Getting to Know Selectable Outputs


Two words, tucked together inside the "plug-and-play" agreement, are causing more than a few quizzical expressions lately — especially since the Federal Communications Commission approved the collaborative work of cable and consumer-electronics companies last month.

The words: "Selectable outputs."

"Selectable outputs," as a technical term, is puzzling because its component words are ordinary. We all know what "selectable" means, and we all know what "outputs" are.

If you're like me, when you hear the two together, "selectable outputs" makes sense, at first. You think you know what it means: A choice of plugs.

Not so simple

By then, the conversation containing "selectable outputs" probably corkscrewed into the acronyms of copyright talk. Suddenly — maybe as you're trying to backwards-conjugate the HDTV verb "down-rez" — you realize that the whole "selectable output" scene is noisy with subtleties.

("Down-rez," for what it's worth, doesn't backwards or forward conjugate, but it's an accepted shop-talk verb to describe the lessening of picture resolution.)

As a reference point, here's how "selectable outputs" is used within the 78-page memorandum of understanding sent by cable and consumer-electronics (CE) companies to the FCC last December: "The parties agree to publicly advocate the elimination of any MVPD device obligation to respond to commands as to selectable output controls …"


At its core, the "selectable outputs" riddle taunts the connectors on the backsides of CE devices and cable and satellite boxes. More specifically, it anoints certain connectors trustworthy of carrying copyrighted, digital material across their pins – but not others.

Talk backwards

What's "selectable" about a "selectable output," for example, is whether that output can be selected to not work, when the payload is copyrighted digital video.

That could happen, CE technologists say, if studios injected a sort of "cripple code" into their digital video payload. The code alerts a cable or satellite set-top box to disable certain outputs. The bits stop there.

Which outputs are at stake? Right now, there are four possible connectors ("outputs") — two analog, two digital — that come with digital and high-definition TVs. Analog outputs include RGB, for red/green/blue component output, or the (splendidly nerdy) YPbPr.

The digital outputs: IEEE-1394 "firewire," and "DVI," for digital visual interface.

Recall that connector conversations almost always come in twos: The name of the connector, and the name of the copy protection that safeguards whatever gushes out of that connector. The 1394/firewire connector uses "5C" protection, and DVI uses "HDCP," or "High bandwidth Digital Copy Protection." (For details on connectors and copyright protection, see the Jan. 13, 2003 edition.)

A black hole

Analog has no bodyguard, which is why it's called "the analog hole." This is "hole" as in "black hole." Content theoretically falls into it and disappears. Or, worse, copyrighted material gets duplicated zillions of times and shared over the Internet.

It is precisely this fear of rebel duplication and distribution (by studios and copyright holders) that begat the notion of "selectable outputs," which, in turn, begat the counter-notion of "no selectable outputs" from the CE industry.

Why? Say you're a TV manufacturer. Last year, or the year before, you sold a guy an HDTV set, for the equivalent of his last three paychecks. Maybe it had an analog connector and 1394, but not DVI.

One night, the TV doesn't seem to work. Naturally, this happens just as the family settles in for a movie. It happened because a code inside the movie disabled its transit to the screen. Would that be okay with you? What would you say to your customer?

(Were this to actually happen, technologists say, movie studios would probably allow the DVI/HDCP connector/copy protection duo, because it handily has but one setting: Copy never.)

Cable 'gave'

All major negotiations have some give and take. In the early plug-and-play discussions, "no selectable outputs" was one of cable's "gives" to the CE side, but with a very specific proviso: Satellite providers must also agree to "no selectable outputs."

That reasoning: If DirecTV and EchoStar aren't exposed to the same rules, a studio could give them an earlier release window on a popular movie.

The thing to know about the two words "selectable outputs," whether or not a "no" precedes them, is that they nearly always have the same word trailing them: "Control." And when a control lever is in play between partners and rivals – variously cable, satellite, CE and Hollywood — it's a control lever worth watching.

Speaking of which: At press time last week, the FCC was on the brink of releasing details about its approval of the overall plug-and-play agreement. Its position on "selectable outputs" was one that observers were hawkishly awaiting.

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