osmo-v5/tests/answer_detect.c

/* Testing the answer tone algorithm of libecho
 *
 * (C) 2023 by Andreas Eversberg <andreas@eversberg.eu>
 * All Rights Reserved
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 */

#include <stdio.h>
#include <string.h>
#include <stdint.h>
#include <stdbool.h>
#include <stdlib.h>
#include <math.h>

#include "../src/libecho/answertone.h"

#define db2level(db)	pow(10, (double)(db) / 20.0)

#define ANS_dB		-13.0
#define ANS_DURATION	4
#define ANS_PHASE_REV	0.450
#define SAMPLERATE	8000
#define BANDWIDTH	100.0

float tone[SAMPLERATE * ANS_DURATION];
int16_t tone_int[SAMPLERATE * ANS_DURATION];

static void gen_ans(float frequency, float level)
{
	double phase = 0.0, rev = 0.0;
	int i;

	for (i = 0; i < SAMPLERATE * ANS_DURATION; i++) {
		/* given tone */
		tone[i] = sin(2.0 * M_PI * frequency * (double)i / (double)SAMPLERATE + phase);
		/* 15 Hz amplitude modulation */
		tone[i] *= 1.0 + sin(2.0 * M_PI * 15.0 * (double)i / (double)SAMPLERATE) * 0.2;
		/* given level */
		tone[i] *= level;
		tone_int[i] = tone[i] * 32767.0;
		/* apply phase reversal */
		rev += 1.0 / (double)SAMPLERATE;
		if (rev >= ANS_PHASE_REV) {
			rev -= ANS_PHASE_REV;
			phase += M_PI;
		}
	}
}

static enum at_fail perform_test(struct answer_tone *at, float frequency, float level, float *phase1_p, float *phase2_p)
{
	enum at_fail fail;
	int offset = 0;
	float _frequency;

	gen_ans(frequency, level);

	answertone_init(at, SAMPLERATE);

	memcpy(at->buffer, tone + offset, sizeof(*at->buffer) * at->buffer_size);
	offset += at->buffer_size;
	answertone_check(at, phase1_p, &_frequency);
	memcpy(at->buffer, tone + offset, sizeof(*at->buffer) * at->buffer_size);
	offset += at->buffer_size;
	fail = answertone_check(at, phase2_p, &_frequency);

	switch (fail) {
	case AT_FAIL_MIN_LEVEL:
		printf("failed, level too low\n");
		break;
	case AT_FAIL_MAX_NOISE:
		printf("failed, too noisy\n");
		break;
	case AT_FAIL_MAX_FREQUENCY:
		printf("failed, frequency too much off\n");
		break;
	case AT_FAIL_NONE:
		printf("ok\n");
	}

	return fail;
}

static void _assert(bool what)
{
	if (what) {
		printf("The result of this test was as expected.\n\n");
		return;
	}
	printf("*\nThe result of this test was not as expected, please FIX!.\n*\n");
	exit(-1);
}

int main(void)
{
	struct answer_tone answer_tone, *at = &answer_tone;
	int offset;
	enum at_fail fail;
	float phase1, phase2, _frequency;
	int rc;

	printf("Test chunk with perfect tone: ");
	fail = perform_test(at, 2100, db2level(ANS_dB), &phase1, &phase2);
	_assert(!fail);
	printf("Check phase: %.3f == %.3f\n", phase1, phase2);
	_assert(fabsf(phase1 - phase2) < 0.001);
	printf("Test chunk with 2101 Hz tone: ");
	fail = perform_test(at, 2101, db2level(ANS_dB), &phase1, &phase2);
	_assert(!fail);
	printf("Check phase: %.3f != %.3f\n", phase1, phase2);
	_assert(fabsf(phase1 - phase2) > 0.001);
	printf("Test chunk with 2121 Hz tone: ");
	fail = perform_test(at, 2121, db2level(ANS_dB), &phase1, &phase2);
	_assert(!fail);
	printf("Test chunk with -26 dBm0 tone: ");
	fail = perform_test(at, 2100, db2level(-26), &phase1, &phase2);
	_assert(!fail);
	printf("Test chunk with 2123 Hz tone: ");
	fail = perform_test(at, 2123, db2level(ANS_dB), &phase1, &phase2);
	_assert(fail);
	printf("Test chunk with -28 dBm0 tone: ");
	fail = perform_test(at, 2100, db2level(-28), &phase1, &phase2);
	_assert(fail);

	printf("Test chunk with long sequence of the tone: ");
	gen_ans(2100+10, db2level(ANS_dB-8));
	answertone_init(at, SAMPLERATE);
	for (offset = 0; offset <= (double)SAMPLERATE * ANS_PHASE_REV - at->buffer_size; offset += at->buffer_size) {
		memcpy(at->buffer, tone + offset, sizeof(*at->buffer) * at->buffer_size);
		fail = answertone_check(at, &phase1, &_frequency);
		switch (fail) {
		case AT_FAIL_MIN_LEVEL:
			printf("level too low\n");
			_assert(false);
			break;
		case AT_FAIL_MAX_NOISE:
			printf("too noisy\n");
			_assert(false);
			break;
		case AT_FAIL_MAX_FREQUENCY:
			if (offset == 0)
				break;
			printf("frequency too much off\n");
			_assert(false);
			break;
		case AT_FAIL_NONE:
			;
		}
	}
	printf("ok\n");
	_assert(true);

	printf("Test complete process with long sequence of the tone: ");
	gen_ans(2100+10, db2level(ANS_dB-8));
	answertone_init(at, SAMPLERATE);
	rc = answertone_process(at, tone_int, SAMPLERATE * ANS_DURATION);
	if (rc > 0)
		printf("tone detected\n");
	else
		printf("no tone detected\n");
	answertone_exit(at);
	_assert(rc > 0);

	return 0;
}