Developer Reference

  • 2020
  • 10/21/2020
  • Public Content
Contents

DFTInv_PackToR
,
DFTInv_PermToR
,
DFTInv_CCSToR

Computes the inverse discrete Fourier transform of a real signal.

Syntax

Case 1: Input data in
Pack
format
IppStatus ippsDFTInv_PackToR_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTInv_PackToR_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
pDFTSpec
, Ipp8u*
pBuffer
);
Case
2
: Input data in
Perm
format
IppStatus ippsDFTInv_PermToR_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTInv_PermToR_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
pDFTSpec
, Ipp8u*
pBuffer
);
Case
3
: Input data in
CCS
format
IppStatus ippsDFTInv_CCSToR_32f(const Ipp32f*
pSrc
, Ipp32f*
pDst
, const IppsDFTSpec_R_32f*
pDFTSpec
, Ipp8u*
pBuffer
);
IppStatus ippsDFTInv_CCSToR_64f(const Ipp64f*
pSrc
, Ipp64f*
pDst
, const IppsDFTSpec_R_64f*
pDFTSpec
, Ipp8u*
pBuffer
);
Include Files
16s_Sfs
flavors:
ipps.h
Domain Dependencies
16s_Sfs
:
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 packed complex values.
pDst
Pointer to the output array containing real values.
pBuffer
Pointer to the work buffer.
Description
These functions compute the inverse DFT of a real signal. The input data (that is in the frequency-domain) are represented in several possible packed formats: Pack, Perm, or CCS. Tables show how the input data can be represented in the packed formats.
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.
If the external buffer is not specified (
pBuffer
is set to
NULL
), then the function itself allocates the memory needed for operation.
ippsDFTInv_PackToR
. This function computes the inverse DFT for input data in
Pack
format.
ippsDFTInv_PermToR
. This function computes the inverse DFT for input data in
Perm
format.
ippsDFTInv_CCSToR
. This function computes the inverse DFT for input data in
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 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.

Product and Performance Information

1

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