Decomposes the MLT input signal to the form of the DCT input signal.
Syntax
IppStatus ippsDecomposeMLTToDCT_G722_16s(const Ipp16s* pSrcSpch, Ipp16s* pSrcDstSpchOld, Ipp16s* pDstSpchDecomposed);
IppStatus ippsDecomposeMLTToDCT_G7221_16s(const Ipp16s* pSrcSpch, Ipp16s* pSrcDstSpchOld, Ipp16s* pDstSpchDecomposed, int len);
Parameters
pSrcSpch |
Pointer to the source vector. |
pSrcSpchOld |
Pointer to the source/destination vector of of the previous speech frame. |
pDstSpchDecomposed |
Pointer to the destination decomposed speech vector. |
len |
Number of elements on the source and destination vectors, possible values: 320, 640. |
Description
The functions ippsDecomposeMLTToDCT are declared in the ippsc.h file. These functions decompose the input signal by windowing, overlapping and summation to the form suitable for the DCT operation required for modulated lapped transform (MLT) coefficients calculation. The function ippsDecomposeMLTToDCT_G722 operates with the vector of the fixed length [320]. The function ippsDecomposeMLTToDCT_G7221 operates with the vector of the len length.
If l = len, l2 = len /2, and v=pDstSpchDecomposed, then the calculation is performed as follows:
where
and
The input signal pSrcSpch is stored in pSrcDstSpchOld for use in the next frame.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointer is NULL. |
ippStsSizeErr |
Indicates an error when the len has an illegal value. |