AC3Tools Pro is the complete suite for AC3 files processing that enables to decode AC3 files into two-channel MP3, WMA, WAV or Ogg Vorbis files.
It's also able to extract each channel from an original AC3 file into separate files and recompose WAV PCM files into AC3. AC3Tools Pro supports Dolby Prologic and Dolby Prologic II profiles to maintain full-bandwidth surround sound.