ffmpeg flac to wav
# ffmpeg will not change sample rate unless you tell it to
# (or the output codec does not support it, but then it will most probably fail).
# So this should be enough:
ffmpeg -i input.flac output.wav
# ffmepg will however not preserve bit depth and default to 16-bit encoding,
# so if your input is 24 bit, you have to use:
ffmpeg -i input.flac -c:a pcm_s24le output.wav