| 摘要 |
PROBLEM TO BE SOLVED: To provide a vector quantization method which is better correlated with the subjective sound quality. SOLUTION: In a new method to quantize the LPC coefficient by a sound coding device, a new target of the weighted error is used, in which the impulse response from an LPC filter 21 of the coding device is sampled by each frame, the sample is filtered using a perceptually weighted filter 47, and processed by a computer 39, the autocorrelation function of the weighted impulse response is calculated, the Jacobean matrix for LSF(linear spectrum frequency) is calculated, the correlation matrix of the row of the Jacobean matrix, and the weighted LSF is calculated by multiplying the correlation matrix. |
