When encoding an audio stream for use in a webcast, the audio signal is passed through a processor known as a codec (coder/decoder) that performs the conversion to a streaming media format suitable for the Internet. The current version of the codecs used to convert to the Windows Media format is not supported on the Mac OS X operating system.
Even though Microsoft supports this third-party codec in the Windows Media player for Mac OS Classic (version 8/9), Microsoft does not intend to update the Windows Media player for Mac OS X to support this third-party codec. Users of Mac OS X therefore will not be able to access these encoded webcasts. There is an ongoing dialogue between Microsoft and our encoding partner in the hope that this compatibility issue will eventually be resolved.
Potential Solutions:
If the webcast you are attempting to listen to was encoded in the Real format, simply select this format when provided a choice. Another alternative is to utilize a MS Windows-based PC or a Macintosh running an earlier version of the Mac OS to listen to the webcast.