LSFToLPC

Converts LSF coefficients to the LP coefficients.

Syntax

IppStatus ippsLSFToLPC_G723_16s(const Ipp16s* pSrcLSF, Ipp16s* pDstLPC);

IppStatus ippsLSFToLPC_G723_16s_I (Ipp16s* pSrcLSFDstLPC);

Parameters

pSrcLSF	Pointer to the input LSF coefficients vector [10], in Q15.
pDstLPC	Pointer to the output LP coefficients vector [10], in Q13.
pSrcLSFDstLPC	Pointer to the input LSF and output LP coefficients vector [10], in Q15 and Q13, respectively.

Description

The function ippsLSFToLPC_G723 is declared in the ippsc.h file. This function converts a set of 10th order LSF coefficients to the LP coefficients as follows:

1. Convert LSF coefficients to the LSP coefficients as: q_i = cos (ω_i) , i = 0...9

2. Calculate the LP coefficients using the same algorithm as in the function ippsLSPToLPC_G729 with the only difference in rounding mode required for G.723.1 bit-exact compliance.

Return Values

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