Searches the ACELP fixed codebook for the excitation.
Syntax
IppStatus ippsACELPFixedCodebookSearch_G723_16s(const Ipp16s* pSrcFixedCorr, const Ipp16s* pSrcMatrix, Ipp16s* pDstFixedSign, Ipp16s* pDstFixedPosition, Ipp16s* pResultGrid, Ipp16s* pDstFixedVector, Ipp16s* pSearchTimes);
IppStatus ippsACELPFixedCodebookSearch_G723_32s16s(const Ipp16s* pSrcFixedCorr, Ipp32s* pSrcDstMatrix, Ipp16s* pDstFixedSign, Ipp16s* pDstFixedPosition, Ipp16s* pResultGrid, Ipp16s* pDstFixedVector, Ipp16s* pSearchTimes);
Parameters
pSrcFixedCorr |
Pointer to the correlation between residual and impulse response vector [60] |
pSrcMatrix |
Pointer to the elements of Toepliz matrix [416]. |
pSrcDstMatrix |
Pointer to the input and output elements of Toepliz matrix [416]. |
pDstFixedSign |
Pointer to the signs of the fixed vector [4]. |
pDstFixedPosition |
Pointer to the positions of the fixed vector [4]. |
pResultGrid |
Pointer to the beginning grid location. |
pDstFixedVector |
Pointer to the fixed vector [60]. |
pSearchTimes |
Pointer to the input and output maximum search time |
Description
The function ippsACELPFixedCodebookSearch_G723 is declared in the ippsc.h file. This function searches the ACELP fixed codebook for the excitation in the 5.3Kbps encoder. It is applied in subframes as follows:
1. There are four non-zero pulses in the fixed vector as given by:
n = 0,...,59
where αk and mk, k =0..3 are the signs and positions of the fixed vector respectively.
2. Search for the parameters αk and mk, k =0..3 , that minimize the following error:
where Φ(i,j) is the Toepliz matrix.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointers is NULL. |