CombinedFilter_G728

Applies the combined filter to multiple samples.

Syntax

IppStatus ippsCombinedFilterZeroInput_G728_16s(const Ipp16s* pSyntCoeff, const Ipp16s* pWgtCoeff, Ipp16s* pDstWgtZIR, IppsCombinedFilterState_G728_16s* pMem);

IppStatus ippsCombinedFilterZeroState_G728_16s(const Ipp16s* pSyntCoeff, const Ipp16s* pWgtCoeff, Ipp16s* pSrcDstExc, Ipp16s excSfs, Ipp16s* pDstSpeech, Ipp16s* pSpeechSfs, IppsCombinedFilterState_G728_16s* pMem);

Parameters

pSyntCoeff

Pointer to the filter coefficients vector [50]: a1, ..., a50 in Q14.

pWgtCoeff

Pointer to the filter coefficients vector [20]: B1 , ..., B10, A1 , ..., A10 in Q14.

pSrcDstExc

Pointer to the output gain-scaled excitation vector [5].

excSfs

The input scale of the previous gain-scaled excitation vector.

pDstWgtZIR

Pointer to the output zero input response vector [5] of the combined filter.

pDstSpeech

Pointer to the output quantized speech vector [5].

pSpeechSfs

The output scale of the quantized speech vector.

pMem

Pointer to the combined filter state structure.

Description

The functions ippsCombinedFilterZeroInput_G728 and ippsCombinedFilterZeroState_G728 are declared in ippsc.h file.

ippsCombinedFilterZeroInput_G728. This function calculates the zero-input response of the combined filter by superposing two filters, specifically, the 50s-order synthesis filter and the 10s-order IIR filter according to the transfer function:



ippsCombinedFilterZeroState_G728_16s. This function first performs filtering of the gain-scaled excitation vector through the zero-state combined filter (see the above function). The memory of combined filter is then updated by adding zero-state responses of the synthesis and the IIR filters which it is combined of. The quantized speech output vector is obtained as a by-product of the memory updates.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

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

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