- Broadcast engineering and IT related links and stuff. Maybe some music, films and other things.
Friday, December 30, 2005
Tuesday, December 20, 2005
Happy Christmas to you!
If you want to see our family Christmas newsletter see here.
Oh, the link above is to the Podsafe For Peace record which has a great back-story (courtesy of the Daily Source Code - see the link in the Podcast section, right). The song is cheesy as a big omelet but I love it!
Causes of colour
Monday, December 19, 2005
"The perils of colour-space conversion" - an article for the Root6 Dr. Watson newsletter
An important aspect of the production/post-production chain is maintaining correct colourimetry. If the director of photography or the lighting-cameraman want that certain shade of red to be correctly delivered to the viewer then attention needs to be paid to the correct representation from the camera (be it standard or high definition or even film) through all transfer operations (potentially going between resolutions, YUV/RGB colour spaces and bit depths) to the final display surface (be it a CRT, LCD or even cinema screen). In truth colour-space management for film is a complex issue best handled by specialists like Filmlight (who are represented in the UK by Root6) and is perhaps beyond the scope of some technical notes in a newsletter! That said there are many points worth making if you are acquiring or delivering for high definition television and worried about going between colour spaces.
The CIE Chromaticity diagram (first published in 1931!) shows the gamut of human vision – essentially any display surface is a subset of this diagram and will be a triangle with red, green and blue apexes and white (actually monochrome – as the luminance of the image is reduced it tends through grey to black) in the centre. In the case of “illuminant D” (AKA “D6500” or “EBU phosphors”) – the standard definition colour standard used since the sixties in Europe we enjoy a slightly wider red range than our colonial cousins but every gamut (television, film or print) is a poor compromise on what your eyes can handle. This is where the problem begins – you have a very critical instrument at your disposal to see these differences.
Part of the problem is that all of our machines acquire images in the RGB space (TV cameras, Telecines, graphics workstations etc.) but for the most part we post-produce in a YUV space (with the exception of Sony’s new HDCam SR format, an RGB high-definition VTR) which represents an immediate lowering of the colour space. This has been the case for a long time and is well understood. Manufacturers have agreed a common “matrix” for transcoding. To make the luminance portion of the component signal the following is used:
y = 0.299 * r + 0.587 * g + 0.114 * b
Well, this is the case for standard definition (AKA “601”), but for high-def (AKA “709”):
y = 0.213 * r + 0.715 * g + 0.072 * b
Which, even if you’re not so into the maths, will give different values for the luminance (the overall level and hence look of the picture). This makes it doubly important that you get your cameraman to record some colour bars at the head of each rushes tape and that your editor checks alignment on his scope before he starts adding captions etc. The best of breed digital picture instruments are from Tektronics who Root6 are pleased to represent.
If you find you have a colour space issue (particularly going between standard and high definition formats) then the Belle Nuit Montage test chart is a good starting point. It can highlight all the common transcoding errors – be it the limited 8-bit range of old D1 videotape to some of the sub-sampling issues associated with HDCam. You can download the file at various resolutions from their website and by injecting it at the start of your workflow any inadequacies are quickly revealed and can be corrected.
Friday, December 16, 2005
DVS in Hannover
Stephan & Emanuelle from Post Logic, Chia from DVS (our trainer), myself and Ben (Root6) who enjoyed the fact that we got to hire a 5-series BMW!
We also got taken through the hardware of the Clipster from a maintenance point of view and spent the last day doing SAN configuration. Their SAN is based around ADIC's StoreNext file system and as such allows you to have clients using all the common OSes - Windows, Linux, Unix (variants as well as IRIX for SG) as well as OS-X Tiger. They use X24 raidheads to control the array and so the system is not burdened with RAID operations (unlike a Unity).
Wednesday, December 07, 2005
Colourise black and white images
Anyhow - I thought an application for this (other than making Stan Laurell look unwell!) would be to give a new look to digital images that you'd previously made monochrome.
Tuesday, December 06, 2005
Engineering page at suitetv.com
...numerous awards for their work in commercials, short-form and broadcast programming, and their creativity is reflected in the company's impressive client base. No matter how complex your post production problem, you can be sure it will be....blah blah blahYou get the pictures.
Anyhow - The Suite (in Newman Street) have a really cute engineering page - just a bunch of pictures captured from the CCTV and looped in high speed - I was entranced - you see a guy fixing a VTR, them someone drinking tea, then someone installing something on a PC - it's great!
Monday, December 05, 2005
Saturday, December 03, 2005
If I got a tattoo.....
I installed a new v7 Protools on Friday - wrong (set for -14dBfs), Avid still ship set for -20dBfs and countless other bits of kit come in at -24dBfs. Perhaps these people just don't understand (or can't be bothered!).
Friday, December 02, 2005
Leitch routers and inheriting old gear
Anyhow - back to the Leitch - I could get the video level control panel to talk to the chasis and route but every time I attached an audio panel it wouldn't route both sides of the stereo pair - in the end I set the audio panel to issue commands on all levels bar the video and that did the trick. It's a bit of a bodge but works - until they try and attach an RS422 level (and then I'll get the call - probably at night!). I'm thankful I paid attention to the ESAM protocol when I was building Oasis's machine room - once you have a feel for how that works you can pretty much understand how any modern router's control system operates.
Back to inheriting old gear - monitors are the worst because the client expects them to look as good as the rest of the install - even with soft ten-year-old tubes they think the new setup will bring life back to those displays that should either be re-tubed or retired! A job we did earlier this year was a good example - the client had origional series 16x9 PVMs - even when new they weren't colour accurate but ten years down the track - well. Suffice to say Sony no longer make the SDi input board for that monitor and so we had to feed them analogue component (which in most instances is my prefered method - the analogue output of an Adrenaline BOB, for example, is a better picture than the 8-bit conversion done in the monitor input card) but the YUV was from a Decklink card! I'll stop now before my blood boils!
Friday, November 25, 2005
VideoReDo
Guess what show I was cutting when I grabbed that screenshot!
Thursday, November 24, 2005
What the Dell's going on?!
This got me wondering about the larger relationship between software and hardware and I pondered back to twenty years ago when I was doing a degree in maths and programming. At the time object-orientated languages were thin on the ground (Smalltalk was the only one I had any exposure to) and so working with either a procedural language (C, Pascal, COBOL etc.) or a functional language (LISP, Prolog) the developer could see how the abstraction applied to the final assembled code. All the programmers I graduated with (for example) could also code in Z80 and x86 assembler - not too many programmers can do that today. There was even the idea of induction to prove code. This was an idea that came from defense contracting that allowed you to show that a routine (typically in LISP) was good for every case by showing it worked for the specific case of n=1 and then for the general n+1 case. You could have confidence that a subroutine or even a whole program would work properly every time. Shoot forward to a few years ago when I was still running engineering for Resolution and I had to commission a database application that would support a 24-7 reality TV show and the programmer refused to stand by what he wrote - there was no way he'd be on call-out to fix any bugs we discovered down the line. It seems that as software development has moved into the realms of bolting objects together the idea of robustness has gone (get a programmer to explain the idea of garbage collection and why it is necessary in modern languages).
This is well illustrated if you compare the state of the two biggest NLE applications in the late 90's - Avid and Lightworks.
- Avid v.7, which if you used/installed/fixed it you'll know, was a capable application that needed a 300Mhz computer to run on a typically required 256megs of memory. It crashed often and took many minutes to boot. Judging by the multitude of error messages I got familiar with it was written in at least four languages and had components in it that hadn't been re-written in a decade (I know v.1 came out in 1991 but even today it has elements of EditDroid, the Lucas Film application that Avid acquired in the late 80's).
- Lightworks v.6, by comparison was a stable product that crashed once a month (on average), booted in under thirty seconds (due in part to DTX - they wrote their own disk handler rather than rely on an off-the-shelf OS!) and had an incredibly modest hardware requirement - a 66Mhz '486 with 64megs of RAM! It also came on three floppies!
Compare all this to how far hardware has come - back when I was doing that degree the 25Mhz '386 was the fastest cheap processor around and even then people were sounding the death-knell for the CISC architecture. The Von Neumann bottlekneck was perceived as a real problem for traditional processor design and RISC chips (especially the T800 series of transputers) were going to save IT. BUT, hardware design got better and all those problems haven't held back the Moore's Law express-train.
Tuesday, November 22, 2005
Tri Level Syncs
The thing to remember is that unlike HD-SDi video tri-syncs can be distributed much like normal black & burst - the same cables, jackfields, and even DAs and routers can be used to carry them. Equipment that uses tri-syncs will often need it's reference input switched (one day it's a 24P job, the next it's a 1080i (50 field) one) and so small composite routers and multi-o/p SPGs are a good idea.
The horizontal timing reference point for a standard bi-level sync signal is defined as the 50% point of the falling edge of the horizontal sync pulse. In order to ascertain this point precisely, it is necessary to clamp both black-level and sync-tip level and derive a value half way between. If the signal is in any way distorted, this will give H timing inaccuracy. With a relatively pedestrian standard def signal (line rate in the province of 15 Khz) this isn't such a big deal, but with 1080 lines per frame this becomes more significant and with a tri-level sync signal, the timing reference point is the rising edge of the sync signal as it passes through the black-level. This point is much easier to determine accurately, and can be implemented relatively easily. It is also more immune to signal distortion.
Monday, November 14, 2005
Sony's DRM "Root Kit" controversy
Anyhow - a very funny post on Sysinternal (who broke the story origionally):
f you want a more concrete proof, try to rename your favourite ripping software as $sys$whatever.exe and then run it again. You'll notice that the DRM system can no longer detect it, and thus you'll get good copy of the track you try to rip instead of one filled with noise.There is a worry that virus and other malware authors can exploit this loophole - but the idea that the very thing that Sony were trying to prevent now gets easier is funny.
Thats just hilarious. I think everyone should simply not worry about removing the rootkit, as this is too difficult, and then just do at Matti says, and use the rootkit to make your favorite ripping tool immune to the DRM. On second thought, is their software breaking the DMCA? It provides a method to bypass copyright protection that they install? Hmm...
A list of Sony/BMG disks that you should avoid.
23rd November update: It now appears that Sony had bundled the open source Lame encoder as part of the XCP install - in clear violation of the GNU public license. It seems it's OK for Sony BMG to install software on your PC that stops you from making legitimate use of the music you purchased and at the same time they're ripping off other people's IP!
You couldn't make it up!
Sunday, November 13, 2005
"He's running a bit rich"
Thursday, November 10, 2005
Operation Christmas Child
There is an anti-American undercurrent in the newspapers aimed at the chattering classes and I don't like it. Every American I've met (here and in the States) has been an entirely reasonable person. Surely you can hold a view that you dissapprove of Bush and the war and yet still feel affectionate towards normal Americans.
Anyhow - it's not too late - the couple of hours it'll take you to fill a shoebox with some goodies (and maybe £10 out of your Christmas budget) will be time and cash better spent than you'll ever realise.
Wednesday, November 09, 2005
Mix tapes!
Tuesday, November 08, 2005
Cerberus FTP server
It transpired that there was a hotfix over the weekend that "...addresses some compatibility issues with IIS and passive FTP transfers" - well, if the issue was it used to work then they have indeed addressed it with the now it doesn't solution! I suppose I could un-install IIS and re-install (not forgetting to disable auto-hotfix!) and spend half a day getting the configuration right but I tried Cerberus (Rupert mentioned it yesterday) and was amazed - installed and configured in twenty minutes and all my users are happy again. Yet another one of those cases of grasping the nettle and realising how easy it is to break away from Microsoft and how much better things seem to work afterwards.
Monday, November 07, 2005
Virtual desktop PPMs
11th Nov Update - Rupert has got this working with ExpressPro - very neat. In Settings you need to tell the audio tool to use the system mixer - select "mix" or "wave mix" in your Windows mixer tool record setting and you'll be off to the races!
Friday, November 04, 2005
Audiophile at I-Like-Jam
The Intelligent Chip is a one inch square, bright orange plastic wafer that, when placed on top of a compact disc player for 2-3 seconds, upgrades the disc (CD, DVD or SACD) being played at the time. The sound of the upgraded disc has more detail and articulation, better dynamics and an absence of "digital harshness." Voices are more human-sounding and less synthetic. The upgrade is permanent. Inside the white translucent Intelligent Chip case are two ultrathin, clear polycarbonate sheets, one on each side of the Chip. The manufacturer's product brochure states, "The Intelligent Chip should be put back into the packing case after using, because the packing case can protect the quantum material of the Intelligent Chip, preventing them from leaking."The nonesense goes on with reference to Schrodinger's cat and other quantum ideas, the summary is the best;
The Intelligent Chip works via coherent quantum superposition and quantum entanglement, in which two coherent light sources - the CD laser and the quantum dot laser in the chip - interact strongly with the atoms and molecules in the CD's polycarbonate layer to produce long-lasting, superior transparency for better optical signal to noise ratio (SNR). Laser light escapes the player via a number of small holes and gaps in the player case. The emitted light from the quantum dot laser instantly comingles with the CD laser light in the room and inside the player.Now what has escaped these people's attention is that with some CD players you can get the CD to show the number of errors in the bitstream (the Red Book standard specifies Miller Coding so errors are easy to spot). I used to have a Sony machine in the early nineties that had a maintenance mode that would make the display show the error count rather than track number etc. I had several disks that could play end to end with no errors - so, how can improving the s/n of the bitstream signal improve the final analogue sound if the digital signal wasn't noisey enough to give errors in the first place?!
However - the $1,500 power cord really got my goat! I wrote an email to the dude;
Hi,I'll let you know what comes back!
I just read your review of this power cable - did you write this for a joke or is it a paid-for "advertorial" for the company concerned?
If this power cable produced a measurable difference in sound reproduction why didn't you include some measurements (Total Harmonic Distortion, bandwidth figures, signal-to-noise etc.)? - Would you know how to measure these things?
"...like most other AC products, it will undergo changes in sound for three to five days after its application to a component. Judging the absolute merits of any AC product within this "settling period" will most often prove misleading. "
What, precisely, happens to a power cord during this "bedding in" period? For such a high sum you'd expect the manufacturer to burn the cable in for you!
What, in your view, makes this a good power cord? What was the impedance per metre? What about the capacitance? Do they make a different design for 50hz users? If it is so optimised the difference between 50 and 60Hz is surely significant.
Surely improvements and order of magnitude more significant than this could be achieved by hard-wiring the amp's mains input to the incoming mains feed from the street - even then they have merely used copper cabling for the mile back to the substation.
Regards,
Phil Crawley,
I really feel it's important to stand up against this pseudo-science and trickery.
Thursday, November 03, 2005
Hurray - I'll be able to park!
Wednesday, November 02, 2005
I'm Yoda, I'm a soldier
Tuesday, November 01, 2005
Monday, October 31, 2005
Sunday, October 30, 2005
Bit of blue for the dads!"
Looks a bit like Fujifilm from the 1970's - green cast on everything (like all my childhood photos!)
Do you think they told them camera operators that they shouldn't let the actors see them! A bit like those shows where they trap dodgy plumbers with a PD150 hidden in a rucksack!
For me it really spoils the enjoyment because it puts something in the way, I can't help feeling like it's shot on a sound stage and is somehow less honest than it could have been.
Monday, October 24, 2005
I was around a friend's place yesterday - very nice meal Victoria, thanks! Anyhow - They'd had a Jornada 820 sitting in the cupboard from ages ago and I remembered I had THE ONLY wireless card that had a CE2.11 driver for it - The Lucent WaveLan Silver. I used to have a Jornada back in 1999/2000 and lived with it for more than a year and loved it. It booted in under a second and the battery lasted all day (and the following day as well!). I wish I still had it as folks ported Linux to it. I might start trawling eBay.
So, I loaded up the driver and got the machine working on their wireless network. It really was a capable little sub-laptop - a bit long in the tooth (the version of pocket IE works with very few modern websites) but fast (no hard drive - everything is in memory). Pocket Office still opens current versions of Word and Excel files too.
Norton Internet Security Suite is the worst bit of software ever! Bob had it installed on three of his machines in the hope that all the things it promised (freedom from Spam, Viruses and other nasties) were real. Two of the machines had the LDN Trojan which tries to open up an SMTP route through your internet connection and four minutes after boot it attempts to send out a shed-load of spam. Now the Norton firewall detected that activity but rather than temporarily blocking port 23 and telling you it pops several hundred windows that you can't close quick enough. I ended up having to tug the mains and re-boot. The bundled version of Anti-virus (even after an update) wasn't able to catch the nasty. So - after removing Norton and replacing it with AVG Free (and making sure the Windows firewall was on and working) Bob's comments was "wow this feels like a new computer - applications launch quickly and it feels like there is a 3Ghz processor under the covers!". Norton was letting him down similarly on all three machines! AVG had no problem catching the trojan and killing it.
Friday, October 21, 2005
Thursday, October 20, 2005
I saw this sign in Cafe Nero, Camden Town. It really does say
Hazelnuts, chocolate, contains nutsI shall think twice about buying coffee from there again! Maybe the coffee contains caffeine!
Wednesday, October 19, 2005
Hi Phil
So here I am checking out who's linking to our Lynn Parsons podcast page and your blog pops up! Freaky. I'm the producer of the show and I might perhaps play a couple of the characters but obviously I can't give too many secrets away!
If you've pretty much given up on conventional radio (like I have - bar The Today Programme) then check out Lynn's podcast - see the right-hand bar.
Tuesday, October 18, 2005
The annual big job at Hawley Crescent is nearly finished! I think
we'll be out of here by the end of today. It has been a funny job by comparison
with the Post Rooms (the one we did last year - see here).
We didn't project manage the whole of this one, rather we were the cabling and
equipment contractor and so a few of the decisions were taken out of our hands.
They have a big network of G5s running the usual assortment of FCP, After
Effects and Photoshop and the intention is that (eventually) they will all hang
off the SAN - it was to be a Terrablock but quite late in the day became an
Apple XSAN. I'm not sure that was a great choice but there you go!
Monday, October 17, 2005
- The card has to have a unique IRQ assigned to it. Now with the machine I put it in the P&P BIOS insisted on giving it the same interrupt as at least one other card. I tried all the tricks and eventually (in the last PCI slot - why is it always the last?!) managed to get it hogging the same interrupt as the onboard USB. I could do without USB so disabled it and we were nearly there.
- The card is demanding when capturing from the Freeview feed (why? it isn't having to decode/re-encode any video, just file away the MPEG2 stream as delivered) - I suppose extracting a stream from the 38meg MUX is a pretty clever thing to do.
- I get much better TiVO-style live TV pause when driving the display at 16 bit colour rather than 32 bit (millions of colours). The resolution seems irrelevant as does driving the video overlay surface directly or via DirectDraw - that confused me.
- On the AMD Athlon XP1700 chip there is just enough poke - if I hit that machine over the network for either file transfer or VNC while it's recording it drops frames. I've got a couple of bids on eBay for XP1900 chips at the moment!
- Media Portal looks like a good alternative to Compro's app (which is fine) - Saul has good things to say about Media Portal (even going as far as saying it's better than Windows MediaCentre!). Two of the things they recommend is starting from a fresh XP install and using a different drive for capturing to that where your Windows swap-partition is located. I think I'll give those recommendations a go.
Sunday, October 16, 2005
I pushed the boat out to replace my old Hauppauge PVR250 card. The Hauppauge was good but it suffered from only having an analogue UHF tuner. Because it has an MPEG2 encoder on board you can capture high bit-rate (12mBits long-GOP) streams without burdening the processor. In it's place I'd got a VideoMate DVB-T200 which has both analogue and DVB capture. The quality of the Freeview stations is superb and after having to monkey around with the BIOS to for it the assign a unique IRQ to the card it performs well (but on my 1.7Ghz media PC it does hammer the processor).
Download a clip from last week's Scrapheap Challenge to see what I mean - captured on the card and then compressed to DivX (plus a bit of de-interlacing and re-sizing for square pixels) using VirtualDub.
Oh, but the important part of the post was to see my old mate Dave Beach on the show - Dave had called me to let me know a couple of weeks back. I used to work with him at Resolution - he is the best wedding DJ in the world and all round good guy and it was good to hear from him again - he's currently editing for Formula One.
Friday, October 14, 2005
Despite the whinging of the Murdock-controlled tabloid-media(see below) we do need a strong BBC. A couple of days back the Beeb revealed the increase they expect to see in the license fee. Who else is pushing digital terrestrial TV in the country? Who else is pushing radio (and soon TV)-on-demand? Who else will offer a decent archive of publicly accessible content? Not ITV, that's for sure. The Beeb have a long history of technical innovation in content delivery and we can't afford to loose that. Freeview would have disappeared but for the Beeb's intervention (much to the chagrin of Sky).
I watched a couple of BBC3 shows this week - Tiny Tearaways is their child behavior meets Big Brother show. That makes it sound awful but in the face of the kind of thing ITV offers - Children out of control or somesuch (probably with "from hell" in the title!) it is a joy - really life-affirming and offering good and practical instruction to parents (and my chum Martin Begley works on that show).
Spendaholics documents the profligate behavior of young adults and the stupid financial choices they make. Most of the show is taken up with realistic financial and psychological advise putting this week's subject back on track to being solvent. Again, the things I've seen on ITV offer no way out and glorify the choices of the chav generation.
The BBC offers remarkable value for money when compared to Sky and the ITV network. If you compare the £140 per annum cost of the BBC license fee with the cost of even the most modest Sky package or the £350 that the cost of ITV-based advertising places on the average family's annual grocery bill then you realise that the license fee is less of a tax than having to fund ITV. I have a choice if I pay the license fee - I do because I value the Beeb but I have several friends who don't have a TV in the house and so don't have to pay for the BBC but they do have to pay for ITV regardless.
footnote - The article in The Sun I linked to describes some BBC staff going to the IBC conference in Amsterdam. It is the biggest trade show for the industry outside of NAB in Vegas and the BBC would be remiss if they didn't send a few people to it. Root6 sent about a dozen folks this year as we feel it's important to stay ahead of the game. You gotta hate The Sun and all the lies it peddles.
Thursday, October 13, 2005
Stuart was doing a fibre job today and emailed me this picture that he took on his 'phone. What you can see is the view down the microscope as seen by the little video camera we have as part of our Tritec fusion splicer - the fibre on the left is a normal 62.5 micron core from a piece of loose tube cable, cleaved and ready for the laser. On the right is a pig-tail end that Stuart said "was hard to prepare"(!) - quite a gross manufacturing fault, me thinks! I shall take this up with our supplier.
Wednesday, October 12, 2005
I've been having an ongoing discussion with a co-worker this last week about audio wiring. More specifically about lifting the ground. To define, it's when you don't connect the ground wire in a balanced, hot/cold/ground, connection. Now I personally have firm opinions on wiring based on what I have been taught and what has worked for me for years, but I am no expert by any leniency of definition. And I thought it would be informative for all on the list to hear a discussion on some of these issues so that they can evaluate what work is done when they hire an installer. I'm going to ask a few questions that will hopefully not display my personal opinions but open the topic up for discussion. This discussion is more than welcome to cover not only Avid editing bays, but also portable field systems and audio mix stages. I'm also interested in knowing if a clean electrical supply for the building makes a difference in how you decided to wire.Nine times out of ten you "get away with it" using the same supply throughout a building. The BBC really set the standard in the UK for segregating domestic (aka "cooking" mains) from technical power supply and the reasons have now largely changed because of the move from linear power supplies to switch-mode supplies in pro-equipment. Pre the eighties pretty much everything had a linear supply and so a clean mains supply was essential and so it was common to segregate the mains for the production chain from the sockets used to plug in vacuum cleaners etc. Since then we see a lot more switch-mode supplies which tend to be more immune to mains-bourne noise but the concern now is the large potential difference that can occur between different earth feeds. The worst case is plugging a bit of kit in one room on the technical supply (and hence the tech earth) and connecting it via tie lines to another device that is powered by the domestic supply. Since both devices will (probably) have a common signal and chassis earth an potential difference between the earths will be effectively dumped onto the signal screen - depending on how the receiving bit of kit terminates the feed you get mains hum of the audio and hum-bars on any analogue video. Digital signals are effected in that you're more likely to get transmission errors - splats on the AES audio.
When would you, or would you ever, lift the ground on an analogue audio signal in a deck and mixer configuration? At what point would you lift the ground if you were too (deck or mixer)?As a "get me out of gaol quick" I'd lift the earth in situation I'd described - I'd make sure I fixed the mains supply problem first though. Loosing the electrostatic shielding that the screen gives you probably looses you six dBs of noise performance as well.
When would you, or would you ever, lift the ground on an analogue audio signal in a configuration where all of the audio passes through a half or full norm patch bay? At what point would you lift the ground if you were too (patchbay or device)? Would you tie/strap/buss (the practice of using a wire to connect all the grounds of all the jacks to one another and then connect to the rack) the grounds together on either the half or full norm patchbay?The modern practise is to take signal-earth through the jackfield on each position and terminate in ABS krone blocks. If you view your jackfields as a re-assignable resource then you should make them AES capable and that pretty much dictates earth integrity. By having individual screens you also avoid the problem of dumping mains hum onto every feed on a jackfield if the problem I described (above) happens.
When would you, or would you ever, lift the ground on an AES audio signal in a deck and mixer configuration? At what point would you lift the ground if you were too (deck or mixer)?I'd never lift AES earths! ISTR that when AES was starting to hit in the late eighties the spec document said you should take the shield all the way to the krone block and segregate it with a 10pF capacitor if you had earth mismatch problems - again, you really should get your tech earth sorted! AES is so unreliable an interface (1.4mBits over 110ohm twisted pair cable!) that I tend to put it over 75ohm co-ax whenever possible - see an article on my blog
When would you, or would you ever, lift the ground on an AES audio signal in a configuration where all of the audio passes through a full norm patch bay? At what point would you lift the ground if you were too (patchbay or device)?Previous answer
When building a cable for analogue audio that goes from balanced to unbalanced do you wire [T/T R/S S/S], [T/T R/T S/S], [T/T R/x S/S], [T/T R/S S/x]? And why that way? (and yes, I do know that one should actually use a matchbox or something, but indulge me please) (T=tip, R=ring, S=sleeve, x=not connected) (balanced is TRS, unbalanced is TS)With the proviso that you DON'T mix balanced and unbalanced on a jackfield - you run the risk of unbalancing the whole facility and hence destroy any noise immunity that common-mode rejection is bringing you - I take the view that tieing the cold and screen together is no longer a good way to go as most kit now terminates feeds in op-amps rather than a rep-coil. Loosing six dBs of level seems a reasonable trade-off compared to slowly burning out the receiving stage in the DA, etc.
I've designed/supervised the install of many small and large facilities/studios/OB trucks over the last decade and without exception I've never had to deal with induced mains hum or noisy audio because of balanced/unbalanced problems by following the principles above. Rep-coils (passive match-packs) are a superb way of isolating audio feeds that may have induced mains hum.
Tuesday, October 11, 2005
Wednesday, October 05, 2005
"I have seen the future of rock and roll, and it's name is Bruce Springsteen" - Jon Landau, Rolling Stone Magazine, 1974
Interestingly there were a couple of facilities engineers and MDs there and they didn't seem to get it - the one quote I'll remember for a while was "we could use one in reception..."! I suppose when folks first looked at colour TV, stereo audio, digital video etc etc there were folks who couldn't see how to make it fit into their workflow and therefore couldn't see any value in it. I was blown away, however.
They also had a very cool compression system for reducing the data-load on 32-bit high dynamic range images.
Monday, October 03, 2005
There is no question that this would be a boneheaded move, and as I see more and more chitchat about the possibilities, I'm now convinced that this is all a publicity stunt and the Apple community is being used—once again—by the company's marketing department.The implication is that it slipped out of Cuppertino far too easily. This is stealth alpha-testing by Apple!
That said, I will admit that the possibility does exist that Apple doesn't want its OS in the wild, since it could potentially hurt hardware sales. At least that's the way the company might see it. This assertion does assume that the Apple marketing department is brain-dead....
The other article I saw was in PCW and something there rang true;
.....forthcoming Intel-based Mac OSX operating system on a non-Apple PC. They say on some PCs it appears to run faster than the version on current G5 MacsThis seems to be borne out by Avid who have always maintained it's easier optimise for PC compared to G5 - see a previous blog entry here.
Sunday, October 02, 2005
Saturday, October 01, 2005
Thursday, September 29, 2005
- Digi002, ExpressPro Studio, and eight channel audio.
To get eight channels in and out of a Digi002 console you need to use ADAT 'light-pipe' which necessitates a converter of some sort. Quite why a "pro" product relies on a domestic-style interface for multi-channel work is another topic (not too many VTRs, multi-track tapes or disks come with ADAT, but still). The thing that has really bitten us in the backside is that neither of the models Avid recommend work reliably with the Digi002 (the Fostex UC-8 and the Dua2) and the one gadget that does work (the Alesis A14) only works on short ADAT cables (this is a single-mode fibre - in any industrial grade application you'd expect it to work over kilometres, not be limited to three metres!). This flies in the face of Avid's advice - "you can run long ADAT fibres, but don't try and extend the FireWire between the workstation and the Digi002" - well, precisely the reverse is true! Big shout to my colleague Chris Bailey for figuring this all out and to Joel and Rhys who I worked late with last night out in the sticks in Hertforshire testing this (amongst other things).
- Mojo analogue video performance - still bad, noisy when in component mode (yet Avid claim it's broadcast quality - where, precisely?!). See a previous post here.
- Adrenaline and NTSC reference - when using Adrenaline in 525 mode it has to have a proper Sc-H consistent sync source - this is fine, but by letting people get away with a cheap'n'cheerful black & burst generator in PAL mode you give clients the expectation that they've gotten away with additional expense - if you're going to lower the bar then do it consistently or not at all.
- This pinched from the Avid-L today
Almost as shocking as the actually time code problem is that Avid refuses to comment on it or address it. Pretty shameful.
How about if I say that we're aware of it and committed to fix it? Would that be enough? Sincerely, Jeremy Kezer (Jeremy is Avid's principle engineer)
Monday, September 26, 2005
we'll never need more than three VTRs because even with the second network (what was to become BBC2) we'd only need one per network and a spare
There is no reason anyone would want a computer in their home.Ken Olson, Digital Equipment Corporation (1977)
I think there is a world market for maybe five computers.Thomas Watson, IBM (1943)
640k ought to be enough for anybody.Bill Gates, Microsoft Corporation (1981)
Computers in the future may weigh no more than 1.5 tons.Popular Mechanics (1949)
Why does it prove so hard to be realistic about the future? I think (in part) people find the implications of Moore's Law hard to believe - but it's been good for nearly half a century. In five years we will have the following;
- More than a terrabyte of storage in the PC you buy from PC World
- More than ten gigs of RAM in that PC
- A graphics card that can manipulate cinema resolution images in realtime
- 100BaseT internet connection at home
- An OS that crashes more often, requires ten times the resources of today and lets you word-process at roughly the level of efficiency as you could in the early nineties under Windows 3 on a '486!
Sunday, September 25, 2005
Thursday, September 22, 2005
Anyhow - I was going over in my mind how much we make use of the internet in that area - we do all our communication over Skype (what a cost-saver!) and then there's the website. We get photos and video back from them and we're about to turn the (modest) merchandise section of the website (see here) into a full e-commerce venture. It's even turned Sarah into a web designer!
Tuesday, September 20, 2005
I did reflect on my MP3 listening habits over the last couple of years that really started in 2001 with Chris Parillo's radio show "Call for help" that used to come out of a station in Des Moine. Someone (I don't recall who) who lived in the area used to snag the audio and make it available as an MP3. He put me onto Total Recorder that I've been using ever since to grab internet radio streams (in effect creating PodCasts from anything that streams).
In closing I'm also really enjoying my friend Kevin Cade's cast First Person Show - he interviews interesting people - that's it!
Wednesday, September 14, 2005
The next cable down in the photo is their new 7731A co-ax - just like a garden hose but supposedly good for 165 metres.
The next one down is a sample of Belden "NanoTwist" cat5 cable - optimized for video-type applications rather than network traffic. The degree of twist difference between the four pairs is minimised w.r.t. normal cat5. I'll be trying this - particularly to see if I can get a Scene Double extender to go any further.
The last piece is called "banana peel" multi-coax. It is intended for A/V applications and can be much more easily terminated than multi SD01.
The thing that disappointed me was that on the fibre front all the cable suppliers were concentrating on the old-school single-mode IP type applications and not the kind of SAN applications we're cabling for.
Monday, September 12, 2005
Saturday, September 10, 2005
Coffee is one of the things I really enjoy - decent cappaccino or cafe latte - it's all good with me! Sarah got me one of these for my birthday and I have to say it is a superb gadget - really well made. The top and bottom section are both single-piece castings and the screw sections are well machined with proper inset-gaskets. I predict I'll be enjoying a brew out of this bad boy for years to come. The kids like it because it looks like a cow!
Friday, September 09, 2005
I've bought a couple of these puppies for folks and I am so impressed - £23 for a 256meg flash MP3 player - they also do a 512 & 1gig version.
Ways they score over the iPod Shuffle:
Regular USB storage device - plug it into any Windows/Linux/Mac and it appears as a drive that you can drag tunes onto. You don't have to install iTunes and then lock your music player to a specific computer,
It has a screen - you can see what tune's up next and navigate the very easy to use menus,
Third of the price!
No embarrassing white headphones!
Just the thing for listening to spoken content that hasn't come from iTunes,
Uses replaceable batteries - normal or rechargable - none of that sending it back to Apple when the batteries die (and evey iPod owner I know moans about that!),
Sound quality comparable (or better) than an iPod,
Smaller.
Ways an iPod scores over this:
"It's a design classic, darling"
I suppose that in the end free-markets always gravitate towards mediocrity - The Sun, The Ford Escort, Westlife, McDonalds, the iPod.
Wednesday, September 07, 2005
I saw this at the new BBC Broadcast Center - they donated it to Science Museum a couple of years ago but have it back on loan. It is the Beeb's very first transmitter and could kick out a whopping 1.5kW of radiated power! On the right-hand side of the picture you can see four triodes (made by Osram - not just light-bulbs for those boys!) which I'm assuming makes up a dual-darlington type output stage. Aside from that I couldn't remember enough transmitter theory and valve configurations to guess at which bits did what. There is another good page on the BBC's history site.
I noticed that the transmitter was housed at Savoy Hill House on The Strand - a building now occupied by the IIE, my institute.
Tuesday, September 06, 2005
Today I had a quick trip to Peckham to look at the first of the fifty-odd desks for the MTV install we're currently working on. My main concern was that we could run the fibres through the rear leg without bending them too much - it's all good. I'll post pics of the them when they're all in Hawley Crescent.
Monday, September 05, 2005
However - don't believe what you read on manufacturer's websites!
“All the systems worked incredibly well. We had a few glitches to begin with but, thanks to the support of Root6, these were fixed very quickly. Reliability wasn’t an issue — we had very few issues with FCP during the three weeks and Xsan performed fantastically”.It wasn't all that!
Sunday, September 04, 2005
I've tried to take this view of broadcast engineering - a competent engineer should be able to re-head a VTR, rack a studio camera, install the OS & software so as to make an Avid work, repair & colour balance a monitor, line-up an audio compressor and be able to drive AutoCAD.
Saturday, September 03, 2005
This is a great idea - you see videotape used as a backup medium in television systems - currently Avid's DS-Nitris machine can backup onto tape (but you can watch the tape back and recognise the images and keys etc.) but way back when (in the eighties!) Quantel had a backup system that used UMatic tape. If you had a DLS6001 or a pre-version 5 Paintbox you could use cheap low-band tape as a data tape. If you watched the recording back it looked like VITC all the way down the picture. Very clever (although I seem to remember taking nearly a day once at Lime Grove to get the alignment of the Schmitt trigger right so that it worked!).
Friday, September 02, 2005
Phil - your blog is the absolute business - always a great read - even if some of the tech details are way beyond me (or beyond my interests).
Today I was reminded of some pics you posted when they craned the Resolutions mobile in to the Fame Academy house on Highgate hill a few years ago. You can see the connection with my pics above - a crane would have been great today.
Tim is an OB engineer and sent me some pics of a company he works for sometimes and a bit of bother they got into moving a truck - the details shall remain secret!
Anyhow - here are some pics from an occasion I had to move a truck I'd built for Resolution - over the wall into the Fame Academy in Highgate, North London. £1 million in the air!
Thursday, September 01, 2005
So, I put up a PLUGE signal (so no colour, only luminance), cranked up the gain on the (digital) vectorscope and looked at the colour-in-the-noise (as if you were doing a quick colour balance on a studio camera looking at a chip chart). Tweak the chroma gain on the G5 and the colour caste shifts!. I hate those cards - they are so domestic! Now - the DeckLink defenders will say "but you can unlock the colour components and tweak them separately" - try it - one effects the other terribly - as with their analogue and digital stages they have used some half-arsed implementation that goes to prove that even in 2005 $895 doesn't buy you a broadcast-capable interface card.
So, you can really only use the analogue component output if you don't care about the colour balance (and presumably if you don't want to lay back to analogue tape) - and don't even think about using it at the same time as the SDi.
Catch up with previous reasons why I hate them here and here.
Saturday, August 27, 2005
Thursday, August 25, 2005
Saturday, August 13, 2005
After a couple of days in San Diego having meetings about parking links trucks etc. I finally got to go to Mexico - our fixer took us as far as the tiny military airfield in Encelada (an hour south of Tijuana - the border town near San Diego) where we got on a Cesna 104 that flew us the two-hundred miles to the island. We made a couple of passes of the airstrip and noticed the wrecked remains of other aircraft at either end! It is a very basic facility - just a dirt track big enough to land on. On landing we were met by some folks who work as conservationists (the Mexican government recently declared the island a nature reserve). We borrowed their truck and went about five miles inland (it took an hour! Very rough terain). Then we had to hike across very rough terrain (it is a volcanic island) for a couple of hours. Fortunately the Mexicans had come around the other way with a quad bike and so I was able to make it to within a few hundred metres of the beach.
Once on the beach (half an hour down a very steep ravine) I was able to take a couple of GPS readings (you gotta be able to see the bird if you're going to get pictures back to London!) and take a few photos.
If you want to see a few more pics from the day look at my photo blog (link in the right hand bar). What an adventure - I hope the show all comes together now - it'll be called Shark Watch on Channel Five in October.
I have to say I really enjoyed being with the various Americans and Mexicans - incredibly hospitable and friendly - they wanted to talk about Manchester United and Arsenal! I have been on other recces in the UK and found them to be lonely, uptight experiences but these guys made it a joy.
Monday, August 08, 2005
So, I have to go away this weekend to recce this location for a show that will be on Channel Five in October - it looks really remote - 250 miles off the Mexican coast with only goats for company! I'll be going to San Diego on Thursday and then heading down Mexico way to get a light plane to the island. I'll post a load of photos on my picture blog (see the right hand links bar).
Guadalupe Island on Wikipedia
An Oceanic Wonder
This is a nice pic that Sarah found online - I'm quite looking forward to it!