Registering MPEG2 Codecs

This topic applies to Windows XP Media Center Edition only.

Windows XP Media Center Edition maintains two registry keys that it uses to determine which codec to use to play back MPEG2 video and audio files. The first registry key specifies the computer manufacturer's preferred MPEG2 codec, and the second lists all of the Media Center compatible codecs that are currently installed on the computer. When Media Center needs to play back an MPEG2 file, it uses the manufacturer's preferred codec, if one is specified. If not, it uses the first Media Center compatible codec listed in the registry. If the registry specifies no preferred or compatible codecs, Media Center uses the standard DirectShow filter merit to choose a codec.

To ensure that Media Center always uses a compatible MPEG2 codec, manufacturers of Media Center computers should specify the preferred MPEG2 codec at the following registry location:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\Media Center\Service\Video

The key data should be as follows:

PreferredMPEG2VideoDecoder=REG_SZ "{MPEG2 Video CLSID GUID}"
PreferredMPEG2AudioDecoder=REG_SZ "{MPEG2 Audio CLSID GUID}"

The setup program for a Media Center compatible MPEG2 codec should register the codec by creating two instances of the following registry key—one for the video codec and one for the audio codec:

[HKEY_CLASSES_ROOT\CLSID\{083863F1-70DE-11d0-BD40-00A0C911CE86}\Instance\<Your Codec CLSID here>\Capabilities]

The key data should be as follows: