Applies the hybrid window and computes autocorrelation coefficients.
Syntax
IppStatus ippsWinHybrid_G729E_16s32s (const Ipp16s* pSrcSynthSpeech, Ipp32s* pDstInvAutoCorr, IppsWinHybridState_G729E_16s* pMem);
IppStatus ippsWinHybrid_G729E_32f(const Ipp32f* pSrcSynthSpeech, Ipp32f* pDstInvAutoCorr, IppsWinHybridState_G729E_32f* pMem);
Parameters
pSrcSynthSpeech |
Pointer to the input synthesized speech vector [144]. |
pDstInvAutoCorr |
Pointer to the output autocorrelation vector [31]. |
pMem |
Pointer to the memory of hybrid windowing module. |
Description
The function ippsWinHybrid_G729E is declared in the ippsc.h file. This function applies the hybrid window to input synthesized speech and computes autocorrelation coefficients as follows.
1. First, the input speech vector is multiplied by the hybrid window:
Sw+L(k) = Sw(k)* w(144 - k), k = 0, .., 144.
where w(k) = sin((k +1) * 0.047783) for k = 0, .., 34, and w(k) = sin(36*0.0477783)*a(35- k) for k = 35, .., 144.
Here a = 0.9928337491 so that a40=0.75 and a160 = 0.754 = 0.31640625 .
2. Second, the autocorrelation of the windowed speech is calculated by the formulas:
3. Third, the output autocorrelation is computed and the memory is updated as follows:
mem[k] = 0.31640625*mem[k] + Rrec(k) ,
pDstInvAutoCorr[k] = mem[k] + R(k), k = 0, ..,30.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointers is NULL. |