non-uniform quantising logarithmic compression

The kind of compression often applied to a sound waveform.

Logarithmic compression is a good match for the human ear's

sensitivity but cannot handle zero amplitude (for which the

logarithm is negative infinity). There are two standard

compression functions which give a smooth transition between

the logarithmic function and a linear segment passing through

the origin: mu-law (North America) and A-law (ITU-T).

(1995-02-21)