/*
 * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 * Copyright (C) 2005-2014, Anthony Minessale II <anthm@freeswitch.org>
 *
 * 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.
 *
 * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application
 *
 * The Initial Developer of the Original Code is
 * Anthony Minessale II <anthm@freeswitch.org>
 * Portions created by the Initial Developer are Copyright (C)
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *
 * Anthony Minessale II <anthm@freeswitch.org>
 *
 *
 * switch_resample.c -- Resampler
 *
 */

#include <switch.h>
#include <switch_resample.h>
#ifndef WIN32
#include <switch_private.h>
#endif
#include <speex/speex_resampler.h>

#define NORMFACT (float)0x8000
#define MAXSAMPLE (float)0x7FFF
#define MAXSAMPLEC (char)0x7F
#define QUALITY 0

#ifndef MIN
#define MIN(a,b) ((a) < (b) ? (a) : (b))
#endif

#ifndef MAX
#define MAX(a,b) ((a) > (b) ? (a) : (b))
#endif

#define resample_buffer(a, b, c) a > b ? ((a / 1000) / 2) * c : ((b / 1000) / 2) * c

SWITCH_DECLARE(switch_status_t) switch_resample_perform_create(switch_audio_resampler_t **new_resampler,
															   uint32_t from_rate, uint32_t to_rate,
															   uint32_t to_size,
															   int quality, uint32_t channels, const char *file, const char *func, int line)
{
	int err = 0;
	switch_audio_resampler_t *resampler;
	double lto_rate, lfrom_rate;

	switch_zmalloc(resampler, sizeof(*resampler));

	if (!channels) channels = 1;

	resampler->resampler = speex_resampler_init(channels, from_rate, to_rate, quality, &err);

	if (!resampler->resampler) {
		free(resampler);
		return SWITCH_STATUS_GENERR;
	}

	*new_resampler = resampler;
	lto_rate = (double) resampler->to_rate;
	lfrom_rate = (double) resampler->from_rate;
	resampler->from_rate = from_rate;
	resampler->to_rate = to_rate;
	resampler->factor = (lto_rate / lfrom_rate);
	resampler->rfactor = (lfrom_rate / lto_rate);
	resampler->channels = channels;

	//resampler->to_size = resample_buffer(to_rate, from_rate, (uint32_t) to_size);

	resampler->to_size = switch_resample_calc_buffer_size(resampler->to_rate, resampler->from_rate, to_size) / 2;
	resampler->to = malloc(resampler->to_size * sizeof(int16_t) * resampler->channels);
	switch_assert(resampler->to);

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(uint32_t) switch_resample_process(switch_audio_resampler_t *resampler, int16_t *src, uint32_t srclen)
{
	int to_size = switch_resample_calc_buffer_size(resampler->to_rate, resampler->from_rate, srclen) / 2;

	if (to_size > resampler->to_size) {
		resampler->to_size = to_size;
		resampler->to = realloc(resampler->to, resampler->to_size * sizeof(int16_t) * resampler->channels);
		switch_assert(resampler->to);
	}

	resampler->to_len = resampler->to_size;
	speex_resampler_process_interleaved_int(resampler->resampler, src, &srclen, resampler->to, &resampler->to_len);
	return resampler->to_len;
}

SWITCH_DECLARE(void) switch_resample_destroy(switch_audio_resampler_t **resampler)
{

	if (resampler && *resampler) {
		if ((*resampler)->resampler) {
			speex_resampler_destroy((*resampler)->resampler);
		}
		free((*resampler)->to);
		free(*resampler);
		*resampler = NULL;
	}
}

SWITCH_DECLARE(switch_size_t) switch_float_to_short(float *f, short *s, switch_size_t len)
{
	switch_size_t i;
	float ft;
	for (i = 0; i < len; i++) {
		ft = f[i] * NORMFACT;
		if (ft >= 0) {
			s[i] = (short) (ft + 0.5);
		} else {
			s[i] = (short) (ft - 0.5);
		}
		if ((float) s[i] > MAXSAMPLE)
			s[i] = (short) MAXSAMPLE / 2;
		if (s[i] < (short) -MAXSAMPLE)
			s[i] = (short) -MAXSAMPLE / 2;
	}
	return len;
}

SWITCH_DECLARE(int) switch_char_to_float(char *c, float *f, int len)
{
	int i;

	if (len % 2) {
		return (-1);
	}

	for (i = 1; i < len; i += 2) {
		f[(int) (i / 2)] = (float) (((c[i]) * 0x100) + c[i - 1]);
		f[(int) (i / 2)] /= NORMFACT;
		if (f[(int) (i / 2)] > MAXSAMPLE)
			f[(int) (i / 2)] = MAXSAMPLE;
		if (f[(int) (i / 2)] < -MAXSAMPLE)
			f[(int) (i / 2)] = -MAXSAMPLE;
	}
	return len / 2;
}

SWITCH_DECLARE(int) switch_float_to_char(float *f, char *c, int len)
{
	int i;
	float ft;
	long l;
	for (i = 0; i < len; i++) {
		ft = f[i] * NORMFACT;
		if (ft >= 0) {
			l = (long) (ft + 0.5);
		} else {
			l = (long) (ft - 0.5);
		}
		c[i * 2] = (unsigned char) ((l) & 0xff);
		c[i * 2 + 1] = (unsigned char) (((l) >> 8) & 0xff);
	}
	return len * 2;
}

SWITCH_DECLARE(int) switch_short_to_float(short *s, float *f, int len)
{
	int i;

	for (i = 0; i < len; i++) {
		f[i] = (float) (s[i]) / NORMFACT;
		/* f[i] = (float) s[i]; */
	}
	return len;
}


SWITCH_DECLARE(void) switch_swap_linear(int16_t *buf, int len)
{
	int i;
	for (i = 0; i < len; i++) {
		buf[i] = ((buf[i] >> 8) & 0x00ff) | ((buf[i] << 8) & 0xff00);
	}
}


SWITCH_DECLARE(void) switch_generate_sln_silence(int16_t *data, uint32_t samples, uint32_t channels, uint32_t divisor)
{
	int16_t s;
	uint32_t x, i, j;
	int sum_rnd = 0;
	int16_t rnd2 = (int16_t) switch_micro_time_now() + (int16_t) (intptr_t) data;

	if (channels == 0) channels = 1;

	assert(divisor);

	if (divisor == (uint32_t)-1) {
		memset(data, 0, samples * 2);
		return;
	}

	for (i = 0; i < samples; i++, sum_rnd = 0) {
		for (x = 0; x < 6; x++) {
			rnd2 = rnd2 * 31821U + 13849U;
			sum_rnd += rnd2;
		}

		s = (int16_t) ((int16_t) sum_rnd / (int) divisor);

		for (j = 0; j < channels; j++) {
			*data = s;
			data++;
		}


	}
}

SWITCH_DECLARE(uint32_t) switch_merge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
{
	int i;
	int32_t x, z;

	if (channels == 0) channels = 1;

	if (samples > other_samples) {
		x = other_samples;
	} else {
		x = samples;
	}

	for (i = 0; i < x * channels; i++) {
		z = data[i] + other_data[i];
		switch_normalize_to_16bit(z);
		data[i] = (int16_t) z;
	}

	return x;
}


SWITCH_DECLARE(uint32_t) switch_unmerge_sln(int16_t *data, uint32_t samples, int16_t *other_data, uint32_t other_samples, int channels)
{
	int i;
	int32_t x;

	if (channels == 0) channels = 1;

	if (samples > other_samples) {
		x = other_samples;
	} else {
		x = samples;
	}

	for (i = 0; i < x * channels; i++) {
		data[i] -= other_data[i];
	}

	return x;
}

SWITCH_DECLARE(void) switch_mux_channels(int16_t *data, switch_size_t samples, uint32_t orig_channels, uint32_t channels)
{
	switch_size_t i = 0;
	uint32_t j = 0;

	switch_assert(channels < 11);

	if (orig_channels > channels) {
		if (channels == 1) {
			for (i = 0; i < samples; i++) {
				int32_t z = 0;
				for (j = 0; j < orig_channels; j++) {
					z += (int16_t) data[i * orig_channels + j];
				}
				switch_normalize_to_16bit(z);
				data[i] = (int16_t) z;
			}
		} else if (channels == 2) {
			int mark_buf = 0;
			for (i = 0; i < samples; i++) {
				int32_t z_left = 0, z_right = 0;
				for (j = 0; j < orig_channels; j++) {
					if (j % 2) {
						z_left += (int16_t) data[i * orig_channels + j];
					} else {
						z_right += (int16_t) data[i * orig_channels + j];
					}
				}
				/* mark_buf will always be smaller than the size of data in bytes because orig_channels > channels */
				switch_normalize_to_16bit(z_left);
				data[mark_buf++] = (int16_t) z_left;
				switch_normalize_to_16bit(z_right);
				data[mark_buf++] = (int16_t) z_right;
			}
		} 
	} else if (orig_channels < channels) {

		/* interesting problem... take a give buffer and double up every sample in the buffer without using any other buffer.....
		   This way beats the other i think bacause there is no malloc but I do have to copy the data twice */
#if 1
		uint32_t k = 0, len = samples * orig_channels;

		for (i = 0; i < len; i++) {
			data[i+len] = data[i];
		}

		for (i = 0; i < samples; i++) {
			for (j = 0; j < channels; j++) {
				data[k++] = data[i + samples];
			}
		}

#else
		uint32_t k = 0, len = samples * 2 * orig_channels;
		int16_t *orig = NULL;

		switch_zmalloc(orig, len);
		memcpy(orig, data, len);

		for (i = 0; i < samples; i++) {
			for (j = 0; j < channels; j++) {
				data[k++] = orig[i];
			}
		}

		free(orig);
#endif

	}
}

SWITCH_DECLARE(void) switch_change_sln_volume_granular(int16_t *data, uint32_t samples, int32_t vol)
{
	double newrate = 0;
	// change in dB mapped to ratio for output sample
	// computed as (powf(10.0f, (float)(change_in_dB) / 20.0f))
	static const double pos[SWITCH_GRANULAR_VOLUME_MAX] = {
		  1.122018,   1.258925,   1.412538,   1.584893,   1.778279,   1.995262,   2.238721,   2.511887,   2.818383,   3.162278,
		  3.548134,   3.981072,   4.466835,   5.011872,   5.623413,   6.309574,   7.079458,   7.943282,   8.912509,  10.000000,
		 11.220183,  12.589254,  14.125375,  15.848933,  17.782795,  19.952621,  22.387213,  25.118862,  28.183832,  31.622776,
		 35.481335,  39.810719,  44.668358,  50.118729,  56.234131,  63.095726,  70.794586,  79.432816,  89.125107, 100.000000,
		112.201836, 125.892517, 141.253784, 158.489334, 177.827942, 199.526215, 223.872070, 251.188705, 281.838318, 316.227753
	};
	static const double neg[SWITCH_GRANULAR_VOLUME_MAX] = {
		0.891251, 0.794328, 0.707946, 0.630957, 0.562341, 0.501187, 0.446684, 0.398107, 0.354813, 0.316228,
		0.281838, 0.251189, 0.223872, 0.199526, 0.177828, 0.158489, 0.141254, 0.125893, 0.112202, 0.100000,
		0.089125, 0.079433, 0.070795, 0.063096, 0.056234, 0.050119, 0.044668, 0.039811, 0.035481, 0.031623,
		0.028184, 0.025119, 0.022387, 0.019953, 0.017783, 0.015849, 0.014125, 0.012589, 0.011220, 0.010000,
		0.008913, 0.007943, 0.007079, 0.006310, 0.005623, 0.005012, 0.004467, 0.003981, 0.003548, 0.000000  // NOTE mapped -50 dB ratio to total silence instead of 0.003162
	};
	const double *chart;
	uint32_t i;

	if (vol == 0) return;

	switch_normalize_volume_granular(vol);

	if (vol > 0) {
		chart = pos;
	} else {
		chart = neg;
	}

	i = abs(vol) - 1;

	switch_assert(i < SWITCH_GRANULAR_VOLUME_MAX);

	newrate = chart[i];

	if (newrate) {
		int32_t tmp;
		uint32_t x;
		int16_t *fp = data;

		for (x = 0; x < samples; x++) {
			tmp = (int32_t) (fp[x] * newrate);
			switch_normalize_to_16bit(tmp);
			fp[x] = (int16_t) tmp;
		}
	} else {
		memset(data, 0, samples * 2);
	}
}

SWITCH_DECLARE(void) switch_change_sln_volume(int16_t *data, uint32_t samples, int32_t vol)
{
	double newrate = 0;
	double pos[4] = {1.3, 2.3, 3.3, 4.3};
	double neg[4] = {.80, .60, .40, .20};
	double *chart;
	uint32_t i;

	if (vol == 0) return;

	switch_normalize_volume(vol);

	if (vol > 0) {
		chart = pos;
	} else {
		chart = neg;
	}

	i = abs(vol) - 1;

	switch_assert(i < 4);

	newrate = chart[i];

	if (newrate) {
		int32_t tmp;
		uint32_t x;
		int16_t *fp = data;

		for (x = 0; x < samples; x++) {
			tmp = (int32_t) (fp[x] * newrate);
			switch_normalize_to_16bit(tmp);
			fp[x] = (int16_t) tmp;
		}
	}
}

struct switch_agc_s {
	switch_memory_pool_t *pool;
	uint32_t energy_avg;
	uint32_t margin;
	uint32_t change_factor;
	char *token;
	int vol;
	uint32_t score;
	uint32_t score_count;
	uint32_t score_sum;
	uint32_t score_avg;
	uint32_t score_over;
	uint32_t score_under;
	uint32_t period_len;
	uint32_t low_energy_point;
};


SWITCH_DECLARE(void) switch_agc_set(switch_agc_t *agc, uint32_t energy_avg, 
											   uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len)
{
	agc->energy_avg = energy_avg;
	agc->margin = margin;
	agc->change_factor = change_factor;
	agc->period_len = period_len;
	agc->low_energy_point = low_energy_point;

	agc->score = 0;
	agc->score_count = 0;
	agc->score_sum = 0;
	agc->score_avg = 0;
	agc->score_over = 0;
	agc->score_under = 0;
}

SWITCH_DECLARE(switch_status_t) switch_agc_create(switch_agc_t **agcP, uint32_t energy_avg, 
												  uint32_t low_energy_point, uint32_t margin, uint32_t change_factor, uint32_t period_len)
{
	switch_agc_t *agc;
	switch_memory_pool_t *pool;
	char id[80] = "";

	switch_assert(agcP);

	switch_core_new_memory_pool(&pool);
	
	agc = switch_core_alloc(pool, sizeof(*agc));
	agc->pool = pool;

	switch_agc_set(agc, energy_avg, low_energy_point, margin, change_factor, period_len);


	switch_snprintf(id, sizeof(id), "%p", (void *)agc);
	switch_agc_set_token(agc, id);

	*agcP = agc;

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(void) switch_agc_destroy(switch_agc_t **agcP)
{
	switch_agc_t *agc;

	switch_assert(agcP);

	agc = *agcP;
	*agcP = NULL;

	if (agc) {
		switch_memory_pool_t *pool = agc->pool;
		switch_core_destroy_memory_pool(&pool);
	}
}

SWITCH_DECLARE(void) switch_agc_set_energy_avg(switch_agc_t *agc, uint32_t energy_avg)
{
	switch_assert(agc);

	agc->energy_avg = energy_avg;
}

SWITCH_DECLARE(void) switch_agc_set_energy_low(switch_agc_t *agc, uint32_t low_energy_point)
{
	switch_assert(agc);

	agc->low_energy_point = low_energy_point;
}

SWITCH_DECLARE(void) switch_agc_set_token(switch_agc_t *agc, const char *token)
{
	agc->token = switch_core_strdup(agc->pool, token);
}

SWITCH_DECLARE(switch_status_t) switch_agc_feed(switch_agc_t *agc, int16_t *data, uint32_t samples, uint32_t channels)
{
	
	if (!channels) channels = 1;

	if (agc->vol) {
		switch_change_sln_volume_granular(data, samples * channels, agc->vol);
	}
							
	if (agc->energy_avg) {
		uint32_t energy = 0;
		int i;

		for (i = 0; i < samples * channels; i++) {
			energy += abs(data[i]);
		}

		if (samples) { 
			agc->score = energy / samples * channels;
		}
		agc->score_sum += agc->score;
		agc->score_count++;
								
		if (agc->score_count > agc->period_len) {
									
			agc->score_avg = (int)((double)agc->score_sum / agc->score_count);
			agc->score_count = 0;
			agc->score_sum = 0;
									
			if (agc->score_avg > agc->energy_avg) {
				if (agc->score_avg - agc->energy_avg > agc->margin) {
					switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] OVER++ SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
									  agc->token, agc->score_avg, agc->energy_avg, agc->margin);
					agc->score_over++;
				} else {
					agc->score_over = 0;
				}
			} else {
				agc->score_over = 0;
			}

			if (agc->score_avg < agc->low_energy_point) {
				agc->score_under = agc->change_factor + 1;
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] BELOW LOW POINT, SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
								  agc->token, agc->score_avg, agc->energy_avg, agc->margin);
			} else if (((agc->score_avg < agc->energy_avg) && (agc->energy_avg - agc->score_avg > agc->margin))) {
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] UNDER++ SCORE AVG: %d ENERGY AVG: %d MARGIN: %d\n", 
								  agc->token, agc->score_avg, agc->energy_avg, agc->margin);
				agc->score_under++;
			} else {
				agc->score_under = 0;
			}

			switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] AVG %d over: %d under: %d\n", 
							  agc->token, agc->score_avg, agc->score_over, agc->score_under);

			if (agc->score_over > agc->change_factor) {
				agc->vol--;
				switch_normalize_volume_granular(agc->vol);
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] VOL DOWN %d\n", agc->token, agc->vol);
				//agc->score_over = 0;
			} else if (agc->score_under > agc->change_factor) {
				agc->vol++;
				switch_normalize_volume_granular(agc->vol);
				switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_DEBUG1, "[%s] VOL UP %d\n", agc->token, agc->vol);
				//agc->score_under = 0;
			}

		}

	}

	return SWITCH_STATUS_SUCCESS;
}


/* 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:
 */