Buffer the LSP (or LSF) coefficients and previous log energy coefficients.
Syntax
IppStatus ippsEncDTXBuffer_GSMAMR_16s(const Ipp16s* pSrcSpch, const Ipp16s* pSrcLsp, Ipp16s* pValResultUpdateIndex, Ipp16s* pSrcDstLspBuffer, Ipp16s* pSrcDstLogEnergyBuffer);
IppStatus ippsDecDTXBuffer_GSMAMR_16s(const Ipp16s* pSrcSpch, const Ipp16s* pSrcLsf, Ipp16s* pValResultUpdateIndex, Ipp16s* pSrcDstLsfBuffer, Ipp16s* pSrcDstLogEnergyBuffer);
Parameters
pSrcSpch |
Pointer to the input speech signal, in the length of 160, in Q15.0. |
pSrcLsp |
Pointer to the LSP for this frame, in the length of 10, in Q0.15. |
pSrcLsf |
Pointer to the LSF coefficients of the current frame, in the length of 10, in Q0.15. |
pValResultUpdateIndex |
Pointer to the previous memory update index. On output, points to the current memory update index. It is circularly increased between 0 and 7. |
pSrcDstLspBuffer |
Pointer to the LSP coefficients of eight previous frames, in the length of 80, in Q0.15. On output, points to the LSP coefficients of eight most recent frames (including the current frame), in the length of 80, in Q0.15. |
pSrcDstLsfBuffer |
Pointer to the LSF coefficients of eight previous frames, in the length of 80, in Q0.15. |
pSrcDstLogEnergyBuffer |
Pointer to the logarithm energy coefficients of eight previous frames, in the length of 8, in Q5.10. On output, points to the log energy coefficients of eight most recent frames (including the current frame), in the length of 8, in Q5.10. |
Description
The functions ippsEncDTXBuffer_GSMAMR and ippsDecDTXBuffer_GSMAMR are declared in ippsc.h file. These functions buffer the LSP (or LSF) coefficients and previous log energy coefficients. These LSPs (or LSFs) and energy coefficients will be used for SID frame to extract necessary parameters. The memory update index indicates which part of the buffer will be updated, and it saves the cost for some memory copy. The log energy is computed as follows:
where
N is the frame length
s is the input speech signal.
Return Values
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointers is NULL. |