| 摘要 |
PROBLEM TO BE SOLVED: To prevent the occurrence of aliasing noise while performing appropriate high-frequency interpolation on a compressed sound signal and output a high-quality sound using a simple configuration.SOLUTION: At the time of high-frequency interpolation, an LPF unit 110 extracts, from an inputted compressed sound signal CAD, a signal LPD of prescribed bandwidth that is an object of harmonics generation. Subsequently, a harmonics generation unit 120 whose input/output characteristic is non-linear generates, on the basis of the signal LPD, a harmonics-containing signal HMD that includes a harmonics signal component in which the highest order is limited. Next, an HPF unit 130 extracts, from the harmonics-containing signal HMD, a signal component of signal-missing bandwidth in which a signal component was missed when the compressed sound was generated from a pre-compression sound, and generates a signal HBD. Then, a synthesis unit 140 synthesizes the compressed sound signal CAD and the signal HBD. |
