freeswitch/libs/spandsp/tests/dc_restore_tests.c
2012-03-28 21:43:13 +08:00

96 lines
2.7 KiB
C

/*
* SpanDSP - a series of DSP components for telephony
*
* dc_restore_tests.c - Tests for the dc_restore functions.
*
* Written by Steve Underwood <steveu@coppice.org>
*
* Copyright (C) 2001 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.
*/
/*! \page dc_restore_tests_page DC restoration tests
\section dc_restore_tests_page_sec_1 What does it do?
*/
#if defined(HAVE_CONFIG_H)
#include "config.h"
#endif
#include <stdlib.h>
#include <stdio.h>
#include <memory.h>
#include <time.h>
//#if defined(WITH_SPANDSP_INTERNALS)
#define SPANDSP_EXPOSE_INTERNAL_STRUCTURES
//#endif
#include "spandsp.h"
int main (int argc, char *argv[])
{
awgn_state_t noise_source;
dc_restore_state_t dc_state;
int i;
int idum = 1234567;
int16_t dirty;
int estimate;
int min;
int max;
int dc_offset;
dc_offset = 5000;
awgn_init_dbm0(&noise_source, idum, -10.0);
dc_restore_init(&dc_state);
for (i = 0; i < 100000; i++)
{
dirty = awgn(&noise_source) + dc_offset;
dc_restore(&dc_state, dirty);
if ((i % 1000) == 0)
{
printf("Sample %6d: %d (expect %d)\n",
i,
dc_restore_estimate(&dc_state),
dc_offset);
}
}
/* We should have settled by now. Look at the variation we get */
min = 99999;
max = -99999;
for (i = 0; i < 100000; i++)
{
dirty = awgn(&noise_source) + dc_offset;
dc_restore(&dc_state, dirty);
estimate = dc_restore_estimate(&dc_state);
if (estimate < min)
min = estimate;
if (estimate > max)
max = estimate;
}
printf("Spread of DC estimate for an offset of %d was %d to %d\n", dc_offset, min, max);
if (min < dc_offset - 50 || max > dc_offset + 50)
{
printf("Test failed.\n");
exit(2);
}
printf("Test passed.\n");
return 0;
}
/*- End of function --------------------------------------------------------*/
/*- End of file ------------------------------------------------------------*/