Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 3/22/2024
Public
Document Table of Contents

FFTInv_PackToR, FFTInv_PermToR, FFTInv_CCSToR

Computes the inverse fast Fourier transform (FFT) of a real signal.

Syntax

Case 1: Not-in-place operation on input data in Pack format

IppStatus ippsFFTInv_PackToR_32f(const Ipp32f* pSrc, Ipp32f* pDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_PackToR_64f(const Ipp64f* pSrc, Ipp64f* pDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Case 2: In-place operation on input data in Pack format

IppStatus ippsFFTInv_PackToR_32f_I(Ipp32f* pSrcDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_PackToR_64f_I(Ipp64f* pSrcDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Case 3: Not-in-place operation on input data in Perm format

IppStatus ippsFFTInv_PermToR_32f(const Ipp32f* pSrc, Ipp32f* pDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_PermToR_64f(const Ipp64f* pSrc, Ipp64f* pDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Case 4: In-place operation on input data in Perm format

IppStatus ippsFFTInv_PermToR_32f_I(Ipp32f* pSrcDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_PermToR_64f_I(Ipp64f* pSrcDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Case 5 Not-in-place operation on input data in CCS format

IppStatus ippsFFTInv_CCSToR_32f(const Ipp32f* pSrc, Ipp32f* pDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_CCSToR_64f(const Ipp64f* pSrc, Ipp64f* pDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Case 6: In-place operation on input data in CCS format

IppStatus ippsFFTInv_CCSToR_32f_I(Ipp32f* pSrcDst, const IppsFFTSpec_R_32f* pFFTSpec, Ipp8u* pBuffer);

IppStatus ippsFFTInv_CCSToR_64f_I(Ipp64f* pSrcDst, const IppsFFTSpec_R_64f* pFFTSpec, Ipp8u* pBuffer);

Include Files

ipps.h

Domain Dependencies

Headers: ippcore.h, ippvm.h

Libraries: ippcore.lib, ippvm.lib

Parameters

pFFTSpec

Pointer to the FFT specification structure.

pSrc

Pointer to the input array.

pDst

Pointer to the output array containing real values.

pSrcDst

Pointer to the input and output for the in-place operation.

pBuffer

Pointer to the external work buffer.

Description

Use these functions with the external work buffer pBuffer. Once the work buffer is allocated, it can be used for all following calls to the functions computing FFT. The use of an external buffer improves performance significantly, especially for the small size transforms.

The size of the external buffer must be previously computed by the function ippsFFTGetSize_R.

ippsFFTInv_PackToR. This function computes the inverse FFT of input data in Pack format.

ippsFFTInv_PermToR. This function computes the inverse FFT of input data in Perm format.

ippsFFTInv_CCSToR. This function computes the inverse FFT of input data in CCS format.

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error when one of the specified pointers with exception of pBuffer is NULL.

ippStsContextMatchErr

Indicates an error when the specification identifier pFFTSpec is incorrect.

ippStsMemAllocErr

Indicates an error when no memory is allocated.