Computes the forward discrete Fourier transform of a complex signal.
Syntax
Case 1: Operation on real data type
IppStatus ippsDFTFwd_CToC_32f(const Ipp32f* pSrcRe, const Ipp32f* pSrcIm, Ipp32f* pDstRe, Ipp32f* pDstIm, const IppsDFTSpec_C_32f* pDFTSpec, Ipp8u* pBuffer);
IppStatus ippsDFTFwd_CToC_64f(const Ipp64f* pSrcRe, const Ipp64f* pSrcIm, Ipp64f* pDstRe, Ipp64f* pDstIm, const IppsDFTSpec_C_64f* pDFTSpec, Ipp8u* pBuffer);
Case 2: Operation on complex data type
IppStatus ippsDFTFwd_CToC_32fc(const Ipp32fc* pSrc, Ipp32fc* pDst, const IppsDFTSpec_C_32fc* pDFTSpec, Ipp8u* pBuffer);
IppStatus ippsDFTFwd_CToC_64fc(const Ipp64fc* pSrc, Ipp64fc* pDst, const IppsDFTSpec_C_64fc* pDFTSpec, Ipp8u* pBuffer);
Include Files
ipps.h
Domain Dependencies
Flavors declared in ipps.h:
Headers: ippcore.h, ippvm.h
Libraries: ippcore.lib, ippvm.lib
Parameters
pDFTSpec |
Pointer to the DFT 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. |
pBuffer |
Pointer to the work buffer. |
Description
These functions compute the forward DFT according to the pDFTSpec specification parameters: the transform len, the normalization flag, and the specific code hint.
The functions operating on the complex data type process the input complex array pSrc and store the result in pDst.
The functions operating on the real data type (processing complex signals represented by separate real pSrcRe and imaginary pSrcIm parts) store the result separately in pDstRe and pDstIm, respectively.
Use this function with the external work buffer pBuffer.
Required buffer size must be computed by the corresponding function ippsDFTGet BufSize_C prior to using DFT computation functions.
Note
Data vectors for these functions must be aligned to an appropriate number of bytes that is determined by the SIMD width that is supported by the customer's platform - use ippMalloc function for such alignment.
The forward DFT functionality can be described as follows:
where k is the index of elements in the frequency domain, n is the index of elements in the time domain, N is the input signal len, and A is a multiplier defined by flag. Also, x(n) is pSrc[n] and X(k) is pDst[k].
Product and Performance Information |
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Performance varies by use, configuration and other factors. Learn more at www.Intel.com/PerformanceIndex. Notice revision #20201201 |
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 pDFTSpec is incorrect. |
ippStsMemAllocErr |
Indicates an error when no memory is allocated. |
ippStsFftFlagErr |
Indicates an error when the flag value is incorrect. |