| 摘要 |
PROBLEM TO BE SOLVED: To efficiently execute compression encoding by dividing a band, executing-encoding, making the digital acoustic signal of frequency area information, obtaining a residual signal between the digital acoustic signal and an original signal and multiplexing the residual signal with the digital acoustic signal. SOLUTION: Signals which are band-dividing to uniform 32 bands by a band dividing filter 1 are supplied to a maximum value selection part 2 and a quantizer 4. The selection part 2 outputs a maximum value S and the maximum value S decides the number of bits in a bit distribution part 3. The quantizer 4 reduces the number of the bits of respective pieces of sub-band data in the signal of the filter 1 based on bit distribution information from the distribution part 3. Sub-band data adjusted to lowest bit information by an inverse quantizer 5 are supplied to a band dividing filter 6 and are converted into the signals of time area information. A residual calculation part calculates an operation error occurred in band division/synthesis by the filters 1 and 6 and outputs it as the residual signal. A multiplexer 9 generates a bit stream for sub-data from the quantizer 4 and the residual signal from a calculation part 8. |
