Special Arguments
This section describes the flag and hint arguments used by the Fourier transform functions.
The Fourier transform functions require you to specify the
flag
and
hint
arguments.
The
flag
argument specifies the result normalization method. The following table lists the possible values for the
flag
argument. Specify one and only one of the represented values in the
flag
argument. The
A
and
B
factors are multipliers used in the DFT computation.
Value
| A
| B
| Description
|
|---|---|---|---|
IPP_FFT_DIV_FWD_BY_N | 1/ N | 1
| Forward transform is done with the 1/ N normalization.
|
IPP_FFT_DIV_INV_BY_N | 1
| 1/ N | Inverse transform is done with the 1/ N normalization.
|
IPP_FFT_DIV_BY_SQRTN | 1/ N 1/2 | 1/ N 1/2 | Forward and inverse transform is done with the 1/
N 1/2 normalization.
|
IPP_FFT_NODIV_BY_ANY | 1
| 1
| Forward or inverse transform is done without the 1/
N or 1/N 1/2
normalization.
|