Patent ID: 7516064

Claim:
A method for generating an output signal that comprises: receiving samples of a source signal having spectral content; applying a primary transform to overlapping segments of the samples to generate a plurality of sets of spectral coefficients, wherein each set of spectral coefficients has time-domain aliasing artifacts and represents the spectral content of a respective source signal segment for a set of frequencies; generating one or more sets of hybrid-transform coefficients by applying a secondary transform to one or more blocks of the spectral coefficients representing spectral content of the source signal for a particular frequency in the set of frequencies across time, wherein the number of spectral coefficients in each of the one or blocks representing the particular frequency is adapted in response to a block-length control signal and the length of the secondary transform that is applied to each of the one or more blocks of spectral coefficients is adapted in response to the block-length control signal; and assembling information representing the one or more sets of hybrid-transform coefficients and the block-length control signal into the output signal.