| 摘要 |
PURPOSE: To prevent a band to which no bit of a high frequency band is allocat ed from existing by allocating the number of bits of an irreducible minimum for the specified band. CONSTITUTION: The number of bits (information amount) allocated to the whole bands are set in an initial value zero bit, and SMRs (signal masking ratio) of respective bands are calculated. NMRs (noise masking ratio) are calculated from the SMRs and SNRs(signal noise ratio) of respective bands. Together with that, SARs(signal minimum audible limit ratio) are calculated. The band having the maximum NMR among respective bands is detected, and the band is defined No. 16. The No. 16 is made a NMRB(maximum noise masking ratio band), and whether or not the NMR of the No. 16 arrives at a minimum allocation threshold value is judged, and when smaller than the minimum allocation threshold value, bit allocation is ended. Then, by allocating the number of lowest bits even for the band of a small dynamic range by using auditory sense, the bands to which no bit are allocated are reduced. |
