| 摘要 |
<P>PROBLEM TO BE SOLVED: To compress a waveform data, while selecting an optimal quantization system and other conditions in each part of the waveform data. <P>SOLUTION: A quantizing and normalizing portion 62 sequentially selects a trial mode, having the highest compression rate from among a plurality of candidate modes, and converts an original waveform sample Sn to a residue code. An inverse quantizing and reverse normalizing portion 66 and an adder 65 generate a restored waveform sample #Xn from the residue code. A mode-analyzing portion 68 determines whether an S/N ratio of #Xn to Sn is equal to or smaller than an allowable value, and makes the quantizing and normalizing portion 62 select another trial mode, when it is determined that the S/N ratio is not smaller than the predetermined allowable value. When the S/N ratio of #Xn becomes equal to or smaller than the allowable value, the residue code, and the like, is forwarded to a frame-loading portion 90 to make a frame constituted. <P>COPYRIGHT: (C)2008,JPO&INPIT |
