Phil's technical blog

Phil & Hugh's first podcast - Fibre 101; what every broadcast engineer should know

2012-01-26T09:24:00.003Z

I've been bugging various industry friends to join me in an engineer's focused podcast for a few years now. Only my pal Hugh Waters (@hugh_waters on Twitter) stepped up and we have a whole series planned in this format.

Coming soon; Mains & Electrical Safety as well as TV Colourimetry.

The podcast RSS URL is http://blip.tv/phil-crawley/rss/itunes/ which contains low res, SD TV and 720-line version so if you drop it into iTunes make sure you've set it for what flavour you prefer.

AES pinouts for old Sony PCM800 recorder

2012-01-15T13:48:00.002Z

Struggled to find this the other day.

Re-formatting PDFs to read nicely on Kindle

2012-01-07T21:52:00.005Z

The Kindle is a great little machine (and the £89 keyboard-less version is excellent value). If you buy books or newspapers from Amazon they are perfectly formatted for the 6" screen and arrive in the proprietary file format. However, most of us have a stack of PDFs (books, work material etc) that you can drop into the /documents folder on the Kindle, but if they're formatted for A4 printing then you're either looking at very small text or trying to zoom & scroll the display.

k2PDFopt does a very good job or re-flowing the pages of a PDF (keeping diagrams in the correct place) to fit the 6" screen. I haven't yet tried the Windows or Linux versions but the Mac build is a bit fiddly (make sure you read the install instructions!) and you can't be shy of the command line!

My home AV rig

2012-01-02T17:11:00.008Z

I'm often asked what I use at home for music/TV/movies - nothing fancy (haven't got a 5.1 rig yet!) because money has been tight for the last few years and I try and follow the ex-work/cheap-on-eBay way of getting things done. As a family we all listen to podcasts and music on 'phones/iPods/USB-stick-in-car and since we don't have any consistent manufacturer for anything we keep everything as MP3s and DivX AVIs or MPEG2 (for off air recordings of TV shows).

Music - I started encoding my music in 1999 when I got my first MP3 player (the mighty Diamond Rio 500 in case you remember!) and so experimented with different encoders and data rates. At the time I concluded that the Fraunhofer MP3 encoder at 128kBits/sec was adequate if I was using ear-buds or in the car. I quickly changed my mind and have been encoding all my music at 192kBits/sec using variable bit-rate. I have blind-tested myself on good speakers and conclude that for my middle-aged hearing I can't spot the difference between uncompressed and that data rate. MP3 is the way to go as I have a mix of playback devices (iPhone for personal listening, Dell Digital Audio receiver for the living room along with various PCs & other-brand 'phones & MP3 players for the rest of the family). Consequently I always set iTunes to encode to MP3;

I often hear people banging on about FLAC and Apple Lossless but I'm not that bothered. I tend to listen to music for the lyrics and chord progressions, not that last 0.01% of perceived fidelity. I spend my life listening to proper speakers (i.e. thousands of pounds a pair) either from behind a mixing desk or in a dubbing suite so don't try impress me with what you bought in the high-street! I know what good audio sounds like.

TV recording and video playback - I'm using Windows 7 on a ten year-old workstation to make recordings off air; two £15 no-name Maplin-special USB DVB-T sticks allow multiple recordings via Windows Media Centre. I keep thinking I'll buy a DVB-T2 stick so I can make FreeviewHD recordings but I haven't yet, partly because iPlayerHD is so good. The machine that feeds the living room TV is the same machine machine that is the kitchen iTunes/radio machine - it has two soundcards and dual-display. In there kitchen there is a mini keyboard and mouse and in the living room a hand-held RF mouse. You wouldn't know it was the same computer save for when you want to fast-forward the video playback whilst someone in the kitchen is trying to find a song in iTunes and the mouse pointer jumps off your screen!

Commercial removal/editing - I used to be a big fan of ComSkip as it is an excellent automated ad-break remover for Transport Stream video. However, I watch so little commercial television that I've found my regular MPEG editor Video Redo to be just as good;
DVD / BluRay - I grabbed a Sony S370 on eBay for £70 and it is an excellent machine; actually better than the S380 that replaced it (Sony lost the right to several codecs). It supports several online video services.
iPlayer - we used to use the Wii as an iPlayer machine and it is really good, but standard definition only. In fact I picked up a Wii with a faulty DVD drive for my Mum and loaded the iPlayer client onto it and she uses it as her BBC on demand machine. We now use the Sony BluRay player as it supports HD iPlayer and the pictures at 5mBits/sec are indistinguishable from off-air HD playback. Even the SD content looks better than the Wii's output.

So that's it - I'm not in a position to spend thousands of pounds but I am pleased the way I've got it all working for virtually no money.

Subtitling software and my new Bluray player

2011-12-05T09:44:00.007Z

Occasionally my PVR makes an incomplete recording of a film that Sarah and I wanted to watch. It was the case last week with the Italian film Couscous and so I didn't feel too bad snagging a copy from a torrent site. However, when we sat down to watch it I realised there were no subtitles (either burned into the video or as a separate text file). "Not a problem" I thought - straight to one of the many sites that carry subtitles for every film ever released and I grabbed a likely looking .sit file for the movie. After discovering that Microsoft have pretty much removed all subtitle support from Windows 7 (my PVR is MediaCentre) I tried watching it with that old faithful backup VLC player (an order of magnitude better than WMP12 in every respect!) - a good example of where open-source software makes the closed-source equivalent look very silly - but I discovered the subtitles in the file were a consistent twelve seconds late. I suppose the subtitler was working off a different version of the film, maybe he started his frame count with all the film and distribution company bumpers?

Again, no worries, I fired up my previous standby for manipulating subtitle files DivXLand Media Subtitler only to discover it can't slip ever sub in a file by a defined amount. In every other respect it s an excellent utility handling twenty-odd file formats and having auto-timing functionality as well as individual sub-sync features, but couldn't handle this problem easily.

So, bit of Googling revealed another free and excellent utility Subtitle Edit which offers pretty much the same toolset but with the ability to slip the sync on groups of subs. Just what I needed; it has a better preview facility as well so you can drop into various places of the video file to check the captions are consistently running to time and it will automatically pull captions a few frames either way when the audio waveform doesn't quite match with the start frame-code of the subtitle.

After this VLC played the .avi & .sit combo perfectly but not WMP12 or MediaCentre. At that point my thoughts turned to my new (2nd hand!) Bluray player; a Sony BDP-S370 which we've had for a week (£70 on the eBay) and have been mightily impressed with it's network video functionality. It's the best iPlayer machine I've found so far bar none (much better than the Wii, Virgin Media & Tivo) and it will happily play the file and display the subtitles either off a thumb-drive or via the network using DNLA.

RS422 / Sony P2 protocol and serial stuff!

2011-11-23T13:18:00.003Z

When running P2 protocol over RS422 (i.e. Sony VTR remotes) there is no hardware handshaking so RTS and CTS (Request To Send and Clear To Send) aren’t used; a bit like the old 3-wire XModem/YModem/Kermit protocols used in RS232 (remember RS422 is just a balanced version of RS232).

We base our RS422 wiring on the Quartz remote standard (Quartz were one of the first firms to use RJ45s & cat5 for RS422 remotes):

However – I know for certain that Probel use a different standard and many places are wired to whatever the local standard is; remember – until ten years ago most places wired ‘422 on star-quad cable rather than cat5e/6. I don’t know if current model Evertz routers have maintained the Quartz standard – I bet they have given they bought Quartz for its router business.

Whatever wiring standard is used always make sure that pins 2 & 7 are a twisted pair and likewise 3 & 8 otherwise you lose all the advantage of common-mode noise rejection that balanced RS422 brings.

Finally you need to be certain if a place is wired for chassis earth (pin 1 on a 9-pin) or signal earth (pins 4 & 6 on 9-pin). Signal earth is best as there is always a chance of earth-hum between areas when you tie chassis earths together but hopefully properly designed kit with balanced lines have the signal earth floating WRT to power/chassis ground. BUT, you have to stick with the local standard; if the engineer has wired only chassis earths you need to continue using pin 1 or even shorting pins 1, 4 & 6 at the remote end.

Remote control options

2011-11-10T17:55:00.005Z

If (like me) you find yourself as the default tech support provider for friends and family you've no doubt wondered about remote desktop software - VNC, RDP, Apple remote desktop, or any of the paid-for managed services (Go To Assist, LogMeIn etc).

I think there are several things to bear in mind;

NAT routers in the way? If you're merely using remote desktop to go between machines on the same LAN then this isn't an issue but if you have to take control of your Mum's laptop and you're both behind routers then you either have to have made a hole in her's or be using a protocol that supports NAT translation.
IP address - again, the person you're trying to reach may well be on a dynamically assigned IP address.
Bitmap vs remote GUI rendering; VNC sends a bitmap (admittedly compressed) and so maybe sluggish whereas Windows RDP or Apple remote desktop send GUI primatives which render at the remote end.
What combination of OSes are you using? Running Windows but supporting someone on a Mac? The remote desktop client built into OS-X since Tiger falls back to VNC if the remote machine isn't a Mac - nice touch.

So - in the case of my Father-in-law's Windows XP desktop machine I use VNC every time - This is because I don't know if he's going to call me during the working day (when I'm using an OS-X laptop) or in the evening when I'm likely on a Windows 7 or XP desktop. Since his machine is fixed I had the liberty of installing a DynDNS account on his router (so I hit a username.dyndns.org address rather than trying to discover his internet-facing IP address) and I opened a hole in his routers firewall (so traffic on TCP port 5900 gets mapped through to his PC). With all that in place I know I can grab control of his desktop using TightVNC (my favorite VNC client) under Windows or the built-in remote desktop of Snow Leopard;

On the other hand my Mum has a laptop which may or may not be at her house. Since she is running Windows 7 and I can always get to a Win7 machine she Instant Messages me with a Windows RDP support request and after a bit of typing in confirming codes it works well without having to worry about IP addresses or NAT traversal.

That leaves the paid-for server-based systems like Log Me In and Go To Assist which require no software installed (it's done via a quick Java download) and take care of NAT traversal etc.

So - you pays for money, you takes your choice. I prefer VNC because it's open and works across OSes. It does require a bit of work to send it across the public internet. After that Windows RDP is fine if you have contemporary Windows boxes. I suspect at some point I'll sign up to Go To Assist and pay as it is very convenient and works entirely well across networks and OSes.

VNC connected to my home Windows 7 media machine, running inside a Windows 7 virtual machine on my Macbook Pro under OS-X

TCP/IP Congestion Avoidance

2011-11-04T21:38:00.003Z

TCP/IP is a jolly clever protocol that now forms the bulk of the traffic that runs across the Internet. Given that routers and gateways along a packets route are entirely at liberty to drop packets without informing either the sender or the recipient (it's up to the client/server to figure out packet sequence and if any packets were lost) there is a very clever way that the IP stack in your computer does packet collision avoidance.
So when TCP establishes a connection it goes through an IP-slow-start. In essence the stack has to "sneak-up" on a transmission speed where packets are being lost faster than they're being sent; when that occurs the stack backs off until packet failure is happening less than new packets are being sent. The initial condition is that the stack can send two packets without getting a confirmation. For every confirmed packet the stack can increase the maximum segment size by one so that two packets can become three and so on. After that there are several commonly used strategies, most commonly "TCP Reno" and "TCP Tahoe". Tahoe reduces the congestion window to one MTU ("Maximum transmission Unit" - typically a 1550 byte packet in Windows) and then go back to the IP-slow-start. Reno halves the size of the congestion window and so backs off slower than Tahoe but hopefully the link has recovered fast enough to make that a better strategy than Reno.

Anyway - as ever the Wikipedia article is very comprehensive;
http://en.wikipedia.org/wiki/TCP_congestion_avoidance_algorithm

Bill Mallonee's new record

2011-10-21T14:18:00.002+01:00

Best thing I've heard so far this year - full band/studio album from the most talented song-writer still working in the USA.

&amp;amp;amp;lt;a href="http://billmalloneemusic.bandcamp.com/track/carolina-carolina-3"&amp;amp;amp;gt;CAROLINA, CAROLINA by Bill Mallonee&amp;amp;amp;lt;/a&amp;amp;amp;gt;

"...noisy, jangle-y, lush, passionate, Rickenbakers, hooks, '60's, '70's...cobalt blue skies;"

all songs by Bill Mallonee
released 02 October 2011
Bill Mallonee: vocals, guitars (electric, acoustic, hi-string) harmonicas
Muriah Rose: vocals, piano, organ, mellotron
Bert Shoaff: bass
Kevin Heuer: drums, percussion

Save us from Media Studies students!

2011-10-19T17:49:00.003+01:00

I was on the train on the way up to Manchester this morning - on the next table along were four undergraduates on the way to the BBC for a recruitment day out and clearly part of their day was to propose potential new programme formats. Well - they spoke very loudly and earnestly about their ideas for radical new television shows and all made notes in their moleskin notebooks. Their ideas were so derivative and tired it made me chuck and I made a note of some of them;

"Darts players - wives & girlfriends" - a reality show investigating the love lives of darts players. @bendavison tells me it's been done already, sigh.
A series of documentaries that challenge racism by featuring the apparently growing Bollywood porn industry...!
"Strictly come prancing"- reality show for jockeys.
"Blaggers with attitude"; documentary series following people around the festivals who manage to score free stuff; t-shirts etc.
"Bankrupt celeb finance boot-camp"; broke Z-listers learning how to manage the money they get from Heat Magazine.
"Boyle Baron" - singer Susan Boyle learns the ins and outs of the oil industry.
"The Grapes of Hoff"- David Hasselhoff becomes a vintner.
"Frankie goes to Bollywood" - ex. members of the 80s band learn Indian dance moves; they also discussed if it should be for Comic Relief(!)
"The Yids are alright" - Pete Townsend explores Jewish culture.
"Train of thought"- a gameshow set on the West Coast Mainline. Different stations would signal different rounds. Would suit Alan Titchmarsh?

So - BBC, stop employing media-studies graduates and instead give English/History/Classics students a shot at making some original TV.

If you see any of these formats on BBC3 in eighteen months time you read it here first!

The Monty Hall problem

2011-09-30T16:43:00.006+01:00

This is a scenario made popular by the American game-show "Let's make a deal"; The host, the eponymous Monty shows the contestant three doors and tells them there is a car behind one of the doors and booby prizes (typically goats) behind the other two. The contestant gets to choose a door and then Monty opens one of the doors they didn't choose showing them a goat. He then offers them the chance to change their mind. Initially most people say something like "..it's fifty-fifty, so no, I won't change" - but it's not 50/50, changing your mind at this point doubles your chance of getting the car.

Possibly because I did a year of Game Theory on my degree the first thought I had when I initially heard this problem was "where are the odds invested?". When you pick your first door your odds are a third. However - two-thirds odds are invested behind the other two doors and when Monty shows you which of those doors has a goat you know that none of the odds are now behind the door he just showed you; the car can't be behind that door (Monty showed you the goat). Your original door still has a third of the odds and so now the final door MUST carry the two-thirds odds that you didn't choose initially. Changing your mind now doubles your odds.

It's not a straight fifty-fifty because Monty introduced some new information half-way through the game. He showed you which of the two-thirds doors don't have the car.

The Wikipedia article is very good - I nicked the picture from there.

The problem is interesting because it shows how little innate understanding of game theory (and statistics, and probability) most people have. You gotta trust the maths, not your instincts.

Recovering corrupt flash memory cards

2011-09-29T10:10:00.003+01:00

The good thing about paid-for photo-recovery software is that they have an easy trial-model; they show you the images and videos they can recover and you stump-up your $50 to register the software and get at your pictures. I've had varying success with a coule of paid-for apps but I came across PhotoRec yesterday (it's part of a larger suite of tools).
Now, granted, the pay apps have nice GUIs while PhotoRec runs in the UNIX shell in a text-based interface, but it requires little interaction and gets the job done. It also runs on just about any common OS platform from Mac OS X to Windows to Linux to Solaris, etc. Link in the title.

Couple of quick things that have caught my eye

2011-09-16T12:08:00.006+01:00

http://en.wikipedia.org/wiki/Graded-index_fiber

http://rob.rho.org.uk/2011/09/mmmm_pie.html

The surprising truth about what motivates us.

Things that peaked my interest at IBC

2011-09-14T13:34:00.003+01:00

I spent just a couple of days over at the RAI in Amsterdam. It was splendid to catch up with some old pals and Bryant Broadcast do an excellent night out. My main observation is that 3D/stereoscopic was no where near as prominent as it was last year and as the number of network delivery solutions increases the number of 'proper' transmitter companies seems to drop.

Newtek - updates to TriCaster, new model & control panel. The new 450 is very similar to the 850 but has only four HD inputs (against eight). The other things that I think are significant;

3Play - their "poor man's EVS" has been improved. Running on what looks like a Tricaster 850 chassis it now has eight inputs and can run two outputs simultaneously. For sports slow-mo it is an excellent quick turn-around solution at the fraction of the cost of EVS.
VTR-style control for the DDRs in Tricaster; might suite some people.
Tricaster Extreme upgrade - allows for eight ISO records (can be either cameras or other internal/external sources, at different rasters and codecs than the main record).
They fixed the AUX audio in embedded HD-SDi I'd been moaning about!
The network sources (iVGA feeds) can now carry audio as well.

VidCheck - file-based QC is getting good! In fact this one looks like it needs serious consideration! I have a demo license on the way and will report back. Along with being able to test all the usual codecs etc it does full ITU.1770 audio loudness AND has numerous correction facilities; Tektronix AND Eyeheight, you might say.

Containers: MPEG-2 TS, MPEG-2 PS, MXF, MP4, MOV, ASF, AVI, LXF, GXF, FLV, F4V
Formats: Web, SD, HD, D-Cinema and many custom formats
Video: MPEG-2, IMX, XDCAM, D10, HDV, DV25, DVCPro50, DVCPro100/HD, AVC/H.264, VC-1, ProRes, DNxHD/VC-3, MJPEG
Audio: MPEG, PCM, WAV, AAC, stereo, 5.1 / 7.1 Dolby, multiple different language tracks

The really significant thing is the price €5k with paid options (DolbyE, ProRes etc) in the hundreds rather than thousands of pound. It also seems to handle multi-core computers much better, a single instance scaling to 28 cores.

AutoQue - they make broadcast monitors, who would have thunk it? They seem to be pitching them very much against the JVC DT-V24 series at the bottom end (a grand cheaper) and the VuTrix at the edit suite/grade-1 end (again, a lot cheaper). I have demo stock coming so I will write a bit more when I've seen them.

Other things worthy of note - Tek now have all their 3D analysis tools in the WVR/WFM-8000 series 'scopes. I had a very informative half-hour with Lee Ballinger from Tektronix going over them.

Security and the Diginotar debacle

2011-09-09T20:03:00.004+01:00

You might have been following the trouble that the Dutch SSL-certificate issuing firm Diginotar have been suffering recently. It transpires that Iranian hackers have got into their system and have spent several months issuing themselves wildcard certs for well known domains, most notably *.google.com - it essentially means these ne'er-do-wells can sign certificates that look like they have come from Google and your browser would be none the wiser. In fact it's not that severe unless you've been the victim of another attack;

Man-in-the-middle attack - you might be in a coffee shop where someone has managed to poison the ARP-table in the router and inserted themselves into your wireless comms. If they served up the fraudulent cert they could make any domain (especially there own server) look like you were securely connected to.
DNS-poisoning attack - as highlighted by Dan Kaminsky a couple of years ago it is possible to for elderly versions of BIND and more contemporary versions of IIS to incorrectly serve up DNS look-ups. Once this is in place the fraudulent cert on the same server would have you believing you had a secure connection.
Corporate decrypting proxies; many corporations install their own certificate on all client machines and essentially do a man-in-the-middle SSL intercept. Your traffic to Amazon.com is encrypted, but it goes via the proxy where it is momentarily decrypted for your boss to look at! If a corporate proxy was compromised dodgy SSL certificates could have you believing you had an encrypted connection to Amazon.

All of this raises issues with SSL - when I first started using an SSL browser (Netscape Navigator v.2 IIRC in '95!) there were around seven or eight trusted issuing CAs. Now there are hundreds (including the Hong Kong Post Office!) and it comes as no surprise that some of them get compromised sometimes. What I don't understand is why browsers don't keep a record of the CA associated with domains and when they see a change (particularly if a cert had time to run) inform the user? There is a plugin I use for Firefox called "Certificate Patrol" that does just that and it's easy to use and unobtrusive.
Now then - the whole Diginotar story started three months ago and they didn't spill the beans until last week; security is never served by secrecy. Also - it took Apple far to long to patch Safari. I think if you're concerned about network security then avoid Safari on OS-X.

Sony BVM-E250 OLED broadcast monitor

2011-08-27T18:46:00.003+01:00

I had an hour or so to set up a new Sony OLED grade-1 next to a Vutrix HD Pro-24 (their grade-1 LCD display which I like) - the Sony is twice as expensive as the Vutrix (£20k vs £10k). OLED as a technology is supposed to have a number of advantages over thin film transistor (TFT - the important bit of an LCD display. A few are;

In a TFT layer the polarisation of light is twisted through 90 degrees to allow the pixel to be illuminated by the virtue of the fact that the front filter is 90 degrees offset from the rear. In effect the transistor stops the light from the fluorescent (or nowadays LED) source. Since the light source is a few millimeters behind the pixel there are chromatic distortions inherent and since thin-film transistors don't shut-off all the light when turned off there are black-level issues. These are the two best known problems with LCD monitors in film & TV grading.
Thin-film transistors have a limit to how quickly they can be cycled - typ. 16ms at best (I know some manufacturers claim faster but it's smoke & mirrors). OLEDs can be cycled a lot quicker for better response.
In a TFT display the place where the colour is made (the three sub-pixel RGB transistors) is physically separate from the light source - not so with OLEDs where the illuminating LED is also the colour-maker.

So - with deeper blacks and fewer chromatic problems you'd think OLEDs were the way forward. The only thing to consider is the life-span. The blue OLED elements have an estimated life of 10k hours (around a third of the backlight of an LCD). Also - the metameristic character of OLEDs is different and so colour-management tools will need to be upgraded (I just spent £7k on a new LCD photometer!).

I thought out of the box the pictures on the BVM were very good - close to the VuTrix I'd just calibrated to illuminant-D (6504K at 80Cd/m2 for peak white). Response seemed as good with much better blacks, particularly from different angles. The monitor's de-interlacer didn't seem as good as I'd have expected for video-shot material but camera pans etc looked better than the VuTrix.

Overall I was impressed, but not an extra £10k impressed!

UPNP has always been a bad idea!

2011-08-26T13:46:00.003+01:00

UPNP is a protocol that allows an application to open up ports on a router so that incoming packets from the Internet get to the correct IP address on the LAN. It's typically used to allow the XBox360 to set up open ports through your router to allow multi-player gaming. If both XBoxes are behind NAT routers there is no way that unsolicited traffic from one can make it to the other (hey, I never wanted your bullets to hit me!). Skype suffers thus if both callers are behind NAT routers (i.e. in most cases; who has an internet-facing IP address on their machine nowadays?) - details here). More recent versions of Skype will make use of UPNP if it's on the router.
You won't be surprised to learn that it's a Microsoft technology and I've always encouraged people to disable it on their routers. Any piece of malware inside your network can open ports and invite any other nasties in. In the case of XBox there are about four ports you need to open up for the Live! service to work. Anyhow - it turns out that Linksys routers have a bug that allows UPNP activation on the WAN side - that's right, with the correctly formatted packets you can open ports through a Linksys router from the Internet. Using something like UPNP Port Mapper will allow you to scan Internet IP addresses and open ports on those routers.

The title link is to the article on The H.

Flame ain't all that

2011-08-25T16:05:00.005+01:00

The facility that I'm building at the moment has a couple of Flame Premium suites - the very best version of Autodesk's TV and film compositing and finishing tool. Now I know very little about Autodesk products - I've never really worked in facilities where they were used. Flame, Smoke and the rest of them have been around for nearly twenty years and so you'd think they are what software people would describe as "mature products".
Anyway - a currently model Flame runs on an HP Z800 workstation with a Kona K3 card for video i/o (more about that in a minute!), an nVidia 4500 for desktop and their own proprietary fibre attached storage called "stone". They can typically handle two streams of 2k in realtime.
All very good, but everything is specified in a system - even down to the Eizo monitor you can use for the desktop display. This is because the SDi output for preview (which is not the output of the K3) is made by looping the 2nd DVI output of the graphics card into a daughter card that converts it to SDi. Consequentially you often see bits of the GUI on the HD video monitor. Now the reason for them specifying a certain model of GUI monitor becomes evident - they have to run the output at a rate near video for the DVI output to be convertible! This gets even more silly when you find out you have to use their own provided long DisplayPort cable to run it. We'd run in LC loose-tube fibre with DVI extenders which initially only worked whilst Linux was booting in text mode (i.e. before the X11 display subsystem could run). I had to throw in a Lindy EDID manager to fool Linux into thinking it really had the Eizo directly connected before we could run the desktop (and hence the Flame application).
This, along with a ton of little bits that the kit ships with; an 8-port ethernet hub, Lucid AES->analogue converters etc gives the impression they expect you to install the system on your dining room table rather than in a pro video facility. It really has the feel of a v.7 Avid from 1996! Cobbled together from third-party bits and only just running (everything on the hairy edge).
It reminds me of the Abekas DVEous (again, 1996) - one of the design engineers confided in me that if every bit of silicon on the video-processing board only performed to published spec then the system couldn't work. They relied on everything outperforming itself.

Mute the TV automatically!

2011-08-18T11:25:00.003+01:00

I've been a fan of ComSkip (a PVR plugin that automatically detects/removes TV adverts from recorded MPEG2 transport streams) and I firmly believe that technology will allow us to 'tame' various media sources - advert blocking in Firefox makes the web a nicer place, for example. Anyway - this is great, what a project;

iPhone 4 battery fault? NO!

2011-08-17T10:22:00.006+01:00

Yesterday my iPhone 4 starting showing all the signs of a failed battery - the back of the 'phone was hot and it could hold a charge for around three hours. Darn - replacement handset with all the attendant messing around (although it a lot easier than it ever was on Windows Mobile!).
Anyhow - Googling around brought up a few sites with folks suggesting the mail daemon can get stuck trying to synchronise with Exchange and merely turning off push and letting the 'phone entirely discharge (or doing the hard-reset method of holding down the home and power buttons until the 'phone has powered off and restarted) and then re-enabling push sorts it.

settings>mail,contacts,calendar>fetch new data>advanced

By jove - it did the job. I can only assume the handset burns through the battery by keeping a data connection open continually.

I haven't blogged much recently because I've been on holiday. Pics here

Making iPhone ringtones from MP3s

2011-07-19T14:02:00.003+01:00

1. Start iTunes and find the song you want to convert. (It must be an MP3.)
2. Right-click the song and choose Get Info.
3. Click the Options tab.
4. Check the Start Time and Stop Time boxes, then enter times for each (no more than 30 seconds apart, the maximum length for a ringtone). I used 0:00 and 0:30, respectively, as "Spit It Out" has a perfect ascending lead-in.
5. Click OK, then right-click the song again and choose Create AAC Version. You should immediately see a new 30-second version of the song. You need to make your import settings are set for AAC (I normally leave them as MP3).
6. Drag that version out of iTunes and into the folder of your choice.
7. Delete the 30-second version from iTunes and undo the Start Time/Stop Time changes to the original.
8. Open the folder containing the 30-second AAC file you dragged out of iTunes, then change the file extension from .m4a to .m4r. Double-click it and it immediately gets added to iTunes' ringtone library.
9. Finally, sync your iPhone. When it's done, you can head into the settings and select your new ringtone.

Couple of gems; Spanish Flea and Hawaii 5-0

Two location-based things I'd like from my smartphone

2011-06-23T17:38:00.003+01:00

Location aware mute; I'd love to have a silent setting that unset itself when you moved more that (say) 50m from your current location. I have often put my iPhone into silent mode for a meeting and then noticed later in the day that I've missed several call because I forgot to take it out of that mode. Also - time-based silent-mode. I'd like my 'phone to auto-silence every Sunday 10:30 - 12:30 'cause I'm in church (for example).
Location aware alarm; I've often missed a train stop because I've fallen asleep listening to a podcast or music. Why can't I set an alarm that rings in my earbuds when I get within five miles (say) of a location? Also - the ability to announce the time every ten minutes in the earbuds would be great.

Bitcoin

2011-06-16T14:32:00.004+01:00

Unlike other digital currencies, Bitcoin avoids central authorities and issuers. Bitcoin uses a distributed database spread across nodes of a peer-to-peer network to journal transactions, and uses digital signatures and proof-of-work to provide basic security functions, such as ensuring that bitcoins can be spent only once per owner and only by the person who owns them.

My introduction to Bitcoin was via Steve Gibson's "Security Now" podcast; (check out episode 287 here). Along with the Wikipedia article my interest was peaked. Bitcoin seems to be a real, credible digital currency that is cryptographically secure. However - a currency needs to appeal to more than engineers and the economists are up in arms about it - read the very entertaining exchange here.

For the moment Bitcoins are trading for 1 BTC: 20$

Estimating the time a job takes

2011-06-12T18:29:00.003+01:00

For the last eight years I have spent a lot of my time quoting for broadcast installation builds. From small single edit suites to £1.5m broadcast editing centers I think I have a good feel for how long most jobs take. I recently did a search of my arrogated purchase orders folder and discovered I've bought more than 500 equipment cabinets, nearly 1000 video jackfields, and just over 100 kilometers of bulk fibre optic cable - all in the last eight years!
Anyhow - I often get quotes thrown back at me by chief engineers who assume I'm trying to fiddle them and they will typically say;

You've quoted ten days for a wiremen to wire those audio patch panels back to krone blocks; I'm sure my guy could do it in seven.

Even as a chief engineer he's probably only built one or two big machine rooms in his time. He might think he has experience of wiring technical facilities, but I've hired and paid wiremen to do many hundreds of audio panels in recent years. Possibly more than all the panels every chief engineer in Soho will oversee this decade! I know how long things take.

Anyway - for the last five years I've done an audit at the end of each year to compare the number of wiremen and engineer days each job used against what I thought when I quoted. It turns out that I naturally underestimate the time required by around 25% - If I quote 100 wireman days it'll be nearer to 130 when all is said and done. This isn't down to me not knowing how long each part of the job takes - it's a function of wasted time;

Client won't provide passes to everyone and so guys have to wait idle in rooms or go looking for the pass.
Deliveries are late, guys are idle
Customers change their mind, but not enough (or it isn't politic) to warrant a change order
Faulty parts - we always have to replace those for free!
Various other things you didn't expect.

So - I've made it my habit to still estimate the number of days as I think it should be and then add on the 25% extra. Consequently my quotes have been getting a lot more accurate over the last few of years. I also discovered the same effect with parts but in the other direction; I always over-estimate the amount of cable/connectors required by around 10%.

So far I haven't done anything about that!

Tektronix WVR5200

2011-06-02T18:04:00.004+01:00

During a manic day I was fortunate enough to bump into my old Tektronix mucker Tom Perry who had a new WVR5200 in his rucksack and gave me a quick in-the-street demo! It seems like a much more complete instrument than the current WVR5000 'scope and I can't believe it won't cannibalize their WVR7000 and 8000-series business. The things that stood out for me are:

Much improved four-tile monitoring with four inputs that can be configured as 4 x SDi (270M, 1.48G, or 3G - yes!) or 2 x dual-link. With four discrete inputs you can display all four at once.
An SDi o/p that can be any of the inputs OR a test output with bars or pathological signal.
Audio loudness - and up to 16 channels via embedded groups
Full Java control (the 5000 lacked this)

So I think this is excellent - the only thing missing is physical layer measurements. Some of the better features are paid-for upgrades (license key) but at £4.5k this represents superb value.
I shall write more when I've had one in to evaluate.

Tricaster tally-light interface for EX3s

2011-05-24T14:09:00.005+01:00

One of my favorite parts of the job is prototyping and making little interface units so that equipment from different manufacturers can talk to each other.

This gadget allows the Tricaster TXCD850 studio production system to light the tallies on Sony EX3 cameras; although the Tricaster has "wet"-style GPI outputs it can drive the 12V needed for the lights. So, simple buffer circuit with relays to drive the studio tallies;

There are some photos in a Facebook album - click the title link.

Extending Sony 8-pin camera remotes

2011-05-23T15:50:00.019+01:00

How far can the camera control signals from any smaller Sony camera go? If you talk to Mr Sony it's around 50m (the longest cable they sell) - but as the pictures (below) suggest it's at least the length of a box of cat5e cable! The CCA5 cable they sell is north of £500 so I recommend you hot-foot it over to RS, the Hirose ends are part numbers 685-1166 and 685-1163 for the lady and the gentleman and by consulting my scrappy wiring notes (above) you can brew your own for a tiny fraction of the cost. You can also adapt the cable to send down existing structured cable routes (cat5e / cat6 / cat7).

The title-link is to the F23's maintenance manual; that SR field-recorder has every Sony standard interface on it and so you can find the pinouts for whatever you might be using on your EX3 for example.
Rather splendidly the DC supply that runs back from the camera to the remote is the unregulated feed and so even if you loose a few volts down your home-brewed cable the regulator in the RM-B150 won't care; if you want to you can even power that device locally and not worry about volts coming back from the camera.

Old SVHS machines, the half line and archive ingest

2011-05-17T14:43:00.007+01:00

As every superhero knows it's the second half of line 23, field one, that active content starts in a PAL signal yet come the start of field 2 line 336 starts as a full line with the corresponding half line at the end of field 2 on line 623. Consequently without a reference signal the only way to tell the difference between field one and two is by the half line at the top of field 1 (well, the broad pulses at line 3 vary but most equipment is field-locked by the time you get to that point in the scan).
We've been testing an ingest/archive solution at the workshop for an African state broadcaster who have a large analogue archive (SVHS and BetaSP). Capturing off the SVHS deck they'd provided for testing (a Panasonic AG-7550) we got some very strange effects. The route is this;

Analogue VT -> AJA FS/1 processor -> SDi into Content Agent uncompressed AVI

this is then compressed to 50 Mbit/s MPEG2 transport stream (I-frame only) and mux'ed into an MXF OP-1A and onto the shared storage. The file is then QC'ed on another machine with a Decklink SDi o/p running OpenCube MXF playback software. Both the input to the CA and the output of the QC are displayed on a JVC DT-V24 video monitor and Tek WVR5000 waveform.

All the clips captured off the SVHS were field-reversed by the time they got to the QC and so we assumed that there was some problem with the capture. After a lot of testing and head-scratching I discovered that the internal TBC on the Panasonic was removing the half-line at the start of field 1 and from then on the capture was marking F1 as F2 and vice-versa.

If you look at the output of the QC machine you can see the half line at the top of the frame, but the motion of the replaced video suggests the fields are reversed. In fact the fields are in the correct order but the capture card has marked them incorrectly and so by the time they are multiplexed and played out they are in the wrong order. The Tek shows the missing half-line at the start of field 1 (on input) and since there is a half line on replay it seems it must be there on field 2; hence the confusion by the capture card.

Turning off the AG-7550's TBC and relying only on the FS/1 showed the half line return to the start of field one and the problem disappeared.

Varying standards...!

2011-05-13T21:47:00.004+01:00

Recently we installed five bays worth of equipment at a big facility - of course we did all the usual; Scope of Works, Method Statement, etc and when we'd finished all the usual test results - particularly electrical safety (since we all live in a 17th Edition world now). Now this machine room (one of several) was more than fifty cabinets and so you'd think they've sorted out all of their standards. However - when were handing over we were met with the following criticisms;

"You've mounted all the storage chassis flush with the front of the bays; our standard is that they are proud of the rack-strip". I went around the all other cabinets and they were an almost 50/50 mix of mounted proud and mounted flush...?
"You've attached the earthing straps to the front mounting-point of the bay, our standard is to the rear". I went around the all the other cabinets and discovered the only bays in the whole comms room with earthing straps were the ones we'd just installed.
"Our standard for PDUs is for 10-amp IEC outlets - even when they're feeding C19 (16A input) equipment, you've installed 16A PowerConn outlet PDUs" - we have to certify what we do to appropriate standards (that pesky 17th Edition again!) - no death-leads when you use us...

So I left confused, they'd taken us on to do a job they clearly didn't want/weren't able to do but they had nothing but ridiculous criticism by the end of the job. There doesn't seem to be any camaraderie amongst engineers anymore.

iPhone vs Windows Mobile

2011-04-23T22:09:00.002+01:00

I'm very pleased to have recently upgraded to an iPhone 4 handset. It really is much better at running the v.4 software than the iPhone 3 and reminded me of the reasons I was pleased to leave Windows Mobile behind and how some of those things are starting to bedevil Apple.

Windows Mobile was effectively unsupported from the moment you owned the handset. In seven years and six handsets I never had a manufacturer-pushed upgrade. On a couple of occasions I managed to find slightly hookey versions (from other networks etc) than upgraded versions slightly but it never worked well. This seems to be playing out again with WM 'phone 7 for mobiles (or whatever they're calling it!); a year out of the gate and there has been one update that bricked a lot of handsets! MS are still asleep at the wheel when it comes to cell 'phones.
With Windows mobile you have to hit the right hardware/OS version combo; A couple of handsets I owned were early in OS cycles (the first WM6 ones for example) and they weren't man enough for the new version of the OS. A couple (the HTC M1000 and the Vodafone V1615) were right before OS upgrades and worked brilliantly. The iPhone is starting to suffer this; nobody should run V4 on a v3 handset and expect the nice experience they remembered when they first got the iPhone.

It's an interesting time in smartphones; I wonder who will take third place after the iPhone and Android (or the other way around) - Blackberry or Nokia/Windows Mobile?

"Schneier's Law"

2011-04-21T21:53:00.002+01:00

Anyone can invent a security system that he himself cannot break. I've said this so often that Cory Doctorow has named it "Schneier's Law": When someone hands you a security system and says, "I believe this is secure," the first thing you have to ask is, "Who the hell are you?" Show me what you've broken to demonstrate that your assertion of the system's security means something.

Bruce Schneier is such an insightful chap - his blog is required reading if you have any interest in security or crypto; and really that should extend to anyone who is involved in networks. The grain of truth I take from this law is that you have to have to certain level of understanding of a subject to recognise your own ignorance. My dad had an expression "...you're not even wrong" - being so far removed from the truth that you're not even on the same field as people who understand the problem (even if they've come to the right or wrong conclusion).

I'm so busy at work at the moment I'm not blogging to much.

Video post production a 'dying industry' - yikes!

2011-03-29T11:19:00.004+01:00

This is a table nicked from the Wall Street Journal (via my pal Hugh - @hugh_waters on Twitter). On one hand it's very worrying but on the other hand it's what I've suspected.

The equipment required for TV post production is now a £1.5k laptop and not a room that cost a million quid to install (twenty years ago). It's why audio still makes money (you still need an expensive room even thought the equipment is cheap) and why OBs, studios etc will always be profitable.
Post production is largely run by owner-operators; folks who have an emotional attachment to it and will do work at a loss for the love of it and have a far too optimistic view of the future.

I don't know what the answer is - I'm going to try and concentrate on designing/building audio suites, TV studios etc and avoid edit rooms!

Side channel attacks with encrypted data

2011-03-21T13:27:00.004Z

In cryptography, a side channel attack is any attack based on information gained from the physical implementation of a cryptosystem, rather than brute force or theoretical weaknesses in the algorithms. For example, timing information, power consumption, electromagnetic leaks or even sound can provide an extra source of information which can be exploited to break the system.

Several examples that I think are interesting are;

Secure web applications; Bruce Schneier's excellent blog (which is required reading if you have any interest in security/crypto) describes the attack carried out on the IRS's (what they call the Inland Revenue in the US) online tax form site;
...it leaks a fairly accurate estimate of your Adjusted Gross Income (AGI). This happens because the exact set of questions you have to answer, and the exact data tables used in tax preparation, will vary based on your AGI. To give one example, there is a particular interaction relating to a possible student loan interest calculation, that only happens if your AGI is between $115,000 and $145,000 -- so that the presence or absence of the distinctively-sized message exchange relating to that calculation tells an eavesdropper whether your AGI is between $115,000 and $145,000. By assembling a set of clues like this, an eavesdropper can get a good fix on your AGI, plus information about your family status, and so on.
Compromise of HDCP; The encryption used over HDMI displays is industrial strength and cannot be broken by brute force methods (not in this universe, anyway!) - instead by freezing the memory used by a software BluRay player you can be assured that the volume-key is somewhere in memory. By stepping through 128-bits at a time and having a try at decrypting the first few frames of video (which are very clear when they are decrypted) you quickly find the key for that BluRay or HD-DVD disk.
The use of 'cribs' when decrypting Enigma traffic; Bletchley Park had typically less than a day to decrypt most traffic captured from German wireless telegraphy as they changed the rotor-positions in the Enigma machines every twenty-four hours. Apparently the intelligence gained by the French who were experts at recognizing the morse-key style of German operators (and hence were able to track which army group Fritz or Herman worked for) along with a knowledge the ten most profane German swear words and ten most common German girl's names meant they code-breakers had a head-start with seed-words which cut down the key-space to a manageable size that was process-able by 1942 mechanical computers!

Interesting though these examples are, the one that really peaked my fancy this week was the side-channel attach described by the Associated for Computing Machinery on the encryption used in VOIP systems. It turns out that most VOIP systems (Skype included) use variable-bitrate compression ahead of the encryption process (typ. AES at 128-bits). It turns out that by training a Markov Model with the encrypted data (yet knowing what the words spoken were) you can subsequently get around 50% accuracy with data streams from unknown talkers. Given that English has a lot of redundancy you could glean most of what was being said!

Read all about it here.

Blackmagic, have the courage of your convictions!

2011-03-17T16:47:00.006Z

I've often bad-mouthed Blackmagic as they often build to price rather than spec. In the past when I've complained about their interpretation of the SDi spec they've always said that so long as they can light-up a monitor they're 'democratizing digital video' or some such(!) Anyhow - Joel showed me that they are now featuring screen-grabs from a Tek rasteriser on their website; they weren't so keen on it five years ago!

People's expense accounts depend on their unquantifiable skills!

2011-03-12T10:47:00.002Z

In 1999 the Super Audio CD format was released - higher sampling rate and longer word-length than the venerable 44.1Khz/16-bit Red Book standard that traces it lineage back to the late seventies and the Sony F1 digital audio system.
I've spoken to audio engineers who have made a very good career out of there being a benefit in re-mastering recordings to this newer standard. Their contention is that the difference is "night and day" (please go back and read that post).
Anyway - in 2007 a couple of chaps from the AES did a double-blind test to see if audio professionals could tell the difference - it turns out they can do no better than random. Remember - that was audio engineers, dubbing mixers, and other people who know what to listen for in properly recorded audio. Mix Magazine did a very good write-up under the title of The Emperor's New Sampling Rate!

This all reminded me of a project I was involved in at Oasis TV in the late nineties where we were home-brewing an audio-FX server for the dubbing suites. At the time 9 gigabyte SCSI drives were £1,500 and so compression was implied! None of the dubbing mixers liked this idea and so I made up a CD of various recordings; spot-effects, different music styles, dry vocal recordings and finished mixed programme. The compression we were using was MP2 (so not as good as the now-ubiquitous MP3) at 128, 164, and 192 kBits per sec (as well as uncompressed).
Remember - these were the golden-ears listening on £10k matched amp/speaker combos. It turns out that somewhere between 164 and 192kBits per sec these guys dropped to about 50% accuracy in discerning the compressed audio from the original.
Actually I think it's a bit more complicated than what these two double-blind tests suggest; I store all my music at 192kbit MP3 encoded using LAME 3.9 - for 99% of my music I can't hear the difference. However;

On some passages (typ. splash cymbals and some acoustic guitar parts) I am aware of compression artefact's.
An old VT editor once told me (around fifteen years ago) that although he liked the look of (the then new) DV format he felt more tired after a day of editing DV footage compared to BetaSP - the differences aren't immediately clear but over time one is better (in some way?) than the other.

I do believe that you can only get to the truth of these things by statistical analysis - I place no faith in audio professionals who expect their view to be taken seriously without the numbers to back it up. Their salaries depend on them being able to 'hear' the differences - if they are there or not.

Stuxnet

2011-03-11T16:27:00.007Z

I've been following the Stuxnet worm in the technical press and it is fair to say that this is probably the world's first weaponised computer worm. In a very real sense this is cyberwar.
From Bruce Schneier's excellent blog;

Stuxnet was expensive to create. Estimates are that it took 8 to 10 people six months to write. There's also the lab setup--surely any organization that goes to all this trouble would test the thing before releasing it--and the intelligence gathering to know exactly how to target it. Additionally, zero-day exploits are valuable. They're hard to find, and they can only be used once. Whoever wrote Stuxnet was willing to spend a lot of money to ensure that whatever job it was intended to do would be done.

Symantec's report is very thorough but somewhat long!
The best expose on the whole subject is Steve Gibson's podcast on the subject;

http://media.grc.com/sn/sn-291.mp3

Tony Drummond-Murray presents...!

2011-03-01T10:42:00.000Z

This talk will start with the early methods of TV recording using film (Telerecording) and will briefly touch on some of the problems associated with TV cameras of this era. From there it will move on to Videotape recording (VTR), and will be illustrated with a few historical slides showing the early equipment. "VTR" is a vast field in this context, covering Recording, Playback, Editing (physical cutting and electronic splicing), Transverse and Helical scan tape formats, slow-motion and freeze-frame, and so on....

I've known Tony for many years, he is a great guy and a good speaker. We have staff meeting that night so I'll miss this unfortunately.

Ever need to slow down ethernet?

2011-02-24T14:15:00.005Z

I've had a few occasions when I've had to force gigabit down to 100BaseT or even 100 down to 10BaseT. My preferred method is to force the NIC down to the appropriate speed but if you aren't using Windows (OS-X, Linux or an embedded device) then a hardware solution is needed.

Distance - 100BaseT only goes 100m over cat5e but 10BaseT goes 300m; If you find yourself in that situation then an old 10BaseT hub at the far end does the job.
Equipment reports 100BaseT but is only reliable at 10BaseT; my Squeezebox network MP3 player is running a hacked OS and works a lot more reliably at 10BaseT. I achieved this by swapping the green/white and orange cores in the network cable. This degrades the common-mode rejection performance of the cable and means the ethernet switch ramps the circuit down to 10BaseT.
Gigabit too fast? Just make off a cable with the blue and brown pairs excluded. Gigabit needs all four pairs and if the switch only sees the Green and Orange pairs it will assume 100BaseT.

My Presentations at BVE 2011

2011-02-17T10:33:00.003Z

I've been representin' at the Broadcast Video Expo show in Earls Court. I'll blog about some of the things I've seen at the show later this week but in the meantime here are the slides from my three seminars;

These are all tasters for the training days I run at root6.

Rise times in HD TriSyncs

2011-02-04T17:59:00.009Z

To my shame I haven't blogged for a month! We are starting to pick up at work with projects on the go and the BVE trade show at Earls Court in just over a week (I'm presenting each day - will post my slides next week).

These are two traces from two separate TriSync generators - The blue trace represents a correct waveform and as every superhero will realise you're looking at the line timing pulse. Here is the diagram from rec-709 (the spec for HD video);

It clearly shows that rise time is to be equal between the start, middle and end of the line-sync pulse. The rep from the manufacturer of the green pulse insisted that his waveform was a lot sharper - but given the ringing on it I think they just aren't filtering it properly to comply with the rise time spec - seen here (again from rec-709) as being 4 clock cycles +/- 1.5

Thanks to an unnamed ex-colleague(!) for engaging me in this conversation! The link in the title is to the summary document PDF of rec-709.

Hopes for 2011

2011-01-04T13:42:00.002Z

Teradici PCoIP starts working with Snow Leopard - Apple broke USB HIDs in 10.6 and so standard USB cards (which the Teradici HBA looks like to the OS) are not recognised (as they were in Leopard and are in XP, Win7 & any Linux).
Someone launches a USB DVB-T2 adaptor - seriously, I want to upgrade my PVR to FreeviewHD!
The industry starts to pick up; at some point effort for the BBC move to Salford and the Olympics have to trickle down to London-based SIs
The Dolby PRM-4020 monitor starts to ship in the UK - see here.
UK broadcasters start to take HD seriously before getting all excited about 3D
UK broadcasters start to treat SD channels with some technical quality before getting too excited about HD!
3D in the cinema dies on the vine - the number of folks choosing to pay for it when they have a choice dropped off consistently throughout 2010 and so presumably at some point it will become economically nonviable.
The root6 tech podcast eventually takes off (watch this space!).

Monitoring in 5.1

2010-12-20T13:06:00.005Z

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.

Rio / Sonic Blue / Dell Digital audio receiver

2010-12-15T13:03:00.008Z

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

Crazy Mark's crazy guitar sale

2010-11-29T13:22:00.004Z

Nice pictures of all the guitars here.

To see all of his other guitar/effects/amp sales;

Takamine Santa Fe PSF 49c - Item number: 140484237305

Marshall JCM2000 DSL 50 head & 1960 JCM 4 x 12 cabinet - Item number: 140484241514

Line6 Pod2 guitar effects system w/ floorboard control - Item number: 140484243550

Art & Lutherie all cedar solid top - 12 string guitar - Item number: 140484246365

Almansa cutaway classical guitar - Item number: 140484248162

Boss Octaver pedal OC-3 - Item number: 140484249361

Marshall G50R guitar amp - Item number: 140484253604

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

2010-11-25T15:41:00.004Z

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

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

2010-11-18T15:09:00.004Z

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.

High Dynamic Range video

2010-11-10T09:22:00.008Z

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.

Most memorable gigs I've ever been to

2010-10-28T16:52:00.002+01:00

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

Babbage's Analytical Engine

2010-10-13T09:08:00.003+01:00

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.

Replacing the DVD drive in an XBox360

2010-10-11T10:14:00.016+01:00

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;

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.

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.

Replacement Xbox 360 DVD Drive

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.

Original/Broken Firmware Key

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.

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.

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.

Replace the DVD drive into the XBox and test - you don't need to re-build the case and re-attach the hard drive.

Resources;
SLAX Linux live CD
Firmware Toolbox

The end of universal benefits?

2010-10-07T12:47:00.003+01:00

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.

Even leaving Virgin Media was painful!

2010-09-16T12:03:00.004+01:00

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!

"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.

Things at IBC 2010 that tickled my fancy

2010-09-15T08:45:00.003+01:00

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

A year with the iPhone - what apps?

2010-08-24T09:18:00.005+01:00

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;

Some notes on monitor calibration

2010-08-17T13:28:00.002+01:00

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.

Internet security - when should you pay?

2010-07-31T15:22:00.007+01:00

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.

Colour calibration probes for less than a grand?

2010-07-29T17:05:00.004+01:00

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.

How to serve your Wiki off DropBox

2010-07-23T13:06:00.006+01:00

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 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

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

2010-07-22T15:15:00.002+01:00

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.

Tektronix and audio loudness measurement

2010-07-09T15:08:00.002+01:00

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.

Reducing electricity usage

2010-06-29T11:00:00.006+01:00

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.

Root6 training

2010-06-16T21:41:00.002+01:00

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.

2010 update for Optical cabling specification for fibre‐channel SANs

2010-06-07T08:40:00.001+01:00

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.

Requirements for Electrical Supply for Systems Integration projects

2010-06-04T11:52:00.001+01:00

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.

DVI, HDMI and Display Port

2010-05-25T12:22:00.010+01:00

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!

Blackmagic Videohub & RS422

2010-04-19T13:03:00.007+01:00

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!

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

2010-04-15T09:57:00.005+01:00

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; "...so 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.

My blog is blocked in UAE!

2010-04-12T10:18:00.002+01:00

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).

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

2010-04-06T17:37:00.006+01:00

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'.

Again - DRM penalises legitimate users only

2010-03-15T09:50:00.005Z

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!)

JVC monitor calibration software

2010-03-11T10:01:00.007Z

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"(!)

Some more notes on Return Loss

2010-03-02T10:34:00.003Z

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

Cause of return loss in cat5e cable

2010-03-01T18:09:00.003Z

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.

Understanding HD & 3G-SDI Video In HD

2010-02-11T08:50:00.004Z

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.

All your paywalls are belong to us!

2010-02-10T08:56:00.004Z

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.

Cory Doctorow is a genius!

2010-02-09T14:16:00.003Z

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.

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

2010-02-04T11:33:00.002Z

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).

Upturn?

2010-02-03T09:00:00.003Z

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

Glitch Takes Eutelsat W2 Out of Action

2010-01-29T11:54:00.002Z

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.

BT HomeHub madness!

2010-01-25T16:06:00.002Z

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.

The importance of a consistent earth with technical mains

2010-01-12T09:01:00.003Z

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.

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

2010-01-09T08:57:00.000Z

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.

Every Windows user to get pop-up menu of internet browsers

2009-12-17T01:00:00.001Z

Every person who owns a computer with Microsoft Windows is to be offered their choice of internet browsers in an automatic pop-up menu following an agreement today between the software company and the European Union.

I know liberals never like to see one sunflower grow any bigger than the others but this is plainly ridiculous - as one of the comments reads; "..when can I have a choice of a Ford engine in my Vauxhall car?" - and when has anyone ever been stopped from using whatever browser they want? Will Apple ever be obliged to let me use Windows Media Player to manage my iPhone? It seems wrong to punish a company for being successful when they behave exactly like everyone else. You know that if Steve Jobs ran a company with greater than 10% market share Apple would behave twice as aggressively.
I haven't used IE for six years but I don't think the EU should be able dictate to a company how they should configure their OS. Let's remember Microsoft are in the position they are because of market forces - they behave in a relatively ethical manner; they don't pollute, they don't use third-world slave labour and they don't do deals with brutal dictators.

Just sayin'.....

Day of the Triffids

2009-12-16T09:17:00.004Z

This is one of my favorite pieces of post-apocalyptic fiction. I read the book when I was a young teenager and really enjoyed the BBC production in my mid-teens. Good old Auntie Beeb have made the entire series available on YouTube (link above) at a very reasonable resolution. On my laptop the fullscreen playback is almost indistinguishable from the DVDs. Nice to see they've kept the 4x3 aspect that it was originally shot in.
Watch episode 2 - all the exteriors are shot in/around Primrose Hill near our workshop.

However, I read online this morning that the Beeb have a new production that they're showing over the holiday. From Wikipedia;

It is produced by Stephen Smallwood and directed by Nick Copus (EastEnders, The 4400). The script is by Patrick Harbinson, who has written episodes of the British dramas Soldier Soldier and Heartbeat, and the American series ER and Law & Order.

Filmed in the south-east of England, the new adaptation stars Dougray Scott as Dr Bill Masen; the confirmed supporting cast includes Joely Richardson as Jo Playton, Brian Cox as Dennis Masen, Vanessa Redgrave as Durrant, Eddie Izzard as Torrence and 90210 star Jason Priestley as Coker. Broadcast dates are 28 & 29 December 2009 on BBC1

So that's Christmas viewing for me sorted out!

Edit suite stories

2009-12-15T09:13:00.001Z

Just a great group on Facebook - a good read every day. I know not everyone does the Facebook thing but this really is a reason to start!

I am not a climate change denier

2009-12-07T10:50:00.007Z

The Climate Change Secretary Ed Miliband has acknowledged that there is "further to go" to persuade people in both the UK and around the world that global warming is man-made.

Interviewed by Today presenter on Humphreys on the opening day of the United Nations' climate change conference on Copenhagen, Mr Miliband said that those who denied the existence of a connection between human activity and global warming were "profoundly irresponsible".

And he said that the Copenhagen conference would be seen as successful if it led to "a deal consistent with science" which saw global emissions peaking in 2020.

Also - read this article on ScientificAmerican.com

Going to see Martyn Joseph tomorrow night

2009-12-02T16:34:00.002Z

It's been a couple of years but looking forward to seeing the "Welsh Springsteen/Dylan/Bragg"!

Why beauty in art is important

2009-11-29T17:13:00.006Z

Philosopher Roger Scruton presents a provocative essay on the importance of beauty in the arts and in our lives. In the 20th century, Scruton argues, art, architecture and music turned their backs on beauty, making a cult of ugliness and leading us into a spiritual desert. The link is to the page on the iPlayer.

Beauty is not popular among professional architects, just as the pursuit of beauty is not popular among visual artists: it suggests costly sacrifices, and a scaling down of pretensions for the sake of people whom they don't need to know. But the controversy over modern architecture remains real and important: for it reflects the need of ordinary people that appearances be respected, so that the place where they find themselves can also be shared as a home.

He crystallized some thoughts for me - I've always felt uneasy with art that has to assert it's own artistic relevance. I've always thought that true art doesn't need to be declared as such - a working man (who didn't go to St Martins!) should be able to recognize something that has artistic worth, he doesn't need Messrs Hirst and the Chapmans to tell him.
Whilst I was watching I did a Twitter search and was surprised how aggressive the people who disagreed with his thesis are - they just insult him rather than address what he's saying. I've stuck a quick sample at the end - some make for strong reading!
I suppose anybody who stands against an accepted orthodoxy gets flack - maybe it strengthens what he says!

emberson @Archispeak ....and as for Scruton and his cronies.....the talking dead?
sunwukung Roger Scruton in an unbearable old fart.
purpleparoxysm "as meaningless as a laugh, shout or smile" - i think that's your fundamental problem Scruton. What a twat and what an 'ugly' man & mind.
maty0609 Roger Scruton, get out of my face...This is rubbish you're saying...
Me-cold_2_normal Benjihotaylor Roger Scruton doesn't half talk a load of crap!
davidTrussler Ideas themselves cannot be beautiful, according to Roger Scruton, thus dismissing all Conceptual Art. Totally reactionary rubbish.
Daviesstock Watching some pretentious high-brow intellectual masturbating on the nature of Beauty, presented by Roger Scrotum, er, I mean Scruton...
NiteWaves roger scruton is a boring old cunt
danielnothing Roger Scruton: an arsehole?
unityzer0 fuck you Roger Scruton.
magnetite I think Duchamp's bog IS beautiful, Scruton you cock.

Quartz - excellent products AND tech support

2009-11-26T13:17:00.002Z

I was around at a customers' today - their Quartz 32x32 HD/RS422 Xenon router had stopped talking to it's control panels. Normally that is down to the coax 'QBus' cable that runs around all of the devices - like old-school 50ohm ethernet-over-coax - is prone to having a break in the middle or loosing a term from one end. However - this wasn't the case. A quick call to their tech support and you get an engineer who knows the products - can tell you what each board-LED means and what low-level commands you can send over the RS232 to illicit diagnostic information. In short order I re-loaded the configuration and the whole matrix was back up and running.

Beware of your DVI's blanking width!

2009-11-25T16:16:00.003Z

You think you know a certain signal standard but then some nuance of interpretation jumps up and bites you on the backside! Here are excerpts from an email conversation, mine are in italics, the manufacturer's in bold.

....we have a pair of VS-66HDMIs that pass signals fine at resolutions sub 1920x1200 but when you hit that resolution the output flickers and won't lock. Taking the router out of the circuit but using the same cables allows the monitor to lock to the signal fine. The two sources are; Apple MacPro with nVidia GForce GT120 graphics card Apple G5 with ATI Radio 9600 Pro graphics card. Suffice to say we've done the usual powering down etc and tried different cables in case something is on the hairy edge of spec but with different sources that seems unlikely.

Thanks for your e-mail, the details of which I sent off to our R&D people. I have now had a response, in which they said;

"When we mention 1900x1200 we mean narrow blanking. With regular 1900x1200 blanking the bandwidth is higher than the chipset capabilities."

When I asked if the VS-66HDCP matrix (6 x 6 DVI matrix) was any different the answer came back;

"They are the same and use the same chipset. You may be able to set the PC's output to narrow blanking."

So I guess the next question is whether you can adjust the PC’s to provide narrow blanking.

OK, thanks for looking into it xxxx. I had a chat with Apple Engineering late yesterday (we’re a re-seller) and they say that no stock graphics card that has shipped with either a G5 or MacPro in the last five years supports narrow DVI blanking at 1920x1200! In the case of nVidia cards that setting is exposed in the PC driver (I checked on a couple of Windows machines and that is indeed the case – although the installed default was standard rather than narrow blanking) but there is no way to get to it with OS-X.

It seems you should change your advertising to read ‘doesn’t support Macs at hi-res’ or ‘not for use with Macs & monitors greater than 23” display’ something like that. Given that an awful lot of people in the creative industries use Apple computers this isn’t an unusual requirement of a product and if someone reads the copy “Up to UXGA, 1920x1200, 1080p.” You’d forgive them for assuming that it will work with their Apple computer running at 1920x1200.

It puts us in a spot as we now have to source another pair of switchers to sort out our customer.

So there you go - I'm pinning my hopes on the Gefen equivelent. They seem to recognise that a lot of people in the TV industry use Macs!

BBC iPlayer on the Wii

2009-11-18T09:44:00.002Z

The Wii has been able to access iPlayer for ages via the rubbish browser it has but the launch of an iPlayer app (or channel in Nintendo speak!) means you have a proper interface and the Wii playback of MPEG4 video has been improved with the most recent system update.
I spent a while monkeying around with it this morning and it is excellent - the interface is really usable and the playback quality is excellent. This is the best iPlayer machine we have at home.

The birth of Radar

2009-11-17T22:30:00.002Z

I went to an excellent lecture at my institute with a real engineering gentleman - Laurence Tandy. He reminded me of some of the senior engineers at the Beeb. He clearly had a lot of love for his subject and enjoyed talking about the development of radar from before the war until now. His subject is magnetrons which I've had brushes with when on placement at transmitters (when I was at the Beeb) but never really understood how they work. His explanation was excellent and I came away having really learnt something.
Along with his explanation of the various technique he related several incidents concerning the war and his time spent assisting Robert Watson-Watt - the father of radar. He started as an eighteen year-old lab tech in 1938 and worked his way up to Master Specification Officer for Microwave Power Devices at the government-run Telecommunications Research Establishment from where he retired in 1981.

The great 3G cable shoot-out

2009-11-13T16:49:00.006Z

Thanks to Simon Hillman for tabulating them in a way that makes trends clear. The link in the title is the directory with the A1 plots.

The tests based on a pathological signal are more extensive and test for six cable types - three HD and three SD. Since we were trying to spot trends due to cable length we feel this is the most informative of the sets of data. Simon re-did a subset using only the three HD types and 1080/50P colour bars to test for jitter which (as you'd expect) doesn't vary to any degree with length but you can see the relative damage barrels and U-Links do.

The conclusions that spring out are;

At 3G using coax specified for HD 60m seems to be the workable cable length before attenuation becomes an issue and the eye closes below 400mV.
SD coax goes about half the distance - this seems counter-intuitive as most SD coax has a notional analogue bandwidth (+/- 6dBs) of 360Mhz - three octave less than HD coax. Clearly the signal recovery in the WFM8300 is at play.
The variation between the best (most expensive) and worst cable at HD before the signal becomes sub-optimal (i.e. worse than 3dBs attenuation) is less than 10m with Belden 1694 coming out on top.
The 8300 was still able to recover a signal at 150m with Belden but only 120m with the Draka DC DVC13C. At these length the mean time between corrupt video frames would be unacceptable.
The Condufil 1694-equivelent tracks the more expensive Belden cable very well.

As mentioned this was really a test of run-lengths for a practical guide to cabling TV facilities. In the bulk of the tests we used the correct BNC crimp connectors and the proper tools for the brands of BNCs (attached by an experienced wireman) - We did try and provoke jitter by mixing up connectors with cable but it seemed to make scant difference. It does seem for 3G HD video the newer style 4.5Ghz are to be preferred over the original HD-type cable.

In the end I suspect that these results will represent the best possible world as Tektronix gear is known to drive a coax line optimally and has excellent return loss on its inputs. Other manufactures are less so and if our experience with 1.48G 4:2:2 HD is anything to go by the massive variation in the quality of line-drivers and receivers will make these results meaningless. Nobody (particularly in these hard economic times) builds a facility with only Sony and Tektronix equipment.

Many thanks to Tom & Lee at Tek for the loan of the equipment and advice and Simon and Graham at Bryant for providing the various cable types, ends & tools. Please note all original information and test results are the property and copyright of root6

update: After IBC 2010 I had dinner with a couple of the guys from Condufil and they told me that the trick with high frequency coax is the consistency of the dialectric. The best examples use nitrogen to inflate the dialectric foam whereas budget cable is manufactured with a mechanical extrusion method. In their words this if the difference between Belden & Condufil vs Draka. This seems to be borne our by our tests.

BBC cuts HDTV bit-rate

2009-11-12T09:49:00.000Z

Data rates on Freesat have been ramped down - now below ten megabits per sec for H.264 - this is likely to reflect what Freeview HD will look like when Mux-B gets fired up from Crystal Palace this December.

Danielle Nagler, the recently-appointed head of BBC HD, admitted that the BBC had reduced the HD channel’s bit rate. She claimed that there was no evidence that a reduction in bit-rate reduced the picture quality.

I have to say that if you're the head of HD for probably the most prestigious broadcaster in the world and you believe there is no correlation between bitrate and perceived picture quality then you got the job under false pretenses as you know nothing about the technicalities of DVB.
Why didn't they give me that job! I know pretty much everything about SD, HD, DVB-T, OFDM, QAM etc etc!

It reminds me of the facilities (oh, and Quantel!) that used to claim 8-bits was better than ten!

TriCaster - killed by Quicktime v.7.6.1

2009-11-10T13:30:00.002Z

I had a very jolly morning at the College of Law on Store Street replacing a TriCaster Studio (the one with virtual sets etc.) - last job of the morning (or so I thought!) was to install the current rev of Quicktime to allow playback of ProRes clips. QT 7.6.1 kills TriCaster - I wound up having to repave the machine from it's restore partition which (interestingly) is a Linux drive that boots from Grub!

iPhone - burning my leg!

2009-11-09T14:49:00.002Z

On Saturday morning when I was enjoying my pancakes I noticed my iPhone was roasting hot - there was a strip a few mm wide across the back of the device (where the Apple logo is ironically!) that was too hot to touch. I quickly powered it down and once it was cool it started up again OK - I cycled all the radios (WiFi, Bluetooth, 3G etc) and it all seemed to be working except the battery discharged in about half an hour (it had been full before the hot leg incident). Subsequently it would hold a charge for just a few hours and less than an hour if you made a couple of calls or listened to any tunes.
O2 swapped it out without any fuss (even supplied a complete new set of accessories - handy to have another charger!) and iTunes restore function leaves you with a 'phone that is in exactly the same state as when you last sync'ed - must less painful than the numerous Windows mobiles I've had over the years.
I can only assume that one cell in the battery pile had internally shorted and burnt out and that the 'phone is able to run on 5/6th of the voltage.

Bad movie transfers - part 2

2009-11-04T08:26:00.002Z

In my effort to call out broadcasters for v.poor quality movie transfers for transmission my latest pint of bile is directed towards five and the terrible copy of Groundhog Day they put out on Sunday evening. I sat down to watch it last night and was amazed it passed any kind of QC process - 4x3 1" (or maybe VHS!) bump-up.
I watched the MPEG2 transport stream (i.e. I recorded it off Freeview without re-compression) and so it was the data as delivered.

RS422 - still with us! My notes

2009-11-02T14:59:00.003Z

They print nicely - make them full page.

The curse of the 'Engineering Project Manager'

2009-10-28T12:29:00.000Z

I heard this very moving report on the radio this morning - it concerns a fatal Nimrod crash in Afghanistan in 2006 and lays the blame at the engineering procedures for maintaining the aircraft.
I can see exactly how this happens - engineering managers who describe themselves as 'facilitators' - to whom everything is a hand-off to someone else and who won't be doing any of the design/build/test work themselves nor will they have any responsibility for the system once it's in and working. I always felt when I ran engineering in facilities that there was immense worth in the people who would be operating and looking after a system having a say (or complete involvement in) it's design and build. In effect me and my engineers owned the systems we devised.
I quite like LinkedIn - it's a Facebook for the over-40s! Anyway on your profile you can solicit recommendations from people who you've worked with in the past and these get displayed as part of your resume.
Now then, a few years ago I was sitting on two job offers - root6 (the one I took) and chief engineer at a rather large facility that was pioneering a tapeless workflow for their major client (a big international broadcaster). A ex-colleague was the caretaker engineer and a couple of days after what I thought was an excellent interview (secured me an offer) he called and warned me about what was essentially a poisoned-chalice. Their 'systems architect' had lumbered them with a build that missed one tape in six and took many times longer than realtime to transfer clips from the backup system to the editing SAN. Those two facts alone killed their workflow and for a year they were the biggest hirers of VTRs (on trestle tables!) in London. He hadn't seen all the pieces working together in demonstration and had taken the manufacturers' words for it - suffice to say they were all pointing at each other! Over the next two years they made it all work but it wasn't a happy ride for the facility or the client.
Anyway - I found a recommendation for this chap on LinkedIn - about what a bang-up engineering architect he was and delivered ahead of time/below budget etc etc. I just goes to show - don't believe anything you read on the internet and don't trust engineers who don't own the system they are delivering.

A Eng Funds no.21 September 1988

2009-10-27T10:54:00.000Z

Another BBC photo from a couple of decades ago! There's me in the back row. Mark Chambers (rear left) and I shared a flat - he worked in OBs at Kendal Avenue. Tim Cowin (between me and Mark) worked in Radio and Jim Binks (below Tim) now works at EMS.
Anyone else you know?