| 摘要 |
PROBLEM TO BE SOLVED: To make possible realizing extrapolation and interpolation of an acoustic signal even in a frequency area coefficient with different conversion sectional lengths by obtaining a pseudo frequency area coefficient with the same conversion section from the frequency area coefficient with different conversion sectional lengths and performing the extrapolation or interpolation using that. SOLUTION: The frequency area coefficient b is constituted of an N point frequency area coefficient vector in second and fourth time sections, and is constituted of four pieces of N/4 point frequency area coefficient sub-vectors in a third time section. At this time, when the correct frequency area coefficient is omitted in the third section, though the frequency area coefficients b2, b4 become an after extrapolation frequency area coefficient e as it is in the third time sections in front/behind, the coefficient e2 extrapolated and synthesized from the frequency area coefficient b2 of just before time section becomes the after extrapolation frequency area coefficient b'3 in the third section. Thus, even when the conversion sectional lengths are different according to the time section, the matter that the extrapolation/interpolation become impossible is eliminated, and the omitted acoustic signal is synthesized. |
