CONVERSION OF SYNTHETIC SPECTRUM COMPONENT FOR ENCODE AND LESS COMPLICATED TRANSFORMER CODE

PROBLEM TO BE SOLVED: To improve quality of transformer coded signal. SOLUTION: In an audio coding system, an audio encoding transmitter expresses an encoded spectrum component as a normalized numerical value expressed by a floating point. This transmitter provides first and second control parameters used to transformer-code the encoded spectrum parameter. A transformer coder decodes the component encoded by using the first control parameter partially and encodes the component by using the second control parameter again. The transmitter decides the second control parameter by analyzing the effect of arithmetic computation in partial decoding processing to specify where the floating point expression loses normalization. An index related to the numerical value losing normalization is corrected, and the corrected index is used to calculate the second control parameter. COPYRIGHT: (C)2011,JPO&INPIT