Visible to Intel only — GUID: GUID-F5D7B460-6ABF-45B4-8B3F-E9FA809FD3FD
Visible to Intel only — GUID: GUID-F5D7B460-6ABF-45B4-8B3F-E9FA809FD3FD
FFTInv_CToC
Computes the inverse fast Fourier transform (FFT) of a complex signal.
Syntax
Case 1: Not-in-place operation on real data type
IppStatus ippsFFTInv_CToC_32f(const Ipp32f* pSrcRe, const Ipp32f* pSrcIm, Ipp32f* pDstRe, Ipp32f* pDstIm, const IppsFFTSpec_C_32f* pFFTSpec, Ipp8u* pBuffer);
IppStatus ippsFFTInv_CToC_64f(const Ipp64f* pSrcRe, const Ipp64f* pSrcIm, Ipp64f* pDstRe, Ipp64f* pDstIm, const IppsFFTSpec_C_64f* pFFTSpec, Ipp8u* pBuffer);
Case 2: Not-in-place operation on complex data type
IppStatus ippsFFTInv_CToC_32fc(const Ipp32fc* pSrc, Ipp32fc* pDst, const IppsFFTSpec_C_32fc* pFFTSpec, Ipp8u* pBuffer);
IppStatus ippsFFTInv_CToC_64fc(const Ipp64fc* pSrc, Ipp64fc* pDst, const IppsFFTSpec_C_64fc* pFFTSpec, Ipp8u* pBuffer);
Case 3: In-place operation on real data type
IppStatus ippsFFTInv_CToC_32f_I(Ipp32f* pSrcDstRe, Ipp32f* pSrcDstIm, const IppsFFTSpec_C_32f* pFFTSpec, Ipp8u* pBuffer);
IppStatus ippsFFTInv_CToC_64f_I(Ipp64f* pSrcDstRe, Ipp64f* pSrcDstIm, const IppsFFTSpec_C_64f* pFFTSpec, Ipp8u* pBuffer);
Case 4: In-place operation on complex data type
IppStatus ippsFFTInv_CToC_32fc_I(Ipp32fc* pSrcDst, const IppsFFTSpec_C_32fc* pFFTSpec, Ipp8u* pBuffer);
IppStatus ippsFFTInv_CToC_64fc_I(Ipp64fc* pSrcDst, const IppsFFTSpec_C_64fc* 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 containing complex values. |
pDst |
Pointer to the output array containing complex values. |
pSrcRe |
Pointer to the input array containing real parts of the signal. |
pSrcIm |
Pointer to the input array containing imaginary parts of the signal. |
pDstRe |
Pointer to the output array containing real parts of the signal. |
pDstIm |
Pointer to the output array containing imaginary parts of the signal. |
pSrcDst |
Pointer to the input and output array containing complex values (for the in-place operation). |
pSrcDstRe |
Pointer to the input and output array containing real parts of the signal(for the in-place operation). |
pSrcDstIm |
Pointer to the input and output array containing imaginary parts of the signal(for the in-place operation). |
pBuffer |
Pointer to the external work buffer. |
Description
This function computes the inverse FFT of a complex signal according to the pFFTSpec specification parameters: the transform order, the normalization flag, and the specific code hint. The FFT specification structure must be initialized by the ippsFFTInit_C function beforehand.
The function flavors using the complex data type, for example with the 32fc suffixes, process the input complex array pSrc and store the result in pDst. Their in-place flavors use the complex array pSrcDst.
The function flavors using the real data type and processing complex signals represented by separate real pSrcRe and imaginary pSrcIm parts, for example with the 32f suffixes, store the result separately in pDstRe and pDstIm, respectively. Their in-place flavors uses separate real and imaginary arrays pSrcDstRe and pSrcDstIm, respectively.
Use this function 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 ippsFFTGetSize_C function.
The length of the FFT must be a power of 2.
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. |