Spreadtrum Communications Corporation

Spreadtrum Communications (shanghai) Co., Ltd.

Heyun Huang

Fuhuei Lin

Tan Li

Fu-Huei Lin

Benhao Zhang

An audio encoding method and a corresponding decoding method are provided. Accordingly, the pre-echo effect of the audio transient signal is eliminated and the distortion of the transient signal is mitigated. The technical solution includes performing time-domain processing on an input audio transient signal; dividing sampling points x,x, . . . , xof an input frame into L segments; calculating an energy Efor each segment; calculating an average energy Efor each segment of the input frame; calculating a multiplying parameter &#x3bb;corresponding to each segment by virtue of &#x3bb;=r(bitrate)*E/E; multiplying the sampling points of all the segments of the input frame by corresponding multiplying parameter &#x3bb;, obtaining the processed sampling points x',x&#x2032;, . . . , x&#x2032;; and sending the multiplying parameter &#x3bb;to a code stream for transportation; performing time-frequency transformation and coding on the processed sampling points x&#x2032;,x&#x2032;, . . . , x&#x2032; and outputting to the code stream.

Audio encoding/decoding for reducing pre-echo of a transient as a function of bit rate

A method for post-processing of speech signals includes using a pitch correction filter, a pitch weight parameter adjustor, and a first pitch enhancement filter to process the input signal into a first output signal; summing both the input signal and the first output signal as a second output signal; and using a second pitch enhancement filter to process the second output signal. Furthermore, another method for post-processing of speech signals includes using a second pitch enhancement filter to process the input signal into a second output signal; using a pitch correction filter, a pitch weight parameter adjustor, and a first pitch enhancement filter to process the second output signal into a first output signal; and summing both the second output signal and the first output signal as a final output signal. The two methods can simultaneously realize pitch emphasis and enhancement with low computation complexity.

Methods and apparatus for post-processing of speech signals

A method for detecting voice activity comprises pre-processing a first frame in an audio frame sequence, receiving a subsequent frame as a current frame, calculating weighted linear prediction energy of the current frame based on N-order linear prediction coefficients, determining whether the current frame contains a noise or speech, if a speech is indicated, performing linear prediction analysis on the current frame to derive new N-order linear prediction coefficients and updating the coefficients with the derived one; if a nose is indicated and not the last frame, repeating the calculating and determining process. The corresponding device comprises a component for storing Nth-order linear prediction coefficients, a component for performing linear prediction analysis, a component for computing weighted linear prediction energy and a component for determining whether the current frame contains speech or noise based on calculated weighted linear prediction energy.

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Shanghai, China

Heyun Huang