Intel® Integrated Performance Primitives Developer Guide and Reference

ID 790148
Date 11/07/2023
Public

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Document Table of 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.