OpenLoopPitchSearchNonDTX

Computes the OLP lag.

Syntax

IppStatus ippsOpenLoopPitchSearchNonDTX_GSMAMR_16s(const Ipp16s* pSrcWgtLpc1, const Ipp16s* pSrcWgtLpc2, const Ipp16s* pSrcSpch, Ipp16s* pValResultPrevMidPitchLag, Ipp16s* pValResultVvalue, Ipp16s* pSrcDstPrevPitchLag, Ipp16s* pSrcDstPrevWgtSpch, Ipp16s* pDstOpenLoopLag, Ipp16s* pDstOpenLoopGain, IppSpchBitRate mode);

Parameters

pSrcWgtLpc1	Pointer to the 44-element vector of weighted LP coefficients, represented using Q3.12. These LP coefficients comprise the numerator of the perceptual weighting filter.
pSrcWgtLpc2	Pointer to the 44-element vector of weighted LP coefficients, represented using Q3.12. These LP coefficients comprise the denominator of the perceptual weighting filter.
pSrcSpch	Pointer to the 170-element input speech vector, represented using Q15.0.
pValResultPrevMidPitchLag	Pointer to a vector of median filtered pitch lags from the five previous voiced speech half-frames, represented using Q15.0. On output, points to the updated vector of median filtered pitch lags from the five previous voiced speech half-frames, represented using Q15.0. This argument is valid only for 10.2 kbps frames.
pValResultVvalue	Pointer to the adaptive parameter v, represented using Q0.15. On output, points to the updated adaptive parameter v, represented using Q0.15. This argument is valid only for 10.2 kbps frames.
pSrcDstPrevPitchLag	Pointer to a five-element vector of pitch lags associated with the five most recent voiced speech half-frames. On output, points to the updated five-element vector of pitch lags associated with the five most recent voiced speech half-frames. This argument is valid only for 10.2 kbps frames.
pSrcDstPrevWgtSpch	Pointer to a 143-element vector containing the perceptually weighted speech associated with the previous frame, represented using Q15.0. On output, points to the updated 143-element vector containing the perceptually weighted speech associated with the previous frame, represented using Q15.0.
pDstOpenLoopLag	Pointer to a two-element vector of OLP lags. For 5.15 and 4.75 kbps frames, only the first vector element contains a valid lag value, since only one lag is estimated. For all other bit rates, both vector elements contain valid pitch lag values.
pDstOpenLoopGain	Pointer to a two-element vector containing optimal OLP gains, represented using Q15.0. This argument is valid only for 10.2 kbps frames.
mode	Bit rate specifier. Values between IPP_SPCHBR_4750 and IPP_SPCHBR_12200 are valid.

Description

The function ippsOpenLoopPitchSearchNonDTX_GSMAMR is declared in ippsc.h file. This function computes the OLP lag (as well as optimal pitch gain for 10.2 kbps frames only) when both DTX and VAD are disabled. The search algorithm is described in Open-Loop Pitch Search (OLP).

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is NULL.
ippStsRangeErr	Indicates an error when mode is not a valid element of the enumerated type IppSpchBitRate.