Patent ID: 8566085

Claim:
A preprocessing method, comprising: obtaining characteristic information of a current frame signal; identifying whether the current frame signal requires no coding operation of removing Long Term Correlation (LTC) according to the characteristic information of the current frame signal and preset information; and if the current frame signal requires no coding operation of removing LTC, performing a coding operation of removing Short Term Correlation (STC) for the current frame signal; if the current frame signal requires the coding operation of removing LTC, performing coding operations of removing both LTC and STC for the current frame signal; wherein the characteristic information of the current frame signal is an energy value of the current frame signal; the identifying of whether the current frame signal requires no coding operation of removing LTC according to the characteristic information of the current frame signal and the preset information comprises: judging whether the energy value of the current frame signal is less than an absolute energy threshold, wherein the absolute energy threshold corresponds to a frame length of the current frame signal; and identifying that the current frame signal requires no coding operation of removing LTC if the energy value is less than the absolute energy threshold.