| 摘要 |
PROBLEM TO BE SOLVED: To generate coding data in which an excellent S/N is secured in a reproduced signal even when input signals are changed in various ways. SOLUTION: A standard deviation arithmetic means 3 obtains a standard deviation σ of an amplitude distribution as to an input signal corresponding to a prescribed block processing signal among block processing signals x(n). A quantization bit number control means 4 provides an output of a quantization bit number control signal sCQB to set an allocated quantization bit number to be allocated in the case of coding the block processing signal x(n) corresponding to the standard deviation σ to be obtained to a quantization means 5. The quantization means 5 quantizes the block processing signal x(n) received sequentially based on the quantization bit number control signal sCQB and provides an output of the quantization signal to a coding means 6, which encodes the received quantization signal DQ(n). Thus, an optimum allocated quantization bit number is set in response to the amplitude of an input signal and coded data quantity is reduced by suppressing signal deterioration at decoding (at inverse quantization). |
