This article was previously published under Q306494
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This article describes the MP3 encoding plug-in for Windows Media Player for Windows XP.
Windows Media Player for Windows XP has MP3 encoding plug-in support. To enable the Windows Media Player to encode MP3 files, you must license and install a compatible MP3 encoder. Windows Media Player supports only Audio Compression Manager (ACM) functions to communicate with the MP3 encoders. Therefore, the codec must be an ACM codec. For more information about ACM codec development, view the following MSDN Web site:
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You must have administrator rights on the computer to change any of the following settings. The following registry keys must be set by the third-party, compatible MP3 encoder. The following list describes the Windows Media Player for Windows XP MP3 encoding registry settings:
Note that the value for PreferredCodec is limited to 255 characters. The PreferredCodecPath key must contain the fully-qualified path to the location of the codec as well as the file name of the codec.
MP3 Compression Only
Windows Media Player for Windows XP supports only plugging in an MP3 encoder. Using any other compression creates invalid MP3 files. Therefore, the only compression support that is provided by the codec is for MP3. The codec accept only raw data and output-compressed data.