Patent ID: 8290782

Claim:
A method of compressing a digitized audio signal representing a sound, said signal having an audio bandwidth, in an audio compression system representing sound samples or spectral values using a scale-factor plus data format, wherein a sample is represented as a product of a scale factor and an associated quantityâ€”the method comprising the steps of: receiving a digital signal representing a sound; organizing samples into at least one audio frame, said frame comprising a plurality of temporally sequential samples representing a time interval; for each frame, processing said plurality of temporally sequential samples into a plurality of subband signals, each subband signal representative of a respective subband frequency range and comprising a time sequence of audio samples within said subband frequency range; converting said subband signals into a format expressing each filtered audio sample as a product of a) a scale factor, represented in a scale factor field and b) a quantity, represented in a quantity field; organizing in two dimensions the scale factor fields of said subband signals at least one tile corresponding to each frame said tile comprising a matrix of scale factors organized by time as a first dimension, and a subband frequency range as a second dimension; processing said at least one tile with a two dimensional orthogonal transform to produce for each said tile a respective scale factor coefficient matrix (SCM); compressing each said SCM to produce a compressed coefficient matrix representing the scale factors in a tile in a compressed format; packing said compressed coefficient matrix in a data format for transmission.