SynthesisFilter_G729

Reconstructs the speech signal from LP coefficients and residuals.

Syntax

IppStatus ippsSynthesisFilter_G729_16s(const Ipp16s* pSrcResidual, const Ipp16s* pSrcLPC, Ipp16s* pSrcDstSpch);

IppStatus ippsSynthesisFilterZeroStateResponse_NR_16s(const Ipp16s* pSrcLPC, Ipp16s* pDstImp, int len, int scaleFactor);

IppStatus ippsSynthesisFilter_G729E_16s(const Ipp16s* pLPC, int order, const Ipp16s* pSrc, Ipp16s* pDst, int len, const Ipp16s* pMem);

IppStatus ippsSynthesisFilter_G729E_16s_I(const Ipp16s* pLPC, int order, Ipp16s* pSrcDst, int len, const Ipp16s* pMem);

IppStatus ippsSynthesisFilter_G729_32f(const Ipp32f* pLpc, int order, const Ipp32f* pSrc, Ipp32f* pDst, int len, Ipp32f* pMem);

Parameters

pSrcResidual

Pointer to the LP residual signal vector [40].

pSrcLPC

Pointer to the LP coefficients vector [11], in Q12 for 16s data.

pSrcDstSpch

Pointer to the synthesized and updated speech. Elements pSrcDstSpch[0...39] are the present synthesized speech, pSrcDstSpch[-10...-1] are the history to be used.

pLPC

Pointer to the LP coefficients vector [order+1].

order

The filter order. (pLPC[order+1] vector must be supplied on input.)

pSrc

Pointer to the source vector [len].

pDst

Pointer to the destination speech vector [len].

pSrcDst

Pointer to the source and destination vector [len].

pDstImp

Pointer to the destination zero state impulse response vectore [len].

len

Length of the source and destination vectors.

pMem

Pointer to the filter memory vector [order] supplied for filtering.

scaleFactor

Scale factor for the input LP coefficients and output impulse response, accordingly.

Description

These functions are declared in the ippsc.h file.

The function ippsSynthesisFilter_G729_16s uses the default LP filter of 10-th order to reconstruct speech signal from the residual signal as:



n = 0,1,...,39 .

The function ippsSynthesisFilterZeroStateResponse_NR_16s performs the same operation as ippsSynthesisFilter_NR_16s for the same parameters, but uses no memory and processes the impulse input vector pSrc which is set as

pSrc[0] = 2scaleFactor, pSrc[i] = 0 , i = 1,... len - 1.

The functions ippsSynthesisFilter_G729E_16s, ippsSynthesisFilter_G729E_16s_I, and ippsSynthesisFilter_G729_32f perform synthesis filtering of the order given by the parameter order and operate like ippsSynthesisFilter_G729_16s function for the default order 10.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error when one of the specified pointers is NULL.

ippStsSizeErr

Indicates an error when order is less than or equal to 0.

ippStsOverflow

Indicates a warning that an overflow has occurred.

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