DVR-MS is a proprietary audio and video file format developed and solely owned by Microsoft. It uses the MPEG-2 standard Compression for video and audio compresses using MPEG-1 layer II. This format extends standards by adding metadata within the compression to allow room for information about the content as well as Digital Rights Management (DRM).
The DVR feature in Windows Media Center Edition saves recorded broadcasts in this format and with the added DRM, if the program is flagged as copyrighted, it will automatically append DRM standards on the media and only allow it to be played on the machine that recorded it. Files recorded without DRM can be moved and played back on any machine with Windows XP SP1 and up, so long as the Windows Media Player is version 9 with hotfix 810243 applied. Recently, with the release of Media Player 10, Microsoft included a transcoder within MP10 that allows users to convert non-DRM files from DVR-MS to WMV and allowing this file to be synched with portable media devices. This move apparently was to give more functionality to their Zune player released in late 2006.
There are several third-party applications that can convert DVR-MS to other formats and Mac OS X has a free utility called MPlayer that will load DVR-MS files.
