Wednesday, August 10, 2005

TV technology, slippery reporting, and cultural bias: Promise TV

A story that did the rounds last month: Promise TV’s demo at OpenTech of a personal video recorder which, unlike current commercial product, records multiple channels simultaneously.

Some necessary background: the word multiplex has a very specific meaning in the digital TV arena. A multiplex is a collection of services—TV, radio, or data channels—grouped together into one massive stream of data, also known as a transport stream. A multiplex is broadcast on a single specific frequency on the distribution system, which may be terrestrial, cable, or satellite. This is very specifically different to analogue TV, in which a frequency carries only one service; digital TV compresses the data to squeeze multiple services onto each frequency. A network consists of one or more multiplexes; for example, the UK’s terrestrial Freeview network is made up of six multiplexes. And finally, the distribution system may itself carry multiple networks; for example, the same satellite transponder may used to carry programming from several different network providers.

What this means is that to show, or record, a digital TV service, you need to do two levels of filtering: first you tune to the relevant carrier frequency, which gets you a transport stream full of services; and then you fish out the service you want and discard the rest. It also means that if you want to show or record two services simultaneously, you may need to tune to two different frequencies simultaneously, depending on whether the two services are on the same or differing multiplexes. Current PVR/DVR boxes handle this by having two tuners.

The other thing that’s important to know is that a transport stream carries a large amount of data at a formidable data rate: 40Mbits/s is a fairly typical rate for a satellite multiplex. This is fast enough to fill a 160G hard drive in about eight hours. Current PVR/DVR boxes sidestep this torrent of data by recording services, not entire transport streams: a single service at under 5MBits/s is a lot more manageable. The cost of this, though, is that it makes recording selective: you have to tell the box what to record beforehand. Good programme information helps you to choose and schedule recordings, and some products (like TiVo) record programmes speculatively based on your previous habits. But still, the much-vaunted ability to pause and rewind live TV only applies to the channel you’re watching: if you’re watching ABC and realise that you’ve missed the start of the movie on NBC, you’re out of luck.

This is Promise TV’s premise: rather than record selectively, why not simply record everything and let you sort it out later? Their prototype is PC-based, with what appears to be three DVB-T (digital terrestrial) tuner cards, and a boatload of hard disks—the last making it a furiously expensive endeavor, although storage prices are always falling.

But here’s where the slippery reporting begins. Eyewitness reports, and Promise TV’s own recently-posted description, state that the prototype records twelve services from three of the six Freeview multiplexes. And Freeview, being free-to-air, carries a lot less programming than the UK’s pay-to-view cable and satellite services.

Cory Doctorow led off with a breathless report in BoingBoing:

What the Promise does is grab the entire broadcast TV multiplex—all the channels being broadcast in the UK—slices them up according to the free, over-the-air electronic programming guide, and stores an entire month’s worth. Why program a TiVo to get certain shows for you when you can record every single show on the air, all at once[?]
Whoa there: careful with that terminology. “Multiplex” has, as I explained above, a very specific meaning in the TV field; it certainly does not mean “all broadcast channels”. Grabbing a multiplex simply means you’re grabbing a collection of channels.

But that misunderstanding aside, there’s also some terribly imprecise reporting here. Firstly, the Promise demo clearly didn’t record “all the channels being broadcast in the UK”; it recorded a subset of the Freeview channels. And secondly: “all the channels being broadcast in the UK” is terribly vague in itself. What exactly constitutes “all channels”? Just as in the US: what channels you receive depends on what provider you subscribe to. And as I noted above, Freeview is itself a small subset of what’s available on the subscription providers.

But it’s too late to stuff the “records everything on UK television” meme back into the bottle: it makes too attractive a hook for other reporters. Daniel Terdiman at CNet seems to have picked up the BoingBoing report (although, to be fair, he did also talk directly to Promise TV):

When Cory Doctorow visited last weekend’s OpenTech conference in London, he was stunned to see a box about the size of a 1990-era VCR boasting some pretty forward-looking capabilities.

The box was a prototype of a digital video recorder from Ascot, England, start-up Promise TV that can record and index an entire week’s worth of British digital-television programming.
While this does accurately reduce the recording time from BoingBoing’s reported month to a week, note again the suggestion of “records all programming“ and the vagueness over exactly what “all programming” means: “digital television programming” covers a lot of different transmission methods and providers.

Ryan Block at Engadget picks up reporting directly from the CNet piece:

Not that we have a problem with a bigass 3.2TB DVR intended to basically intended to record an entire week’s worth of televised programming—is the case with Promise TV’s shortly forthcoming device they showed off at OpenTech [...]
Again, the suggestion is that it records “all programming”. Although Ryan does pick up on the issue of multiple tuners, he gets a little lost in the technology:

Second are the tuners: what, you going to rock a tuner dedicated for every channel?
No: you’d need (“to rock”?) a tuner dedicated to each multiplex; still a lot more tuners than current boxes, but not exponentially more. In the comments, Ryan is defensive about his second-hand reporting:

Maybe if I was at OpenTech, which I wasn’t, or if Promise published any information on their device, which they didn’t. I only have what I’ve got to work with, and that’s a couple crappy, information-light articles.
Maybe crappy, information-light articles don’t form a strong foundation for further reportage, hmm?

And then the reporting takes a stranger turn. Eric Hellweg at Technology Review described the demo as:

A prototype personal video recorder (PVR), called Promise TV, that successfully recorded and stored all the shows running for a week on all 12 channels in the UK.
“All 12 channels”? What on earth has happened here? My guess: the pervasive “records everything on UK TV” meme started by BoingBoing got conflated with some more accurate information (“12 channels”) on the prototype’s capabilities. Throw in some vaguely-remembered cultural bias—“oh, Britain, they don’t get much TV there do they?”—and we get the resulting nonsensical statement: the UK has only 12 TV channels.

My suspicion of cultural bias is strengthened by Eric’s closing sentence:

Then again, [Promise TV developer] Ludlam probably hasn’t experienced the literally hundreds of channels available in the United States—not all of them as must-see TV as, for instance, classic episodes of Monty Python’s Flying Circus.
Uh-huh, yep, that’s exactly what British TV is. Who needs hundreds of channels? All Monty Python, all the time, that’s us.

Well, no. While the UK still only has five analogue terrestrial channels, there’s no shortage of multichannel digital TV in the UK. And it’s arguably more advanced than the US. The UK adopted digital terrestrial very early (although with mixed success; the current free-to-air offering was built from the remains of a failed subscription service) and Sky were similarly aggressive in pushing towards digital satellite. You want hundreds of channels? We’ve got hundreds of channels.

The last link in the chain is this frankly bizarre report by Jen Seagrest at TV Squad, which directly links the Technology Review article:

Ever wish your DVR recorded more than two channels at once? [...] Evidentally the Brits want it too as I guess there is a dire need to record the Snooker matches on all four broadcast network channels at once.

Promise TV is a product in the making at the BBC labs in the UK. It will record every channel at once, not just the two that Tivo and other DVR’s can do presently.

To be fair the UK only has 12 channels total on thier satellite system. If they could get it to record 120 channels at once that would be getting somewhere. (Of course, if they could get more than 12 channels in the UK I’d move there in a second.)
As I said in the comments there: “pack your bags”. The UK gets way, way more than 12 channels on all its digital services.

The shift in focus to satellite is an odd invention; the Promise TV demonstration was clearly on digital terrestrial, although most of the subsequent reporting has just vaguely said “television” without specifying the distribution system.

But the cultural bias here is clear: Jen believes, and wants to believe, that UK TV is backwards. “All four broadcast channels” puts a subtle emphasis on “all”: oh, those poor wacky snooker-loving TV-deprived Brits. It seems churlish to mention that it’s actually been five channels for eight years now, or that the endless hours of snooker were always confined to BBC2. She accepts, and embellishes upon, the claim that UK TV has only 12 channels without challenging it with even the most cursory of research.

This is poor reporting; and a good example of why mainstream journalists criticise bloggers. TV Squad, as part of the Weblogs, Inc. portfolio, is positioned as a trade publication; its bloggers are paid; is it too much to expect at least some journalistic standards?


Ahhhh... OK. I realised that americans generally have a pretty distorted view of the world (largely through their own media services) but this takes the biscuit.

Come on guys, bang the rocks together! The world is a lot bigger than the US borders and there is a hell of a lot going on out there. We brits do NOT spend all day watching monty python, drinking tea and complaining about the weather. Nor do we believe that most yanks are inbred rednecks who eat only fast food and shoot guns all the time.

Do the research and if you are proved wrong, have the decency to print corrections!