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Microsoft has moved to debunk a paper written by a software expert that criticises digital rights management (DRM) features of its new Windows Vista operating system.
But the software giant has defended its policy of facilitating content publishers who seek to degrade the quality of high-definition video and
audio that is played over computer connections they do not approve of.
Auckland University computer science researcher Peter Gutmann caused an internet sensation with a paper released this month that claimed Vista was "broken by design" by built-in mechanisms designed to stop high-definition movies from being copied.
"The sheer obnoxiousness of Vista's content protection may end up being the biggest incentive to piracy yet created," Gutmann wrote.
Home user versions of Vista, an operating system that has been five years in development, will go on sale on January 30, with the first copies set to be sold by New Zealand retailers staying open for a midnight unveiling.
In a carefully worded blog posting rebutting many of Gutmann's criticisms, Microsoft's lead program manager for video, Dave Marsh, said playback would only be degraded for premium content - which is paid for and may be downloaded via the internet, and only if the copyright holder desired to do so.
"Image constraint will typically result in content being played at no worse than standard definition television resolution," wrote Marsh.
In the case of built-in or external high-definition players that did not meet the standards of copyright holders, HD video would be downscaled to slightly better than standard DVD quality.
Marsh admitted that Vista's content protection features would consume more computing power. "The use of additional [central processing unit] cycles is inevitable."
But he rejected claims that Vista's DRM features would make computers less reliable.
Critics of Microsoft, including Gutmann, suggested Microsoft's approach to DRM would encourage piracy as people would look for ways to by-pass copyright mechanisms. Hackers have already succeeded in cracking the security features of next generation HD-DVD and Blu-ray discs.
Marsh pointed out that Microsoft's DRM provisions were no different to those included in standalone hardware devices designed to prevent unauthorised copying.
A new wave of high-definition players and screens come with high-bandwidth digital copyright protection (HDCP), which protects content as it is sent over the connections between HD players and TV screens.
HDCP players will degrade video quality for playback on TV screens that are not HDCP-compliant - at the moment that mean most screens.
While the debate sparked by Gutmann's paper may not materially affect Vista's reception, Vista's DRM features constitute the most criticised aspect of the new operating system. Those features are tucked into the millions of copies of Vista that have already shipped.
The question now is to what extent movie and music publishers seek to use those features to protect their content.