DFTGetBufSize

Determines the size of work buffer that can be used by the DFT functions.

Syntax

IppStatus ippiDFTGetBufSize_R_32s(IppiDFTSpec_R_32s* pDFTSpec, int* pBufferSize);

IppStatus ippiDFTGetBufSize_R_32f(IppiDFTSpec_R_32f* pDFTSpec, int* pBufferSize);

IppStatus ippiDFTGetBufSize_C_32fc(IppiDFTSpec_C_32fc* pDFTSpec, int* pBufferSize);

Parameters

pDFTSpec	Pointer to the previously initialized DFT context structure.
pBufferSize	Pointer to the size of the external work buffer to be used by the DFT functions.

Description

The function ippiDFTGetBufSize is declared in the ippi.h file. This function determines the size in bytes of an external memory buffer that can be used by DFT functions with context pDFTSpec as a workspace during calculations.

If you want to use external buffering, call this function after pDFTSpec initialization. Use the computed pBufferSize value as the size in bytes of an external buffer to be allocated by means of the functions ippMalloc or ippsMalloc_8u. Note that the allocated memory can be freed only by the functions ippFree or ippsFree respectively. Refer to the chapter 3 “Support Functions” of the Intel IPP Reference Manual, vol.1 for more details about the memory allocation functions.

Return Values

ippStsNoErr	Indicates no error. Any other value indicates an error or a warning.
ippStsNullPtrErr	Indicates an error condition if pDFTSpec pointer is NULL.
ippStsContextMatchErr	Indicates an error condition if a pointer to an invalid pDFTSpec structure is passed.