Decomposes inverse DCT output signal to the form of the MLT output signal.
Syntax
IppStatus ippsDecomposeDCTToMLT_G722_16s(const Ipp16s* pSrcSpchDecomposed, Ipp16s* pSrcDstSpchDecomposedOld, Ipp16s* pDstSpch);
IppStatus ippsDecomposeDCTToMLT_G7221_16s(const Ipp16s* pSrcSpchDecomposed, Ipp16s* pSrcDstSpchDecomposedOld, Ipp16s* pDstSpch, int len);
Parameters
pSrcSpchDecomposed |
Pointer to the source vectorPointer to the source windowed speech vector [320 or len]. |
pSrcDstSpchDecomposedOld |
Pointer to the source and destination windowed speech vector [160 or len/2] of the previous frame. |
pDstSpch |
Pointer to the destination speech vector [320 or len]. |
len |
Number of elements on the source and destination vectors, possible values: 320, 640. |
Description
The functions ippsDecomposeDCTToMLT are declared in the ippsc.h file. These functions perform inverse decomposition of the inverse DCT output by windowing, overlapping and summation, and restore speech signal. The function ippsDecomposeDCTToMLT_G722 operates with the source vector of the fixed length [320]. The function ippsDecomposeDCTToMLT_G7221 operates with the source vector of the len length.
If l = len, l2 = len /2, and u=pSrcSpchDecomposed, uold=pSrcDstSpchDecomposedOld , y=pDstSpch, then the calculation is performed as follows:
where
The unused second half of the input signal is stored for use with 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. |