DFTInv_CToC
DFTInv_CToC
Computes the inverse discrete Fourier transform of a complex
signal.
Syntax
Case 1: Operation on real data type
IppStatus ippsDFTInv_CToC_32f(const Ipp32f*
pSrcRe
, const Ipp32f*
pSrcIm
, Ipp32f*
pDstRe
, Ipp32f*
pDstIm
, const IppsDFTSpec_C_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTInv_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 ippsDFTInv_CToC_32fc(const Ipp32fc*
pSrc
, Ipp32fc*
pDst
, const IppsDFTSpec_C_32fc*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTInv_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 inverse DFT according
to the pDFTSpec
specification
parameters: the transform len
, the
normalization flag
, and the specific
code hint
. The functions using the complex data type, for example with
32fc
suffixes, process the input complex array pSrc
and store the result in pDst
. The functions using the real data type and processing complex signals
represented by separate real
pSrcRe
and imaginary pSrcIm
parts, for
example with 32f
suffixes, store the result
separately in pDstRe
and pDstIm
, respectively. The function can be used with the external work buffer
pBuffer
to avoid memory allocation within the
functions. Once the work buffer is allocated, it can be used for all following calls to the
functions computing DFT. As internal allocation of memory is too expensive operation and depends
on operating system and/or runtime libraries used - the use of an external buffer improves
performance significantly, especially for the small size transforms.Required buffer size must be computed by the corresponding function
ippsDFTGet BufSize_C
prior to using DFT
computation functions. If the external buffer is not specified (
pBuffer
is set to NULL
), then the function itself allocates the memory needed
for operation.Optimization Notice
|
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Intel's compilers may or may not optimize to the same degree for non-Intel microprocessors for optimizations that are not unique to Intel microprocessors. These optimizations include SSE2, SSE3, and SSSE3 instruction sets and other optimizations. Intel does not guarantee the availability, functionality, or effectiveness of any optimization on microprocessors not manufactured by Intel. Microprocessor-dependent optimizations in this product are intended for use with Intel microprocessors. Certain optimizations not specific to Intel microarchitecture are reserved for Intel microprocessors. Please refer to the applicable product User and Reference Guides for more information regarding the specific instruction sets covered by this notice.
Notice revision #20110804
|
Return Values
- ippStsNoErr
- Indicates no error.
- ippStsNullPtrErr
- Indicates an error when one of the specified pointers with exception ofpBufferisNULL.
- ippStsContextMatchErr
- Indicates an error when the specification identifierpDFTSpecis incorrect.
- ippStsMemAllocErr
- Indicates an error when no memory is allocated.
- ippStsFftFlagErr
- Indicates an error when theflagvalue is incorrect.