| 摘要 |
<p>PURPOSE: To reduce a memory amount required for calculating an SMR(Signal to Mask Ratio) in sub-band encoding. CONSTITUTION: This circuit is provided with a sub-band filter 12A dividing sound samples SI of 1152 per one frame into 32 sub-bands to output 32 signals SFA, SFB, an FFT circuit 111A performing FFT processing to the sound sample SI at every sound sample group of respective 512 and outputting the first half, the second half power spectra PSA, PSB, a calculation circuit 113A calculating the first half, the second half respective SMR signals SMA, SMB from the sub-band signals SFA, SFB and the power spectra PSA, PSB and a comparator circuit 115 selectively outputting the larger one between the signals SMA, SMB as the SMR.</p> |
