There are high-quality free windows utilities to convert between different audio formats -- wma, wav, mp3, rm. I have links to them on this page. Also on this page I have some very simple batch files which convert all files in the current directory.
For each of the following batch files, I'd save the batch file in c:\windows for convenience, so it's on the path.
Convert mp3 to wav. Requires lame.
for %%I in (*.mp3) do lame --decode "%%I" "%%~nI.wav"
Convert wmp3 to wma. Requires Windows Media Encoder.
for %%I in (*.mp3) do cscript.exe "\program files\windows media components\encoder\wmcmd.vbs" -input "%%I" -output "%%~nI.wma" -profile a128
Convert rm realaudio to wav. Requires mplayer and codecs. Will screw up output filenames if they had commas in them.
for %%I in ("*.rm" "*.ram" "*.ra") do mplayer "%%I" -ao pcm:fast:file="%%~nI.wav" -vc null -vo null
Download a .rm file from a realaudio stream. Requires mplayer and codecs. A web-page with a button to stream realaudio will usually have a shortcut to a ".rm" or ".ram" file somewhere. Download this file onto your hard disk and examine in in notepad. It will usually have a link to the actual stream, in the form "rtsp://somesite.com/file.ra".
mplayer "rtsp://somesite.com/file.ra" -dumpstream -dumpfile download.rm -bandwidth 99999999
Convert wav to mp3. Requires lame
for %%I in (*.wav) do lame --preset extreme --priority 0 "%%I" "%%~nI.mp3"
// radio2mp3.bat: for converting wav into highly-compressed mp3 for %%I in (*.wav) do lame -h -V9 --priority 0 "%%I" "%%~nI.mp3"
Convert wma to wav. Requires mplayer.
// This goes in the file wma2wav.bat: for %%I in (*.wma) do call c:\windows\wma2wav1.bat "%%I" "%%~nI.wav" // This goes in the file wma2wav1.bat: mplayer %1 -ao pcm:fast:file="temp.wav" -vc null -vo null ren temp.wav %2
Here I'm putting the output of mplayer into "temp.wav" before renaming it to the real filename. This gets around the problem that mplayer screws up filenames with commas in them.