WavPack allows users to compress (and restore) both 16 and 24-bit audio files
in the .WAV format. It also supports multichannel streams and high frequency
sampling rates. Like other lossless compression schemes the data reduction
varies with the source, but it is generally between 25% and 50% for typical
popular music and somewhat better than that for classical music and other
sources with greater dynamic range.

WavPack also incorporates a unique "hybrid" mode that provides all the
advantages of lossless compression with an additional bonus. Instead of
creating a single file, this mode creates both a relatively small, high-quality
lossy file that can be used all by itself, and a "correction" file that (when
combined with the lossy file) provides full lossless restoration. For some
users, this means never having to choose between lossless and lossy compression.

WWW: http://www.wavpack.com/