ref: d9a4973b8eba02cca15eb5852ef4e3293ab57dea
parent: 96ad78fad9e887c9dd91af6ec7a7b47af2b60d67
author: Erik de Castro Lopo <erikd@mega-nerd.com>
date: Sun Feb 22 07:22:57 EST 2004
Prepare for ussing KISS FFT.
--- a/tests/calc_snr.c
+++ b/tests/calc_snr.c
@@ -26,10 +26,6 @@
#include <string.h>
#include <math.h>
-#if (HAVE_FFTW3 == 1)
-
-#include <fftw3.h>
-
#define MAX_SPEC_LEN (1<<18)
#define MAX_PEAKS 10
@@ -75,109 +71,6 @@
return snr ;
} /* calculate_snr */
-
-
-
-/*-
-
-The analogues to
-
- rfftw_create_plan
- rfftw_one
-
-with
-
- FFTW_REAL_TO_COMPLEX
- FFTW_COMPLEX_TO_REAL
-
-directions are
-
- fftw_plan_r2r_1d
-
-with kind
-
- FFTW_R2HC or
- FFTW_HC2R
-
-followed by fftw_execute. The stride etcetera arguments of
-rfftw are now in fftw_plan_many_r2r.
-
-Instead of
-
- rfftwnd_create_plan or
- rfftw2d_create_plan or
- rfftw3d_create_plan
-
-followed by
-
- rfftwnd_one_real_to_complex or
- rfftwnd_one_complex_to_real
-
-you now use
-
- fftw_plan_dft_r2c or
- fftw_plan_dft_r2c_2d or
- fftw_plan_dft_r2c_3d or
- fftw_plan_dft_c2r or
- fftw_plan_dft_c2r_2d or
- fftw_plan_dft_c2r_3d
-
-respectively, followed by fftw_execute. As usual, the
-strides etcetera of
-
- rfftwnd_real_to_complex or
- rfftwnd_complex_to_real
-
-are no specified in the advanced planner routines,
-
- fftw_plan_many_dft_r2c or
- fftw_plan_many_dft_c2r
-
-
--*/
-
-
-
-
-static void
-log_mag_spectrum (double *input, int len, double *magnitude)
-{ fftw_plan plan = NULL ;-
- double maxval ;
- int k ;
-
- if (input == NULL || magnitude == NULL)
- return ;
-
- plan = fftw_plan_r2r_1d (len, input, magnitude, FFTW_R2HC, FFTW_ESTIMATE | FFTW_PRESERVE_INPUT) ;
- if (plan == NULL)
- { printf ("%s : line %d : create plan failed.\n", __FILE__, __LINE__) ;- exit (1) ;
- } ;
-
- fftw_execute (plan) ;
-
- /* (k < N/2 rounded up) */
- maxval = 0.0 ;
- for (k = 1 ; k < len / 2 ; k++)
- { magnitude [k] = sqrt (magnitude [k] * magnitude [k] + magnitude [len - k - 1] * magnitude [len - k - 1]) ;- maxval = (maxval < magnitude [k]) ? magnitude [k] : maxval ;
- } ;
-
- memset (magnitude + len / 2, 0, len / 2 * sizeof (magnitude [0])) ;
-
- /* Don't care about DC component. Make it zero. */
- magnitude [0] = 0.0 ;
-
- /* log magnitude. */
- for (k = 0 ; k < len ; k++)
- { magnitude [k] = magnitude [k] / maxval ;- magnitude [k] = (magnitude [k] < 1e-15) ? -200.0 : 20.0 * log10 (magnitude [k]) ;
- } ;
-
- return ;
-} /* log_mag_spectrum */
-
/*==============================================================================
** There is a slight problem with trying to measure SNR with the method used
** here; the side lobes of the windowed FFT can look like a noise/aliasing peak.
@@ -290,18 +183,95 @@
return snr ;
} /* find_snr */
+/*==============================================================================
+*/
+
+#if (HAVE_FFTW3 == 1)
+
+#include <fftw3.h>
+
+static void
+log_mag_spectrum (double *input, int len, double *magnitude)
+{ fftw_plan plan = NULL ;+
+ double maxval ;
+ int k ;
+
+ if (input == NULL || magnitude == NULL)
+ return ;
+
+ plan = fftw_plan_r2r_1d (len, input, magnitude, FFTW_R2HC, FFTW_ESTIMATE | FFTW_PRESERVE_INPUT) ;
+ if (plan == NULL)
+ { printf ("%s : line %d : create plan failed.\n", __FILE__, __LINE__) ;+ exit (1) ;
+ } ;
+
+ fftw_execute (plan) ;
+
+ /* (k < N/2 rounded up) */
+ maxval = 0.0 ;
+ for (k = 1 ; k < len / 2 ; k++)
+ { magnitude [k] = sqrt (magnitude [k] * magnitude [k] + magnitude [len - k - 1] * magnitude [len - k - 1]) ;+ maxval = (maxval < magnitude [k]) ? magnitude [k] : maxval ;
+ } ;
+
+ memset (magnitude + len / 2, 0, len / 2 * sizeof (magnitude [0])) ;
+
+ /* Don't care about DC component. Make it zero. */
+ magnitude [0] = 0.0 ;
+
+ /* log magnitude. */
+ for (k = 0 ; k < len ; k++)
+ { magnitude [k] = magnitude [k] / maxval ;+ magnitude [k] = (magnitude [k] < 1e-15) ? -200.0 : 20.0 * log10 (magnitude [k]) ;
+ } ;
+
+ return ;
+} /* log_mag_spectrum */
+
#else /* (! HAVE_FFTW3) */
-double
-calculate_snr (float *data, int len)
-{ double snr = 200.0 ;+#include "kiss_fft.h"
- data = data ;
- len = len ;
+static void
+log_mag_spectrum (double *input, int len, double *magnitude)
+{ fftw_plan plan = NULL ;- return snr ;
-} /* calculate_snr */
+ double maxval ;
+ int k ;
+ if (input == NULL || magnitude == NULL)
+ return ;
+
+ plan = fftw_plan_r2r_1d (len, input, magnitude, FFTW_R2HC, FFTW_ESTIMATE | FFTW_PRESERVE_INPUT) ;
+ if (plan == NULL)
+ { printf ("%s : line %d : create plan failed.\n", __FILE__, __LINE__) ;+ exit (1) ;
+ } ;
+
+ fftw_execute (plan) ;
+
+ /* (k < N/2 rounded up) */
+ maxval = 0.0 ;
+ for (k = 1 ; k < len / 2 ; k++)
+ { magnitude [k] = sqrt (magnitude [k] * magnitude [k] + magnitude [len - k - 1] * magnitude [len - k - 1]) ;+ maxval = (maxval < magnitude [k]) ? magnitude [k] : maxval ;
+ } ;
+
+ memset (magnitude + len / 2, 0, len / 2 * sizeof (magnitude [0])) ;
+
+ /* Don't care about DC component. Make it zero. */
+ magnitude [0] = 0.0 ;
+
+ /* log magnitude. */
+ for (k = 0 ; k < len ; k++)
+ { magnitude [k] = magnitude [k] / maxval ;+ magnitude [k] = (magnitude [k] < 1e-15) ? -200.0 : 20.0 * log10 (magnitude [k]) ;
+ } ;
+
+ return ;
+} /* log_mag_spectrum */
+
#endif
/*
@@ -311,4 +281,3 @@
**
** arch-tag: 7ae937c5-53a5-45d8-8aa2-793de9c35f0a
*/
-