kopia lustrzana https://github.com/Dsplib/libdspl-2.0
297 wiersze
11 KiB
C
297 wiersze
11 KiB
C
/*
|
||
* Copyright (c) 2015-2019 Sergey Bakhurin
|
||
* Digital Signal Processing Library [http://dsplib.org]
|
||
*
|
||
* This file is part of libdspl-2.0.
|
||
*
|
||
* is free software: you can redistribute it and/or modify
|
||
* it under the terms of the GNU Lesser General Public License as published by
|
||
* the Free Software Foundation, either version 3 of the License, or
|
||
* (at your option) any later version.
|
||
*
|
||
* DSPL 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 Lesser General Public License
|
||
* along with Foobar. If not, see <http://www.gnu.org/licenses/>.
|
||
*/
|
||
|
||
#include <stdlib.h>
|
||
#include <string.h>
|
||
#include "dspl.h"
|
||
|
||
|
||
#ifdef DOXYGEN_ENGLISH
|
||
/*! ****************************************************************************
|
||
\ingroup FILTER_CONV_GROUP
|
||
\fn int conv_fft_cmplx(complex_t* a, int na, complex_t* b, int nb,
|
||
fft_t* pfft, int nfft, complex_t* c)
|
||
\brief Complex vectors fast linear convolution by using fast Fourier
|
||
transform algorithms
|
||
|
||
Function convolves two complex vectors \f$ c = a * b\f$ length `na` and `nb`
|
||
in the frequency domain by using FFT algorithms. This approach provide
|
||
high-performance convolution which increases with `na` and `nb` increasing.
|
||
The output convolution is a vector `c` with length equal to `na + nb - 1`.
|
||
|
||
\param[in] a
|
||
Pointer to the first vector `a`. \n
|
||
Vector size is `[na x 1]`. \n \n
|
||
|
||
\param[in] na
|
||
Size of the first vector `a`. \n \n
|
||
|
||
\param[in] b
|
||
Pointer to the second vector `b`. \n
|
||
Vector size is `[nb x 1]`. \n \n
|
||
|
||
\param[in] nb
|
||
Size of the second vector `b`. \n \n
|
||
|
||
\param[in] pfft
|
||
Pointer to the structure `fft_t`. \n
|
||
Function changes `fft_t` structure fields so `fft_t` must
|
||
be clear before program returns. \n \n
|
||
|
||
\param[in] nfft
|
||
FFT size. \n
|
||
This parameter set which FFT size will be used
|
||
for overlapped frequency domain convolution. \n
|
||
FFT size must be more of minimal `na` and `nb` value.
|
||
For example if `na = 10`, `nb = 4` then `nfft` parameter must
|
||
be more than 4. \n
|
||
|
||
\param[out] c
|
||
Pointer to the convolution output vector \f$ c = a * b\f$. \n
|
||
Vector size is `[na + nb - 1 x 1]`. \n
|
||
Memory must be allocated. \n \n
|
||
|
||
\return `RES_OK` if convolution is calculated successfully. \n
|
||
Else \ref ERROR_CODE_GROUP "code error". \n \n
|
||
|
||
Example:
|
||
\include conv_fft_cmplx_test.c
|
||
|
||
Program output:
|
||
|
||
\verbatim
|
||
c[ 0] = -1.00 -0.00j d[ 0] = -1.00 +0.00j
|
||
c[ 1] = -6.00 +4.00j d[ 1] = -6.00 +4.00j
|
||
c[ 2] = -15.00 +20.00j d[ 2] = -15.00 +20.00j
|
||
c[ 3] = -28.00 +56.00j d[ 3] = -28.00 +56.00j
|
||
c[ 4] = -45.00 +120.00j d[ 4] = -45.00 +120.00j
|
||
c[ 5] = -55.00 +210.00j d[ 5] = -55.00 +210.00j
|
||
c[ 6] = -65.00 +300.00j d[ 6] = -65.00 +300.00j
|
||
c[ 7] = -75.00 +390.00j d[ 7] = -75.00 +390.00j
|
||
c[ 8] = -85.00 +480.00j d[ 8] = -85.00 +480.00j
|
||
c[ 9] = -95.00 +570.00j d[ 9] = -95.00 +570.00j
|
||
c[ 10] = -105.00 +660.00j d[ 10] = -105.00 +660.00j
|
||
c[ 11] = -115.00 +750.00j d[ 11] = -115.00 +750.00j
|
||
c[ 12] = -125.00 +840.00j d[ 12] = -125.00 +840.00j
|
||
c[ 13] = -135.00 +930.00j d[ 13] = -135.00 +930.00j
|
||
c[ 14] = -145.00 +1020.00j d[ 14] = -145.00 +1020.00j
|
||
c[ 15] = -124.00 +1080.00j d[ 15] = -124.00 +1080.00j
|
||
c[ 16] = -99.00 +1016.00j d[ 16] = -99.00 +1016.00j
|
||
c[ 17] = -70.00 +820.00j d[ 17] = -70.00 +820.00j
|
||
c[ 18] = -37.00 +484.00j d[ 18] = -37.00 +484.00j
|
||
\endverbatim
|
||
|
||
\author Sergey Bakhurin www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
#ifdef DOXYGEN_RUSSIAN
|
||
/*! ****************************************************************************
|
||
\ingroup FILTER_CONV_GROUP
|
||
\fn int conv_fft_cmplx(complex_t* a, int na, complex_t* b, int nb,
|
||
fft_t* pfft, complex_t* c)
|
||
\brief Линейная свертка двух комплексных векторов с использованием алгоритмов
|
||
быстрого преобразования Фурье
|
||
|
||
Функция рассчитывает линейную свертку двух векторов \f$ c = a * b\f$ используя
|
||
секционную обработку с перекрытием в частотной области. Это позволяет сократить
|
||
вычислительные операции при расчете длинных сверток.
|
||
|
||
\param[in] a
|
||
Указатель на первый вектор \f$a\f$. \n
|
||
Размер вектора `[na x 1]`. \n \n
|
||
|
||
\param[in] na
|
||
Размер первого вектора. \n \n
|
||
|
||
\param[in] b
|
||
Указатель на второй вектор \f$b\f$. \n
|
||
Размер вектора `[nb x 1]`. \n \n
|
||
|
||
\param[in] nb
|
||
Размер второго вектора. \n \n
|
||
|
||
\param[in] pfft
|
||
Указатель на структуру `fft_t` алгоритма
|
||
быстрого преобразования Фурье. \n
|
||
Функция изменит состояние полей структуры `fft_t`,
|
||
поэтому структура должна быть очищена перед выходом из
|
||
программы для исключения утечек памяти. \n
|
||
|
||
\param[in] nfft
|
||
Размер алгоритма БПФ который будет использован для расчета
|
||
секционной свертки с перекрытием. \n
|
||
Данный параметр должен быть больше чем минимальное значение
|
||
размеров сворачиваемых векторов. \n
|
||
Например если `na=10`, а `nb=4`, то параметр `nfft` должен быть больше 4. \n
|
||
Библиотека поддерживает алгоритмы БПФ составной длины
|
||
\f$n = n_0 \times n_1 \times n_2 \times \ldots \times n_p \times m\f$,
|
||
где \f$n_i = 2,3,5,7\f$, а \f$m \f$ --- произвольный простой множитель
|
||
не превосходящий 46340 (см. описание функции \ref fft_create).
|
||
Однако, максимальное быстродействие достигается при использовании длин равных
|
||
степени двойки.
|
||
|
||
\param[out] c
|
||
Указатель на вектор свертки \f$ c = a * b\f$. \n
|
||
Размер вектора `[na + nb - 1 x 1]`. \n
|
||
Память должна быть выделена. \n \n
|
||
|
||
\return
|
||
`RES_OK` если свертка рассчитана успешно. \n
|
||
В противном случае \ref ERROR_CODE_GROUP "код ошибки".
|
||
|
||
\note
|
||
Данная функция наиболее эффективна при вычислении длинных сверток.
|
||
|
||
Пример использования функции:
|
||
|
||
\include conv_fft_cmplx_test.c
|
||
|
||
Результат работы:
|
||
\verbatim
|
||
c[ 0] = -1.00 -0.00j d[ 0] = -1.00 +0.00j
|
||
c[ 1] = -6.00 +4.00j d[ 1] = -6.00 +4.00j
|
||
c[ 2] = -15.00 +20.00j d[ 2] = -15.00 +20.00j
|
||
c[ 3] = -28.00 +56.00j d[ 3] = -28.00 +56.00j
|
||
c[ 4] = -45.00 +120.00j d[ 4] = -45.00 +120.00j
|
||
c[ 5] = -55.00 +210.00j d[ 5] = -55.00 +210.00j
|
||
c[ 6] = -65.00 +300.00j d[ 6] = -65.00 +300.00j
|
||
c[ 7] = -75.00 +390.00j d[ 7] = -75.00 +390.00j
|
||
c[ 8] = -85.00 +480.00j d[ 8] = -85.00 +480.00j
|
||
c[ 9] = -95.00 +570.00j d[ 9] = -95.00 +570.00j
|
||
c[ 10] = -105.00 +660.00j d[ 10] = -105.00 +660.00j
|
||
c[ 11] = -115.00 +750.00j d[ 11] = -115.00 +750.00j
|
||
c[ 12] = -125.00 +840.00j d[ 12] = -125.00 +840.00j
|
||
c[ 13] = -135.00 +930.00j d[ 13] = -135.00 +930.00j
|
||
c[ 14] = -145.00 +1020.00j d[ 14] = -145.00 +1020.00j
|
||
c[ 15] = -124.00 +1080.00j d[ 15] = -124.00 +1080.00j
|
||
c[ 16] = -99.00 +1016.00j d[ 16] = -99.00 +1016.00j
|
||
c[ 17] = -70.00 +820.00j d[ 17] = -70.00 +820.00j
|
||
c[ 18] = -37.00 +484.00j d[ 18] = -37.00 +484.00j
|
||
\endverbatim
|
||
|
||
\author Бахурин Сергей. www.dsplib.org
|
||
***************************************************************************** */
|
||
#endif
|
||
int DSPL_API conv_fft_cmplx(complex_t* a, int na, complex_t* b, int nb,
|
||
fft_t* pfft, int nfft, complex_t* c)
|
||
{
|
||
|
||
int La, Lb, Lc, Nz, n, p0, p1, ind, err;
|
||
complex_t *pa, *pb;
|
||
complex_t *pt, *pA, *pB, *pC;
|
||
|
||
if(!a || !b || !c)
|
||
return ERROR_PTR;
|
||
if(na < 1 || nb < 1)
|
||
return ERROR_SIZE;
|
||
|
||
if(na >= nb)
|
||
{
|
||
La = na;
|
||
Lb = nb;
|
||
pa = a;
|
||
pb = b;
|
||
}
|
||
else
|
||
{
|
||
La = nb;
|
||
pa = b;
|
||
Lb = na;
|
||
pb = a;
|
||
}
|
||
|
||
Lc = La + Lb - 1;
|
||
Nz = nfft - Lb;
|
||
|
||
if(Nz <= 0)
|
||
return ERROR_FFT_SIZE;
|
||
|
||
pt = (complex_t*)malloc(nfft*sizeof(complex_t));
|
||
pB = (complex_t*)malloc(nfft*sizeof(complex_t));
|
||
pA = (complex_t*)malloc(nfft*sizeof(complex_t));
|
||
pC = (complex_t*)malloc(nfft*sizeof(complex_t));
|
||
|
||
memset(pt, 0, nfft*sizeof(complex_t));
|
||
memcpy(pt+Nz, pb, Lb*sizeof(complex_t));
|
||
|
||
err = fft_cmplx(pt, nfft, pfft, pB);
|
||
if(err != RES_OK)
|
||
goto exit_label;
|
||
|
||
p0 = -Lb;
|
||
p1 = p0 + nfft;
|
||
ind = 0;
|
||
while(ind < Lc)
|
||
{
|
||
if(p0 >=0)
|
||
{
|
||
if(p1 < La)
|
||
err = fft_cmplx(pa + p0, nfft, pfft, pA);
|
||
else
|
||
{
|
||
memset(pt, 0, nfft*sizeof(complex_t));
|
||
memcpy(pt, pa+p0, (nfft+La-p1)*sizeof(complex_t));
|
||
err = fft_cmplx(pt, nfft, pfft, pA);
|
||
}
|
||
}
|
||
else
|
||
{
|
||
memset(pt, 0, nfft*sizeof(complex_t));
|
||
if(p1 < La)
|
||
memcpy(pt - p0, pa, (nfft+p0)*sizeof(complex_t));
|
||
else
|
||
memcpy(pt - p0, pa, La * sizeof(complex_t));
|
||
err = fft_cmplx(pt, nfft, pfft, pA);
|
||
}
|
||
|
||
if(err != RES_OK)
|
||
goto exit_label;
|
||
|
||
for(n = 0; n < nfft; n++)
|
||
{
|
||
RE(pC[n]) = CMRE(pA[n], pB[n]);
|
||
IM(pC[n]) = CMIM(pA[n], pB[n]);
|
||
}
|
||
|
||
|
||
if(ind+nfft < Lc)
|
||
err = ifft_cmplx(pC, nfft, pfft, c+ind);
|
||
else
|
||
{
|
||
err = ifft_cmplx(pC, nfft, pfft, pt);
|
||
memcpy(c+ind, pt, (Lc-ind)*sizeof(complex_t));
|
||
}
|
||
if(err != RES_OK)
|
||
goto exit_label;
|
||
|
||
p0 += Nz;
|
||
p1 += Nz;
|
||
ind += Nz;
|
||
}
|
||
|
||
exit_label:
|
||
if(pt) free(pt);
|
||
if(pB) free(pB);
|
||
if(pA) free(pA);
|
||
if(pC) free(pC);
|
||
|
||
return err;
|
||
}
|