/*
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2010, Eric des Courtis <eric.des.courtis@benbria.com>
 *
 * Version: MPL 1.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * Eric des Courtis <eric.des.courtis@benbria.com>
 * Copyright (C) Benbria. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Eric des Courtis <eric.des.courtis@benbria.com>
 * Piotr Gregor <piotrgregor@rsyncme.org>
 *
 * mod_avmd.c -- Advanced Voicemail Detection Module
 *
 * This module detects single frequency tones (used in voicemail to denote
 * the moment caller's voice is started to be recorded, aka. beep sounds,
 * beeps) using modified DESA-2 algorithm.
 */


#include <switch.h>
#include <g711.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <math.h>
#include <float.h>

#ifdef WIN32
	#include <float.h>
	#define ISNAN(x) (!!(_isnan(x)))
	#define ISINF(x) (isinf(x))
#else
	int __isnan(double);
	int __isinf(double);
	#define ISNAN(x) (__isnan(x))
	#define ISINF(x) (__isinf(x))
#endif

#include "avmd_buffer.h"
#include "avmd_desa2_tweaked.h"
#include "avmd_sma_buf.h"
#include "avmd_options.h"
#include "avmd_fir.h"

#include "avmd_fast_acosf.h"


/*! Calculate how many audio samples per ms based on the rate */
#define AVMD_SAMPLES_PER_MS(r, m) ((r) / (1000/(m)))
/*! Minimum beep length */
#define AVMD_BEEP_TIME (2)
/*! How often to evaluate the output of DESA-2 in ms */
#define AVMD_SINE_TIME (1*0.125)
/*! How long in samples does DESA-2 results get evaluated */
#define AVMD_SINE_LEN(r) AVMD_SAMPLES_PER_MS((r), AVMD_SINE_TIME)
/*! How long in samples is the minimum beep length */
#define AVMD_BEEP_LEN(r) AVMD_SAMPLES_PER_MS((r), AVMD_BEEP_TIME)
/*! Number of points in DESA-2 sample */
#define AVMD_P (5)
/*! Guesstimate frame length in ms */
#define AVMD_FRAME_TIME (20)
/*! Length in samples of the frame (guesstimate) */
#define AVMD_FRAME_LEN(r) AVMD_SAMPLES_PER_MS((r), AVMD_FRAME_TIME)
/*! Conversion to Hertz */
#define AVMD_TO_HZ(r, f) (((r) * (f)) / (2.0 * M_PI))
/*! Minimum absolute pressure/amplitude */
#define AVMD_MIN_AMP (17.0)
/*! Minimum beep frequency in Hertz */
#define AVMD_MIN_FREQUENCY (440.0)
/*! Minimum frequency as digital normalized frequency */
#define AVMD_MIN_FREQUENCY_R(r) ((2.0 * M_PI * AVMD_MIN_FREQUENCY) / (r))
/*!
 * Maximum beep frequency in Hertz
 * Note: The maximum frequency the DESA-2 algorithm can uniquely
 * identify is 0.25 of the sampling rate. All the frequencies
 * below that level are detected unambiguously. This means 2kHz
 * for 8kHz audio. All the frequencies above 0.25 sampling rate
 * will be aliased to frequencies below that threshold,
 * i.e. OMEGA > PI/2 will be aliased to PI - OMEGA.
 * This is not a problem here as we are interested in detection
 * of any constant amplitude and frequency sine wave instead
 * of detection of particular frequency.
 * In case of DESA-1, frequencies up to 0.5 sampling rate are
 * identified uniquely.
 */
#define AVMD_MAX_FREQUENCY (2000.0)
/*! Maximum frequency as digital normalized frequency */
#define AVMD_MAX_FREQUENCY_R(r) ((2.0 * M_PI * AVMD_MAX_FREQUENCY) / (r))
#define AVMD_VARIANCE_RSD_THRESHOLD (0.000025)
#define AVMD_AMPLITUDE_RSD_THRESHOLD (0.0148)

/*! Syntax of the API call. */
#define AVMD_SYNTAX "<uuid> < start | stop | set [inbound|outbound|default] | load [inbound|outbound] | reload | show >"

/*! Number of expected parameters in api call. */
#define AVMD_PARAMS_API_MIN 1u
#define AVMD_PARAMS_API_MAX 2u
#define AVMD_PARAMS_APP_MAX 30u
#define AVMD_PARAMS_APP_START_MIN 0u
#define AVMD_PARAMS_APP_START_MAX 20u

#define AVMD_READ_REPLACE	0
#define AVMD_WRITE_REPLACE	1


/* don't forget to update avmd_events_str table if you modify this */
enum avmd_event
{
	AVMD_EVENT_BEEP = 0,
	AVMD_EVENT_SESSION_START = 1,
	AVMD_EVENT_SESSION_STOP = 2
};
/* This array MUST be NULL terminated! */
const char* avmd_events_str[] = {
	[AVMD_EVENT_BEEP] = "avmd::beep",
	[AVMD_EVENT_SESSION_START] = "avmd::start",
	[AVMD_EVENT_SESSION_STOP] = "avmd::stop",
	NULL /* MUST be last and always here */
};

#define AVMD_CHAR_BUF_LEN 20u
#define AVMD_BUF_LINEAR_LEN 160u

enum avmd_app
{
	AVMD_APP_START_APP = 0,
	AVMD_APP_STOP_APP = 1,
	AVMD_APP_START_FUNCTION = 2 /* deprecated since version 1.6.8 */
};

enum avmd_detection_mode
{
	AVMD_DETECT_AMP = 0,
	AVMD_DETECT_FREQ = 1,
	AVMD_DETECT_BOTH = 2,
	AVMD_DETECT_NONE = 3
};

/* Prototypes */
SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_avmd_shutdown);
SWITCH_MODULE_LOAD_FUNCTION(mod_avmd_load);
SWITCH_MODULE_DEFINITION(mod_avmd, mod_avmd_load, mod_avmd_shutdown, NULL);
SWITCH_STANDARD_API(avmd_api_main);
SWITCH_STANDARD_APP(avmd_start_app);
SWITCH_STANDARD_APP(avmd_stop_app);
SWITCH_STANDARD_APP(avmd_start_function);

struct avmd_settings {
	uint8_t debug;
	uint8_t report_status;
	uint8_t fast_math;
	uint8_t require_continuous_streak;
	uint16_t sample_n_continuous_streak;
	uint16_t sample_n_to_skip;
	uint8_t require_continuous_streak_amp;
	uint16_t sample_n_continuous_streak_amp;
	uint8_t simplified_estimation;
	uint8_t inbound_channnel;
	uint8_t outbound_channnel;
	enum avmd_detection_mode mode;
	uint8_t detectors_n;
	uint8_t detectors_lagged_n;
};

/*! Status of the beep detection */
typedef enum {
	BEEP_DETECTED,
	BEEP_NOTDETECTED
} avmd_beep_state_t;

/*! Data related to the current status of the beep */
typedef struct {
	avmd_beep_state_t beep_state;
	size_t last_beep;
} avmd_state_t;

struct avmd_session;
typedef struct avmd_session avmd_session_t;

struct avmd_buffer {
	sma_buffer_t sma_b;
	sma_buffer_t sqa_b;

	sma_buffer_t sma_b_fir;
	sma_buffer_t sqa_b_fir;

	sma_buffer_t sma_amp_b;
	sma_buffer_t sqa_amp_b;

	uint8_t resolution;
	uint8_t offset;
	double amplitude_max;
	size_t samples_streak, samples_streak_amp; /* number of DESA samples in single streak without reset needed to validate SMA estimator */
};

struct avmd_detector {
	switch_thread_t *thread;
	switch_mutex_t *mutex;
	uint8_t flag_processing_done;
	uint8_t flag_should_exit;
	enum avmd_detection_mode result;
	switch_thread_cond_t *cond_start_processing;
	struct avmd_buffer buffer;
	avmd_session_t *s;
	size_t samples;
	uint8_t idx;
	uint8_t lagged, lag;
};

/*! Type that holds avmd detection session information. */
struct avmd_session {
	switch_core_session_t *session;
	switch_mutex_t *mutex;
	struct avmd_settings settings;
	uint32_t rate;
	circ_buffer_t b;
	size_t pos;
	double f;
	avmd_state_t state;
	switch_time_t start_time, stop_time, detection_start_time, detection_stop_time;
	size_t frame_n;
	uint8_t frame_n_to_skip;

	switch_mutex_t *mutex_detectors_done;
	switch_thread_cond_t *cond_detectors_done;
	struct avmd_detector *detectors;
};

static struct avmd_globals
{
	switch_mutex_t *mutex;
	struct avmd_settings settings;
	switch_memory_pool_t *pool;
	size_t session_n;
} avmd_globals;

static void avmd_process(avmd_session_t *session, switch_frame_t *frame, uint8_t direction);

static switch_bool_t avmd_callback(switch_media_bug_t * bug, void *user_data, switch_abc_type_t type);
static switch_status_t avmd_register_all_events(void);

static void avmd_unregister_all_events(void);

static void avmd_fire_event(enum avmd_event type, switch_core_session_t *fs_s, double freq, double v_freq, double amp, double v_amp, avmd_beep_state_t beep_status, uint8_t info,
		switch_time_t detection_start_time, switch_time_t detection_stop_time, switch_time_t start_time, switch_time_t stop_time, uint8_t resolution, uint8_t offset, uint8_t idx);

static enum avmd_detection_mode avmd_process_sample(avmd_session_t *s, circ_buffer_t *b, size_t sample_n, size_t pos, struct avmd_detector *d);

/* API [set default], reset to factory settings */
static void avmd_set_xml_default_configuration(switch_mutex_t *mutex);
/* API [set inbound], set inbound = 1, outbound = 0 */
static void avmd_set_xml_inbound_configuration(switch_mutex_t *mutex);
/* API [set outbound], set inbound = 0, outbound = 1 */
static void avmd_set_xml_outbound_configuration(switch_mutex_t *mutex);

/* API [reload], reload XML configuration data from RAM */
static switch_status_t avmd_load_xml_configuration(switch_mutex_t *mutex);
/* API [load inbound], reload + set inbound */
static switch_status_t avmd_load_xml_inbound_configuration(switch_mutex_t *mutex);
/* API [load outbound], reload + set outbound */
static switch_status_t avmd_load_xml_outbound_configuration(switch_mutex_t *mutex);

/* bind reloadxml callback */
static void avmd_reloadxml_event_handler(switch_event_t *event);

/* API command */
static void avmd_show(switch_stream_handle_t *stream, switch_mutex_t *mutex);

static void* SWITCH_THREAD_FUNC
avmd_detector_func(switch_thread_t *thread, void *arg);

static uint8_t
avmd_detection_in_progress(avmd_session_t *s);

static switch_status_t avmd_launch_threads(avmd_session_t *s) {
	uint8_t idx;
	struct avmd_detector *d;
	switch_threadattr_t *thd_attr = NULL;

	idx = 0;
	while (idx < s->settings.detectors_n) {
		d = &s->detectors[idx];
		d->flag_processing_done = 1;
		d->flag_should_exit = 0;
		d->result = AVMD_DETECT_NONE;
		d->lagged = 0;
		d->lag = 0;
		switch_threadattr_create(&thd_attr, avmd_globals.pool);
		switch_threadattr_stacksize_set(thd_attr, SWITCH_THREAD_STACKSIZE);
		if (switch_thread_create(&d->thread, thd_attr, avmd_detector_func, d, switch_core_session_get_pool(s->session)) != SWITCH_STATUS_SUCCESS) {
			return SWITCH_STATUS_FALSE;
		}

		if (s->settings.debug) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "AVMD: started thread idx=%u\n", idx);
		}

		++idx;
	}

	idx = 0;
	while (idx < s->settings.detectors_lagged_n) {
		d = &s->detectors[s->settings.detectors_n + idx];
		d->flag_processing_done = 1;
		d->flag_should_exit = 0;
		d->result = AVMD_DETECT_NONE;
		d->lagged = 1;
		d->lag = idx + 1;
		switch_threadattr_create(&thd_attr, avmd_globals.pool);
		switch_threadattr_stacksize_set(thd_attr, SWITCH_THREAD_STACKSIZE);
		if (switch_thread_create(&d->thread, thd_attr, avmd_detector_func, d, switch_core_session_get_pool(s->session)) != SWITCH_STATUS_SUCCESS) {
			return SWITCH_STATUS_FALSE;
		}

		if (s->settings.debug) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "AVMD: started lagged thread idx=%u\n", s->settings.detectors_n + idx);
		}

		++idx;
	}

	return SWITCH_STATUS_SUCCESS;
}

static void avmd_join_threads(avmd_session_t *s) {
	uint8_t idx;
	struct avmd_detector *d;
	switch_status_t status;

	idx = 0;
	while (idx < s->settings.detectors_n) {
		d = &s->detectors[idx];
		switch_mutex_lock(d->mutex);
		if (d->thread != NULL) {
			d->flag_should_exit = 1;
			d->samples = 0;
			switch_thread_cond_signal(d->cond_start_processing);
			switch_mutex_unlock(d->mutex);
			switch_thread_join(&status, d->thread);
			d->thread = NULL;
			switch_mutex_destroy(d->mutex);
			switch_thread_cond_destroy(d->cond_start_processing);
		} else {
			switch_mutex_unlock(d->mutex);
		}
		++idx;
	}
	idx = 0;
	while (idx < s->settings.detectors_lagged_n) {
		d = &s->detectors[s->settings.detectors_n + idx];
		switch_mutex_lock(d->mutex);
		if (d->thread != NULL) {
			d->flag_should_exit = 1;
			d->samples = 0;
			switch_thread_cond_signal(d->cond_start_processing);
			switch_mutex_unlock(d->mutex);
			switch_thread_join(&status, d->thread);
			d->thread = NULL;
			switch_mutex_destroy(d->mutex);
			switch_thread_cond_destroy(d->cond_start_processing);
		} else {
			switch_mutex_unlock(d->mutex);
		}
		++idx;
	}
}

static switch_status_t avmd_init_buffer(struct avmd_buffer *b, size_t buf_sz, uint8_t resolution, uint8_t offset, switch_core_session_t *fs_session) {
	INIT_SMA_BUFFER(&b->sma_b, buf_sz, fs_session);
	if (b->sma_b.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sma_b.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	INIT_SMA_BUFFER(&b->sqa_b, buf_sz, fs_session);
	if (b->sqa_b.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sqa_b.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	INIT_SMA_BUFFER(&b->sma_b_fir, buf_sz, fs_session);
	if (b->sma_b_fir.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sma_b_fir.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	INIT_SMA_BUFFER(&b->sqa_b_fir, buf_sz, fs_session);
	if (b->sqa_b_fir.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sqa_b_fir.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	INIT_SMA_BUFFER(&b->sma_amp_b, buf_sz, fs_session);
	if (b->sma_amp_b.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sma_amp_b.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	INIT_SMA_BUFFER(&b->sqa_amp_b, buf_sz, fs_session);
	if (b->sqa_amp_b.data == NULL) {
		return SWITCH_STATUS_FALSE;
	}
	memset(b->sqa_amp_b.data, 0, sizeof(BUFF_TYPE) * buf_sz);

	b->amplitude_max = 0.0;
	b->samples_streak = 0;
	b->samples_streak_amp = 0;
	b->resolution = resolution;
	b->offset = offset;

	return SWITCH_STATUS_SUCCESS;
}

/*! \brief The avmd session data initialization function.
 * @param avmd_session A reference to a avmd session.
 * @param fs_session A reference to a FreeSWITCH session.
 * @details Avmd globals mutex must be locked.
 */
static switch_status_t init_avmd_session_data(avmd_session_t *avmd_session, switch_core_session_t *fs_session, switch_mutex_t *mutex)
{
	uint8_t		 idx, resolution, offset;
	size_t		  buf_sz;
	struct avmd_detector *d;
	switch_status_t status = SWITCH_STATUS_SUCCESS;

	if (mutex != NULL)
	{
		switch_mutex_lock(mutex);
	}

	/*! This is a worst case sample rate estimate */
	avmd_session->rate = 48000;
	INIT_CIRC_BUFFER(&avmd_session->b, (size_t) AVMD_BEEP_LEN(avmd_session->rate), (size_t) AVMD_FRAME_LEN(avmd_session->rate), fs_session);
	if (avmd_session->b.buf == NULL) {
		status =  SWITCH_STATUS_MEMERR;
		goto end;
	}
	avmd_session->session = fs_session;
	avmd_session->pos = 0;
	avmd_session->f = 0.0;
	avmd_session->state.last_beep = 0;
	avmd_session->state.beep_state = BEEP_NOTDETECTED;
	switch_mutex_init(&avmd_session->mutex, SWITCH_MUTEX_DEFAULT, switch_core_session_get_pool(fs_session));
	avmd_session->frame_n = 0;
	avmd_session->detection_start_time = 0;
	avmd_session->detection_stop_time = 0;
	avmd_session->frame_n_to_skip = 0;

	buf_sz = AVMD_BEEP_LEN((uint32_t)avmd_session->rate) / (uint32_t) AVMD_SINE_LEN(avmd_session->rate);
	if (buf_sz < 1) {
		status = SWITCH_STATUS_MORE_DATA;
		goto end;
	}
	avmd_session->detectors = (struct avmd_detector*) switch_core_session_alloc(fs_session, (avmd_session->settings.detectors_n + avmd_session->settings.detectors_lagged_n) * sizeof(struct avmd_detector));
	if (avmd_session->detectors == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Can't allocate memory for avmd detectors!\n");
		status = SWITCH_STATUS_NOT_INITALIZED;
		goto end;
	}
	idx = 0;
	resolution = 0;
	while (idx < avmd_session->settings.detectors_n) {
		++resolution;
		offset = 0;
		while ((offset < resolution) && (idx < avmd_session->settings.detectors_n)) {
			d = &avmd_session->detectors[idx];
			if (avmd_init_buffer(&d->buffer, buf_sz, resolution, offset, fs_session) != SWITCH_STATUS_SUCCESS) {
				status = SWITCH_STATUS_FALSE;
				goto end;
			}
			d->s = avmd_session;
			d->flag_processing_done = 1;
			d->flag_should_exit = 1;
			d->idx = idx;
			d->thread = NULL;
			switch_mutex_init(&d->mutex, SWITCH_MUTEX_DEFAULT, switch_core_session_get_pool(fs_session));
			switch_thread_cond_create(&d->cond_start_processing, switch_core_session_get_pool(fs_session));
			++offset;
			++idx;
		}
	}
	idx = 0;
	resolution = 1;
	offset = 0;
	while (idx < avmd_session->settings.detectors_lagged_n) {
			d = &avmd_session->detectors[avmd_session->settings.detectors_n + idx];
			if (avmd_init_buffer(&d->buffer, buf_sz, resolution, offset, fs_session) != SWITCH_STATUS_SUCCESS) {
				status = SWITCH_STATUS_FALSE;
				goto end;
			}
			d->s = avmd_session;
			d->flag_processing_done = 1;
			d->flag_should_exit = 1;
			d->idx = avmd_session->settings.detectors_n + idx;
			d->thread = NULL;
			switch_mutex_init(&d->mutex, SWITCH_MUTEX_DEFAULT, switch_core_session_get_pool(fs_session));
			switch_thread_cond_create(&d->cond_start_processing, switch_core_session_get_pool(fs_session));
			++idx;
	}
	switch_mutex_init(&avmd_session->mutex_detectors_done, SWITCH_MUTEX_DEFAULT, switch_core_session_get_pool(fs_session));
	switch_thread_cond_create(&avmd_session->cond_detectors_done, switch_core_session_get_pool(fs_session));

end:
	if (mutex != NULL)
	{
		switch_mutex_unlock(mutex);
	}
	return status;
}

static void avmd_session_close(avmd_session_t *s) {
	uint8_t				 idx;
	struct avmd_detector	*d;
	switch_status_t		 status;

	switch_mutex_lock(s->mutex);

	switch_mutex_lock(s->mutex_detectors_done);
	while (avmd_detection_in_progress(s) == 1) {
		switch_thread_cond_wait(s->cond_detectors_done, s->mutex_detectors_done);
	}
	switch_mutex_unlock(s->mutex_detectors_done);

	idx = 0;
	while (idx < (s->settings.detectors_n + s->settings.detectors_lagged_n)) {
		d = &s->detectors[idx];
		switch_mutex_lock(d->mutex);
		d = &s->detectors[idx];
		d->flag_processing_done = 0;
		d->flag_should_exit = 1;
		d->samples = 0;
		switch_thread_cond_signal(d->cond_start_processing);
		switch_mutex_unlock(d->mutex);

		switch_thread_join(&status, d->thread);
		d->thread = NULL;

		switch_mutex_destroy(d->mutex);
		switch_thread_cond_destroy(d->cond_start_processing);
		++idx;
	}
	switch_mutex_unlock(s->mutex);
	switch_mutex_destroy(s->mutex_detectors_done);
	switch_thread_cond_destroy(s->cond_detectors_done);
	switch_mutex_destroy(s->mutex);
}

/*! \brief The callback function that is called when new audio data becomes available.
 * @param bug A reference to the media bug.
 * @param user_data The session information for this call.
 * @param type The switch callback type.
 * @return The success or failure of the function.
 */
static switch_bool_t avmd_callback(switch_media_bug_t * bug, void *user_data, switch_abc_type_t type) {
	avmd_session_t *avmd_session;
	switch_codec_t *read_codec;
	switch_codec_t *write_codec;
	switch_frame_t *frame;
	switch_core_session_t *fs_session;
	switch_channel_t *channel = NULL;


	avmd_session = (avmd_session_t *) user_data;
	if (avmd_session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No avmd session assigned!\n");
		return SWITCH_FALSE;
	}
	if ((type != SWITCH_ABC_TYPE_INIT) && (type != SWITCH_ABC_TYPE_CLOSE)) {
		switch_mutex_lock(avmd_session->mutex);
	}
	fs_session = avmd_session->session;
	if (fs_session == NULL) {
		if (type != SWITCH_ABC_TYPE_INIT) {
			switch_mutex_unlock(avmd_session->mutex);
		}
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No FreeSWITCH session assigned!\n");
		return SWITCH_FALSE;
	}

	channel = switch_core_session_get_channel(fs_session);
	if (channel == NULL) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No channel for FreeSWITCH session!\n");
		return SWITCH_FALSE;
	}

	switch (type) {

		case SWITCH_ABC_TYPE_INIT:
			if ((SWITCH_CALL_DIRECTION_OUTBOUND == switch_channel_direction(channel)) && (avmd_session->settings.outbound_channnel == 1)) {
				read_codec = switch_core_session_get_read_codec(fs_session);
				if (read_codec == NULL) {
					switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_WARNING, "No read codec assigned, default session rate to 8000 samples/s\n");
					avmd_session->rate = 8000;
				} else {
					if (read_codec->implementation == NULL) {
						switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_WARNING, "No read codec implementation assigned, default session rate to 8000 samples/s\n");
						avmd_session->rate = 8000;
					} else {
						avmd_session->rate = read_codec->implementation->samples_per_second;
					}
				}
			}
			if ((SWITCH_CALL_DIRECTION_INBOUND == switch_channel_direction(channel)) && (avmd_session->settings.inbound_channnel == 1)) {
				write_codec = switch_core_session_get_write_codec(fs_session);
				if (write_codec == NULL) {
					switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_WARNING, "No write codec assigned, default session rate to 8000 samples/s\n");
					avmd_session->rate = 8000;
				} else {
					if (write_codec->implementation == NULL) {
						switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_WARNING, "No write codec implementation assigned, default session rate to 8000 samples/s\n");
						avmd_session->rate = 8000;
					} else {
						avmd_session->rate = write_codec->implementation->samples_per_second;
					}
				}
			}
			avmd_session->start_time = switch_micro_time_now();
			/* avmd_session->vmd_codec.channels =  read_codec->implementation->number_of_channels; */
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session),SWITCH_LOG_INFO, "Avmd session initialized, [%u] samples/s\n", avmd_session->rate);
			break;

		case SWITCH_ABC_TYPE_READ_REPLACE:
			frame = switch_core_media_bug_get_read_replace_frame(bug);
			avmd_process(avmd_session, frame, AVMD_READ_REPLACE);
			break;

		case SWITCH_ABC_TYPE_WRITE_REPLACE:
			frame = switch_core_media_bug_get_write_replace_frame(bug);
			avmd_process(avmd_session, frame, AVMD_WRITE_REPLACE);
			break;

		case SWITCH_ABC_TYPE_CLOSE:
			avmd_session_close(avmd_session);
			switch_mutex_lock(avmd_globals.mutex);
			if (avmd_globals.session_n > 0) {
				--avmd_globals.session_n;
			}
			switch_mutex_unlock(avmd_globals.mutex);
			break;

		default:
			break;
	}

	if ((type != SWITCH_ABC_TYPE_INIT) && (type != SWITCH_ABC_TYPE_CLOSE)) {
		switch_mutex_unlock(avmd_session->mutex);
	}
	return SWITCH_TRUE;
}

static switch_status_t avmd_register_all_events(void) {
	size_t idx = 0;
	const char *e = avmd_events_str[0];
	while (e != NULL)
	{
		if (switch_event_reserve_subclass(e) != SWITCH_STATUS_SUCCESS) {
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't register subclass [%s]!\n", e);
			return SWITCH_STATUS_TERM;
		}
		++idx;
		e = avmd_events_str[idx];
	}
	return SWITCH_STATUS_SUCCESS;
}

static void avmd_unregister_all_events(void) {
	size_t idx = 0;
	const char *e = avmd_events_str[0];
	while (e != NULL)
	{
		switch_event_free_subclass(e);
		++idx;
		e = avmd_events_str[idx];
	}
	return;
}

static void avmd_fire_event(enum avmd_event type, switch_core_session_t *fs_s, double freq, double v_freq, double amp, double v_amp, avmd_beep_state_t beep_status, uint8_t info,
		switch_time_t detection_start_time, switch_time_t detection_stop_time, switch_time_t start_time, switch_time_t stop_time, uint8_t resolution, uint8_t offset, uint8_t idx) {
	int res;
	switch_event_t *event;
	switch_time_t detection_time, total_time;
	switch_status_t status;
	switch_event_t *event_copy;
	char buf[AVMD_CHAR_BUF_LEN];

	status = switch_event_create_subclass(&event, SWITCH_EVENT_CUSTOM, avmd_events_str[type]);
	if (status != SWITCH_STATUS_SUCCESS) {
		return;
	}
	switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Unique-ID", switch_core_session_get_uuid(fs_s));
	switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Call-command", "avmd");
	switch (type)
	{
		case AVMD_EVENT_BEEP:
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Beep-Status", "DETECTED");
			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%f", freq);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Frequency truncated [%s], [%d] attempted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Frequency", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Frequency", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%f", v_freq);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Error, truncated [%s], [%d] attempeted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Frequency-variance", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Frequency-variance", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%f", amp);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Amplitude truncated [%s], [%d] attempted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Amplitude", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Amplitude", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%f", v_amp);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Error, truncated [%s], [%d] attempeted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Amplitude-variance", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Amplitude-variance", buf);

			detection_time = detection_stop_time - detection_start_time;
			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%" PRId64 "", detection_time);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Detection time truncated [%s], [%d] attempted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detection-time", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detection-time", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%u", resolution);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Error, truncated [%s], [%d] attempeted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-resolution", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-resolution", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%u", offset);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Error, truncated [%s], [%d] attempeted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-offset", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-offset", buf);

			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%u", idx);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Error, truncated [%s], [%d] attempeted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-index", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Detector-index", buf);
			break;

		case AVMD_EVENT_SESSION_START:
			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%" PRId64 "", start_time);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Start time truncated [%s], [%d] attempted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Start-time", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Start-time", buf);
			break;

		case AVMD_EVENT_SESSION_STOP:
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Beep-Status", beep_status == BEEP_DETECTED ? "DETECTED" : "NOTDETECTED");
			if (info == 0) {
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Stop-status", "ERROR (AVMD SESSION OBJECT NOT FOUND IN MEDIA BUG)");
			}
			total_time = stop_time - start_time;
			res = snprintf(buf, AVMD_CHAR_BUF_LEN, "%" PRId64 "", total_time);
			if (res < 0 || res > AVMD_CHAR_BUF_LEN - 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_s), SWITCH_LOG_ERROR, "Total time truncated [%s], [%d] attempted!\n", buf, res);
				switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Total-time", "ERROR (TRUNCATED)");
			}
			switch_event_add_header_string(event, SWITCH_STACK_BOTTOM, "Total-time", buf);
			break;

		default:
			switch_event_destroy(&event);
			return;
	}

	if ((switch_event_dup(&event_copy, event)) != SWITCH_STATUS_SUCCESS) {
		return;
	}

	switch_core_session_queue_event(fs_s, &event);
	switch_event_fire(&event_copy);
	return;
}

int avmd_parse_u8_user_input(const char *input, uint8_t *output, uint8_t min, uint8_t max) {
	char *pCh;
	unsigned long helper;
	helper = strtoul(input, &pCh, 10);
	if (helper < min || helper > UINT8_MAX || helper > max || (pCh == input) || (*pCh != '\0')) {
		return -1;
	}
	*output = (uint8_t) helper;
	return 0;
}

int avmd_parse_u16_user_input(const char *input, uint16_t *output, uint16_t min, uint16_t max) {
	char *pCh;
	unsigned long helper;
	if (min > max) {
		return -1;
	}
	helper = strtoul(input, &pCh, 10);
	if (helper < min || helper > UINT16_MAX || helper > max || (pCh == input) || (*pCh != '\0')) {
		return -1;
	}
	*output = (uint16_t) helper;
	return 0;
}

static void avmd_set_xml_default_configuration(switch_mutex_t *mutex) {
	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	avmd_globals.settings.debug = 0;
	avmd_globals.settings.report_status = 1;
	avmd_globals.settings.fast_math = 0;
	avmd_globals.settings.require_continuous_streak = 1;
	avmd_globals.settings.sample_n_continuous_streak = 3;
	avmd_globals.settings.sample_n_to_skip = 0;
	avmd_globals.settings.require_continuous_streak_amp = 1;
	avmd_globals.settings.sample_n_continuous_streak_amp = 3;
	avmd_globals.settings.simplified_estimation = 1;
	avmd_globals.settings.inbound_channnel = 0;
	avmd_globals.settings.outbound_channnel = 1;
	avmd_globals.settings.mode = AVMD_DETECT_BOTH;
	avmd_globals.settings.detectors_n = 36;
	avmd_globals.settings.detectors_lagged_n = 1;

	if (mutex != NULL) {
		switch_mutex_unlock(avmd_globals.mutex);
	}
	return;
}

static void avmd_set_xml_inbound_configuration(switch_mutex_t *mutex)
{
	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	avmd_globals.settings.inbound_channnel = 1;
	avmd_globals.settings.outbound_channnel = 0;

	if (mutex != NULL) {
		switch_mutex_unlock(avmd_globals.mutex);
	}
	return;
}

static void avmd_set_xml_outbound_configuration(switch_mutex_t *mutex) {
	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	avmd_globals.settings.inbound_channnel = 0;
	avmd_globals.settings.outbound_channnel = 1;

	if (mutex != NULL) {
		switch_mutex_unlock(avmd_globals.mutex);
	}
	return;
}

static switch_status_t avmd_load_xml_configuration(switch_mutex_t *mutex) {
	switch_xml_t xml = NULL, x_lists = NULL, x_list = NULL, cfg = NULL;
	uint8_t bad_debug = 1, bad_report = 1, bad_fast = 1, bad_req_cont = 1, bad_sample_n_cont = 1,
			bad_sample_n_to_skip = 1, bad_req_cont_amp = 1, bad_sample_n_cont_amp = 1, bad_simpl = 1,
			bad_inbound = 1, bad_outbound = 1, bad_mode = 1, bad_detectors = 1, bad_lagged = 1, bad = 0;

	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	if ((xml = switch_xml_open_cfg("avmd.conf", &cfg, NULL)) != NULL) {

		if ((x_lists = switch_xml_child(cfg, "settings"))) {
			for (x_list = switch_xml_child(x_lists, "param"); x_list; x_list = x_list->next) {
				const char *name = switch_xml_attr(x_list, "name");
				const char *value = switch_xml_attr(x_list, "value");

				if (zstr(name)) {
					continue;
				}
				if (zstr(value)) {
					continue;
				}

				if (!strcmp(name, "debug")) {
					avmd_globals.settings.debug = switch_true(value) ? 1 : 0;
					bad_debug = 0;
				} else if (!strcmp(name, "report_status")) {
					avmd_globals.settings.report_status = switch_true(value) ? 1 : 0;
					bad_report = 0;
				} else if (!strcmp(name, "fast_math")) {
					avmd_globals.settings.fast_math = switch_true(value) ? 1 : 0;
					bad_fast = 0;
				} else if (!strcmp(name, "require_continuous_streak")) {
					avmd_globals.settings.require_continuous_streak = switch_true(value) ? 1 : 0;
					bad_req_cont = 0;
				} else if (!strcmp(name, "sample_n_continuous_streak")) {
					if(!avmd_parse_u16_user_input(value, &avmd_globals.settings.sample_n_continuous_streak, 0, UINT16_MAX)) {
						bad_sample_n_cont = 0;
					}
				} else if (!strcmp(name, "sample_n_to_skip")) {
					if(!avmd_parse_u16_user_input(value, &avmd_globals.settings.sample_n_to_skip, 0, UINT16_MAX)) {
						bad_sample_n_to_skip = 0;
					}
				} else if (!strcmp(name, "require_continuous_streak_amp")) {
					avmd_globals.settings.require_continuous_streak_amp = switch_true(value) ? 1 : 0;
					bad_req_cont_amp = 0;
				} else if (!strcmp(name, "sample_n_continuous_streak_amp")) {
					if(!avmd_parse_u16_user_input(value, &avmd_globals.settings.sample_n_continuous_streak_amp, 0, UINT16_MAX)) {
						bad_sample_n_cont_amp = 0;
					}
				} else if (!strcmp(name, "simplified_estimation")) {
					avmd_globals.settings.simplified_estimation = switch_true(value) ? 1 : 0;
					bad_simpl = 0;
				} else if (!strcmp(name, "inbound_channel")) {
					avmd_globals.settings.inbound_channnel = switch_true(value) ? 1 : 0;
					bad_inbound = 0;
				} else if (!strcmp(name, "outbound_channel")) {
					avmd_globals.settings.outbound_channnel = switch_true(value) ? 1 : 0;
					bad_outbound = 0;
				} else if (!strcmp(name, "detection_mode")) {
					if(!avmd_parse_u8_user_input(value, (uint8_t*)&avmd_globals.settings.mode, 0, 2)) {
						bad_mode = 0;
					}
				} else if (!strcmp(name, "detectors_n")) {
					if(!avmd_parse_u8_user_input(value, &avmd_globals.settings.detectors_n, 0, UINT8_MAX)) {
						bad_detectors = 0;
					}
				} else if (!strcmp(name, "detectors_lagged_n")) {
					if(!avmd_parse_u8_user_input(value, &avmd_globals.settings.detectors_lagged_n, 0, UINT8_MAX)) {
						bad_lagged = 0;
					}
				}
			} // for
		} // if list

		switch_xml_free(xml);
	} // if open OK

	if (bad_debug) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'debug' missing or invalid - using default\n");
		avmd_globals.settings.debug = 0;
	}

	if (bad_report) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'report_status' missing or invalid - using default\n");
		avmd_globals.settings.report_status = 1;
	}

	if (bad_fast) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'fast_math' missing or invalid - using default\n");
		avmd_globals.settings.fast_math = 0;
	}

	if (bad_req_cont) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'require_continuous_streak' missing or invalid - using default\n");
		avmd_globals.settings.require_continuous_streak = 1;
	}

	if (bad_sample_n_cont) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'sample_n_continuous_streak' missing or invalid - using default\n");
		avmd_globals.settings.sample_n_continuous_streak = 3;
	}

	if (bad_sample_n_to_skip) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'sample_n_to_skip' missing or invalid - using default\n");
		avmd_globals.settings.sample_n_to_skip = 0;
	}

	if (bad_req_cont_amp) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'require_continuous_streak_amp' missing or invalid - using default\n");
		avmd_globals.settings.require_continuous_streak_amp = 1;
	}

	if (bad_sample_n_cont_amp) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'sample_n_continuous_streak_amp' missing or invalid - using default\n");
		avmd_globals.settings.sample_n_continuous_streak_amp = 3;
	}

	if (bad_simpl) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'simplified_estimation' missing or invalid - using default\n");
		avmd_globals.settings.simplified_estimation = 1;
	}

	if (bad_inbound) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'inbound_channel' missing or invalid - using default\n");
		avmd_globals.settings.inbound_channnel = 0;
	}

	if (bad_outbound) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'outbound_channel' missing or invalid - using default\n");
		avmd_globals.settings.outbound_channnel = 1;
	}

	if (bad_mode) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'detection_mode' missing or invalid - using default\n");
		avmd_globals.settings.mode = AVMD_DETECT_BOTH;
	}

	if (bad_detectors) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'detectors_n' missing or invalid - using default\n");
		avmd_globals.settings.detectors_n = 36;
	}

	if (bad_lagged) {
		bad = 1;
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "AVMD config parameter 'detectors_lagged_n' missing or invalid - using default\n");
		avmd_globals.settings.detectors_lagged_n = 1;
	}

	/**
	 * Hint.
	 */
	if (bad) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Type 'avmd show' to display default settings. Type 'avmd ' + TAB for autocompletion.\n");
	}

	if (mutex != NULL) {
		switch_mutex_unlock(mutex);
	}

	return SWITCH_STATUS_SUCCESS;
}

static switch_status_t avmd_load_xml_inbound_configuration(switch_mutex_t *mutex) {
	if (avmd_load_xml_configuration(mutex) != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_TERM;
	}

	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	avmd_globals.settings.inbound_channnel = 1;
	avmd_globals.settings.outbound_channnel = 0;

	if (mutex != NULL) {
		switch_mutex_unlock(avmd_globals.mutex);
	}
	return SWITCH_STATUS_SUCCESS;
}

static switch_status_t avmd_load_xml_outbound_configuration(switch_mutex_t *mutex) {
	if (avmd_load_xml_configuration(mutex) != SWITCH_STATUS_SUCCESS) {
		return SWITCH_STATUS_TERM;
	}

	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	avmd_globals.settings.inbound_channnel = 0;
	avmd_globals.settings.outbound_channnel = 1;

	if (mutex != NULL) {
		switch_mutex_unlock(avmd_globals.mutex);
	}
	return SWITCH_STATUS_SUCCESS;
}

static void avmd_show(switch_stream_handle_t *stream, switch_mutex_t *mutex) {
	const char *line = "=================================================================================================";
	if (stream == NULL) {
		return;
	}

	if (mutex != NULL) {
		switch_mutex_lock(mutex);
	}

	stream->write_function(stream, "\n\n");
	stream->write_function(stream, "%s\n\n", line);
	stream->write_function(stream, "%s\n", "Avmd global settings\n\n");
	stream->write_function(stream, "debug						  \t%u\n", avmd_globals.settings.debug);
	stream->write_function(stream, "report status				  \t%u\n", avmd_globals.settings.report_status);
	stream->write_function(stream, "fast_math					  \t%u\n", avmd_globals.settings.fast_math);
	stream->write_function(stream, "require continuous streak	  \t%u\n", avmd_globals.settings.require_continuous_streak);
	stream->write_function(stream, "sample n continuous streak	 \t%u\n", avmd_globals.settings.sample_n_continuous_streak);
	stream->write_function(stream, "sample n to skip			   \t%u\n", avmd_globals.settings.sample_n_to_skip);
	stream->write_function(stream, "require continuous streak amp  \t%u\n", avmd_globals.settings.require_continuous_streak_amp);
	stream->write_function(stream, "sample n continuous streak amp \t%u\n", avmd_globals.settings.sample_n_continuous_streak_amp);
	stream->write_function(stream, "simplified estimation		  \t%u\n", avmd_globals.settings.simplified_estimation);
	stream->write_function(stream, "inbound channel				\t%u\n", avmd_globals.settings.inbound_channnel);
	stream->write_function(stream, "outbound channel			   \t%u\n", avmd_globals.settings.outbound_channnel);
	stream->write_function(stream, "detection mode				 \t%u\n", avmd_globals.settings.mode);
	stream->write_function(stream, "sessions					   \t%"PRId64"\n", avmd_globals.session_n);
	stream->write_function(stream, "detectors n					\t%u\n", avmd_globals.settings.detectors_n);
	stream->write_function(stream, "detectors lagged n			 \t%u\n", avmd_globals.settings.detectors_lagged_n);
	stream->write_function(stream, "\n\n");

	if (mutex != NULL) {
		switch_mutex_unlock(mutex);
	}
}

SWITCH_MODULE_LOAD_FUNCTION(mod_avmd_load) {
#ifndef WIN32
	char	err[150];
	int	 ret;
#endif

	switch_application_interface_t *app_interface;
	switch_api_interface_t *api_interface;
	/* connect my internal structure to the blank pointer passed to me */
	*module_interface = switch_loadable_module_create_module_interface(pool, modname);

	if (avmd_register_all_events() != SWITCH_STATUS_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't register avmd events!\n");
		return SWITCH_STATUS_TERM;
	}

	memset(&avmd_globals, 0, sizeof(avmd_globals));
	if (pool == NULL) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No memory pool assigned!\n");
		return SWITCH_STATUS_TERM;
	}
	switch_mutex_init(&avmd_globals.mutex, SWITCH_MUTEX_NESTED, pool);
	avmd_globals.pool = pool;

	if (avmd_load_xml_configuration(NULL) != SWITCH_STATUS_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't load XML configuration! Loading default settings\n");
		avmd_set_xml_default_configuration(NULL);
	}

	if ((switch_event_bind(modname, SWITCH_EVENT_RELOADXML, NULL, avmd_reloadxml_event_handler, NULL) != SWITCH_STATUS_SUCCESS)) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't bind our reloadxml handler! Module will not react to changes made in XML configuration\n");
		/* Not so severe to prevent further loading, well - it depends, anyway */
	}

#ifndef WIN32
	if (avmd_globals.settings.fast_math == 1) {
		ret = init_fast_acosf();
		if (ret != 0) {
			strerror_r(errno, err, 150);
			switch (ret) {

				case -1:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Can't access file [%s], error [%s]\n", ACOS_TABLE_FILENAME, err);
					break;
				case -2:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Error creating file [%s], error [%s]\n", ACOS_TABLE_FILENAME, err);
					break;
				case -3:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Access rights are OK but can't open file [%s], error [%s]\n", ACOS_TABLE_FILENAME, err);
					break;
				case -4:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Access rights are OK but can't mmap file [%s], error [%s]\n",ACOS_TABLE_FILENAME, err);
					break;
				default:
					switch_log_printf(SWITCH_CHANNEL_LOG,SWITCH_LOG_ERROR, "Unknown error [%d] while initializing fast cos table [%s], errno [%s]\n", ret, ACOS_TABLE_FILENAME, err);
					return SWITCH_STATUS_TERM;
			}
			return SWITCH_STATUS_TERM;
		} else
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Advanced voicemail detection: fast math enabled, arc cosine table is [%s]\n", ACOS_TABLE_FILENAME);
	}
#endif

	SWITCH_ADD_APP(app_interface, "avmd_start","Start avmd detection", "Start avmd detection", avmd_start_app, "", SAF_NONE);
	SWITCH_ADD_APP(app_interface, "avmd_stop","Stop avmd detection", "Stop avmd detection", avmd_stop_app, "", SAF_NONE);
	SWITCH_ADD_APP(app_interface, "avmd","Beep detection", "Advanced detection of voicemail beeps", avmd_start_function, AVMD_SYNTAX, SAF_NONE);

	SWITCH_ADD_API(api_interface, "avmd", "Voicemail beep detection", avmd_api_main, AVMD_SYNTAX);

	switch_console_set_complete("add avmd ::console::list_uuid ::[start:stop");
	switch_console_set_complete("add avmd set inbound");	/* set inbound = 1, outbound = 0 */
	switch_console_set_complete("add avmd set outbound");   /* set inbound = 0, outbound = 1 */
	switch_console_set_complete("add avmd set default");	/* restore to factory settings */
	switch_console_set_complete("add avmd load inbound");   /* reload + set inbound */
	switch_console_set_complete("add avmd load outbound");  /* reload + set outbound */
	switch_console_set_complete("add avmd reload");		 /* reload XML (it loads from FS installation
															 * folder, not module's conf/autoload_configs */
	switch_console_set_complete("add avmd show");

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Advanced voicemail detection enabled\n");

	return SWITCH_STATUS_SUCCESS; /* indicate that the module should continue to be loaded */
}

void avmd_config_dump(avmd_session_t *s) {
	struct avmd_settings *settings;

	if (s == NULL) {
		return;
	}
	settings = &s->settings;
	switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_INFO, "Avmd dynamic configuration: debug [%u], report_status [%u], fast_math [%u],"
			" require_continuous_streak [%u], sample_n_continuous_streak [%u], sample_n_to_skip [%u], require_continuous_streak_amp [%u], sample_n_continuous_streak_amp [%u],"
		   " simplified_estimation [%u], inbound_channel [%u], outbound_channel [%u], detection_mode [%u], detectors_n [%u], detectors_lagged_n [%u]\n",
			settings->debug, settings->report_status, settings->fast_math, settings->require_continuous_streak, settings->sample_n_continuous_streak,
			settings->sample_n_to_skip, settings->require_continuous_streak_amp, settings->sample_n_continuous_streak_amp,
			settings->simplified_estimation, settings->inbound_channnel, settings->outbound_channnel, settings->mode, settings->detectors_n, settings->detectors_lagged_n);
	return;
}

static switch_status_t avmd_parse_cmd_data_one_entry(char *candidate, struct avmd_settings *settings) {
	char *candidate_parsed[3];
	int argc;
	const char *key;
	const char *val;

	if (settings == NULL) {
		return SWITCH_STATUS_TERM;
	}
	if (candidate == NULL) {
		return SWITCH_STATUS_NOOP;
	}

	argc = switch_separate_string(candidate, '=', candidate_parsed, (sizeof(candidate_parsed) / sizeof(candidate_parsed[0])));
	if (argc > 2) { /* currently we accept only option=value syntax */
		return SWITCH_STATUS_IGNORE;
	}

	/* this may be option parameter if valid */
	key = candidate_parsed[0];	  /* option name */
	if (zstr(key)) { /* empty key */
		return SWITCH_STATUS_NOT_INITALIZED;
	}
	val = candidate_parsed[1];	  /* value of the option: whole string starting at 1 past the '=' */
	if (zstr(val)) { /* nothing after "=" found, empty value */
		return SWITCH_STATUS_MORE_DATA;
	}
	/* candidate string has "=" somewhere in the middle and some value,
	 * try to find what option it is by comparing at most given number of bytes */
	if (!strcmp(key, "debug")) {
		settings->debug = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "report_status")) {
		settings->report_status = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "fast_math")) {
		settings->fast_math = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "require_continuous_streak")) {
		settings->require_continuous_streak = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "sample_n_continuous_streak")) {
		if(avmd_parse_u16_user_input(val, &settings->sample_n_continuous_streak, 0, UINT16_MAX) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else if (!strcmp(key, "sample_n_to_skip")) {
		if(avmd_parse_u16_user_input(val, &settings->sample_n_to_skip, 0, UINT16_MAX) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else if (!strcmp(key, "require_continuous_streak_amp")) {
		settings->require_continuous_streak_amp = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "sample_n_continuous_streak_amp")) {
		if(avmd_parse_u16_user_input(val, &settings->sample_n_continuous_streak_amp, 0, UINT16_MAX) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else if (!strcmp(key, "simplified_estimation")) {
		settings->simplified_estimation = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "inbound_channel")) {
		settings->inbound_channnel = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "outbound_channel")) {
		settings->outbound_channnel = (uint8_t) switch_true(val);
	} else if (!strcmp(key, "detection_mode")) {
		if(avmd_parse_u8_user_input(val, (uint8_t*)&settings->mode, 0, 2) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else if (!strcmp(key, "detectors_n")) {
		if(avmd_parse_u8_user_input(val, &settings->detectors_n, 0, UINT8_MAX) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else if (!strcmp(key, "detectors_lagged_n")) {
		if(avmd_parse_u8_user_input(val, &settings->detectors_lagged_n, 0, UINT8_MAX) == -1) {
			return SWITCH_STATUS_FALSE;
		}
	} else {
		return SWITCH_STATUS_NOTFOUND;
	}
	return SWITCH_STATUS_SUCCESS;
}

/* RCU style: reads, copies and then updates only if everything is fine,
 * if it returns SWITCH_STATUS_SUCCESS parsing went OK and avmd settings
 * are updated accordingly to @cmd_data, if SWITCH_STATUS_FALSE then
 * parsing error occurred and avmd session is left untouched */
static switch_status_t avmd_parse_cmd_data(avmd_session_t *s, const char *cmd_data, enum avmd_app app) {
	char *mydata;
	struct avmd_settings settings;
	int argc = 0, idx;
	char *argv[AVMD_PARAMS_APP_MAX * 2] = { 0 };
	switch_status_t status = SWITCH_STATUS_SUCCESS;

	if (s == NULL) {
		return SWITCH_STATUS_NOOP;
	}

	memcpy(&settings, &avmd_globals.settings, sizeof (struct avmd_settings));   /* copy globally set settings first */
	if (zstr(cmd_data)) {
		goto end_copy;
	}

	switch (app) {

		case AVMD_APP_START_APP:
			/* try to parse settings */
			mydata = switch_core_session_strdup(s->session, cmd_data);
			argc = switch_separate_string(mydata, ',', argv, (sizeof(argv) / sizeof(argv[0])));
			if (argc < AVMD_PARAMS_APP_START_MIN || argc > AVMD_PARAMS_APP_START_MAX) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
						"Syntax Error, avmd_start APP takes [%u] to [%u] parameters\n",
						AVMD_PARAMS_APP_START_MIN, AVMD_PARAMS_APP_START_MAX);
				switch_goto_status(SWITCH_STATUS_MORE_DATA, fail);
			}
			/* iterate over params, check if they mean something to us, set */
			idx = 0;
			while (idx < argc) {
				switch_assert(argv[idx]);
				status = avmd_parse_cmd_data_one_entry(argv[idx], &settings);
				if (status != SWITCH_STATUS_SUCCESS) {
					if (argv[idx]) {
						switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
							"Error parsing option [%d] [%s]\n", idx + 1, argv[idx]);	/* idx + 1 to report option 0 as 1 for users convenience */
					}
					switch (status)
					{
						case SWITCH_STATUS_TERM:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"NULL settings struct passed to parser\n");
							break;
						case SWITCH_STATUS_NOOP:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"NULL settings string passed to parser\n");
							break;
						case SWITCH_STATUS_IGNORE:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"Syntax error. Currently we accept only option=value syntax\n");
							break;
						case SWITCH_STATUS_NOT_INITALIZED:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"Syntax error. No key specified\n");
							break;
						case SWITCH_STATUS_MORE_DATA:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"Syntax error. No value for the key? Currently we accept only option=value syntax\n");
							break;
						case SWITCH_STATUS_FALSE:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"Bad value for this option\n");
							break;
						case SWITCH_STATUS_NOTFOUND:
							switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR,
									"Option not found. Please check option name is correct\n");
							break;
						default:
							break;
					}
					status = SWITCH_STATUS_FALSE;
					goto fail;
				}
				++idx;
			}
			/* OK */
			goto end_copy;
		default:
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_ERROR, "There is no app with index [%u] for avmd\n", app);
			switch_goto_status(SWITCH_STATUS_NOTFOUND, fail);
	}

end_copy:
	memcpy(&s->settings, &settings, sizeof (struct avmd_settings)); /* commit the change */
	return SWITCH_STATUS_SUCCESS;
fail:
	return status;
}

SWITCH_STANDARD_APP(avmd_start_app) {
	switch_media_bug_t *bug = NULL;
	switch_status_t status = SWITCH_STATUS_FALSE;
	switch_channel_t *channel = NULL;
	avmd_session_t *avmd_session = NULL;
	switch_core_media_flag_t flags = 0;
	const char *direction = "NO DIRECTION";
	uint8_t report = 0;

	if (session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "BUGGG. FreeSWITCH session is NULL! Please report to developers\n");
		return;
	}

	/* Get current channel of the session to tag the session. This indicates that our module is present
	 * At this moment this cannot return NULL, it will either succeed or assert failed, but we make ourself secure anyway */
	channel = switch_core_session_get_channel(session);
	if (channel == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "BUGGG. No channel for FreeSWITCH session! Please report this to the developers.\n");
		goto end;
	}

	bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_avmd_"); /* Is this channel already set? */
	if (bug != NULL) { /* We have already started */
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Avmd already started!\n");
		return;
	}

	/* Allocate memory attached to this FreeSWITCH session for use in the callback routine and to store state information */
	avmd_session = (avmd_session_t *) switch_core_session_alloc(session, sizeof(avmd_session_t));
	if (avmd_session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Can't allocate memory for avmd session!\n");
		status = SWITCH_STATUS_FALSE;
		goto end;
	}
	avmd_session->session = session;

	status = avmd_parse_cmd_data(avmd_session, data, AVMD_APP_START_APP);   /* dynamic configuation */
	switch (status) {
		case SWITCH_STATUS_SUCCESS:
			break;
		case SWITCH_STATUS_NOOP:
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to set dynamic parameters for avmd session. Session is NULL!\n");
			goto end;
		case SWITCH_STATUS_FALSE:
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to set dynamic parameters for avmd session. Parsing error, please check the parameters passed to this APP.\n");
			goto end;
		default:
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to set dynamic parameteres for avmd session. Unknown error\n");
			goto end;
	}
	
	report = avmd_session->settings.report_status;

	status = init_avmd_session_data(avmd_session, session, avmd_globals.mutex);
	if (status != SWITCH_STATUS_SUCCESS) {
		switch (status) {
			case SWITCH_STATUS_MEMERR:
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to init avmd session. Buffer error!\n");
				break;
			case SWITCH_STATUS_MORE_DATA:
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to init avmd session. SMA buffer size is 0!\n");
				break;
			case SWITCH_STATUS_FALSE:
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to init avmd session. SMA buffers error\n");
				break;
			default:
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to init avmd session. Unknown error\n");
				break;
		}
		goto end;
	}

	switch_mutex_lock(avmd_session->mutex);
	if (avmd_session->settings.report_status == 1) { /* dump dynamic parameters */
		avmd_config_dump(avmd_session);
	}
	if ((SWITCH_CALL_DIRECTION_OUTBOUND == switch_channel_direction(channel)) && (avmd_session->settings.outbound_channnel == 1)) {
			flags |= SMBF_READ_REPLACE;
			direction = "READ_REPLACE";
	}
	if ((SWITCH_CALL_DIRECTION_INBOUND == switch_channel_direction(channel)) && (avmd_session->settings.inbound_channnel == 1)) {
			flags |= SMBF_WRITE_REPLACE;
			if (!strcmp(direction, "READ_REPLACE")) {
				direction = "READ_REPLACE | WRITE_REPLACE";
			} else {
				direction = "WRITE_REPLACE";
			}
	}

	if (flags == 0) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Can't set direction for channel [%s]\n", switch_channel_get_name(channel));
		status = SWITCH_STATUS_FALSE;
		goto end_unlock;
	}

	if ((SWITCH_CALL_DIRECTION_OUTBOUND == switch_channel_direction(channel)) && (avmd_session->settings.outbound_channnel == 1)) {
		if (switch_channel_test_flag(channel, CF_MEDIA_SET) == 0) {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Channel [%s] has no codec assigned yet. Please try again\n", switch_channel_get_name(channel));
			status = SWITCH_STATUS_FALSE;
			goto end_unlock;
		}
	}

	status = avmd_launch_threads(avmd_session);
	if (status != SWITCH_STATUS_SUCCESS) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to start detection threads\n");
		avmd_join_threads(avmd_session);
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_INFO, "Joined detection threads\n");
		goto end_unlock;
	}

	status = switch_core_media_bug_add(session, "avmd", NULL, avmd_callback, avmd_session, 0, flags, &bug); /* Add a media bug that allows me to intercept the audio stream */
	if (status != SWITCH_STATUS_SUCCESS) { /* If adding a media bug fails exit */
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Failed to add media bug!\n");

		switch_mutex_unlock(avmd_session->mutex);
		avmd_session_close(avmd_session);
		goto end;
	}

	switch_mutex_lock(avmd_globals.mutex);
	++avmd_globals.session_n;
	switch_mutex_unlock(avmd_globals.mutex);

	switch_channel_set_private(channel, "_avmd_", bug); /* Set the avmd tag to detect an existing avmd media bug */
	avmd_fire_event(AVMD_EVENT_SESSION_START, session, 0, 0, 0, 0, 0, 0, 0, 0, avmd_session->start_time, 0, 0, 0, 0);
	if (avmd_session->settings.report_status == 1) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_INFO, "Avmd on channel [%s] started! direction=%s\n", switch_channel_get_name(channel), direction);
	}

end_unlock:
	switch_mutex_unlock(avmd_session->mutex);

end:
	if (status != SWITCH_STATUS_SUCCESS) {
		if (avmd_session == NULL || report) {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Avmd on channel [%s] NOT started\n", switch_channel_get_name(channel));
		}
	}
	return;
}

SWITCH_STANDARD_APP(avmd_stop_app) {
	switch_media_bug_t  *bug;
	switch_channel_t	*channel;
	avmd_session_t	  *avmd_session;
	switch_time_t	   start_time, stop_time, total_time;
	uint8_t			 report_status = 0;
	avmd_beep_state_t   beep_status = BEEP_NOTDETECTED;

	if (session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "FreeSWITCH is NULL! Please report to developers\n");
		return;
	}

	/* Get current channel of the session to tag the session. This indicates that our module is present
	 * At this moment this cannot return NULL, it will either succeed or assert failed, but we make ourself secure anyway */
	channel = switch_core_session_get_channel(session);
	if (channel == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "No channel for FreeSWITCH session! Please report this to the developers.\n");
		return;
	}

	bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_avmd_");
	if (bug == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Stop failed - no avmd session running on this channel [%s]!\n", switch_channel_get_name(channel));
		return;
	}

	avmd_session = switch_core_media_bug_get_user_data(bug);
	if (avmd_session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_ERROR, "Stop failed - no avmd session object, stop event not fired on this channel [%s]!\n", switch_channel_get_name(channel));
	} else {
		switch_mutex_lock(avmd_session->mutex);
		report_status = avmd_session->settings.report_status;
		beep_status = avmd_session->state.beep_state;
		avmd_session->stop_time = switch_micro_time_now();
		start_time = avmd_session->start_time;
		stop_time = avmd_session->stop_time;
		total_time = stop_time - start_time;
		switch_mutex_unlock(avmd_session->mutex);
		avmd_fire_event(AVMD_EVENT_SESSION_STOP, session, 0, 0, 0, 0, beep_status, 1, 0, 0, start_time, stop_time, 0, 0, 0);
		if (report_status == 1) {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_INFO, "Avmd on channel [%s] stopped, beep status: [%s], total running time [%" PRId64 "] [us]\n", switch_channel_get_name(channel), beep_status == BEEP_DETECTED ? "DETECTED" : "NOTDETECTED", total_time);
		}
	}
	switch_channel_set_private(channel, "_avmd_", NULL);
	switch_core_media_bug_remove(session, &bug);

	return;
}

/*! \brief FreeSWITCH application handler function.
 *  This handles calls made from applications such as LUA and the dialplan.
 */
SWITCH_STANDARD_APP(avmd_start_function) {
	switch_media_bug_t *bug;
	switch_channel_t *channel;

	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "YOU ARE USING DEPRECATED APP INTERFACE. Please read documentation about new syntax\n");
	if (session == NULL) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "No FreeSWITCH session assigned!\n");
		return;
	}

	channel = switch_core_session_get_channel(session);

	bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_avmd_");
	if (bug != NULL) {
		if (strcasecmp(data, "stop") == 0) {
			switch_channel_set_private(channel, "_avmd_", NULL);
			switch_core_media_bug_remove(session, &bug);
			return;
		}
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_WARNING, "Cannot run 2 at once on the same channel!\n");
		return;
	}
	avmd_start_app(session, NULL);
}

SWITCH_MODULE_SHUTDOWN_FUNCTION(mod_avmd_shutdown) {
	size_t session_n;
#ifndef WIN32
	int res;
#endif

	switch_mutex_lock(avmd_globals.mutex);

	session_n = avmd_globals.session_n;
	if (session_n > 0) {
		switch_mutex_unlock(avmd_globals.mutex);
			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "PLEASE DO NOT RELOAD MODULE WHILE SESSIONS ARE RUNNING\n");
	}

	avmd_unregister_all_events();

#ifndef WIN32
	if (avmd_globals.settings.fast_math == 1) {
		res = destroy_fast_acosf();
		if (res != 0) {
			switch (res) {
				case -1:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed unmap arc cosine table\n");
					break;
				case -2:
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Failed closing arc cosine table\n");
					break;
				default:
					break;
			}
		}
	}
#endif

	switch_event_unbind_callback(avmd_reloadxml_event_handler);
	switch_mutex_unlock(avmd_globals.mutex);
	switch_mutex_destroy(avmd_globals.mutex);
	switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_NOTICE, "Advanced voicemail detection disabled\n");
	return SWITCH_STATUS_SUCCESS;
}

/*! \brief FreeSWITCH API handler function. */
SWITCH_STANDARD_API(avmd_api_main) {
	switch_media_bug_t *bug = NULL;
	avmd_session_t *avmd_session = NULL;
	switch_channel_t *channel = NULL;
	int argc;
	const char *uuid = NULL, *uuid_dup = NULL;
	const char *command = NULL;
	char *dupped = NULL, *argv[AVMD_PARAMS_API_MAX + 1] = { 0 };
	switch_core_media_flag_t flags = 0;
	switch_status_t status = SWITCH_STATUS_SUCCESS;
	switch_core_session_t *fs_session = NULL;

	switch_mutex_lock(avmd_globals.mutex);

	if (zstr(cmd)) {
		stream->write_function(stream, "-ERR, bad command!\n-USAGE: %s\n\n", AVMD_SYNTAX);
		goto end;
	}

	dupped = strdup(cmd);
	switch_assert(dupped);
	argc = switch_separate_string((char*)dupped, ' ', argv, (sizeof(argv) / sizeof(argv[0])));

	if (argc < AVMD_PARAMS_API_MIN) {
		stream->write_function(stream, "-ERR, avmd takes [%u] min and [%u] max parameters!\n-USAGE: %s\n\n", AVMD_PARAMS_API_MIN, AVMD_PARAMS_API_MAX, AVMD_SYNTAX);
		goto end;
	}

	command = argv[0];
	if (strcasecmp(command, "reload") == 0) {
		status = avmd_load_xml_configuration(NULL);
		if (avmd_globals.settings.report_status == 1) {
			if (status != SWITCH_STATUS_SUCCESS) {
				stream->write_function(stream, "-ERR, couldn't reload XML configuration\n");
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't reload XML configuration\n");
			} else {
				stream->write_function(stream, "+OK\n XML reloaded\n\n");
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "XML reloaded\n");
			}
			goto end;
		}
	}
	if (strcasecmp(command, "load") == 0) {
		if (argc != 2) {
			stream->write_function(stream, "-ERR, load command takes 1 parameter!\n-USAGE: %s\n\n", AVMD_SYNTAX);
			goto end;
		}
		command = argv[1];
		if (strcasecmp(command, "inbound") == 0) {
			status = avmd_load_xml_inbound_configuration(NULL);
			if (avmd_globals.settings.report_status == 1) {
				if (status != SWITCH_STATUS_SUCCESS) {
					stream->write_function(stream, "-ERR, couldn't load XML configuration\n");
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't load XML configuration\n");
				} else {
					stream->write_function(stream, "+OK\n inbound XML configuration loaded\n\n");
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Inbound XML configuration loaded\n");
				}
				goto end;
			}
		} else if (strcasecmp(command, "outbound") == 0) {
			status = avmd_load_xml_outbound_configuration(NULL);
			if (avmd_globals.settings.report_status == 1) {
				if (status != SWITCH_STATUS_SUCCESS) {
					stream->write_function(stream, "-ERR, couldn't load XML configuration\n");
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_ERROR, "Couldn't load XML configuration\n");
				} else {
					stream->write_function(stream, "+OK\n outbound XML configuration loaded\n\n");
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Outbound XML configuration loaded\n");
				}
				goto end;
			}
		} else {
			stream->write_function(stream, "-ERR, load command: bad syntax!\n-USAGE: %s\n\n", AVMD_SYNTAX);
		}
		goto end;
	}
	if (strcasecmp(command, "set") == 0) {
		if (argc != 2) {
			stream->write_function(stream, "-ERR, set command takes 1 parameter!\n-USAGE: %s\n\n", AVMD_SYNTAX);
			goto end;
		}
		command = argv[1];
		if (strcasecmp(command, "inbound") == 0) {
			avmd_set_xml_inbound_configuration(NULL);
			if (avmd_globals.settings.report_status == 1) {
				stream->write_function(stream, "+OK\n inbound XML configuration loaded\n\n");
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Inbound XML configuration loaded\n");
			}
		} else if (strcasecmp(command, "outbound") == 0) {
			avmd_set_xml_outbound_configuration(NULL);
			if (avmd_globals.settings.report_status == 1) {
				stream->write_function(stream, "+OK\n outbound XML configuration loaded\n\n");
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Outbound XML configuration loaded\n");
			}
		} else if (strcasecmp(command, "default") == 0) {
			avmd_set_xml_default_configuration(NULL);
			if (avmd_globals.settings.report_status == 1) {
				stream->write_function(stream, "+OK\n reset to factory settings\n\n");
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_INFO, "Reset to factory settings\n");
			}
		} else {
			stream->write_function(stream, "-ERR, set command: bad syntax!\n-USAGE: %s\n\n", AVMD_SYNTAX);
		}
		goto end;
	}
	if (strcasecmp(command, "show") == 0) {
		avmd_show(stream, NULL);
		if (avmd_globals.settings.report_status == 1) {
			stream->write_function(stream, "+OK\n show\n\n");
		}
		goto end;
	}

	uuid = argv[0];
	command = argv[1];

	fs_session = switch_core_session_locate(uuid);  /* using uuid locate a reference to the FreeSWITCH session */
	if (fs_session == NULL) {
		stream->write_function(stream, "-ERR, no FreeSWITCH session for uuid [%s]!\n-USAGE: %s\n\n", uuid, AVMD_SYNTAX);
		goto end;
	}

	/* Get current channel of the session to tag the session. This indicates that our module is present
	 * At this moment this cannot return NULL, it will either succeed or assert failed, but we make ourself secure anyway */
	channel = switch_core_session_get_channel(fs_session);
	if (channel == NULL) {
		stream->write_function(stream, "-ERR, no channel for FreeSWITCH session [%s]!\n Please report this to the developers\n\n", uuid);
		goto end;
	}

	bug = (switch_media_bug_t *) switch_channel_get_private(channel, "_avmd_");
	if (bug != NULL) {
		if (strcasecmp(command, "stop") == 0) {
			avmd_session = (avmd_session_t*) switch_core_media_bug_get_user_data(bug);
			if (avmd_session == NULL) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Stop failed - no avmd session object on this channel [%s]!\n", switch_channel_get_name(channel));
				goto end;
			}
			uuid_dup = switch_core_strdup(switch_core_session_get_pool(fs_session), uuid);
			switch_channel_set_private(channel, "_avmd_", NULL);
			switch_core_media_bug_remove(fs_session, &bug);
			avmd_fire_event(AVMD_EVENT_SESSION_STOP, fs_session, 0, 0, 0, 0, 0, 0, 0, 0, avmd_session->start_time, avmd_session->stop_time, 0, 0, 0);
			if (avmd_globals.settings.report_status == 1) {
				stream->write_function(stream, "+OK\n [%s] [%s] stopped\n\n", uuid_dup, switch_channel_get_name(channel));
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_INFO, "Avmd on channel [%s] stopped!\n", switch_channel_get_name(channel));
			}
			goto end;
		}
		if (avmd_globals.settings.report_status == 1) {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Avmd already started!\n");
			stream->write_function(stream, "-ERR, avmd for FreeSWITCH session [%s]\n already started\n\n", uuid);
		}
		goto end;
	}

	if (strcasecmp(command, "stop") == 0) {
		uuid_dup = switch_core_strdup(switch_core_session_get_pool(fs_session), uuid);
		stream->write_function(stream, "+ERR, avmd has not yet been started on\n [%s] [%s]\n\n", uuid_dup, switch_channel_get_name(channel));
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Stop failed - avmd has not yet been started on channel [%s]!\n", switch_channel_get_name(channel));
		goto end;
	}
	if ((SWITCH_CALL_DIRECTION_OUTBOUND == switch_channel_direction(channel)) && (avmd_globals.settings.outbound_channnel == 1)) {
			flags |= SMBF_READ_REPLACE;
	}
	if ((SWITCH_CALL_DIRECTION_INBOUND == switch_channel_direction(channel)) && (avmd_globals.settings.inbound_channnel == 1)) {
			flags |= SMBF_WRITE_REPLACE;
	}
	if (flags == 0) {
		stream->write_function(stream, "-ERR, can't set direction for channel [%s]\n for FreeSWITCH session [%s]. Please check avmd configuration\n\n", switch_channel_get_name(channel), uuid);
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Can't set direction for channel [%s]\n", switch_channel_get_name(channel));
		status = SWITCH_STATUS_FALSE;
		goto end;
	}
	if ((SWITCH_CALL_DIRECTION_OUTBOUND == switch_channel_direction(channel)) && (avmd_globals.settings.outbound_channnel == 1)) {
		if (switch_channel_test_flag(channel, CF_MEDIA_SET) == 0) {
			stream->write_function(stream, "-ERR, channel [%s] for FreeSWITCH session [%s]\n has no read codec assigned yet. Please try again.\n\n", switch_channel_get_name(channel), uuid);
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Channel [%s] has no codec assigned yet. Please try again\n", switch_channel_get_name(channel));
			status = SWITCH_STATUS_FALSE;
			goto end;
		}
	}
	if (strcasecmp(command, "start") != 0) { /* If we don't see the expected start exit */
		stream->write_function(stream, "-ERR, did you mean\n api avmd %s start ?\n-USAGE: %s\n\n", uuid, AVMD_SYNTAX);
		goto end;
	}

	avmd_session = (avmd_session_t *) switch_core_session_alloc(fs_session, sizeof(avmd_session_t)); /* Allocate memory attached to this FreeSWITCH session for use in the callback routine and to store state information */
	status = init_avmd_session_data(avmd_session, fs_session, NULL);
	if (status != SWITCH_STATUS_SUCCESS) {
		stream->write_function(stream, "-ERR, failed to initialize avmd session\n for FreeSWITCH session [%s]\n", uuid);
		switch (status) {
			case SWITCH_STATUS_MEMERR:
				stream->write_function(stream, "-ERR, buffer error\n\n");
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Failed to init avmd session. Buffer error!\n");
				break;
			case SWITCH_STATUS_MORE_DATA:
				stream->write_function(stream, "-ERR, SMA buffer size is 0\n\n");
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Failed to init avmd session. SMA buffer size is 0!\n");
				break;
			case SWITCH_STATUS_FALSE:
				stream->write_function(stream, "-ERR, SMA buffer error\n\n");
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Failed to init avmd session. SMA buffers error\n");
				break;
			default:
				stream->write_function(stream, "-ERR, unknown error\n\n");
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Failed to init avmd session. Unknown error\n");
				break;
		}
		goto end;
	}

	status = switch_core_media_bug_add(fs_session, "avmd", NULL, avmd_callback, avmd_session, 0, flags, &bug); /* Add a media bug that allows me to intercept the reading leg of the audio stream */

	if (status != SWITCH_STATUS_SUCCESS) { /* If adding a media bug fails exit */
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_ERROR, "Failed to add media bug!\n");
		stream->write_function(stream, "-ERR, [%s] failed to add media bug!\n\n", uuid);
		goto end;
	}

	switch_channel_set_private(channel, "_avmd_", bug); /* Set the vmd tag to detect an existing vmd media bug */

	avmd_fire_event(AVMD_EVENT_SESSION_START, fs_session, 0, 0, 0, 0, 0, 0, 0, 0, avmd_session->start_time, 0, 0, 0, 0);
	if (avmd_globals.settings.report_status == 1) {
		stream->write_function(stream, "+OK\n [%s] [%s] started!\n\n", uuid, switch_channel_get_name(channel));
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_INFO, "Avmd on channel [%s] started!\n", switch_channel_get_name(channel));
		switch_assert(status == SWITCH_STATUS_SUCCESS);
	}
end:

	if (status != SWITCH_STATUS_SUCCESS) {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(fs_session), SWITCH_LOG_INFO, "AVMD session NOT started\n");
			if (avmd_globals.settings.report_status == 1) {
				if ((uuid != NULL) && (channel != NULL)) {
					stream->write_function(stream, "+ERR\n [%s] [%s] NOT started!\n\n", uuid, switch_channel_get_name(channel));
				} else {
					stream->write_function(stream, "+ERR\n AVMD session NOT started!\n\n", switch_channel_get_name(channel));
				}
			}
	}
	if (fs_session) {
		switch_core_session_rwunlock(fs_session);
	}

	switch_safe_free(dupped);

	switch_mutex_unlock(avmd_globals.mutex);

	return SWITCH_STATUS_SUCCESS;
}

static int
avmd_decision_amplitude(const avmd_session_t *s, const struct avmd_buffer *b, double v, double rsd_threshold) {
	double a, rsd;
	size_t lpos;

	lpos = b->sma_b.lpos;
	if ((lpos >= AVMD_BEEP_LEN(s->rate) / b->resolution) && ((s->settings.require_continuous_streak_amp == 1 && (b->sma_amp_b.lpos > s->settings.sample_n_continuous_streak_amp) && (b->samples_streak_amp == 0))
			|| (s->settings.require_continuous_streak_amp == 0 && (b->sma_amp_b.lpos > 1)))) {
		a = fabs(b->sma_amp_b.sma);
		if (a < AVMD_MIN_AMP) {
			return 0;
		}
		rsd = sqrt(v) / a;
		if (rsd < rsd_threshold) {
			return 1;
		}
	}
	return 0;
}

static int
avmd_decision_freq(const avmd_session_t *s, const struct avmd_buffer *b, double v, double rsd_threshold) {
	double f, rsd;
	size_t lpos;
	f = AVMD_TO_HZ(s->rate, fabs(b->sma_b_fir.sma));
	if ((f < AVMD_MIN_FREQUENCY) || (f > AVMD_MAX_FREQUENCY)) {
		return 0;
	}
	lpos = b->sma_b.lpos;
	if ((lpos >= AVMD_BEEP_LEN(s->rate) / b->resolution) && ((s->settings.require_continuous_streak == 1 && (b->sma_b.lpos > s->settings.sample_n_continuous_streak) && (b->samples_streak == 0))
			|| (s->settings.require_continuous_streak == 0 && (b->sma_b.lpos > 1)))) {
		rsd = sqrt(v) / f;
		if ((rsd < 0.3 * rsd_threshold) && (b->sma_amp_b.sma >= 0.005 * b->amplitude_max)) {
			return 1;
		}
		if ((rsd < 0.6 * rsd_threshold) && (b->sma_amp_b.sma >= 0.01 * b->amplitude_max)) {
			return 1;
		}
		if ((rsd < rsd_threshold) && (b->sma_amp_b.sma >= 0.015 * b->amplitude_max)) {
			return 1;
		}
	}
	return 0;
}

static void avmd_report_detection(avmd_session_t *s, enum avmd_detection_mode mode, const struct avmd_detector *d) {
	switch_channel_t *channel;
	switch_time_t detection_time;
	double f_sma = 0.0;
	double v_amp = 9999.9, v_fir = 9999.9;

	const struct avmd_buffer *b = &d->buffer;
	const sma_buffer_t *sma_b_fir = &b->sma_b_fir;
	const sma_buffer_t *sqa_b_fir = &b->sqa_b_fir;

	const sma_buffer_t *sma_amp_b = &b->sma_amp_b;
	const sma_buffer_t *sqa_amp_b = &b->sqa_amp_b;

	channel = switch_core_session_get_channel(s->session);

	s->detection_stop_time = switch_micro_time_now();														   /* stop detection timer	 */
	detection_time = s->detection_stop_time - s->detection_start_time;										  /* detection time length	*/
	switch_channel_set_variable_printf(channel, "avmd_total_time", "[%" PRId64 "]", detection_time / 1000);
	switch_channel_execute_on(channel, "execute_on_avmd_beep");
	switch_channel_set_variable(channel, "avmd_detect", "TRUE");
	switch (mode) {

		case AVMD_DETECT_AMP:
			v_amp = sqa_amp_b->sma - (sma_amp_b->sma * sma_amp_b->sma);											   /* calculate variance of amplitude (biased estimator) */
			avmd_fire_event(AVMD_EVENT_BEEP, s->session, 0, 0, sma_amp_b->sma, v_amp, 0, 0, s->detection_start_time, s->detection_stop_time, 0, 0, b->resolution, b->offset, d->idx);
			if (s->settings.report_status == 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_INFO, "<<< AVMD - Beep Detected [%u][%u][%u][%u]: amplitude = [%f](max [%f]) variance = [%f], detection time [%" PRId64 "] [us] >>>\n",
						mode, b->resolution, b->offset, d->idx, sma_amp_b->sma, b->amplitude_max, v_amp, detection_time);
			}
			break;

		case AVMD_DETECT_FREQ:
			f_sma = sma_b_fir->sma;
			v_fir = sqa_b_fir->sma - (sma_b_fir->sma * sma_b_fir->sma);											   /* calculate variance of filtered samples */
			avmd_fire_event(AVMD_EVENT_BEEP, s->session, AVMD_TO_HZ(s->rate, f_sma), v_fir, 0, 0, 0, 0, s->detection_start_time, s->detection_stop_time, 0, 0, b->resolution, b->offset, d->idx);
			if (s->settings.report_status == 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_INFO, "<<< AVMD - Beep Detected [%u][%u][%u][%u]: f = [%f] variance = [%f], detection time [%" PRId64 "] [us] >>>\n",
						mode, b->resolution, b->offset, d->idx, AVMD_TO_HZ(s->rate, f_sma), v_fir, detection_time);
			}
			break;

		case AVMD_DETECT_BOTH:
			v_amp = sqa_amp_b->sma - (sma_amp_b->sma * sma_amp_b->sma);											   /* calculate variance of amplitude (biased estimator) */
			f_sma = sma_b_fir->sma;
			v_fir = sqa_b_fir->sma - (sma_b_fir->sma * sma_b_fir->sma);											   /* calculate variance of filtered samples */
			avmd_fire_event(AVMD_EVENT_BEEP, s->session, AVMD_TO_HZ(s->rate, f_sma), v_fir, sma_amp_b->sma, v_amp, 0, 0, s->detection_start_time, s->detection_stop_time, 0, 0, b->resolution, b->offset, d->idx);
			if (s->settings.report_status == 1) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_INFO, "<<< AVMD - Beep Detected [%u][%u][%u][%u]: f = [%f] variance = [%f], amplitude = [%f](max [%f]) variance = [%f], detection time [%" PRId64 "] [us] >>>\n",
						mode, b->resolution, b->offset, d->idx, AVMD_TO_HZ(s->rate, f_sma), v_fir, sma_amp_b->sma, b->amplitude_max, v_amp, detection_time);
			}
			break;

		default:
			break;
	}
	s->state.beep_state = BEEP_DETECTED;
}

static uint8_t
avmd_detection_in_progress(avmd_session_t *s) {
	uint8_t idx = 0;
	while (idx < (s->settings.detectors_n + s->settings.detectors_lagged_n)) {
		switch_mutex_lock(s->detectors[idx].mutex);
		if (s->detectors[idx].flag_processing_done == 0) {
			switch_mutex_unlock(s->detectors[idx].mutex);
			return 1;
		}
		switch_mutex_unlock(s->detectors[idx].mutex);
		++idx;
	}
	return 0;
}

static enum avmd_detection_mode
avmd_detection_result(avmd_session_t *s) {
	enum avmd_detection_mode res;
	uint8_t idx = 0;
	while (idx < (s->settings.detectors_n + s->settings.detectors_lagged_n)) {
		res = s->detectors[idx].result;
		if (res != AVMD_DETECT_NONE) {
			avmd_report_detection(s, res, &s->detectors[idx]);
			return res;
		}
		++idx;
	}
	return AVMD_DETECT_NONE;
}

/*! \brief Process one frame of data with avmd algorithm.
 * @param session An avmd session.
 * @param frame An audio frame.
 */
static void avmd_process(avmd_session_t *s, switch_frame_t *frame, uint8_t direction) {
	circ_buffer_t *b;
	uint8_t idx;
	struct avmd_detector *d;


	b = &s->b;

	switch_mutex_lock(s->mutex_detectors_done);
	while (avmd_detection_in_progress(s) == 1) {
		switch_thread_cond_wait(s->cond_detectors_done, s->mutex_detectors_done);
	}
	switch_mutex_unlock(s->mutex_detectors_done);

	if (s->state.beep_state == BEEP_DETECTED) {						 /* If beep has already been detected skip the CPU heavy stuff */
		return;
	}

	if (s->frame_n_to_skip > 0) {
		s->frame_n_to_skip--;
		return;
	}

	if (s->settings.debug) {
		switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(s->session), SWITCH_LOG_INFO, "AVMD: processing frame [%zu], direction=%s\n", s->frame_n, direction == AVMD_READ_REPLACE ? "READ" : "WRITE");
	}

	if (s->detection_start_time == 0) {
		s->detection_start_time = switch_micro_time_now();			  /* start detection timer */
	}

	INSERT_INT16_FRAME(b, (int16_t *)(frame->data), frame->samples);	/* Insert frame of 16 bit samples into buffer */

	idx = 0;
	while (idx < (s->settings.detectors_n + s->settings.detectors_lagged_n)) {
		d = &s->detectors[idx];
		switch_mutex_lock(d->mutex);
		d = &s->detectors[idx];
		if (d->result == AVMD_DETECT_NONE) {
			d->flag_processing_done = 0;
			d->flag_should_exit = 0;
			d->samples = (s->frame_n == 0 ? frame->samples - AVMD_P : frame->samples);
			switch_thread_cond_signal(d->cond_start_processing);
		}
		switch_mutex_unlock(d->mutex);
		++idx;
	}

	switch_mutex_lock(s->mutex_detectors_done);
	while (avmd_detection_in_progress(s) == 1) {
		switch_thread_cond_wait(s->cond_detectors_done, s->mutex_detectors_done);
	}
	avmd_detection_result(s);
	switch_mutex_unlock(s->mutex_detectors_done);

	++s->frame_n;
	if (s->frame_n == 1) {
		s->pos += frame->samples - AVMD_P;
	} else {
		s->pos += frame->samples;
	}
	s->pos &= b->mask;

	return;
}

static void avmd_reloadxml_event_handler(switch_event_t *event) {
	avmd_load_xml_configuration(avmd_globals.mutex);
}

static enum avmd_detection_mode avmd_process_sample(avmd_session_t *s, circ_buffer_t *b, size_t sample_n, size_t pos, struct avmd_detector *d) {
	struct avmd_buffer *buffer = &d->buffer;
	uint16_t sample_to_skip_n = s->settings.sample_n_to_skip;
	enum avmd_detection_mode mode = s->settings.mode;
	uint8_t valid_amplitude = 1, valid_omega = 1;
	double omega = 0.0, amplitude = 0.0;
	double f = 0.0, f_fir = 0.0;
	double v_amp = 9999.9, v_fir = 9999.9;

	sma_buffer_t *sma_b = &buffer->sma_b;
	sma_buffer_t *sqa_b = &buffer->sqa_b;

	sma_buffer_t *sma_b_fir = &buffer->sma_b_fir;
	sma_buffer_t *sqa_b_fir = &buffer->sqa_b_fir;

	sma_buffer_t *sma_amp_b = &buffer->sma_amp_b;
	sma_buffer_t *sqa_amp_b = &buffer->sqa_amp_b;

	if (sample_to_skip_n > 0) {
		sample_to_skip_n--;
		valid_amplitude = 0;
		valid_omega = 0;
		return AVMD_DETECT_NONE;
	}

	omega = avmd_desa2_tweaked(b, pos + sample_n, &amplitude);

	if (mode == AVMD_DETECT_AMP || mode == AVMD_DETECT_BOTH) {
		if (ISNAN(amplitude) || ISINF(amplitude)) {
			valid_amplitude = 0;
			if (s->settings.require_continuous_streak_amp == 1) {
				RESET_SMA_BUFFER(sma_amp_b);
				RESET_SMA_BUFFER(sqa_amp_b);
				buffer->samples_streak_amp = s->settings.sample_n_continuous_streak_amp;
				sample_to_skip_n = s->settings.sample_n_to_skip;
			}
		} else {
			if (ISINF(amplitude)) {
				amplitude = buffer->amplitude_max;
			}
			if (valid_amplitude == 1) {
				APPEND_SMA_VAL(sma_amp_b, amplitude);			   /* append amplitude */
				APPEND_SMA_VAL(sqa_amp_b, amplitude * amplitude);
				if (s->settings.require_continuous_streak_amp == 1) {
					if (buffer->samples_streak_amp > 0) {
						--buffer->samples_streak_amp;
						valid_amplitude = 0;
					}
				}
			}
			if (sma_amp_b->sma > buffer->amplitude_max) {
				buffer->amplitude_max = sma_amp_b->sma;
			}
		}
	}

	if (mode == AVMD_DETECT_FREQ || mode == AVMD_DETECT_BOTH) {
		if (ISNAN(omega)) {
			valid_omega = 0;
			if (s->settings.require_continuous_streak == 1) {
				RESET_SMA_BUFFER(sma_b);
				RESET_SMA_BUFFER(sqa_b);
				RESET_SMA_BUFFER(sma_b_fir);
				RESET_SMA_BUFFER(sqa_b_fir);
				buffer->samples_streak = s->settings.sample_n_continuous_streak;
				sample_to_skip_n = s->settings.sample_n_to_skip;
			}
			sample_to_skip_n = s->settings.sample_n_to_skip;
		} else if (omega < -0.99999 || omega > 0.99999) {
			valid_omega = 0;
			if (s->settings.require_continuous_streak == 1) {
				RESET_SMA_BUFFER(sma_b);
				RESET_SMA_BUFFER(sqa_b);
				RESET_SMA_BUFFER(sma_b_fir);
				RESET_SMA_BUFFER(sqa_b_fir);
				buffer->samples_streak = s->settings.sample_n_continuous_streak;
				sample_to_skip_n = s->settings.sample_n_to_skip;
			}
		} else {
			if (valid_omega) {

#if !defined(WIN32) && defined(AVMD_FAST_MATH)
				f =  0.5 * (double) fast_acosf((float)omega);
#else
				f = 0.5 * acos(omega);
#endif /* !WIN32 && AVMD_FAST_MATH */
				f_fir = sma_b->pos > 1 ? (AVMD_MEDIAN_FILTER(sma_b->data[sma_b->pos - 2], sma_b->data[sma_b->pos - 1], f)) : f;

				APPEND_SMA_VAL(sma_b, f); /* append frequency */
				APPEND_SMA_VAL(sqa_b, f * f);
				APPEND_SMA_VAL(sma_b_fir, f_fir); /* append filtered frequency */
				APPEND_SMA_VAL(sqa_b_fir, f_fir * f_fir);
				if (s->settings.require_continuous_streak == 1) {
					if (buffer->samples_streak > 0) {
						--buffer->samples_streak;
						valid_omega = 0;
					}
				}
			}
		}
	}

	if (((mode == AVMD_DETECT_AMP) || (mode == AVMD_DETECT_BOTH)) && (valid_amplitude == 1)) {
		v_amp = sqa_amp_b->sma - (sma_amp_b->sma * sma_amp_b->sma); /* calculate variance of amplitude (biased estimator) */
		if ((mode == AVMD_DETECT_AMP) && (avmd_decision_amplitude(s, buffer, v_amp, AVMD_AMPLITUDE_RSD_THRESHOLD) == 1)) {
			return AVMD_DETECT_AMP;
		}
	}
	if (((mode == AVMD_DETECT_FREQ) || (mode == AVMD_DETECT_BOTH)) && (valid_omega == 1)) {
		v_fir = sqa_b_fir->sma - (sma_b_fir->sma * sma_b_fir->sma); /* calculate variance of filtered samples */
		if ((mode == AVMD_DETECT_FREQ) && (avmd_decision_freq(s, buffer, v_fir, AVMD_VARIANCE_RSD_THRESHOLD) == 1)) {
			return AVMD_DETECT_FREQ;
		}
		if (mode == AVMD_DETECT_BOTH) {
			if ((avmd_decision_amplitude(s, buffer, v_amp, AVMD_AMPLITUDE_RSD_THRESHOLD) == 1) && (avmd_decision_freq(s, buffer, v_fir, AVMD_VARIANCE_RSD_THRESHOLD) == 1))  {
				return AVMD_DETECT_BOTH;
			}
		}
	}
	return AVMD_DETECT_NONE;
}

static void* SWITCH_THREAD_FUNC
avmd_detector_func(switch_thread_t *thread, void *arg) {
	size_t sample_n = 0, samples = AVMD_P;
	size_t pos;
	uint8_t resolution, offset;
	avmd_session_t  *s;
	enum avmd_detection_mode res = AVMD_DETECT_NONE;
	struct avmd_detector *d;


	d = (struct avmd_detector*) arg;
	s = d->s;
	pos = s->pos;
	while (1) {
		switch_mutex_lock(d->mutex);
		while ((d->flag_processing_done == 1) && (d->flag_should_exit == 0)) {
			switch_thread_cond_wait(d->cond_start_processing, d->mutex);
		}
		/* master set processing_done flag to 0 or thread should exit */
		if (d->flag_should_exit == 1) {
			d->flag_processing_done = 1;
			goto end;
		}
		resolution = d->buffer.resolution;
		offset = d->buffer.offset;
		samples = d->samples;

		if (d->lagged == 1) {
			if (d->lag > 0) {
				--d->lag;
				goto done;
			}
			pos += AVMD_P;
		}

		switch_mutex_unlock(d->mutex);
		sample_n = 1;
		while (sample_n <= samples) {
			if (((sample_n + offset) % resolution) == 0) {
				res = avmd_process_sample(d->s, &s->b, sample_n, pos, d);
				if (res != AVMD_DETECT_NONE) {
					break;
				}
			}
			++sample_n;
		}
		switch_mutex_lock(d->mutex);
done:
		d->flag_processing_done = 1;
		d->result = res;
		switch_mutex_unlock(d->mutex);

		switch_mutex_lock(s->mutex_detectors_done);
		switch_thread_cond_signal(s->cond_detectors_done);
		switch_mutex_unlock(s->mutex_detectors_done);
	}
	return NULL;

end:
	switch_mutex_unlock(d->mutex);
	return NULL;
}


/* For Emacs:
 * Local Variables:
 * mode:c
 * indent-tabs-mode:t
 * tab-width:4
 * c-basic-offset:4
 * End:
 * For VIM:
 * vim:set softtabstop=4 shiftwidth=4 tabstop=4 noet:
 */
