A device for producing a gain-smoothed codevector during decoding of an encoded wideband signal from a set of wideband signal encoding parameters, said device comprising: means for finding a codevector in relation to at least one first wideband signal encoding parameter of said set; means for calculating a factor representative of voicing in the wideband signal in response to at least one second wideband signal encoding parameter of said set; means for calculating a smoothing gain using a non linear operation based on said voicing representative factor; and means for amplifying the found codevector with said smoothing gain to thereby produce said gain-smoothed codevector. view more

A pitch analysis device for producing a set of pitch codebook parameters, comprising: a pitch codebook search device configured to generate a pitch code vector based on a digitized input audio data, wherein said digitized input audio data represents an input audio signal that has been sampled and digitized; a) at least two signal paths associated to respective sets of pitch codebook parameters representative of said digitized input audio data, wherein: i) each signal path comprises a pitch prediction error calculating device for calculating a pitch prediction error of said pitch codevector from said pitch codebook search device; and ii) at least one of said at least two signal paths comprises a filter for filtering the pitch codevector before supplying said pitch codevector to the pitch prediction error calculating device of said at least one signal path; and b) a selector for comparing the pitch prediction errors calculated in said at least two signal paths, for choosing the signal path having the lowest calculated pitch prediction error and for selecting the set of pitch codebook parameters associated to the chosen signal path. view more

A decoder for producing a synthesized wideband signal, comprising: a) a signal fragmenting device for receiving an encoded version of a wideband signal previously down-sampled during encoding and extracting from said encoded wideband signal version at least pitch codebook parameters, innovative codebook parameters, and linear prediction filter coefficients; b) a pitch codebook responsive to said pitch codebook parameters for producing a pitch codevector; c) an innovative codebook responsive to said innovative codebook parameters for producing an innovative codevector; d) a combiner circuit for combining said pitch codevector and said innovative codevector to thereby produce an excitation signal; e) a signal synthesis device including a linear prediction filter for filtering said excitation signal in relation to said linear prediction filter coefficients to thereby produce a synthesized wideband signal, and an oversampler responsive to said synthesized wideband signal for producing an over-sampled signal version of the synthesized wideband signal; and f) a high-frequency content recovering device comprising: i) a random noise generator for producing a noise sequence having a given spectrum; ii) a spectral shaping unit for shaping the spectrum of the noise sequence in relation to linear prediction filter coefficients related to said down-sampled wideband signal; and iii) a signal injection circuit for injecting said spectrally-shaped noise sequence in said over-sampled synthesized signal version to thereby produce said full-spectrum synthesized wideband signal. view more