ENCODING METHOD AND DEVICE, DECODING METHOD AND DEVICE, DIGITAL SIGNAL RECORDING METHOD AND DEVICE, RECORDING MEDIUM AND DIGITAL SIGNAL TRANSMITTING METHOD AND DEVICE

PROBLEM TO BE SOLVED: To filter signals in a time domain obtained by decoding signals encoded with high efficiency in a small-scale filtering process and in a simple constitution by adding or subtracting a desired value to/from normalization information in each two-dimensional block and filtering the digital signals. SOLUTION: A high efficiency encoding device divides input digital signals received from an input terminals 100 into prescribed plural frequency bands by band dividing filters 101 and 102, and also performs orthogonal conversion for each frequency band by orthogonal conversion circuits 103 to 105 to obtain spectrum data on the frequency axes. These spectrum data are encoded with adaptive bit allocation by adaptive bit allocation encoding circuits 106 to 108 in each so-called critical band width and in consideration of the human aural characteristics in a low frequency area, and at each band defined by fractionizing the critical band width in consideration of the block floating efficiency in medium and high frequency areas respectively.