Salues MediaKit is a Silverlight library that includes a MP3 decoder to provide raw audio data for consumption.
In Silverlight 3, there isn’t an out-of-the-box method of accessing the raw audio data that the MediaElement produces when playing back MP3.
Saluse MediaKit for Silverlight, includes a custom MediaStreamSource (for use with the MediaElement) that decodes MP3 files and also returns the raw audio data for your use.
The Raw MP3 MediaStreamSource uses a custom SeekableStream that allows MP3 files loaded from any other stream type (HTTP response stream included) to be semi-seekable and works around the issues in using MediaStreamSource over HTTP.
With MediaKit, you can also modify the audio data before it is consumed (by MediaElement, for example) so that you can apply effects (echo), corrections (pitch shift), functionality (pan) in real-time.