Fraunhofer-Gesellschaft Zur Foerderung Der Angewandten Forschung E.V.

Jürgen Koller

Ralf Geiger

Gerald Schuller

Jürgen Herre

Thomas Sporer

Karlheinz Brandenburg

An integer transform, which provides integer output values, carries out the TDAC function of a MDCT in the time domain before the forward transform. In overlapping windows, this results in a Givens rotation which may be represented by lifting matrices, wherein time-discrete sampled values of an audio signal may at first be summed up on a pair-wise basis to build a vector so as to be sequentially provided with a lifting matrix. After each multiplication of a vector by a lifting matrix, a rounding step is carried out such that, on the output-side, only integers will result. By transforming the windowed integer sampled value with an integer transform, a spectral representation with integer spectral values may be obtained. The inverse mapping with an inverse rotation matrix and corresponding inverse lifting matrices results in an exact reconstruction.

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Wümbach, Germany

Jürgen Koller