Device and method for lost frame concealment

摘要

A device and a method for frame lost concealment are disclosed. A pitch period of a current lost frame is obtained on the basis of a pitch period of the last good frame before the current lost frame. An excitation signal of the current lost frame is recovered on the basis of the pitch period of the current lost frame and an excitation signal of the last good frame before the lost frame. Thereby, the hearing contrast of a receiver is reduced, and the quality of speech is improved. Further, in the present invention, a pitch period of continual lost frames is adjusted on the basis of the change trend of the pitch period of the last good frame before the lost frame. Therefore, a buzz effect produced by the continual lost frames is avoided, and the quality of speech is further improved. In addition, by attenuating the energy of the excitation signal obtained from the continual lost frames, the device and method accord with the hearing physiological characteristics of human and reduce the hearing contrast of the receiver.