audiostuff: spandsp-0.0.3/spandsp-0.0.3/tests/noise

comparison spandsp-0.0.3/spandsp-0.0.3/tests/noise_tests.c @ 5:f762bf195c4b

import spandsp-0.0.3

author	Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date	Fri, 25 Jun 2010 16:00:21 +0200
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-:26cd8f1ef0b1
+:f762bf195c4b
+/*
+* SpanDSP - a series of DSP components for telephony
+*
+* noise_tests.c
+*
+* Written by Steve Underwood <steveu@coppice.org>
+*
+* Copyright (C) 2005 Steve Underwood
+*
+* All rights reserved.
+*
+* This program is free software; you can redistribute it and/or modify
+* it under the terms of the GNU General Public License version 2, as
+* published by the Free Software Foundation.
+*
+* 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+*
+* $Id: noise_tests.c,v 1.9 2006/11/19 14:07:27 steveu Exp $
+*/
+/*! \page noise_tests_page Noise generator tests
+\section noise_tests_page_sec_1 What does it do?
+*/
+#ifdef HAVE_CONFIG_H
+#include "config.h"
+#endif
+#include <stdio.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+#include <audiofile.h>
+#include <tiffio.h>
+#include "spandsp.h"
+#if !defined(M_PI)
+# define M_PI           3.14159265358979323846  /* pi */
+#endif
+#define OUT_FILE_NAME   "noise.wav"
+/* Some simple sanity tests for the noise generation routines */
+int main (int argc, char *argv[])
+{
+int i;
+int j;
+int level;
+int clip_high;
+int clip_low;
+int total_samples;
+int seed = 1234567;
+int outframes;
+int16_t value;
+double total;
+double x;
+double p;
+double o;
+int bins[65536];
+int16_t amp[1024];
+noise_state_t noise_source;
+AFfilehandle outhandle;
+AFfilesetup filesetup;
+if ((filesetup = afNewFileSetup()) == AF_NULL_FILESETUP)
+{
+fprintf(stderr, "    Failed to create file setup\n");
+exit(2);
+}
+afInitSampleFormat(filesetup, AF_DEFAULT_TRACK, AF_SAMPFMT_TWOSCOMP, 16);
+afInitRate(filesetup, AF_DEFAULT_TRACK, (float) SAMPLE_RATE);
+afInitFileFormat(filesetup, AF_FILE_WAVE);
+afInitChannels(filesetup, AF_DEFAULT_TRACK, 1);
+if ((outhandle = afOpenFile(OUT_FILE_NAME, "w", filesetup)) == AF_NULL_FILEHANDLE)
+{
+fprintf(stderr, "    Cannot create wave file '%s'\n", OUT_FILE_NAME);
+exit(2);
+}
+/* Generate AWGN at several RMS levels between -50dBOv and 0dBOv. Noise is
+generated for a large number of samples (1,000,000), and the RMS value
+of the noise is calculated along the way. If the resulting level is
+close to the requested RMS level, at least the scaling of the noise
+should be Ok. At high levels some clipping may distort the result a
+little. */
+printf("Testing with quality 7 AWGN\n");
+for (level = -50;  level <= 0;  level += 5)
+{
+clip_high = 0;
+clip_low = 0;
+total = 0.0;
+noise_init_dbov(&noise_source, seed, (float) level, NOISE_CLASS_AWGN, 7);
+total_samples = 1000000;
+for (i = 0;  i < total_samples;  i++)
+{
+value = noise(&noise_source);
+if (value == 32767)
+clip_high++;
+else if (value == -32768)
+clip_low++;
+total += ((double) value)*((double) value);
+}
+printf ("RMS = %.3f (expected %d) %.2f%% error [clipped samples %d+%d]\n",
+log10(sqrt(total/total_samples)/32768.0)*20.0,
+level,
+100.0*(1.0 - sqrt(total/total_samples)/(pow(10.0, level/20.0)*32768.0)),
+clip_low,
+clip_high);
+if (level < -5  &&  fabs(log10(sqrt(total/total_samples)/32768.0)*20.0 - level) > 0.2)
+{
+printf("Test failed\n");
+exit(2);
+}
+}
+printf("Testing with quality 20 AWGN\n");
+for (level = -50;  level <= 0;  level += 5)
+{
+clip_high = 0;
+clip_low = 0;
+total = 0.0;
+noise_init_dbov(&noise_source, seed, (float) level, NOISE_CLASS_AWGN, 20);
+total_samples = 1000000;
+for (i = 0;  i < total_samples;  i++)
+{
+value = noise(&noise_source);
+if (value == 32767)
+clip_high++;
+else if (value == -32768)
+clip_low++;
+total += ((double) value)*((double) value);
+}
+printf ("RMS = %.3f (expected %d) %.2f%% error [clipped samples %d+%d]\n",
+log10(sqrt(total/total_samples)/32768.0)*20.0,
+level,
+100.0*(1.0 - sqrt(total/total_samples)/(pow(10.0, level/20.0)*32768.0)),
+clip_low,
+clip_high);
+if (level < -5  &&  fabs(log10(sqrt(total/total_samples)/32768.0)*20.0 - level) > 0.2)
+{
+printf("Test failed\n");
+exit(2);
+}
+}
+/* Now look at the statistical spread of the results, by collecting data in
+bins from a large number of samples. Use a fairly high noise level, but
+low enough to avoid significant clipping. Use the Gaussian model to
+predict the real probability, and present the results for graphing. */
+memset(bins, 0, sizeof(bins));
+clip_high = 0;
+clip_low = 0;
+level = -15;
+noise_init_dbov(&noise_source, seed, (float) level, NOISE_CLASS_AWGN, 7);
+total_samples = 10000000;
+for (i = 0;  i < total_samples;  i++)
+{
+value = noise(&noise_source);
+if (value == 32767)
+clip_high++;
+else if (value == -32768)
+clip_low++;
+bins[value + 32768]++;
+}
+/* Find the RMS power level to expect */
+o = pow(10.0, level/20.0)*(32768.0*0.70711);
+for (i = 0;  i < 65536 - 10;  i++)
+{
+x = i - 32768;
+/* Find the real probability for this bin */
+p = (1.0/(o*sqrt(2.0*M_PI)))*exp(-(x*x)/(2.0*o*o));
+/* Now do a little smoothing on the real data to get a reasonably
+steady answer */
+x = 0;
+for (j = 0;  j < 10;  j++)
+x += bins[i + j];
+x /= 10.0;
+x /= total_samples;
+/* Now send it out for graphing. */
+if (p > 0.0000001)
+printf("%6d %.7f %.7f\n", i - 32768, x, p);
+}
+printf("Generating AWGN at -15dBOv to file\n");
+for (j = 0;  j < 50;  j++)
+{
+for (i = 0;  i < 1024;  i++)
+amp[i] = noise(&noise_source);
+outframes = afWriteFrames(outhandle,
+AF_DEFAULT_TRACK,
+amp,
+1024);
+if (outframes != 1024)
+{
+fprintf(stderr, "    Error writing wave file\n");
+exit(2);
+}
+}
+/* Generate AWGN at several RMS levels between -50dBm and 0dBm. Noise is
+generated for a large number of samples (1,000,000), and the RMS value
+of the noise is calculated along the way. If the resulting level is
+close to the requested RMS level, at least the scaling of the noise
+should be Ok. At high levels some clipping may distort the result a
+little. */
+printf("Testing with quality 7 Hoth noise.\n");
+for (level = -50;  level <= 0;  level += 5)
+{
+clip_high = 0;
+clip_low = 0;
+total = 0.0;
+noise_init_dbov(&noise_source, seed, (float) level, NOISE_CLASS_HOTH, 7);
+total_samples = 1000000;
+for (i = 0;  i < total_samples;  i++)
+{
+value = noise(&noise_source);
+if (value == 32767)
+clip_high++;
+else if (value == -32768)
+clip_low++;
+total += ((double) value)*((double) value);
+}
+printf ("RMS = %.3f (expected %d) %.2f%% error [clipped samples %d+%d]\n",
+log10(sqrt(total/total_samples)/32768.0)*20.0,
+level,
+100.0*(1.0 - sqrt(total/total_samples)/(pow(10.0, level/20.0)*32768.0)),
+clip_low,
+clip_high);
+if (level < -5  &&  fabs(log10(sqrt(total/total_samples)/32768.0)*20.0 - level) > 0.2)
+{
+printf("Test failed\n");
+exit(2);
+}
+}
+printf("Generating Hoth noise at -15dBOv to file\n");
+level = -15;
+noise_init_dbov(&noise_source, seed, (float) level, NOISE_CLASS_HOTH, 7);
+for (j = 0;  j < 50;  j++)
+{
+for (i = 0;  i < 1024;  i++)
+amp[i] = noise(&noise_source);
+outframes = afWriteFrames(outhandle,
+AF_DEFAULT_TRACK,
+amp,
+1024);
+if (outframes != 1024)
+{
+fprintf(stderr, "    Error writing wave file\n");
+exit(2);
+}
+}
+if (afCloseFile(outhandle))
+{
+fprintf(stderr, "    Cannot close wave file '%s'\n", OUT_FILE_NAME);
+exit(2);
+}
+afFreeFileSetup(filesetup);
+printf("Tests passed.\n");
+return  0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/

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comparison spandsp-0.0.3/spandsp-0.0.3/tests/noise_tests.c @ 5:f762bf195c4b