Post-processes the low-band decoded signal.
IppStatus ippsPostFilterLowBand_AMRWBE_16s(const Ipp16s* pSrcOldPitchLag, const Ipp16s* pSrcOldPitchGain, Ipp16s* pSrcDstSignal, Ipp16s* pOldSynth, Ipp16s* pOldNoise, Ipp16s* pFilterScale, Ipp32s pitchAdjust);
pSrcOldPitchLag |
Pointer to the previous pitch periods for all subframes [16] |
pSrcOldPitchGain |
Pointer to the previous pitch gains for all subframes [16] |
pSrcDstSignal |
Pointer to the proceeding signal [1024]. |
pOldSynth |
Pointer to the synthesis memory of post-filter [503]. |
pOldNoise |
Pointer to the noise memory of post-filter [24]. |
pFilterScale |
Pointer to the noise memory of post-filter scale factor. |
pitchAdjust |
Pitch adjustment flag, if it is NULL, then pitch adjustment is not implemented. |
The function ippsPostFilterLowBand_AMRWBE is declared in ippsc.h file. The decoded signal is first processed by an adaptive pitch enhancer, and then filtered through a long-term prediction filter. Then the obtained long term error signal is low-pass filtered and subtracted from the input signal.
See also 3GPP TS 26.290: “Extended AMR Wideband Speech Codec; Transcoding functions", clauses 6.1.3 [AMRWB+].
ippStsNoErr |
Indicates no error. |
ippStsNullPtrErr |
Indicates an error when one of the specified pointer is NULL. |
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