Packet Loss Concealment for Speech Coding

摘要

A speech coding method of reducing error propagation due to voice packet loss, is achieved by limiting or reducing a pitch gain only for the first subframe or the first two subframes within a speech frame. The method is used for a voiced speech class. A pitch cycle length is compared to a subframe size to decide to reduce the pitch gain for the first subframe or the first two subframes within the frame. A strongly voiced class is decided by checking if the pitch lags are stable and the pitch gains are high enough with the frame; for the strongly voiced frame, the pitch lags and the pitch gains can be encoded more efficiently than other speech classes.

主权项

1. A method of obtaining an excitation for encoding a speech signal, comprising:
determining an initial pitch gain value for each subframe within a frame of the speech signal; reducing or limiting only the initial pitch gain value of the first subframe of the frame to obtain a reduced or limited pitch gain value that is smaller than the initial pitch gain value of the first subframe; obtaining an excitation of a next frame of the speech signal according to the reduced or limited pitch gain value of the first subframe, wherein the next frame of the speech signal is successive to the frame of the speech signal; and encoding the next frame of the speech signal according to the excitation.