mirror of
https://gitee.com/openharmony/third_party_libsnd
synced 2024-11-27 03:50:29 +00:00
fc7a3bea72
Was incorrectly using `DFT_DATA_LENGTH` instead of `DFT_SPEC_LENGTH` to index into `spectrum` array.
150 lines
4.4 KiB
C
150 lines
4.4 KiB
C
/*
|
|
** Copyright (C) 2002-2015 Erik de Castro Lopo <erikd@mega-nerd.com>
|
|
**
|
|
** This program 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 2 of the License, or
|
|
** (at your option) any later version.
|
|
**
|
|
** This program 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
|
|
*/
|
|
|
|
#include <stdio.h>
|
|
#include <stdlib.h>
|
|
#include <math.h>
|
|
|
|
#include "dft_cmp.h"
|
|
#include "utils.h"
|
|
|
|
#ifndef M_PI
|
|
#define M_PI 3.14159265358979323846264338
|
|
#endif
|
|
|
|
#define DFT_SPEC_LENGTH (DFT_DATA_LENGTH / 2)
|
|
|
|
static void dft_magnitude (const double *data, double *spectrum) ;
|
|
static double calc_max_spectral_difference (const double *spec1, const double *spec2) ;
|
|
|
|
/*--------------------------------------------------------------------------------
|
|
** Public functions.
|
|
*/
|
|
|
|
double
|
|
dft_cmp_float (int linenum, const float *in_data, const float *test_data, int len, double target_snr, int allow_exit)
|
|
{ static double orig [DFT_DATA_LENGTH] ;
|
|
static double test [DFT_DATA_LENGTH] ;
|
|
unsigned k ;
|
|
|
|
if (len != DFT_DATA_LENGTH)
|
|
{ printf ("Error (line %d) : dft_cmp_float : Bad input array length.\n", linenum) ;
|
|
return 1 ;
|
|
} ;
|
|
|
|
for (k = 0 ; k < ARRAY_LEN (orig) ; k++)
|
|
{ test [k] = test_data [k] ;
|
|
orig [k] = in_data [k] ;
|
|
} ;
|
|
|
|
return dft_cmp_double (linenum, orig, test, len, target_snr, allow_exit) ;
|
|
} /* dft_cmp_float */
|
|
|
|
double
|
|
dft_cmp_double (int linenum, const double *orig, const double *test, int len, double target_snr, int allow_exit)
|
|
{ static double orig_spec [DFT_SPEC_LENGTH] ;
|
|
static double test_spec [DFT_SPEC_LENGTH] ;
|
|
double snr ;
|
|
|
|
if (! orig || ! test)
|
|
{ printf ("Error (line %d) : dft_cmp_double : Bad input arrays.\n", linenum) ;
|
|
return 1 ;
|
|
} ;
|
|
|
|
if (len != DFT_DATA_LENGTH)
|
|
{ printf ("Error (line %d) : dft_cmp_double : Bad input array length.\n", linenum) ;
|
|
return 1 ;
|
|
} ;
|
|
|
|
dft_magnitude (orig, orig_spec) ;
|
|
dft_magnitude (test, test_spec) ;
|
|
|
|
snr = calc_max_spectral_difference (orig_spec, test_spec) ;
|
|
|
|
if (snr > target_snr)
|
|
{ printf ("\n\nLine %d: Actual SNR (% 4.1f) > target SNR (% 4.1f).\n\n", linenum, snr, target_snr) ;
|
|
oct_save_double (orig, test, len) ;
|
|
if (allow_exit)
|
|
exit (1) ;
|
|
} ;
|
|
|
|
if (snr < -500.0)
|
|
snr = -500.0 ;
|
|
|
|
return snr ;
|
|
} /* dft_cmp_double */
|
|
|
|
/*--------------------------------------------------------------------------------
|
|
** Quick dirty calculation of magnitude spectrum for real valued data using
|
|
** Discrete Fourier Transform. Since the data is real, the DFT is only
|
|
** calculated for positive frequencies.
|
|
*/
|
|
|
|
static void
|
|
dft_magnitude (const double *data, double *spectrum)
|
|
{ static double cos_angle [DFT_DATA_LENGTH] = { 0.0 } ;
|
|
static double sin_angle [DFT_DATA_LENGTH] ;
|
|
|
|
double real_part, imag_part ;
|
|
int k, n ;
|
|
|
|
/* If sine and cosine tables haven't been initialised, do so. */
|
|
if (cos_angle [0] == 0.0)
|
|
for (n = 0 ; n < DFT_DATA_LENGTH ; n++)
|
|
{ cos_angle [n] = cos (2.0 * M_PI * n / DFT_DATA_LENGTH) ;
|
|
sin_angle [n] = -1.0 * sin (2.0 * M_PI * n / DFT_DATA_LENGTH) ;
|
|
} ;
|
|
|
|
/* DFT proper. Since the data is real, only generate a half spectrum. */
|
|
for (k = 1 ; k < DFT_SPEC_LENGTH ; k++)
|
|
{ real_part = 0.0 ;
|
|
imag_part = 0.0 ;
|
|
|
|
for (n = 0 ; n < DFT_DATA_LENGTH ; n++)
|
|
{ real_part += data [n] * cos_angle [(k * n) % DFT_DATA_LENGTH] ;
|
|
imag_part += data [n] * sin_angle [(k * n) % DFT_DATA_LENGTH] ;
|
|
} ;
|
|
|
|
spectrum [k] = sqrt (real_part * real_part + imag_part * imag_part) ;
|
|
} ;
|
|
|
|
spectrum [DFT_SPEC_LENGTH - 1] = 0.0 ;
|
|
|
|
spectrum [0] = spectrum [1] = spectrum [2] = 0.0 ;
|
|
|
|
return ;
|
|
} /* dft_magnitude */
|
|
|
|
static double
|
|
calc_max_spectral_difference (const double *orig, const double *test)
|
|
{ double orig_max = 0.0, max_diff = 0.0 ;
|
|
int k ;
|
|
|
|
for (k = 0 ; k < DFT_SPEC_LENGTH ; k++)
|
|
{ if (orig_max < orig [k])
|
|
orig_max = orig [k] ;
|
|
if (max_diff < fabs (orig [k] - test [k]))
|
|
max_diff = fabs (orig [k] - test [k]) ;
|
|
} ;
|
|
|
|
if (max_diff < 1e-25)
|
|
return -500.0 ;
|
|
|
|
return 20.0 * log10 (max_diff / orig_max) ;
|
|
} /* calc_max_spectral_difference */
|