ref: 06a021bb7ab5a85975a6e27b7cc5255768df3666
dir: libsamplerate/tests/snr_bw_test.c
/*
** Copyright (c) 2002-2016, Erik de Castro Lopo <erikd@mega-nerd.com>
** All rights reserved.
**
** This code is released under 2-clause BSD license. Please see the
** file at : https://github.com/libsndfile/libsamplerate/blob/master/COPYING
*/
#include "src_config.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <time.h>
#if (HAVE_FFTW3)
#include <fftw3.h>
#include <samplerate.h>
#include "util.h"
#define BUFFER_LEN 50000
#define MAX_FREQS 4
#define MAX_RATIOS 6
#define MAX_SPEC_LEN (1<<15)
#ifndef M_PI
#define M_PI 3.14159265358979323846264338
#endif
enum
{ BOOLEAN_FALSE = 0,
BOOLEAN_TRUE = 1
} ;
typedef struct
{ int freq_count ;
double freqs [MAX_FREQS] ;
double src_ratio ;
int pass_band_peaks ;
double snr ;
double peak_value ;
} SINGLE_TEST ;
typedef struct
{ int converter ;
int tests ;
int do_bandwidth_test ;
SINGLE_TEST test_data [10] ;
} CONVERTER_TEST ;
static double snr_test (SINGLE_TEST *snr_test_data, int number, int converter, int verbose) ;
static double find_peak (float *output, int output_len) ;
static double bandwidth_test (int converter, int verbose) ;
int
main (int argc, char *argv [])
{ CONVERTER_TEST snr_test_data [] =
{
{ SRC_ZERO_ORDER_HOLD,
8,
BOOLEAN_FALSE,
{ { 1, { 0.01111111111 }, 3.0, 1, 28.0, 1.0 },
{ 1, { 0.01111111111 }, 0.6, 1, 36.0, 1.0 },
{ 1, { 0.01111111111 }, 0.3, 1, 36.0, 1.0 },
{ 1, { 0.01111111111 }, 1.0, 1, 150.0, 1.0 },
{ 1, { 0.01111111111 }, 1.001, 1, 38.0, 1.0 },
{ 2, { 0.011111, 0.324 }, 1.9999, 2, 14.0, 1.0 },
{ 2, { 0.012345, 0.457 }, 0.456789, 1, 12.0, 1.0 },
{ 1, { 0.3511111111 }, 1.33, 1, 10.0, 1.0 }
}
},
{ SRC_LINEAR,
8,
BOOLEAN_FALSE,
{ { 1, { 0.01111111111 }, 3.0, 1, 73.0, 1.0 },
{ 1, { 0.01111111111 }, 0.6, 1, 73.0, 1.0 },
{ 1, { 0.01111111111 }, 0.3, 1, 73.0, 1.0 },
{ 1, { 0.01111111111 }, 1.0, 1, 150.0, 1.0 },
{ 1, { 0.01111111111 }, 1.001, 1, 77.0, 1.0 },
{ 2, { 0.011111, 0.324 }, 1.9999, 2, 15.0, 0.94 },
{ 2, { 0.012345, 0.457 }, 0.456789, 1, 25.0, 0.96 },
{ 1, { 0.3511111111 }, 1.33, 1, 22.0, 0.99 }
}
},
{ SRC_SINC_FASTEST,
9,
BOOLEAN_TRUE,
{ { 1, { 0.01111111111 }, 3.0, 1, 100.0, 1.0 },
{ 1, { 0.01111111111 }, 0.6, 1, 99.0, 1.0 },
{ 1, { 0.01111111111 }, 0.3, 1, 100.0, 1.0 },
{ 1, { 0.01111111111 }, 1.0, 1, 150.0, 1.0 },
{ 1, { 0.01111111111 }, 1.001, 1, 100.0, 1.0 },
{ 2, { 0.011111, 0.324 }, 1.9999, 2, 97.0, 1.0 },
{ 2, { 0.012345, 0.457 }, 0.456789, 1, 100.0, 0.5 },
{ 2, { 0.011111, 0.45 }, 0.6, 1, 97.0, 0.5 },
{ 1, { 0.3511111111 }, 1.33, 1, 97.0, 1.0 }
}
},
{ SRC_SINC_MEDIUM_QUALITY,
9,
BOOLEAN_TRUE,
{ { 1, { 0.01111111111 }, 3.0, 1, 145.0, 1.0 },
{ 1, { 0.01111111111 }, 0.6, 1, 132.0, 1.0 },
{ 1, { 0.01111111111 }, 0.3, 1, 138.0, 1.0 },
{ 1, { 0.01111111111 }, 1.0, 1, 157.0, 1.0 },
{ 1, { 0.01111111111 }, 1.001, 1, 148.0, 1.0 },
{ 2, { 0.011111, 0.324 }, 1.9999, 2, 127.0, 1.0 },
{ 2, { 0.012345, 0.457 }, 0.456789, 1, 123.0, 0.5 },
{ 2, { 0.011111, 0.45 }, 0.6, 1, 126.0, 0.5 },
{ 1, { 0.43111111111 }, 1.33, 1, 121.0, 1.0 }
}
},
{ SRC_SINC_BEST_QUALITY,
9,
BOOLEAN_TRUE,
{ { 1, { 0.01111111111 }, 3.0, 1, 147.0, 1.0 },
{ 1, { 0.01111111111 }, 0.6, 1, 147.0, 1.0 },
{ 1, { 0.01111111111 }, 0.3, 1, 148.0, 1.0 },
{ 1, { 0.01111111111 }, 1.0, 1, 155.0, 1.0 },
{ 1, { 0.01111111111 }, 1.001, 1, 148.0, 1.0 },
{ 2, { 0.011111, 0.324 }, 1.9999, 2, 146.0, 1.0 },
{ 2, { 0.012345, 0.457 }, 0.456789, 1, 147.0, 0.5 },
{ 2, { 0.011111, 0.45 }, 0.6, 1, 144.0, 0.5 },
{ 1, { 0.43111111111 }, 1.33, 1, 145.0, 1.0 }
}
},
} ; /* snr_test_data */
double best_snr, snr, freq3dB ;
int j, k, converter, verbose = 0 ;
if (argc == 2 && strcmp (argv [1], "--verbose") == 0)
verbose = 1 ;
puts ("") ;
for (j = 0 ; j < ARRAY_LEN (snr_test_data) ; j++)
{ best_snr = 5000.0 ;
converter = snr_test_data [j].converter ;
printf (" Converter %d : %s\n", converter, src_get_name (converter)) ;
printf (" %s\n", src_get_description (converter)) ;
for (k = 0 ; k < snr_test_data [j].tests ; k++)
{ snr = snr_test (&(snr_test_data [j].test_data [k]), k, converter, verbose) ;
if (best_snr > snr)
best_snr = snr ;
} ;
printf (" Worst case Signal-to-Noise Ratio : %.2f dB.\n", best_snr) ;
if (snr_test_data [j].do_bandwidth_test == BOOLEAN_FALSE)
{ puts (" Bandwith test not performed on this converter.\n") ;
continue ;
}
freq3dB = bandwidth_test (converter, verbose) ;
printf (" Measured -3dB rolloff point : %5.2f %%.\n\n", freq3dB) ;
} ;
fftw_cleanup () ;
return 0 ;
} /* main */
/*==============================================================================
*/
static double
snr_test (SINGLE_TEST *test_data, int number, int converter, int verbose)
{ static float data [BUFFER_LEN + 1] ;
static float output [MAX_SPEC_LEN] ;
SRC_STATE *src_state ;
SRC_DATA src_data ;
double output_peak, snr ;
int k, output_len, input_len, error ;
if (verbose != 0)
{ printf ("\tSignal-to-Noise Ratio Test %d.\n"
"\t=====================================\n", number) ;
printf ("\tFrequencies : [ ") ;
for (k = 0 ; k < test_data->freq_count ; k++)
printf ("%6.4f ", test_data->freqs [k]) ;
printf ("]\n\tSRC Ratio : %8.4f\n", test_data->src_ratio) ;
}
else
{ printf ("\tSignal-to-Noise Ratio Test %d : ", number) ;
fflush (stdout) ;
} ;
/* Set up the output array. */
if (test_data->src_ratio >= 1.0)
{ output_len = MAX_SPEC_LEN ;
input_len = (int) ceil (MAX_SPEC_LEN / test_data->src_ratio) ;
if (input_len > BUFFER_LEN)
input_len = BUFFER_LEN ;
}
else
{ input_len = BUFFER_LEN ;
output_len = (int) ceil (BUFFER_LEN * test_data->src_ratio) ;
output_len &= ((~0u) << 4) ;
if (output_len > MAX_SPEC_LEN)
output_len = MAX_SPEC_LEN ;
input_len = (int) ceil (output_len / test_data->src_ratio) ;
} ;
memset (output, 0, sizeof (output)) ;
/* Generate input data array. */
gen_windowed_sines (test_data->freq_count, test_data->freqs, 1.0, data, input_len) ;
/* Perform sample rate conversion. */
if ((src_state = src_new (converter, 1, &error)) == NULL)
{ printf ("\n\nLine %d : src_new() failed : %s.\n\n", __LINE__, src_strerror (error)) ;
exit (1) ;
} ;
src_data.end_of_input = 1 ; /* Only one buffer worth of input. */
src_data.data_in = data ;
src_data.input_frames = input_len ;
src_data.src_ratio = test_data->src_ratio ;
src_data.data_out = output ;
src_data.output_frames = output_len ;
if ((error = src_process (src_state, &src_data)))
{ printf ("\n\nLine %d : %s\n\n", __LINE__, src_strerror (error)) ;
exit (1) ;
} ;
src_state = src_delete (src_state) ;
if (verbose != 0)
printf ("\tOutput Len : %ld\n", src_data.output_frames_gen) ;
if (abs ((int) (src_data.output_frames_gen - output_len)) > 4)
{ printf ("\n\nLine %d : output data length should be %d.\n\n", __LINE__, output_len) ;
exit (1) ;
} ;
/* Check output peak. */
output_peak = find_peak (output, src_data.output_frames_gen) ;
if (verbose != 0)
printf ("\tOutput Peak : %6.4f\n", output_peak) ;
if (fabs (output_peak - test_data->peak_value) > 0.01)
{ printf ("\n\nLine %d : output peak (%6.4f) should be %6.4f\n\n", __LINE__, output_peak, test_data->peak_value) ;
save_oct_float ("snr_test.dat", data, BUFFER_LEN, output, output_len) ;
exit (1) ;
} ;
/* Calculate signal-to-noise ratio. */
snr = calculate_snr (output, src_data.output_frames_gen, test_data->pass_band_peaks) ;
if (snr < 0.0)
{ /* An error occurred. */
save_oct_float ("snr_test.dat", data, BUFFER_LEN, output, src_data.output_frames_gen) ;
exit (1) ;
} ;
if (verbose != 0)
printf ("\tSNR Ratio : %.2f dB\n", snr) ;
if (snr < test_data->snr)
{ printf ("\n\nLine %d : SNR (%5.2f) should be > %6.2f dB\n\n", __LINE__, snr, test_data->snr) ;
exit (1) ;
} ;
if (verbose != 0)
puts ("\t-------------------------------------\n\tPass\n") ;
else
puts ("Pass") ;
return snr ;
} /* snr_test */
static double
find_peak (float *data, int len)
{ double peak = 0.0 ;
int k = 0 ;
for (k = 0 ; k < len ; k++)
if (fabs (data [k]) > peak)
peak = fabs (data [k]) ;
return peak ;
} /* find_peak */
static double
find_attenuation (double freq, int converter, int verbose)
{ static float input [BUFFER_LEN] ;
static float output [2 * BUFFER_LEN] ;
SRC_DATA src_data ;
double output_peak ;
int error ;
gen_windowed_sines (1, &freq, 1.0, input, BUFFER_LEN) ;
src_data.end_of_input = 1 ; /* Only one buffer worth of input. */
src_data.data_in = input ;
src_data.input_frames = BUFFER_LEN ;
src_data.src_ratio = 1.999 ;
src_data.data_out = output ;
src_data.output_frames = ARRAY_LEN (output) ;
if ((error = src_simple (&src_data, converter, 1)))
{ printf ("\n\nLine %d : %s\n\n", __LINE__, src_strerror (error)) ;
exit (1) ;
} ;
output_peak = find_peak (output, ARRAY_LEN (output)) ;
if (verbose)
printf ("\tFreq : %6f InPeak : %6f OutPeak : %6f Atten : %6.2f dB\n",
freq, 1.0, output_peak, 20.0 * log10 (1.0 / output_peak)) ;
return 20.0 * log10 (1.0 / output_peak) ;
} /* find_attenuation */
static double
bandwidth_test (int converter, int verbose)
{ double f1, f2, a1, a2 ;
double freq, atten ;
f1 = 0.35 ;
a1 = find_attenuation (f1, converter, verbose) ;
f2 = 0.495 ;
a2 = find_attenuation (f2, converter, verbose) ;
if (a1 > 3.0 || a2 < 3.0)
{ printf ("\n\nLine %d : cannot bracket 3dB point.\n\n", __LINE__) ;
exit (1) ;
} ;
while (a2 - a1 > 1.0)
{ freq = f1 + 0.5 * (f2 - f1) ;
atten = find_attenuation (freq, converter, verbose) ;
if (atten < 3.0)
{ f1 = freq ;
a1 = atten ;
}
else
{ f2 = freq ;
a2 = atten ;
} ;
} ;
freq = f1 + (3.0 - a1) * (f2 - f1) / (a2 - a1) ;
return 200.0 * freq ;
} /* bandwidth_test */
#else /* (HAVE_FFTW3) == 0 */
/* Alternative main function when librfftw is not available. */
int
main (void)
{ puts ("\n"
"****************************************************************\n"
" This test cannot be run without FFTW (http://www.fftw.org/).\n"
" Both the real and the complex versions of the library are\n"
" required.") ;
puts ("****************************************************************\n") ;
return 0 ;
} /* main */
#endif