DFTFwd_RToPack
,
DFTFwd_RToPerm
,
DFTFwd_RToCCS
DFTFwd_RToPack
,
DFTFwd_RToPerm
,
DFTFwd_RToCCS
Computes the forward discrete Fourier transform of a real
signal.
Syntax
Case 1: Result in
Pack
format
IppStatus ippsDFTFwd_RToPack_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTFwd_RToPack_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
pDFTSpec
, Ipp8u*
pBuffer
);
supported value for <
len
>: integer in the range [2, 64].
Case
2
: Result in
Perm
format
IppStatus ippsDFTFwd_RToPerm_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTFwd_RToPerm_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
pDFTSpec
, Ipp8u*
pBuffer
);
Case
3
: Result in
CCS
format
IppStatus ippsDFTFwd_RToCCS_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTFwd_RToCCS_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
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 real values .
- pDst
- Pointer to the output array containing packed complex values.
- pBuffer
- Pointer to the work buffer.
Description
These functions compute the forward DFT of a real signal. The result of the
forward transform (that is in the frequency-domain) of real signals is represented in several
possible packed formats:
Pack
,
Perm
, or
CCS
. The data can be packed due to the symmetry property of the DFT
transform of a real signal.
Tables
show how the output results are arranged in the packed
formats.
These functions compute the forward DFT
according to the
pDFTSpec
specification parameters: the transform
len
, the normalization
flag
, and the specific code
hint
.
These functions 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.
If the external buffer is not specified (
pBuffer
is set to
NULL
), then the function itself allocates the memory needed
for operation.
ippsDFTFwd_RToPack
Pack
format.
ippsDFTFwd_RToPerm
Perm
format.
ippsDFTFwd_RToCCS
CCS
format.
Optimization Notice
|
|---|
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.