DRM and Displays: Bits on Bytes

Toshiba's blue laser-based optical storage development group has announced that HD DVD players (presuma bly only when playing DRM (Digital Rights Management)-protected content), will down-rez their analog outputs to 480-line standard resolution levels. I'm not sure why this is such a surprise to everyone; my two several-year-old JVC D-VHS decks already do this with D-Theater DRM'd material, and I suspect that the Blu-ray camp has similar plans.

Along similar lines, Microsoft's upcoming Vista (formerly Longhorn) operating system will reportedly enforce a content protection scheme called PVP-OPM (Protected Video Path – Output Protection Management) for high definition video material. At the content owner's discretion, if the interface between your PC and display is DVI with HDCP, or the consumer electronics variant called HDMI (aka PanelLink Cinema), you'll be able to view the material in all its high-def glory. Video transmissions over digital but non-DRM'd interfaces like DVI, or over today's still-pervasive analog interface, will either get down-rez'd to standard definition or you'll get nothing but an error message prompting you to switch to a politically correct cabling scheme. Microsoft is quick to reiterate those 'at the content owner's discretion' words in an attempt to shift the heat away from them. Finger-pointing aside, here's the bottom line; are you ready to buy a new display and graphics card if you want to see inevitably Vista-only content, folks?

Or maybe you won't need to. A black box (really, it's black!) called DVIMAGIC from a company called Spatz-Tech is marketed as a single-input, dual-output DVI extender, but it additionally strips out any HDCP encryption present in the input signal and consequently passes along a DRM-free digital output. DVIHDCP, from the same company, takes in HDCP-soaked DVI from 480i to 1080p resolutions, at 24-to-120 Hz frame rates, and outputs identical-resolution and -framerate analog video. How long will these tempting widgets be allowed to exist? Well, the company's based in Germany, beyond the reach of US court jurisdiction (a loophole that Russia's ALLOFMP3 also exploits, although in this latter case there's also no fear of import shipment blocking thanks to the Internet delivery system).

However, the HDCP spec, unlike prior-generation and more limited DRM schemes like CSS, encompasses the concept of revocation (see DeCSS for why revocation is so desireable in a DRM). Content owners 'could' employ HDCP's SRMs (system renewability messages) to functionally neuter a DVIMAGIC box. But will they? Who knows; to date equipment manufacturers and content developers have been extremely reluctant to pull the revocation trigger for fear of mistakenly disabling law-abiding consumers' gear and enduring the subsequent backlash and restitution costs. DVIMAGIC reminds me of, in the analog domain, Sima's 'video enhancers' that also happen to disable Macrovision content protection and enable DVD dubbing. And I'm also reminded of a whole host of 'black boxes' that, in the days of DAT, stripped out SCMS copy-protection flag bits.

For more on DRM, see my article 'Media security thwarts temptation, permits prosecution' published five years ago (the concepts detailed in it are still surprisingly relevent!) along with Nicholas Cravotta's followup piece entitled 'The war on copying'.