| 摘要 |
<p>A fixed codebook searching device is provided to suppress an increase of an arithmetic operation amount to be minor even if a filter applied to an audio source pulse has a characteristic that cannot be expressed by a lower triangle matrix, and to achieve a quasi-optimum fixed codebook search. The fixed codebook searching device is comprised of an algebraic codebook (101) for generating a pulse audio vector, a convolution arithmetic operation unit (151) for convoluting an impulse response vector that has a value at a negative time with an impulse response of an auditory-sense weighted synthetic filter to generate a second impulse response vector that has a value at a negative time, a matrix generating unit (152) for using the second impulse response vector to generate a Toeplitz type convolution matrix, and a convolution arithmetic operation unit (153) for convoluting the pulse audio source vector generated by the algebraic codebook (101) with the matrix generated by the pulse audio source vector generating unit (152).</p> |
