Developer Reference

  • 2020
  • 07/15/2020
  • Public Content
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
= 2
order
.
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.

Product and Performance Information

1

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Notice revision #20110804