FFTGetBufSize

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

Syntax

IppStatus ippiFFTGetBufSize_R_32s (IppiFFTSpec_R_32s* pFFTSpec, int* pBufferSize);

IppStatus ippiFFTGetBufSize_R_32f (IppiFFTSpec_R_32f* pFFTSpec, int* pBufferSize);

IppStatus ippiFFTGetBufSize_C_32fc (IppiFFTSpec_C_32fc* pFFTSpec, int* pBufferSize);

Parameters

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

Description

The function ippiFFTGetBufSize is declared in the ippi.h file. This function determines the size in bytes of an external memory buffer that can be used by FFT functions with context pFFTSpec as a workspace during calculations. If you want to use external buffering, call this function after pFFTSpec initialization. Use the computed pBufferSize value to set 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 “Support Functions” in 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 pFFTSpec or pBufferSize pointer is `NULL`.
ippStsContextMatchErr	Indicates an error condition if a pointer to an invalid pFFTSpec structure is passed.