What’s Needed For CableCARD with Media Center?

Inside DRM In Windows Vista Set-Top Boxes (ExtremeDRM) | CableLabs, the technical arm of the cable television industry, and Microsoft recently announced that the CableCARD will soon be a part of future Media Center PCs. This is considered an important move for Microsoft and those hoping to position the PC as the center of the home entertainment experience.

 

CableCARD Primer

 

So what is a CableCARD and why is it relevant? Simply stated, the CableCARD slips into some newer televisions and enables the TV to pick up digital cable service without the use of a set top box (STB). The current CableCARD standard only supports “one-way” services, so “two-way” services such as Video on Demand (VOD) and interactive program guides (IPG) are not supported. The industry remains months away from settling on two-way protocols.

 

Because of the Microsoft/CableLabs agreement, CableCARDs can now be used with appropriately equipped PC systems to enable consumers to view digital cable TV services on their home PC.

 

The Politics Behind the Agreement

 

The reason that it has taken so long for Microsoft and CableLabs to come to agreement is that the cable industry simply did not believe that Media Center PC’s were trustworthy when it came to protecting video content. The PC is a relatively open system, one which is easily “accessorized” by new peripherals and software. Once DVD’s Content Scrambling System was cracked, the entire cable industry became very nervous about opening up their content to manipulation by PCs.

 

Microsoft was told to come up with a software and hardware solution that would sufficiently protect video content against piracy and unauthorized duplication. But Microsoft was concerned that such a solution would make the consumer video viewing experience rather cumbersome and unfriendly, thus being antithetical to its larger goal of pushing consumers to view video on their PCs.

 

The Specifics of the Agreement

 

In an attempt to balance these two tensions, Microsoft came up with the Protected Video Path – Output Protection Management (PVP-OPM) and Protected Video Path – User-Accessible Bus (PVP-UAB), a solution designed to ensure that the system is compliant with CableLabs’ specifications and which encrypts video as it passes through the Peripheral Component Interconnect Express (PCIe) bus. These new mechanisms are part of Vista, the next release of Windows.

 

A CableLabs’ compliant system must also use High-bandwidth Digital Copy Protection (HDCP) video outputs for connecting to the monitor. HDCP, and its cousin the High Definition Multimedia Interface (HDMI), are both digital video interfaces that can encrypt the video signal of protected content.

 

The Implications of This Announcement

 

While some consumers will enjoy having digital cable content available through their Media Center PC, others will be disappointed by the rest of the package.

 

First, in order to take advantage of high-definition programming, both older monitors and new Digital Video Interface (DVI) models will not work as they may have expected. When a protected High Definition Television (HDTV) program passes through the new Media Center PC, the PVP-OPM system will check to see if HDCP or HDMI is supported. If so, all is fine. If not, the video’s resolution is reduced from HDTV levels to something equivalent to ordinary DVD levels. So if you have an ordinary analog or DVI monitor, no matter how great its resolution, your HDTV channel will look much fuzzier than you expected. In the industry, this is sometimes called “down-rez’ing”.

 

Meantime, the classic STB continues to gain in sophistication, and it is capable of full two-way services now.

 

Second, there is no guarantee that the first-generation of CableCARD-enabled Media Center PCs will support two-way interactive video services such as VOD and EPGs. Of course, Microsoft hopes such an agreement will be in place by the time Vista comes out (just before the 2006 holiday season). If not, consumers may have to settle for one-way systems until upgrades are available.

 

Third, there is a “thorn” in two-way cable that may be giving Microsoft reason for concern. CableLabs has settled on something called the Open Cable Application Platform (OCAP) for supporting Java applets that can be downloaded into the host device. OCAP is based on a European specification called Multimedia Home Platform (MHP), and it was not developed by Microsoft.

 

As well, Microsoft is very busy working on Internet Protocol Television (IPTV), with the first major U.S. deployment by SBC scheduled for around January 2006. Microsoft’s IPTV vision runs somewhat in competition to CableLabs’ OCAP. Therefore, it remains to be seen how completely Microsoft will support OCAP in a two-way CableCARD-capable Media Center PC.

 

The road to two-way CableCARD-enabled PCs is more complex than it may appear, clouded by not only Microsoft’s own long-term interests, but the interests of the cable companies as well. While it may be surprising to many readers, cable’s support for the CableCARD is only a stepping stone towards a grander vision. Ultimately, they hope the CableCARD will go away altogether, replaced with downloadable security, a move that will make things even more interesting.

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4 thoughts on “What’s Needed For CableCARD with Media Center?

  1. Excellent discussion of the issues surrounding Cable Card. It suggests other questions though, such as:

    What new hardware will be required?

    Will new HD _cable_ tuner cards as opposed to OTA HD tuner cards be needed?

    Will new sound and graphics cards (and drivers) be needed that convert cable encrypted video to HDCP signals.

    Will unencrypted data be DMA’d over PCI, PCI Express, or AGP busses?

    Will Media Center support CableCard content decoding/playback via DirectShow filter graphs?

    If so, how does that mesh with a Protected decode environment in the kernel? Will there be user-mode DS stubs for kernel mode agents?

    Is it true that encrypted HD content will be decrypted once via Cable Card, then re-encrypted to be sent over PCI-Express, then decrypted by the GPU and re-encrypted for HDCP? And similar decryption, re-encryption for Audio?

    This link seems to depict what the architecture was planned to be at one point:

    http://download.microsoft.com/download/9/8/f/98f3fe47-dfc3-4e74-92a3-088782200fe7/TWEN05005_WinHEC05.ppt#287,6,PMP Overview

    Some interesting discussion of PMP here: http://p2pnet.net/story/5591

  2. This article seems to make a pretty big deal out of the lack of "two-way" CableCARD support. But if the main "two-way" features are the IPG and VOD/Pay-per-view, then why would Microsoft care?

    It already has it’s own IPG, and at least one goal of Online Spotlight would seem to be downloading content to Media Center, you know, on demand. Am I missing something here? Is there some other reason the "two-way" CableCARD would be useful in Media Center?

  3. I actually went over the two-way vs. one-way CableCARD issue in a post at http://msmvps.com/chrisl/archive/2005/11/16/75804.aspx.

    Based on the value of what one-way CableCARD adds to Media Center, and then based on what Media Center already has (Guide) or has alterative methods of obtaining (VOD content), I don’t see it a big problem that only one-way support was announced. Two-way would be nice, but any VOB content through CableCARD would be set so you can’t record it, and the EPG is already there. Nice, but not needed.

  4. This is probably more detail than you have right now, but would the monitor’s connection also affect streamed video? That is, if I record in HD, and stream it to an Xbox 360, will it still down-res it just because my computer’s monitor is non-HDCP compliant?

    (And what about HDCP support on the Xbox 360? It’s only got component cables now…)

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