EnvelopFrequency

Computes the frequency envelope parameters.

Syntax

IppStatus ippsEnvelopFrequency_G7291_16s(const Ipp16s pSrc[64], Ipp16s pDstEnvelopFreq[12]);

Parameters

pSrc	Pointer to the original highband input signal.
pDstEnvelopFreq	Pointer to the output frequency envelope parameters.

Description

The function ippsEnvelopFrequency_G7291 is declared in the ippsc.h file. This function calculates the frequency envelope parameters. To calculate 12 frequency envelope parameters, the pSrc signal is windowed and transformed by FFT of length 64. Finally, the frequency envelope parameters are calculated as logarithmic weighted subband energies for 12 evenly spaced and wide overlapping subbands in the FFT domain. See [ITU7291] section 6.5.2.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is NULL.