| 摘要 |
PURPOSE:To reduce processing time for quantization bit number allocation processing by reducing a repetitive part in the quantization bit number allocation processing. CONSTITUTION:A band signal Bmax whose mask level versus maximum signal level ratio SMR is maximized is selected from each band signal Bi of each of bands resulting from an audio signal A divided by a band division means. A mask level versus noise ratio MNRmax is calculated by subtracting the SMR from a signal to noise ratio SNR in an allocatable maximum quantization bit number Nmax. Then the processing as above is implemented to all signals Bi to calculate the sum of bit numbers Nic. When the sum SN exceeds the allocatable quantization bit number LN, (SN-LN) is divided by an allocated band signal number to obtain a quotient U. Then an integral part of the quotient U is subtracted from a tentative allocated quantization bit number Nic of each signal Bi to obtain the allocated quantization bit number Ni. |
