X Lossless Decoder: Lossless audio decoder for Mac OS X

http://tmkk.undo.jp/xld/index_e.html

XLD can decode following formats:
(Ogg) FLAC (.flac/.oga)
Monkey's Audio (.ape)
Wavpack (.wv)
TTA (.tta)
Apple Lossless (.m4a)
TAK (.tak) [Requires Wine, CrossOver Mac or WineBottler]
Shorten (.shn) [SHN v3 only]
AIFF, WAV, etc

XLD supports various output formats. It can convert audio files into
WAVE,
AIFF,
Raw PCM,
Ogg Vorbis (aoTuV),
MPEG-4 AAC (QuickTime/CoreAudio),
MP3 (LAME),
Apple Lossless,
FLAC,
HE-AAC (aacPlus v1/v2),
Wave64,
WavPack
and IETF Opus.