Patent ID: 7460990

Claim:
An audio encoding method, comprising: transforming an input audio signal block into a set of spectral coefficients; dividing the spectral coefficients into plural bands; coding values of the spectral coefficients of at least one of the bands in an output bit stream; for at least one of the other bands, coding said other band in the output bit-stream as a scaled version of a shape of a portion of the at least one of the bands coded as spectral coefficient values; and for each of plural other bands: performing a search to determine which of a plurality of portions of the at least one bands coded as spectral coefficients is more similar in shape to the respective other band; determining whether the determined portion is sufficiently similar in shape to the respective other band; if so, coding the respective other band as a scaled version of the shape of the determined portion; otherwise, coding the respective other band by: performing a search among shapes represented in a fixed codebook for a shape that is more similar in shape to the respective other band; if such similar shape is found in the fixed codebook, coding the respective other band as a scaled version of such similar shape in the fixed codebook; and otherwise, coding the respective other band as a scaled version of a random noise vector.