Sunday, June 24, 2007

The wisdom of comrade Alexie Sayle

Garibaldi, Italian revolutionary, ends up as a kind of biscuit. It's quite interesting, you know, the number of biscuits that are named after revolutionaries.
You've got your Garibaldi, of course, you've got your Bourbons, then of course you've got your Peek Freens Trotsky Assortment.

"Revolutionary biscuits of Italy
Rise up out of your box!
You have nothing to lose but your wafers
Yum yum yum yum yum!

Monday, June 18, 2007

2nd o/p of MacPro display cards

We're exhibiting at Broadcast Live! and whilst setting up the equipment I had real difficulty getting a MacPro to feed a 23" cinema display - actually because it was a 7.5m DVI cable I'd stuck a DVI DA just before the monitor (Apple displays are very fussy about long cables - much more so than Dell/HP/Acer etc. - but hey, they're design classics darling so why conform to the standards?!) and would occasionally see a flash of the OS-X logon screen but v.unreliable. I knew the DA was OK having checked it on an HP8400 workstation and it wasn't until Graham reminded me of the problem I had at The Joint back in January (link in the title of this post) that I thought to try output two of the card - all good! It turns out the DVI DA doesn't return correct DDC data and so XFree86 (as implemented in OS-X) does funny things.

Thursday, June 14, 2007

The how and why of COFDM

Coded Orthogonal Frequency Division Multiplexing (COFDM) is a form of modulation which is particularly well-suited to the needs of the terrestrial broadcasting channel. COFDM can cope with high levels of multipath propagation, with a wide spread of delays between the received signals. This leads to the concept of single-frequency networks in which many transmitters send the same signal on the same frequency, generating “artificial multipath”. COFDM also copes well with co-channel narrowband interference, as may be caused by the carriers of existing analogue services.

This is a very well written explanation of COFDM (as used in both digital terrestrial television and digital radio in the UK) - the workings of the multi-carrier system was something that I never really understood but this opened my eyes (did you realise that every DVB-T mux uses more than 6,000 carriers!). Recently I was explaining to someone how Viterbei decoders work (with particular reference to Digital Betacam VTRs) - again, I didn't realise that COFDM uses a modified Viterbei decoder (the 'soft viterbei decoder').
I wish I hadn't specialised in post-production so early as there are many things the the broadcast chain that I'm rusty/ignorant of.

Wednesday, June 13, 2007

I own a BVW-75P!

Oasis Television are ripping out and starting again and sending a load of their old gear to the dealers and/or skip! They have generously donated me a BetaSP player/recorder - it's one of the ones I looked after during my tenure there (1994-99) and so is an old friend!
The BVW-75P was the first piece of broadcast equipment I got to know very well. During my time in post-production maintenance at the Beeb it ranked with the Questech Charisma and Quantel Paintbox as a device that I could do anything on - I changed more than a hundred head-drums whilst in VTR maintenance and really understood all the workings of it. At the time I promised myself that I'd have one eventually just as a souvenir of what TV engineering used to be. Stripping down and re-building the t-drawer arm assembly is good for the soul!
This one is actually an Ampex-badged one (CVR-75) but it has the more recent board-set; the TBC-12 timebase corrector and the DEC-45 composite decoder.
I am very happy!

Tuesday, June 12, 2007

Monday, June 11, 2007

Broadwave streaming server

I had a need to set up a streaming server for spoken content and since I'd previously done lots of work with RealMedia I checked that out first (if it's OK for the Beeb...!). I'd set up the streaming servers for the first couple of years of Big Brother (when the G2 version was considered clever) - but now it's all Helix servers and the the old NT4 version wouldn't play nicely on the box I was trying it on and the prices have gone UP! 400 streams costs you around $22k in licensing. I only need a few dozen streams and so I looked at Broadwave - this is largely agnostic, negatiating with the browser what codec to serve up. It works very well and starts with Windows Media 9 and tries WM7 and then streamed MP3. There can't be many client machines that can't handle one of those!
The only caveat on the free version is 50-streams and a little logo on playback - that's just fine and doing the business where I needed it.


Sunday, June 10, 2007

Pant-wettingly-funny audio

Here are a couple of half-hour recordings I came across from years ago - they still make me laugh heartily and so I share them (as MP3 format files) for your pleasure.

  • The Quanicles from Michael Biggins - bear in mind that four of the voices are one guy! Even better than the Jerky Boys;
    In this epic series of calls that lasted an entire evening, I play 4 different characters; John Dandell (who is once again in action as a police officer who works specifically for a telephone company), the operator - Joana, the ancient ninja master - master Shreddar (known though out these calls as... the voice.), and the 15 year old - Matt Cheddar. Poor Quan has no idea I am doing all the voices and truly believes that all of these people are real (except for the voice of master Sheddar, who he thinks is Matt) and will do anything to convince the cop (John Dandell) that Matt Cheddar (the teenage mutant ninja turtles fan) is crank calling him. To make things even funnier, I even let one of the characters I am doing, Joana (the operator), side with Quan.

    Just over half an hour long, download here.

  • Robin Williams on Steve Wright (Radio 1 from 10th May 1989) - back them Williams was the king of improv. I've cut the music but left in the bumpers and stings so you can remember how the late eighties sounded! Get it here - listen for the Jimmy Swaggart references.

Friday, June 08, 2007

Isilon

Good news everyone! I have seen the future and it runs OneFS. Yesterday I had one of those Bruce Springsteen moments as Rupert and Rob Anderson (from Isilon) took me through the configuration and operation of their distributed storage system.


The Isilon IQ clustered storage product line addresses enterprises' full spectrum of storage needs - from the highest performance Tier-1 applications to Tier-2 enterprise archive, disk-to-disk backup and disaster recovery. Powered by OneFS, the Isilon IQ family of products creates a single pool of expandable storage that is easy to install and grow - once racked, a 10, 50 or 100+ terabyte cluster takes less than 10 minutes to configure and set up, and capacity can be added on the fly in less than 60 seconds with no downtime.


Their OneFS file-system is distributed across as many nodes as you have and regardless of model (the baby 200 model that has only gig ethernet) or the larger infiniband attached nodes you really can expand and contract the storage pool on the fly and without having to re-format to mount new partitions etc. I imagine this is the kind of technology that makes data centres run smoothly. Yesterday I was able to build a 3 x 2 Terrabyte cluster in a matter of minutes, upgrade the software running on the nodes by upgrading one node only (the OS which is FreeBSD runs on the distributed filing system as well) and then attach a fourth node that was running a previous version of the OS and have it upgrade itself. All this happened while the storage was active and being used and the client workstations didn't see any loss of space or loss of performance! When you compare it to other NAS or SAN solutions it is truly miraculous.
In terms of performance it currently connects to the workstations over gigabit ethernet but they are promising faster connectivity. Traditional performance bottlenecks are addressed by including an IQ Accelerator in you configuration - this essentially gives you a bigger in-road to the storage;
Isilon IQ Accelerators automatically join an Isilon IQ storage cluster in less than 15 seconds and add processing power, memory, bandwidth, and parallel read and write access to a single file system and fully symmetric storage cluster. This is in stark contrast to the limitations of traditional storage and namespace aggregation technologies that require customers to add expensive file server heads and disparate devices to increase performance. These legacy approaches are difficult to manage and fail to aggregate total throughput across a unified storage system.

So, you have a storage pool accessible by a single attachment point which can grow infinitely without the usual performance hit as the filesystem has to address multiple virtualised pools.
I am so impressed - watch this space!

http://www.root6.com/Home/Products/productinfo/network_storage/isilon.htm

Sunday, June 03, 2007

How Avid differs from all other broadcast manufacturers

Avid have this get out of gaol card they play often - it's called the ¨..that's not a supported configuration¨ reason. They play it whenever their badly implemented version of an industry-wide standard doesn't play nicely with other equipment. The first time I came across it was the way they do P2 protocol over RS422 on the ABVB-based Mac systems. I was working at Oasis TV back in 1996 when we started to hook original D5 machines (the Panasonic AJ-D580) up to 9500-based V.7 Avids. We noticed that when capturing the deck would often take off in the wrong direction and then reverse and pre-roll correctly. Often laybacks would fail or be a frame late. Eventually I borrowed a serial sniffer and stuck it across the RS422 out of the Avid and discovered the following.

  • The Avid rarely issued commands in the 17-line window after the start of frame that P2 demands. Consequently the deck would queue the command and ignore it for a frame.

  • The Avid would sometimes issue the pre-roll command before it loaded the counter - the poor old VTR would take off on the pre-roll only to realise that it was going in the wrong direction.
So, a broadcast grade VTR that conforms to every relevent standard doesn't play nicely with Avid's sloppy implmentation of an existing standard and their justification is that "...it's an unsupported configuration"!
I've just put in a couple of machines that rely on an outboard FireWire switcher. I would have sworn it was the switcher that was at fault but I had a Root6 ContentAgent to test the various ports with the VTRs. The Avid Mojos will drop the feed if you do anything with the switcher (like make another route!) and you have to re-launch Media Composer. It makes using FireWire decks a real pain and I didn't realise Mojos were so problematic until Graham sent me the following;
This just mirrors my experiences...
Firewire switches, hubs and splitters don’t work CONSISTENTLY. They just don’t. Firewire patchbays and good quality extenders DO.
I have tested half a dozen of these things and they just don’t work without a reboot, a reset, and a mess around.

The same can be said of SCSI, Fibre Channel, and even the way they handle the PCI bus - see a previous post here for details of their half-arsed ADAT implmentation.
Now, if a Sony VTR refused to record a standard PAL signal or a Grass Valley mixer wouldn't derive a key from an SDi feed then they would sort it out - I never heard the phrase ¨...I'm sorry, that's not a supported configuration¨ until Avid came on the scene!

Wednesday, May 30, 2007

Why don't people use the technical mains?

This is a picture from a facility that shall remain nameless! We did their technical infrastructure wiring a couple of years ago - fibre, mains, as well as data and video and audio. They ran out of cash and so wanted to do the internal cabling within the rooms themselves. So - on all the 16-amp C-form mains outlets (carrying the technical mains supply) I had the electrician leave a male cable-end connector in the Commando socket so it would be easy for them when they came to do the internal wiring. Imagine my surprise when I noticed that they hadn't bothered with the tech mains, preferring to use the domestic 'cooking' supply! So, I went for a walk around the place and guess what - the whole building has every edit suite and grading room running on domestic rather than tech! That's why people get hum bars....

Anyway, it's a perennial problem and I bang on about it often - see here, here, and here.

Saturday, May 26, 2007

Ben Davison's wedding

Sarah and I had a great day out in Croydon (really!) at Ben and Judith's big day - bride looked lovely etc. and the food was excellent! The dude in the right hand picture is Jayson Chase - salesman at Avid and old colleague who'd I'd not seen for a while - nice to catch up.


links: St John the Evangelist, the reception venue.

Thursday, May 24, 2007

100 Gigabit Ethernet

We're just getting to grips with ten-gig ethernet (and the plethora of copper & fibre connectors and standards!) and I notice the Ethernet Alliance are talking about the road to one-hundred gigabit. They have an interesting paper here and if you need a catch-up on where ethernet came from look at the slides of their history presentation.

Wednesday, May 23, 2007

Crystal Vision & TV aspect ratio

I like Crystal Vision - like MurrayPro and Quartz (though for how much longer with them is anyone's guess!) they are small English technology firms that pay attention to detail and care about their customers. You can generally speak to the developer or designer and know you'll get sense (try that with Avid!).
This is a brilliant illustration of the three aspect ratios used in standard def TV.

Monday, May 21, 2007

Macavity - The Mystery Cat; a poem by T S Eliot

Macavity's a Mystery Cat: he's called the Hidden Paw--
For he's the master criminal who can defy the Law.
He's the bafflement of Scotland Yard, the Flying Squad's despair:
For when they reach the scene of crime--Macavity's not there!

Macavity, Macavity, there's no one like Macavity,
He's broken every human law, he breaks the law of gravity.
His powers of levitation would make a fakir stare,
And when you reach the scene of crime--Macavity's not there!
You may seek him in the basement, you may look up in the air--
But I tell you once and once again, Macavity's not there!

Macavity's a ginger cat, he's very tall and thin;
You would know him if you saw him, for his eyes are sunken in.
His brow is deeply lined with thought, his head is highly doomed;
His coat is dusty from neglect, his whiskers are uncombed.
He sways his head from side to side, with movements like a snake;
And when you think he's half asleep, he's always wide awake.

Macavity, Macavity, there's no one like Macavity,
For he's a fiend in feline shape, a monster of depravity.
You may meet him in a by-street, you may see him in the square--
But when a crime's discovered, then Macavity's not there!

He's outwardly respectable. (They say he cheats at cards.)
And his footprints are not found in any file of Scotland Yard's.
And when the larder's looted, or the jewel-case is rifled,
Or when the milk is missing, or another Peke's been stifled,
Or the greenhouse glass is broken, and the trellis past repair--
Ay, there's the wonder of the thing! Macavity's not there!

And when the Foreign Office finds a Treaty's gone astray,
Or the Admiralty lose some plans and drawings by the way,
There may be a scap of paper in the hall or on the stair--
But it's useless of investigate--Macavity's not there!
And when the loss has been disclosed, the Secret Service say:
"It must have been Macavity!"--but he's a mile away.
You'll be sure to find him resting, or a-licking of his thumbs,
Or engaged in doing complicated long division sums.

Macavity, Macavity, there's no one like Macacity,
There never was a Cat of such deceitfulness and suavity.
He always has an alibit, or one or two to spare:
And whatever time the deed took place--MACAVITY WASN'T THERE!
And they say that all the Cats whose wicked deeds are widely known
(I might mention Mungojerrie, I might mention Griddlebone)
Are nothing more than agents for the Cat who all the time
Just controls their operations: the Napoleon of Crime!

Saturday, May 19, 2007

Virgin Media, cable modems and bad tech support

I had my cable go down on Wednesday - it would stay up for half an hour after resetting the cable modem. So - a quick call to their tech support only to be told that it had to be my wireless router - hmm, I began to wish I hadn't blogged that Dilbert cartoon on 12th May! So - I tried another routers and even hooked the ethernet out of the router directly to a couple of computers. Of course when I called back the guy was on his break and I had to start the whole procedure with another person. Anyhow - today I had the tech support visit and the engineer showed me how bad the feed from the cabinet in the street was; -27dBuV - he said he'd normally expect to see -6dBuV! So - at the box end he discovered the port feeding my house was faulty and replaced it - nice signal level at the house. But, when he drove off the ping I was running fell over and the link was down again. I got straight back on the 'phone and this time got a representative who actually knew what he was talking about. When I told him the story and the half hour business he knew exactly what the problem was. A couple of days ago Virgin pushed out a firmware upgrade to the Scientific Atlanta cable modems and it corrupted the data rate sync settings so the buffer in the modem would over-run after n-minutes of use. See these screenshots if you're similarly troubled!

Friday, May 18, 2007

Apple, Amazon may hold future of DRM-free music

The music industry-- struggling with one of its worst-ever sales slumps--will be closely watching how Amazon and Apple fare. If they are successful in moving a lot of songs, then that might convince the other three major record companies to strip DRM from their music. If sales are lackluster, then that might spur the labels to wrap songs in even tighter copy protection, say industry insiders.

Thursday, May 17, 2007

Neutrik OpticalCon Chassis Connectors

I'm looking forward to trying these chaps on a job next week. Here is the sales guff from the Neutrik website.
The chassis connector acts as a "feed-through" allowing simplified installations by connecting a conventional LC-Duplex on the rear. It is built in the standard D size shell and features an automatic sealing cover for maximum dust and dirt protection and a Push-Pull locking mechanism for safe connection. Colored labeling plates are included to identify the fiber mode.

Wednesday, May 16, 2007

The Schubin Report with Mark Schubin

Mark Schubin is one of those well known engineers who has columns in various technology publications and for the last year has been producing a superb podcast. The most recent has a good round-up of test equipment that was shown at NAB this year. The Harris OFI-20B Optical Fibre Identifier seems nothing short of miraculous. It flies in the face of a few of the obervations I made about optical link hacking - I really wish I had a chance to see some of these developments.

Tuesday, May 15, 2007

Making PDFs from any app in Vista

Convert to PDF from any application by simply 'printing' to the PrimoPDF printer - it couldn't be easier! Within minutes, you can create and append high-quality PDFs by converting from Word, Excel, PowerPoint, and virtually any other printable file type.

The only downer is that files inherit the properties of the original file that was used to generate them! So, with AutoCAD (which under Vista you have run as admin) all output PDFs are viewable by local admins only - so (even though I'm a domain admin) I have to adjust their properties before they are usable! Anyhow - in the absence of Adobe making Acrobat work properly with Vista this is a good solution.

Monday, May 14, 2007

Test - apres some hacking!

I woke up this morning (have I turned into Muddy Waters?!) and discovered (thanks to an email from my good pal Kevin Cade - First Person Show podcast, see the light-hand panel) that my blog had a bunch of spam posting to it. I can only assume that my Blogger/Google account has been compromised - time to change that password!
While walking to the bus-stop my eldest said how stupid I was to use the same password for forums and my eBay account - ¨...everyone knows forum moderators are the most dishonest people in the world!¨ - well duh!
He's right - and I think I've just changed the last one that needed changing!