Intel® Integrated Performance Primitives (Intel® IPP) Developer Guide and Reference

ID 790148
Date 3/22/2024
Public
Document Table of Contents

FFTGetSize_R, FFTGetSize_C

Computes sizes of the FFT specification structure and required working buffers.

Syntax

Case 1: Operation on real signal

IppStatus ippsFFTGetSize_R_32f(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

IppStatus ippsFFTGetSize_R_64f(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

Case 2: Operation on complex signal

IppStatus ippsFFTGetSize_C_32f(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

IppStatus ippsFFTGetSize_C_64f(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

IppStatus ippsFFTGetSize_C_32fc(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

IppStatus ippsFFTGetSize_C_64fc(int order, int flag, IppHintAlgorithm hint, int* pSpecSize, int* pSpecBufferSize, int* pBufferSize);

Include Files

ipps.h

Domain Dependencies

Headers: ippcore.h, ippvm.h

Libraries: ippcore.lib, ippvm.lib

Parameters

order

FFT order. The input signal length is N= 2order.

flag

Specifies the result normalization method. The values for the flag argument are described in Flag and Hint Arguments.

hint

This parameter is deprecated. Set the value to ippAlgHintNone.

pSpecSize

Pointer to the FFT specification structure size value.

pSpecBufferSize

Pointer to the buffer size value for FFT initialization function.

pBufferSize

Pointer to the size value of the FFT external work buffer.

Description

These functions compute the following:

  • the size of the FFT specification structure. Computed value stored in pSpecSize.

  • the work buffer size for the FFT structure initialization functions ippsFFTInit_R and ippsFFTInit_C. Computed value is stored in pSpecBufferSize.

  • the size of the FFT work buffer for the different flavors of ippsFFTFwd and ippsFFTInv. Computed value is stored in pBufferSize.

The suffix after the function name indicates the flavors of the FFT functions: ippsFFTGetSize_C is for complex flavors and ippsFFTGetSize_R is for real flavors.

Application Notes

The maximum values for signal length are:

Function Flavor Max Length Order
R_32f 536870912 (2^29) 0..29
R_64f 268435456 (2^28) 0..28
C_32f 268435456 (2^28) 0..28
C_64f 134217728 (2^27) 0..27
C_32fc 268435456 (2^28) 0..28
C_64fc 134217728 (2^27) 0..27

Return Values

ippStsNoErr

Indicates no error.

ippStsNullPtrErr

Indicates an error when one of the specified pointers is NULL.

ippStsFftOrderErr

Indicates an error when the order value is incorrect.

ippStsFftFlagErr

Indicates an error when the flag value is incorrect.

See Also