Wma2mp3

 #!/bin/bash

 for file in $@ ;
  do
   file=`echo $file | sed -e 's/\.wma$//'`
   mplayer -ao pcm -vo null -vc dummy $file.wma
   lame --replaygain-accurate --preset extreme audiodump.wav $file.mp3
   rm *.wav
  done

---

.mpc files?

 #!/bin/bash

 for file in $@ ;
  do
   file=`echo $file | sed -e 's/\.mpc$//'`
   mppdec --silent $file.mpc - | lame --quiet --replaygain-accurate --preset extreme - $file.mp3
  done