Is there anyway to extract the sound track from a flv file on MacOS X? If yes, what are the tool/ways I can do that?
Simply use MPlayer:
This command dumps the whole audio track in the original format into a file called "stream.dump". Thus, the file's audio track is dumped lossless.
Alternatively, try FFmpeg:
Avidemux: all platforms, all manner of video processing tasks including saving audio (optionally without a re-encode quality loss, where possible).