HDCP - The Worst Consumer Nightmare, or the best Digital Content Protection?
Posted by Andrew Ghigo on: 2006-05-06 16:19:08
Self SEO > Personal Tech Articles
As far as the content industry is concerned, all channels of distribution - whether it be through over-the-air signals, Blu-ray or HD DVD, and cable and satellite HDTV, need to be secured.
Now, digital HD content delivered though DVI and HDMI represents the highest quality video available today. While great for the end-customer, it's also great for counterfeiters who can use DVI and HDMI connections to get at a perfect video signal.
This is the background to the birth of High-bandwidth Digital Content Protection - also referred to as HDCP.
HDCP is based on a three-stage - authentication, encryption, and key revocation - process, to control video transmission and delivery up to the very end of the video display process.
Technically speaking, HDCP is pure content protection, not copy protection; restrictions on copying, sharing, etc., will have to be handled by other process in the signal chain e.g. cable and satellite TV boxes, high definition DVD players, etc. What High-bandwidth digital content protection does is simply guarantees that whatever content restrictions are in place, these are enforced by authenticating both the transmitter and the receiver.
HDCP Requirements for inter-operability
An HDCP source requires an HDCP-compliant DVI or HDMI receiver for it to allow the transmission of high definition content. What's more, all active components in the HDTV connectivity chain must be HDCP compliant; otherwise you would not be able to enjoy high definition content.
You may think that it is still possible to continue enjoying high definition content in the way you have done so far - even if your 'old' HDTV is non-HDCP compliant, but...
It is true that most of to-day high definition boxes still support full high-definition through component video, but to prevent pirates from creating high resolution copies, the HDCP standard bans compliant products from converting HDCP-protected content to full-resolution analog form - unless specifically allowed for by the content provider.
What does this mean?
Connecting an HDCP source e.g. a HD-DVD or Blu-ray player, to a non-complaint receiver will - at best - force the source device to down-convert the video resolution through analog outputs to close to standard DVD quality; in a similar manner, DVD-Audio content is restricted to DAT quality on non-HDCP compliant digital audio outputs. At worst - what you get is just a blank output!
In other words, if you want to be certain that you will always be in a position to enjoy the benefits of full resolution high definition content on your television or monitor, your display device needs HDCP support.
Why did HDCP turn out to be the greatest 'nightmare' for early adopters of HDTV?
Being HDCP implies the utilization of a digital interface - in particular, the use of DVI and HDMI inputs and outputs. At the same time, a DVI or HDMI interface does not necessarily imply HDCP compatibility. Many major manufactures have come up during the early years of DVI and HDMI, with products that are not HDCP compliant.
Partly, the reason behind this anomaly is that up to very recent, HDCP was not a requirement. In fact, this digital content protection protocol was adopted by the FCC almost a year after we had started to see the first HDMI-enabled devices on stores shelves, and at a time when DVI had already been around for a number of years.
To a certain extent, this situation has transformed itself into one of the major problems many early adopters of HDTV are facing today - these have ended up paying top-dollar for the first HDTVs to hit the market. Those TVs are truly capable of displaying full high-definition content but they lack the HDCP-compliant HDMI (or DVI) inputs necessary to digitally interface with the latest generation of high definition devices such as HD-DVD and Blu-ray movie players.
The end result is that it would not be possible to watch high definition content on these HDTV sets. At best, what you will get is a down-converted version of the high definition image via the component video out that is a quarter of the 1920x1080 resolution offered by maximum HD.
This down-converting of the image over the analog outputs is enforced by a special digital flag - Image Constraint Token (ICT) - within the digital rights management standard; it is used to protect movies from unauthorized duplication. The decision to set this flag to restrict the output via the players or set-top box video component output is left to the studio or content provider, who can choose to implement ICT on a disc-by-disc or content-by-content basis.
Fortunately, there is some sort of silver lining to this cloud of confusion. Content providers are aware of the difficulties that surround the implementation of HDCP with respect to the present consumer electronics base. In an attempt to show some willingness to meet these consumers - half way - till they upgrade their HDTV gear, some studios have publicly indicated that they would not enforce analog down conversion. Sony Pictures Entertainment has publicly stated that its Blu-ray discs will not carry the ICT; some other studios have indicated that they will follow suit. This means that at least, some of the first Blu-ray discs will be viewable at full high-definition resolution for all HDTV owners. In a similar manner, Universal Studios has indicated that for the time being, they won't down-sample content on their HD-DVD discs.
Be aware however, that not all content providers will follow on the footsteps of Sony and Universal. For example, Warner Pictures - a proponent of ICT - has signaled that it will implement down-conversion on 'at least' some of its initial HD-DVD discs. Further more, those studios that will not implement ICT, are under no obligation to maintain their present position indefinitely, so do not be surprised to see ICT implemented across-the-board within a few years time - especially once the present format war between Blu-ray and HD-DVD is over, and equally important, once the penetration of compliant HDTV sets reaches the right level.
The Bottom Line
We believe that owners of non-compliant HDTVs would still be able to get several more years of enjoyment from their sets - in other words, there is no need to rush and upgrade. This means that you may take all your time to plan your HDTV upgrade but...
Be warned that requirements such as ICT and plans for new devices that will output only via an HDCP/HDMI port, may eventually turn your old HDTV a useless resource! If in the process, you would not manage to upgrade your gear, you may end up with a HDTV set that would be useless when it comes to watching HD content!
(For more information on how this content protection process operates, as well as on related HDCP compliance issues, please visit http://www.practical-home-theater-guide.com/hdcp.html).
Andrew Ghigo â€“ A Telecoms/Electronics engineer by profession, with specialization in digital switching and telecoms fraud management systems.
Editor and publisher of http://www.practical-home-theater-guide.com - a site dedicated to home theater enthusiasts with the scope of serving as a comprehensive home theater guide to home theater systems, product reviews and home theater design.
This article is an excerpt from a series of articles appearing under the
HDTV and HDCP section of the site.
Print this article Tell a friend