ref: ca5618deb1a747f3b46f6240a2b232e632c37b0e
dir: /tests/snr_bw_test.c/
/* ** Copyright (c) 2002-2016, Erik de Castro Lopo <[email protected]> ** 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