DFTGetSize

Computes the size of the FFT context structure and the size of the work buffer.

Syntax

IppStatus ippiDFTGetSize_R_32f (IppiSize roiSize, int flag, IppHintAlgorithm hint, int* pSizeSpec, int* pSizeInit, int* pSizeBuf);

IppStatus ippiDFTGetSize_C_32fc (IppiSize roiSize, int flag, IppHintAlgorithm hint, int* pSizeSpec, int* pSizeInit, int* pSizeBuf);

Include Files

ippi.h

Domain Dependencies

Headers: ippcore.h, ippvm.h, ipps.h

Libraries: ippcore.lib, ippvm.lib, ipps.lib

Parameters

roiSize	Size of the source and destination ROI in pixels.
flag	Flag to choose the option for results normalization. For more information, see Table "Normalization Factors for Fourier Transform Results"
hint	This parameter is deprecated. Set the value to ippAlgHintNone.
pSizeSpec	Pointer to the size of the DFT context structure.
pSizeInit	Pointer to the size of the buffer for the DFT initialization function.
pSizeBuf	Pointer to the size of the DFT external work buffer.

Description

This function computes the following:

Size of the DFT context structure. The result in bytes is stored in the pSpecSize parameter.
Size of the work buffer for the ippiDFTInit functions. The result, in bytes, is stored in the pSizeInit parameter.
Size of the work buffer for the ippiDFTFwd and ippiDFTInv functions. The result, in bytes, is stored in the pSizeBuf parameter.

The suffix after the function name indicates the flavors of the DFT functions: ippiDFTGetSize_C is for complex flavors and ippiDFTGetSize_R is for real flavors.

Return Values

ippStsNoErr	Indicates no error.
ippStsNullPtrErr	Indicates an error when one of the specified pointers is `NULL`.
ippStsFftFlagErr	Indicates an error condition when the flag value is illegal.
ippStsFftOrderErr	Indicates an error when the amount of memory needed to compute the DFT for points in the ROI of size roiSize exceeds the limit.
ippStsSizeErr	Indicates an error condition when the roiSize has a field with a zero or negative value.