Ifft2D - Analog Devices VISUALDSP++ 3.5 Manual

ifft2d

NxN point 2-D inverse input FFT
Synopsis
#include <filter.h>
void ifft2d_fr16(*in, *t, *out, w[], wst, n, block_exponent,
const complex_float *in;
complex_fract16 *t;
complex_fract16 *out;
const complex_fract16 w[];
int wst;
int n;
int *block_exponent;
int scale method;
Description
This function computes a two-dimensional Inverse Fast Fourier Trans-
form of the complex input matrix
complex output matrix
The size of the input array
working buffer
FFT. The function does not impose any special memory alignment
requirements on the arrays. However, benefits in run-time performance
will be realized if the output array is allocated on an address boundary that
is multiple of twice the FFT size. If the input data can be overwritten,
then optimum memory usage can be achieved by specifying the input
array as the output array.
VisualDSP++ 3.5 C/C++ Compiler and Library Manual
for ADSP-219x DSPs
scale_method)
/* pointer to input matrix a[n][n]
/* pointer to working buffer t[n][n] */
/* pointer to output matrix c[n][n]
/* twiddle sequence
/* twiddle factor stride
/* number of FFT points
/* block exponent of output data
/* scaling method desired 0-none,
.
c[n][n]
, the output array
in
is , where represents the number of points in the
t n*n n
DSP Run-Time Library
1-static, 2-dynamic
and stores the result to the
a[n][n]
, and the temporary
out
*/
*/
*/
*/
*/
*/
*/
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