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/* -*- c++ -*- */
/*
* Copyright 2008 Free Software Foundation, Inc.
*
* This file is part of GNU Radio
*
* GNU Radio is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3, or (at your option)
* any later version.
*
* GNU Radio is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <gc_declare_proc.h>
#include <libfft.h>
#include <assert.h>
/*
* v is really vector complex<float>
*/
static void
conjugate_vector(vector float *v, int nelements)
{
vector float k = {1, -1, 1, -1};
int i;
for (i = 0; i < nelements; i++)
v[i] *= k;
}
static void
gcs_fwd_fft_1d_r2(const gc_job_direct_args_t *input,
gc_job_direct_args_t *output __attribute__((unused)),
const gc_job_ea_args_t *eaa)
{
vector float *out = (vector float *) eaa->arg[0].ls_addr; // complex
vector float *in = (vector float *) eaa->arg[1].ls_addr; // complex
vector float *twiddle = (vector float *) eaa->arg[2].ls_addr; // complex
vector float *window = (vector float *) eaa->arg[3].ls_addr; // float
int log2_fft_length = input->arg[0].u32;
int shift = input->arg[1].u32; // non-zero if we should apply fftshift
if (eaa->arg[3].get_size){ // apply window
// FIXME pointwise multiply in *= window
assert(0);
}
fft_1d_r2(out, in, twiddle, log2_fft_length);
if (shift){
// FIXME apply "fftshift" to output data in-place
assert(0);
}
}
GC_DECLARE_PROC(gcs_fwd_fft_1d_r2, "fwd_fft_1d_r2");
static void
gcs_inv_fft_1d_r2(const gc_job_direct_args_t *input,
gc_job_direct_args_t *output __attribute__((unused)),
const gc_job_ea_args_t *eaa)
{
vector float *out = (vector float *) eaa->arg[0].ls_addr; // complex
vector float *in = (vector float *) eaa->arg[1].ls_addr; // complex
vector float *twiddle = (vector float *) eaa->arg[2].ls_addr; // complex
vector float *window = (vector float *) eaa->arg[3].ls_addr; // float
int log2_fft_length = input->arg[0].u32;
int shift = input->arg[1].u32; // non-zero if we should apply fftshift
if (eaa->arg[3].get_size){ // apply window
// FIXME pointwise multiply in *= window
assert(0);
}
if (shift){
// FIXME apply "fftshift" to input data in-place
assert(0);
}
conjugate_vector(in, 1 << (log2_fft_length - 1));
fft_1d_r2(out, in, twiddle, log2_fft_length);
conjugate_vector(out, 1 << (log2_fft_length - 1));
}
GC_DECLARE_PROC(gcs_inv_fft_1d_r2, "inv_fft_1d_r2");
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