The two companies said that Microsoft had licensed Macrovision's technology, which aims to stop people from making copies using analog connections between devices, such as those that typically link a set-top box to a television.
The deal could make it harder for consumers to make permanent copies of TV shows and movies without permission, if they use computers running the Windows operating system. It should also help convince movie studios and other content producers to release their products in new ways online, the companies said.
"We think that long term, the studios will offer more interesting products over the Internet using this technology," said Brad Brunell, Microsoft's general manager of intellectual-property licensing.
Most copy-protection technologies are aimed at preventing digital replication, since a digital copy can be identical to the original in every way. However, modern analog copying can also have high-quality results, and Hollywood studios have worried that their products could be easily copied using methods such as recording the output of a DVD player onto a computer hard drive.
The Macrovision technology has been one attempt to limit this. Rather than scrambling the signal altogether, as digital copy protection typically does, it includes a pulse of electronic energy along with the video as it is played. The pulse is meant to indicate the content should not be recorded. Many devices such as DVD recorders respect this signal and block recording if it is detected.
Under the new deal, Microsoft's Windows Media software will recognize this signal when it is included in incoming analog video streams. For upcoming versions of its Microsoft'soperating systems, the computer will allow users to make a temporary copy that can be stored one day, but that cannot be used after that time.
In future versions of its Media software, including the version in its next Longhorn operating system, Microsoft plans to support an upcoming revision of Macrovision's technology that will allow content to be stored for just 90 minutes, or up to a week.
TiVo isthe new Macrovision technology. Movie studios have discussed using the more flexible version for different pay-per-view content rules.