Abstract: A method and apparatus for the decoding of digital audio data encoded in accordance with layer 1 or 2 of the MPEG format. The inverse quantization of the quantizised data samples and the resealing of the inverse quantizised data samples takes place contemporaneously with windowing of the data samples transformed into the time domain and not contemporaneously with transformation of data samples from the frequency domain into the time domain using a matrix operation. The apparatus has fixed-wire frame unpacking and filter bank units. The frame unpacking unit is used for frame synchronization of a data stream, header decoding, reading of page information, inverse quantization of quantizised subband data samples and resealing of the inverse quantizised data samples. The filter bank unit is used for transformation of rescaled data samples from the frequency domain into the time domain using a matrix operation and for windowing of the data transformed into the time domain.