HDCP stands for High-Bandwidth Digital Content Protection, and represents copy protection technology developed by Intel and licensed through Digital Content Protection LLC. It's specifically designed to foil those who'd like to view pirated HD content, and gets the backing of most major movie studios and other creators of high-definition video source material. These days, most vendors whose hardware can handle high-definition content - including set-top boxes for cable or satellite video, DVD players, HDTV sets and so forth - choose to license HDCP, and typically also require it to be accessed using an HDMI connection. That's why you see an increasing number of HDMI- and HDCP-capable graphics cards and motherboards coming to market these days.

Ostensibly, the Advanced Access Content System (aka AACS) requires the use of an HDMI 1.3 (or better, or equivalent DVI-D) connection with circuitry that can handle HDCP encryption, or it will "downscale" 1080p content to 50% of its actual size (960 x 540, in other words) in the middle of your display. In plainer terms, this means you won't get much pleasure out of your hi-def DVDs or other copy-protected HD sources, if you don't use HDMI or compatible DVI to hook up your high-definition DVD player (and presumably other copy-protected HD sources as they become available) to your display or other AV components. This is a huge downer for those who already own HDTVs that don't support HDMI 1.3, not to mention older HD-DVD players, and other older gear. Thus, the gotcha is that you may some day buy a high-definition DVD, either Blu-ray or HD-DVD, that won't display at 1080 horizontal lines on your HDTV when you fire it up and start watching - but not yet.

The content publishers (movie and TV studios and other outfits that produce copyrighted high-def content) haven't yet turned on the AACS Image Constraint Token (aka ICT). Think of the ICT as a flag that tells the display gear to downscale content if it senses the lack of the right transmission and decoding chain for output of high resolution (1080i and 1080p) content. Right now the ICT isn't turned on in any commercially available pre-recorded materials, either for Blu-ray or HD-DVD. That's because these fledgling technologies and markets don't want to alienate the vast majority of HDTV owners whose equipment doesn't meet the AACS interface and decryption requirements. That's why you can use component video, older HDMI (1.1 or 1.2), VGA or even DVI-I links from player to display (and other points between, where applicable) and still get 1080 output, specifications and copy protection notwithstanding. Today, movie studios get to choose whether they use the flag or not, and so far, they've chosen not to do so, for eminently practical reasons.

It's widely believed (but nowhere officially stated) that use of the ICT has been postponed until no earlier than 2010, but possibly until as late as 2012. Given that the average life of a piece of video or home theatre gear is about five years, that means that today's current equipment may never really have to confront or be affected by this potential gotcha. Especially for those who've already made investments in HDTVs, receivers, and other gear that doesn't conform to AACS requirements, we say use your current connections and deal with ICT enforcement when and as it's invoked. By the time ICT really becomes an issue, most people will probably be ready to buy new equipment anyway, and will probably face an entirely set of different but no doubt equally vexing issues.

Sidebar: Our Troubles With DHCAT

Despite all the help and information from Intel that anybody could ever want, we simply couldn't spend enough time to make either DHCAT 1.5 or 2.0.1 work on our test builds. Where DHCAT 1.5 was concerned, we ran into trouble trying to complete some of the tests where video encoding and decoding were involved. After four unsuccessful installations and test runs that followed, we gave up on that package. This process took us one very long day to work through before we decided to give up, and move on to the latest version

Where DHCAT 2.0.1 was concerned, we encountered an interesting side effect of our machine setup methodology. We routinely reinstalled a clean, fresh OS, with no patches or Windows XP post-SP2 updates (or the MCE 2005 release media in this case, as they slipstream the SP2 material). At first, DHCAT 2.0 failed during installation with no error messages to let us know what was going wrong (to be fair to Intel, not too many install programs produce helpful error messages in any case). It wasn't until we perused a list of post-SP2 patches and updates that we discovered that the Microsoft Installer had been upgraded to version 3.1, which it turns out that DHCAT 2.0 depends on.

Thinking we could get things working by applying all patches and fixes to a test image, we spent the three hours or so it took to download and install the 84 updates from Microsoft Update that this process required (two items were third party hardware related; all others came from Microsoft). After that, it took another four hours or so to get DHCAT itself, plus a media server, various A/V encoders/ decoders, and all the pieces and part necessary to pass the program's system review process to work. But alas, after running a triple set of benchmarks all night long on the Intel T7200 CPU-based system, DHCAT produced no results - only an error log that indicated issues with transcoding video from one format to another.

As this story goes to online posting, the Intel support staff is still working with us to figure out what we must do to complete these benchmarks successfully. If the editors allow it and we can get it working later, we'll report on those results in the next week or two as our schedules permit. Intel has even promised to fly out an engineer to work with us to produce some results, which should make for an interesting follow-on report.