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.
- Broadcast engineering and IT related links and stuff. Maybe some music, films and other things.
Thursday, November 18, 2010
You know you're getting old when.....
OB Trucks you built are knocking about on the 2nd hand market!
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.
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;
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;
- 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.
- 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.
- 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.
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
- Connect the "Original/Broken DVD drive" to your PC via SATA or USB-SATA adaptor.
- 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
- 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.
- 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.
- 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.
- Open Firmware Toolbox (at least v. 4.5.1.6) and choose 'Tools -> Direct Drive Dump (GDR ONLY)
- 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
- 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.
- Connect the replacement DVD drive to your PC via SATA connection.
- Place the DVD drive into MODE B with SLAX
- 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.
- 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.
- Insert a DVD Movie or an XBOX 360 game into the Replacement DVD drive.
- Open Firmware Toolbox and choose 'Tools -> Direct Drive Dump (GDR ONLY)
- 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
- 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.
- 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.
- Choose the version that you would like the fw to report back as. Leave all other options as they are.
- Please note: - Spoofing a drive as itself has the effect of UNSPOOFING it
- Now Click "APPLY SPOOF"
- Choose "Tools->Smart Hack Patcher", a window warning will appear, choose OK.
- 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
- Push the "Generate File" button, if everything goes fine the file will be generated almost instantly
- 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.
- 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.
- With the old broken DVD firmware now loaded you will notice the "Key Information @" area in the center of the 360 Firmware Toolbox application.
- 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.
- 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.
- Paste the Key into the "Key Information
- Click on "Replace Key" and it will update the firmware with the new key you have just pasted.
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.
- Choose "Tools->Direct Drive Flash->Differential Flash Patch". Make sure the DVD drive you want to flash is selected
- Click the "Read Drive and Detect Differences" button, after a few seconds the sectors list below the button should be populated.
- It will now ask you if you would like to keep the keys from the drive.. Choose 'No'.
- Click the "Start Flashing" button and choose the flash mode.. I suggest using the 0047 flasher for 47 drives etc etc..
- After a few seconds the flashing is complete.
Resources;
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?!);
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.
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!
So - I called them to discontinue and start the number-port process and got the following torrent of lies!
- "You won't get more than two megabits per second out of Talk Talk" - well I ran SpeedTest.net several times yesterday and averages 22mBits/sec - faster than my Virgin cable.
- "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).
- "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'!
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 appEven 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!
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.
- 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.
- 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.
- 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.
- 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!
- 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).
- 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.
- 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.
- 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;
- 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.
- 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.
- 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).
- 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.
- 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.
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.
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 www.threeboys.co.uk for an example. Of course it's only editable by about four machines, but that's part of the strength of it.
See www.threeboys.co.uk for an example. Of course it's only editable by about four machines, but that's part of the strength of it.
www.tiddlywiki.com
www.dropbox.com
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.
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.
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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
- 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.
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!
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