<p>An encoding and decoding method and device are provided. The method includes: individually encoding each sample point of an input signal, then generating a core layer encoded signal; encoding all or some of the sample points of the input signal via the core layer so as to generate residual error values, individually comparing the residual error values with an encoding threshold, encoding according to the comparison results, and generating an enhancement layer encoded signal; writing the encoding signals of the core layer and the enhancement layer into a bit stream so as to generate an encoded signal.</p>
