Patent ID: 8017855

Claim:
An apparatus for converting an information signal to a spectral representation, comprising: a window filter configured for windowing the information signal given as a series of samples to obtain a windowed block of the information signal having a length in time; a converter configured for converting the windowed block of samples to a spectral representation having a set of information signal spectral coefficients; a provider configured for providing a first set of complex base function coefficients, a second set of complex base function coefficients and a third set of complex base function coefficients, wherein the base function coefficients of the first set represent a result of a first windowing and transform of a first base function, which has a frequency corresponding to a first frequency value of a first variable spectral coefficient of the spectral representation, the spectral representation comprising variable spectral coefficients, frequency values and bandwidths being associated with the variable spectral coefficients, wherein a frequency spacing of the variable spectral coefficients is variable, wherein the base function coefficients of the second set represent a result of a second windowing and transform of a second base function, which has a frequency corresponding to a second frequency value of a second variable spectral coefficient of the spectral representation, and wherein the base function coefficients of the third set represent a result of a third windowing and transform of the second base function, which has the second frequency value, wherein the first windowing, the second windowing and the third windowing differ in that a window length of a window in the first windowing differs from a window length of a window in the second and the third windowing, and that a window position of the second window and of the third window differ with reference to the second base function; and a weighter configured for weighting the set of information signal spectral coefficients with the first set of base function coefficients, in order to calculate the first variable spectral coefficient of the spectral representation, for weighting the set of information signal spectral coefficients with the second set of base function coefficients, in order to obtain the second variable spectral coefficient of the spectral representation comprising variable spectral coefficients for a first portion of the windowed block of the information signal, and for weighting the set of information signal spectral coefficients with the third set of base function coefficients, in order to obtain the second variable spectral coefficient of the spectral representation comprising variable spectral coefficients for a second portion of the windowed block of the information signal, the second portion of the windowed block of the information signal being different from the first portion of the windowed block of the information signal.