ImpulseResponseTarget_GSMAMR

DEPRECATED. Computes the impulse response and target signal required for the adaptive codebook search.

Syntax

IppStatus ippsImpulseResponseTarget_GSMAMR_16s(const Ipp16s* pSrcSpch, const Ipp16s* pSrcWgtLPC1, const Ipp16s* pSrcWgtLPC2, const Ipp16s* pSrcQLPC, const Ipp16s* pSrcSynFltState, const Ipp16s* pSrcWgtFltState, Ipp16s* pDstImpulseResponse, Ipp16s* pDstLpResidual, Ipp16s* pDstAdptTarget);

Include Files

ippsc.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

pSrcSpch

Pointer to the input speech vector with 50 elements, where elements 0 - 9 are from the previous subframe, and elements 10 - 49 are from the current subframe.

pSrcWgtLPC1

Pointer to a vector with eleven elements of weighted LP coefficients associated with A(z1) on the current subframe, represented using Q3.12 format.

pSrcWgtLPC2

Pointer to a vector with eleven elements of weighted LP coefficients associated with A(z2) on the current subframe, represented using Q3.12 format.

pSrcQLPC

Pointer to a vector with eleven elements of quantized LP coefficients for the current subframe, represented using Q3.12 format.

pSrcSynFltState

Pointer to the vector with ten elements that contains the state of the synthesis filter, represented using Q15.0 format.

pSrcWgtFltState

Pointer to the vector with ten elements that contains the state of the weighting filter, represented using Q15.0 format.

pDstImpulseResponse

Pointer to the vector with 40 elements that contains the impulse response, represented using Q3.12 format.

pDstLpResidual

Pointer to the vector with 40 elements that contains the LP residual, represented using Q15.0 format.

pDstAdptTarget

Pointer to the vector with 40 elements that contains the LP residual, represented using Q15.0 format.

Description

This function computes the impulse response and target signal required for the adaptive codebook search. This function is performed on a subframe basis using the following approach:

  1. The impulse response h( n) of the weighted synthesis filter, H(z)W(z) = A(z1)/[ Â(z) A(z2) , is computed by applying the filters 1/Â(z) and 1/A(z2) to the zero-padded impulse response of the filter A(z1).
  2. The target signal is then obtained by applying to the LP residual resLP(n) the cascaded synthesis and weighting filters 1/Â(z) and A(z1)/A(z2) , respectively. The adaptive codebook search also uses the residual signal resLP(n to update the history of past excitations. The LP residual is obtained by inverse filtering the input speech, that is



Return Values

ippStsNoErr

Indicates no error.

IppStsNullPtrErr

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