Developer Reference

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

DFTGetSize_R
,
DFTGetSize_C

Computes sizes of the DFT work buffer and required working buffers.

Syntax

Case 1: Operation on real signal
IppStatus ippsDFTGetSize_R_32f(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
IppStatus ippsDFTGetSize_R_64f(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
Case 2: Operation on complex signal
IppStatus ippsDFTGetSize_C_32fc(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
IppStatus ippsDFTGetSize_C_32f(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
IppStatus ippsDFTGetSize_C_64fc(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
IppStatus ippsDFTGetSize_C_64f(int
length
, int
flag
, IppHintAlgorithm
hint
, int*
pSizeSpec
, int*
pSizeInit
, int*
pSizeBuf
);
Include Files
ipps.h
Domain Dependencies
Headers:
ippcore.h
,
ippvm.h
Libraries:
ippcore.lib
,
ippvm.lib
Parameters
length
Length of the DFT transform.
flag
Specifies the result normalization method. The values for the
flag
argument are described in the section Flag and Hint Arguments.
hint
This parameter is deprecated. Set the value to
ippAlgHintNone
.
pSizeSpec
Pointer to the DFT specification structure size value.
pSizeInit
Pointer to the buffer size value for DFT initialization functions.
pSizeBuf
Pointer to the size value of the DFT external work buffer.
Description
These functions compute the size of DFT specification structure, the work buffer size for the DFT structure initialization functions
ippsDFTInit_R
and
ippsDFTInit_C
, and size of the DFT work buffer for different flavors of
ippsDFTFwd
and
ippsDFTInv
. Their values in bytes are stored in
pSpecSize
,
pSizeInit
, and
pSizeBuf
respectively.
ippsDFTGetSize_R
function is used for real flavors of the DFT functions.
ippsDFTGetSize_C
function is used for complex flavors of the DFT functions.
Application Notes
The maximum values for
length
are:
Function Flavor
Max
length
C_32fc
134217727 (2^27 - 1)
C_64fc
67108863 (2^26 - 1)
Return Values
ippStsNoErr
Indicates no error.
ippStsNullPtrErr
Indicates an error when one of the specified pointers is
NULL
.
ippStsFftFlagErr
Indicates an error when the
flag
value is incorrect.
ippStsFftOrderErr
Indicates an error when the memory needed to calculate the
length
value of the DFT transform exceeds the limit.
ippStsSizeErr
Indicates an error when
length
is less than, or equal to 0.

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