Developer Reference for Intel® Integrated Performance Primitives
Computes sizes of the FFT specification structure and required working buffers.
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);
ipps.h
Headers: ippcore.h, ippvm.h
Libraries: ippcore.lib, ippvm.lib
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. |
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.
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 |
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. |