anyhow - do email disclaimers annoy you? They do me. A lawyer friend told me that most of them are unenforceable because they assume the disclaimer can carry more legal weight than the contents of the email (which of course they can't, according to Contract Law 101). Cory has a fantastic email sig;

READ CAREFULLY. By reading this email, you agree, on behalf of your employer, to release me from all obligations and waivers arising from any and all NON-NEGOTIATED agreements, licenses, terms-of-service, shrinkwrap, clickwrap, browsewrap, confidentiality, non-disclosure, non-compete and acceptable use policies ("BOGUS AGREEMENTS") that I have entered into with your employer, its partners, licensors, agents and assigns, in perpetuity, without prejudice to my ongoing rights and privileges. You further represent that you have the authority to release me from any BOGUS AGREEMENTS on behalf of your employer.

Thursday, February 04, 2010

1080/50 & 60P playback on a 2002-vintage PC? You betcha!

Brian and I had six of these Compaq W8000 workstation which our tech support department were disposing of. This is the machine that was the penultimate Avid Meridien machine and eight years ago was a real killer workstation-class computer. It has dual 2.2Ghz P4s (so a lot less pokey than the laptop I'm writing this on!) but by gutting the six old machines we made two computers that were pimped out. Add to that a £30 Radeon 3650 AGP (remember that!) card from eBay and you've got a machine that can playback 50P H.264 at 1080 without a slip. This is going to be my new PVR machine (replacing an elderly 2Ghz P4 which has been fine for SD but can't handle HD).

Wednesday, February 03, 2010


It's been years since I saw this many broadcast engineering jobs.

Friday, January 29, 2010

Glitch Takes Eutelsat W2 Out of Action

I don't know if you noticed on Wednesday evening but Channel Five went off the air around eight-thirty. I was having breakfast with the Five engineers on Thursday and they mentioned that Eutelsat W2 carries their DTT distribution (so the feed to the various main-base Freeview transmitters around the UK). Arquiva must have quickly re-routed but it appears that as of today all Eutelsat have been able to do is move the bird to it's 'parking' orbit. It's quite an old satellite (launched in 1998) and was due to be decomissioned this year, but even loosing a few months must be costing a lot of money.

Monday, January 25, 2010

BT HomeHub madness!

The new BT Homehub (their aDSL WiFi router) comes in a very sleek black, but apart from that seems to be the same gadget they've been hawking for a couple of years now. Anyway - I was visiting with Sarah's folks this weekend when her Dad mentioned how slow his Windows XP machine had got (three year-old Dell which I routinely remote desktop into to check-out - make sure his AV is up to date and Windows updat has run etc.). So - I fired it up and it crawled for the first ten minutes and then perked up. A quick run of MSCONFIG.EXE revealed a few start-up services that were taking an age to launch and (hiding inside svchost.exe) they turned out to be FOUR (yes, count 'em!) processes that the BT Homehub2 CD installs.

Now then, this is an ethernet-connected router - the only software you need to configure the router is a web browser but this had piled on a load of crap-ware. It reminded me of the state the machine was in when Dell shipped it! I got rid of all the BT stuff and the machine was back to it's nippy self without any trouble from the router.

Tuesday, January 12, 2010

The importance of a consistent earth with technical mains

This is a paragraph from my standard Scope of Works document that goes to customers of build where I'm not responsible for the technical power;

Electrical requirements for all rooms part of the installation
We recommend an MCB-protected 16A mains feed terminated in a Commando connector. It is vital that the customer’s electrician runs the earths for the rooms back to the same earth bus-bar as the mains feeds to the bays thus creating a technical supply for all production/editing equipment. Failure to observe this request will cause mains hum on all video signal distribution around the new facility.

So we're quite explicit about the need for the need for a proper technical earth and what will probably happen if it's neglected. One of our recent builds has been having niggling problems with corrupt video captures and despite me having twice tested the physical layer performance of all the cabling (using the eye pattern on a Tek WFM7120) the attitude from the customer has been "…it must be the cabling or the routers you provided". After lots of haggling I was there recently and I measured a full 400mV of hum between the 'technical'(!) earth in the suites and the power distribution in the machine room. Given that an HD/SDi signal is only a volt I'm amazed they weren't seeing more corruption.
Now it's the inevitable "..why didn't you test for this and spot it earlier"? Perhaps there's a lesson here in not splitting the job up into many parts and using the cheapest contractor for each. If they'd been my electricians I'd have briefed them and made sure they ran proper tech earths - and I'd have made sure they tested them before handing over to the customer. That's why we'd have been a tad more expensive. As it is we'll no doubt wind up fixing this for free.

Saturday, January 09, 2010

Two more hardware standards Apple play fast 'n' loose with - DVI and Display Port

Another example of a customer splitting an equipment order into bits and not buying the monitors we recommended (saved a full fifty quid on each unit!) has combined with Apple's very poor implementation of 1920x1200 resolution to bit us in the backside.
The newest iteration of MacPro workstations ship with a display card that has a DVI and DisplayPort (with a DP->DVI breakout adapter). Aside from the problem of non-standard blanking as implemented in OS-X's drivers (see my blog entry about Kramer DVI routers) there is a very funny (but consistent effect) if you boot one of those computers with two monitors extended over fibre - you get one display at low-res and the procedure to get two monitors running at 1920x1200 is;

1. Boot the machine with a single monitor connected to the DVI port - increase resolution in increments to 1920x1200 @60hz
2. Reboot
3. Check the resolution sticks.
4. swap the monitor to the Display Port output
5. Reboot
6. Wind up the resolution as per 1. and if OS-X detects the extra monitor turn on display mirroring
7. Reboot
8. If both monitors come back up at 1920x1200 then turn off mirroring and ensure that both monitors are still at 1920x1200
9. Reboot
10. Make sure it's all sticking!

Compare this to the procedure for bringing up a PC-based Avid (running on an HP 8400/8600 workstation, nVidia card);

1. Set both displays for 1920x1200 @60hz

It is so clear that Apple assume you have the machine under your desk and you're using two of their monitors on the pre-made cables they supply. That's not how broadcast facilities are configured and if Apple wants to see FCP used more in film & TV they need to make their implementations of signal standards more robust.