HarmonicFilter

Calculates the harmonic filter.

Syntax

IppStatus ippsHarmonicFilter_16s_I (Ipp16s beta, int T, Ipp16s* pSrcDst, int len);

IppStatus ippsHarmonicFilter_NR_16s (Ipp16s beta, int T, const Ipp16s* pSrc, Ipp16s* pDst, int len);

IppStatus ippsHarmonicFilter_32f_I(Ipp32f beta, int T, Ipp32f* pSrcDst, int len);

beta	The beta factor, in Q15 for 16s data.
T	The integer delay.
pSrc	Pointer to the source vector. Elements pSrc[- T,...,0,...len -1] are used as input.
pDst	Pointer to the destination vector.
pSrcDst	Pointer to the source and destination vector. Elements pSrcDst[ -T,...,0,..., len-1] aree used as input, elements pSrcDst[0,...,len -1] are computed by the function.
len	Number of elements in the source and destination vectors.

These functions are declared in the ippsc.h file.

The functions ippsHarmonicFilter_16s_I and ippsHarmonicFilter_32f_I implement the adaptive pre-filter:

H(z) = 1/(1-β*z^-T), which can be used to enhance the harmonic component of speech.

The calculation is as follows:

pSrcDst[n] = pSrcDst[n] + beta* pSrcDst[n-T], 0 ≤ n < len.

The function ippsHarmonicFilter_NR_16s implements the harmonic noise shaping filter: H(z) = 1+β*z^-T

The calculation is as follows:

pDst[n] = pSrc[n] + beta* pSrc[n-T], 0 ≤ n < len.

Both filters can be used to enhance the harmonic component of the input signal.

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is NULL.
ippStsSizeErr	Indicates an error when len is less than or equal to 0.