Convert mp3 bitrates using lame_enc.dll or similar

I need to programmatically convert mp3 of any bitrate to standard bitrate for audio streaming using C #.
Currently, the buffer is filled with mp3 data from disk and then sent to "listeners" at what should be a constant bit rate (broadcast), but mp3 can be of any bit rate. This makes timing very difficult and should rather be transmitted at standard bitrate instead of the bitrate dictated by the mp3 itself.

Lame seems to be the right coder for the job, but any documentation or example code seems to be related to converting from wav samples to mp3. Not mp3 to mp3. The wrapper exe can do bitrate conversion, but completely without any clue as to what is being passed to beEncodeChunk () .

Does anyone have experience doing things like this with a lame or any similar coder? Do I need to decode the wav and then encode back to mp3 to achieve what I need? I welcome any links or advice with open arms.

thanks