/*
 * 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>
 * Dragos Oancea <dragos@freeswitch.org>
 *
 * switch_jitterbuffer.c -- Audio/Video Jitter Buffer
 *
 */
#include <switch.h>
#include <switch_jitterbuffer.h>
#include "private/switch_hashtable_private.h"

#define NACK_TIME 80000
#define RENACK_TIME 100000
#define MAX_FRAME_PADDING 2
#define MAX_MISSING_SEQ 20
#define jb_debug(_jb, _level, _format, ...) if (_jb->debug_level >= _level) switch_log_printf(SWITCH_CHANNEL_SESSION_LOG_CLEAN(_jb->session), SWITCH_LOG_ALERT, "JB:%p:%s:%d/%d lv:%d ln:%.4d sz:%.3u/%.3u/%.3u/%.3u c:%.3u %.3u/%.3u/%.3u/%.3u %.2f%% ->" _format, (void *) _jb, (jb->type == SJB_TEXT ? "txt" : (jb->type == SJB_AUDIO ? "aud" : "vid")), _jb->allocated_nodes, _jb->visible_nodes, _level, __LINE__,  _jb->min_frame_len, _jb->max_frame_len, _jb->frame_len, _jb->complete_frames, _jb->period_count, _jb->consec_good_count, _jb->period_good_count, _jb->consec_miss_count, _jb->period_miss_count, _jb->period_miss_pct, __VA_ARGS__)

//const char *TOKEN_1 = "ONE";
//const char *TOKEN_2 = "TWO";

struct switch_jb_s;

static inline int check_jb_size(switch_jb_t *jb);

typedef struct switch_jb_node_s {
	struct switch_jb_s *parent;
	switch_rtp_packet_t packet;
	uint32_t len;
	uint8_t visible;
	uint8_t bad_hits;
	struct switch_jb_node_s *prev;
	struct switch_jb_node_s *next;
	/* used for counting the number of partial or complete frames currently in the JB */
	switch_bool_t complete_frame_mark;
} switch_jb_node_t;

typedef struct switch_jb_stats_s {
	uint32_t reset_too_big;
	uint32_t reset_missing_frames;
	uint32_t reset_ts_jump;
	uint32_t reset_error;
	uint32_t reset;
	uint32_t size_max;
	uint32_t size_est;
	uint32_t acceleration;
	uint32_t expand;
	uint32_t jitter_max_ms;
	int estimate_ms;
	int buffer_size_ms;
} switch_jb_stats_t;

typedef struct switch_jb_jitter_s {
	double *estimate;
	uint32_t samples_per_second;
	uint32_t samples_per_frame;
	uint32_t drop_gap;
	switch_jb_stats_t stats;
} switch_jb_jitter_t;

struct switch_jb_s {
	struct switch_jb_node_s *node_list;
	uint32_t last_target_seq;
	uint32_t highest_read_ts;
	uint32_t highest_dropped_ts;
	uint32_t highest_read_seq;
	uint32_t highest_wrote_ts;
	uint16_t highest_wrote_seq;
	uint16_t target_seq;
	uint32_t target_ts;
	uint32_t last_target_ts;
	uint16_t psuedo_seq;
	uint16_t last_psuedo_seq;
	uint32_t visible_nodes;
	uint32_t allocated_nodes;
	uint32_t complete_frames;
	uint32_t frame_len;
	uint32_t min_frame_len;
	uint32_t max_frame_len;
	uint32_t highest_frame_len;
	uint32_t period_miss_count;
	uint32_t consec_miss_count;
	uint32_t period_miss_inc;
	double period_miss_pct;
	uint32_t period_good_count;
	uint32_t consec_good_count;
	uint32_t period_count;
	uint32_t dropped;
	uint32_t samples_per_frame;
	uint32_t samples_per_second;
	uint32_t bitrate_control;
	uint32_t video_low_bitrate;
	uint8_t write_init;
	uint8_t read_init;
	uint8_t debug_level;
	uint16_t next_seq;
	switch_size_t last_len;
	switch_inthash_t *missing_seq_hash;
	switch_inthash_t *node_hash;
	switch_inthash_t *node_hash_ts;
	switch_mutex_t *mutex;
	switch_mutex_t *list_mutex;
	switch_memory_pool_t *pool;
	int free_pool;
	int drop_flag;
	switch_jb_flag_t flags;
	switch_jb_type_t type;
	switch_core_session_t *session;
	switch_jb_jitter_t jitter;
	switch_channel_t *channel;
	uint32_t buffer_lag;
	uint32_t flush;
	uint32_t packet_count;
	uint32_t max_packet_len;
	uint32_t period_len;
	uint32_t nack_saved_the_day;
	uint32_t nack_didnt_save_the_day;
	switch_bool_t elastic;
	switch_codec_t *codec;
};


static int node_cmp(const void *l, const void *r)
{
	switch_jb_node_t *a = (switch_jb_node_t *) l;
	switch_jb_node_t *b = (switch_jb_node_t *) r;

	if (!a->visible) return 0;
	if (!b->visible) return 1;

	return ntohs(a->packet.header.seq) - ntohs(b->packet.header.seq);
}

//http://www.chiark.greenend.org.uk/~sgtatham/algorithms/listsort.c
switch_jb_node_t *sort_nodes(switch_jb_node_t *list, int (*cmp)(const void *, const void *)) {
	switch_jb_node_t *p, *q, *e, *tail;
	int insize, nmerges, psize, qsize, i;

	if (!list) {
		return NULL;
	}

	insize = 1;

	while (1) {
		p = list;
		list = NULL;
		tail = NULL;

		nmerges = 0;  /* count number of merges we do in this pass */

		while (p) {
			nmerges++;  /* there exists a merge to be done */
			            /* step `insize' places along from p */
			q = p;
			psize = 0;
			for (i = 0; i < insize; i++) {
				psize++;
				q = q->next;
				if (!q) break;
			}

			/* if q hasn't fallen off end, we have two lists to merge */
			qsize = insize;

			/* now we have two lists; merge them */
			while (psize > 0 || (qsize > 0 && q)) {

				/* decide whether next switch_jb_node_t of merge comes from p or q */
				if (psize == 0) {
					/* p is empty; e must come from q. */
					e = q; q = q->next; qsize--;
				} else if (qsize == 0 || !q) {
					/* q is empty; e must come from p. */
					e = p; p = p->next; psize--;
				} else if (cmp(p,q) <= 0) {
					/* First switch_jb_node_t of p is lower (or same);
					 * e must come from p. */
					e = p; p = p->next; psize--;
				} else {
					/* First switch_jb_node_t of q is lower; e must come from q. */
					e = q; q = q->next; qsize--;
				}

				/* add the next switch_jb_node_t to the merged list */
				if (tail) {
					tail->next = e;
				} else {
					list = e;
				}

				/* Maintain reverse pointers in a doubly linked list. */
				e->prev = tail;

				tail = e;
			}

			/* now p has stepped `insize' places along, and q has too */
			p = q;
		}

		tail->next = NULL;

		/* If we have done only one merge, we're finished. */
		if (nmerges <= 1)   /* allow for nmerges==0, the empty list case */
			return list;

		/* Otherwise repeat, merging lists twice the size */
		insize *= 2;
	}
}

// static inline void thin_frames(switch_jb_t *jb, int freq, int max);


static inline switch_jb_node_t *new_node(switch_jb_t *jb)
{
	switch_jb_node_t *np;

	switch_mutex_lock(jb->list_mutex);

	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) {
			break;
		}
	}

	if (!np) {
		int mult = 2;

		if (jb->type != SJB_VIDEO) {
			mult = 2;
		} else {
			if (jb->max_packet_len > mult) {
				mult = jb->max_packet_len;
			}
		}

		if (jb->allocated_nodes > jb->max_frame_len * mult) {
			jb_debug(jb, 2, "ALLOCATED FRAMES TOO HIGH! %d\n", jb->allocated_nodes);
			jb->jitter.stats.reset_too_big++;
			switch_jb_reset(jb);
			switch_mutex_unlock(jb->list_mutex);
			return NULL;
		}
		
		np = switch_core_alloc(jb->pool, sizeof(*np));
		jb->allocated_nodes++;
		np->next = jb->node_list;
		if (np->next) {
			np->next->prev = np;
		}
		jb->node_list = np;

	}

	switch_assert(np);
	np->bad_hits = 0;
	np->visible = 1;
	jb->visible_nodes++;
	np->parent = jb;

	switch_mutex_unlock(jb->list_mutex);

	return np;
}

static inline void push_to_top(switch_jb_t *jb, switch_jb_node_t *node)
{
	if (node == jb->node_list) {
		jb->node_list = node->next;
	} else if (node->prev) {
		node->prev->next = node->next;
	}

	if (node->next) {
		node->next->prev = node->prev;
	}

	node->next = jb->node_list;
	node->prev = NULL;

	if (node->next) {
		node->next->prev = node;
	}

	jb->node_list = node;

	switch_assert(node->next != node);
	switch_assert(node->prev != node);
}

static inline void hide_node(switch_jb_node_t *node, switch_bool_t pop)
{
	switch_jb_t *jb = node->parent;

	switch_mutex_lock(jb->list_mutex);

	if (node->visible) {
		node->visible = 0;
		node->bad_hits = 0;
		jb->visible_nodes--;

		if (pop) {
			push_to_top(jb, node);
		}
	}

	if (jb->node_hash_ts) {
		switch_core_inthash_delete(jb->node_hash_ts, node->packet.header.ts);
	}

	if (switch_core_inthash_delete(jb->node_hash, node->packet.header.seq)) {
		if (node->complete_frame_mark && jb->type == SJB_VIDEO) {
			jb->complete_frames--;
			node->complete_frame_mark = FALSE;
		}
	}

	switch_mutex_unlock(jb->list_mutex);
}

static inline void sort_free_nodes(switch_jb_t *jb)
{
	switch_mutex_lock(jb->list_mutex);
	jb->node_list = sort_nodes(jb->node_list, node_cmp);
	switch_mutex_unlock(jb->list_mutex);
}

static inline void hide_nodes(switch_jb_t *jb)
{
	switch_jb_node_t *np;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		hide_node(np, SWITCH_FALSE);
	}
	switch_mutex_unlock(jb->list_mutex);
}

static inline switch_bool_t packet_vad(switch_jb_t *jb, switch_rtp_packet_t *packet, switch_size_t len) {
	void *payload = packet ? (packet->ebody ? packet->ebody : packet->body) : NULL;
	uint16_t payload_len = len;

	if (payload && payload_len > 0) {
		switch_bool_t ret = SWITCH_FALSE, *ret_p = &ret;
		switch_codec_control_type_t ret_t;

		switch_core_media_codec_control(jb->session, SWITCH_MEDIA_TYPE_AUDIO,
						SWITCH_IO_WRITE, SCC_AUDIO_VAD,
						SCCT_STRING, (void *)payload,
						SCCT_INT, (void *)&payload_len,
						&ret_t, (void *)&ret_p);

		return ret;
	}

	return SWITCH_TRUE;
}

static inline void drop_ts(switch_jb_t *jb, uint32_t ts)
{
	switch_jb_node_t *np;
	int x = 0;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) continue;

		if (ts == np->packet.header.ts) {
			hide_node(np, SWITCH_FALSE);
			x++;
		}
	}

	if (x) {
		sort_free_nodes(jb);
	}

	switch_mutex_unlock(jb->list_mutex);
}

static inline switch_jb_node_t *jb_find_lowest_seq(switch_jb_t *jb, uint32_t ts)
{
	switch_jb_node_t *np, *lowest = NULL;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) continue;

		if (ts && ts != np->packet.header.ts) continue;

		if (!lowest || ntohs(lowest->packet.header.seq) > ntohs(np->packet.header.seq)) {
			lowest = np;
		}
	}
	switch_mutex_unlock(jb->list_mutex);

	return lowest;
}

static inline switch_jb_node_t *jb_find_lowest_node(switch_jb_t *jb)
{
	switch_jb_node_t *np, *lowest = NULL;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) continue;

		if (!lowest || ntohl(lowest->packet.header.ts) > ntohl(np->packet.header.ts)) {
			lowest = np;
		}
	}
	switch_mutex_unlock(jb->list_mutex);

	return lowest ? lowest : NULL;
}

static inline uint32_t jb_find_lowest_ts(switch_jb_t *jb)
{
	switch_jb_node_t *lowest = jb_find_lowest_node(jb);

	return lowest ? lowest->packet.header.ts : 0;
}

#if 0
static inline void thin_frames(switch_jb_t *jb, int freq, int max)
{
	switch_jb_node_t *node, *this_node;
	int i = -1;
	int dropped = 0;

	switch_mutex_lock(jb->list_mutex);
	node = jb->node_list;

	while (node && dropped <= max) {
		this_node = node;
		node = node->next;
		
		if (this_node->visible) {
			i++;
		} else {
			continue;
		}

		if ((i % freq) == 0) {
			drop_ts(jb, this_node->packet.header.ts);
			dropped++;
		}
	}

	sort_free_nodes(jb);
	switch_mutex_unlock(jb->list_mutex);
}

static inline switch_jb_node_t *jb_find_highest_node(switch_jb_t *jb)
{
	switch_jb_node_t *np, *highest = NULL;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) continue;

		if (!highest || ntohl(highest->packet.header.ts) < ntohl(np->packet.header.ts)) {
			highest = np;
		}
	}
	switch_mutex_unlock(jb->list_mutex);

	return highest ? highest : NULL;
}


static inline uint32_t jb_find_highest_ts(switch_jb_t *jb)
{
	switch_jb_node_t *highest = jb_find_highest_node(jb);

	return highest ? highest->packet.header.ts : 0;
}

static inline void drop_newest_frame(switch_jb_t *jb)
{
	uint32_t ts = jb_find_highest_ts(jb);

	drop_ts(jb, ts);
	jb_debug(jb, 1, "Dropping highest frame ts:%u\n", ntohl(ts));
}




static inline switch_jb_node_t *jb_find_penultimate_node(switch_jb_t *jb)
{
	switch_jb_node_t *np, *highest = NULL, *second_highest = NULL;

	switch_mutex_lock(jb->list_mutex);
	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) continue;

		if (!highest || ntohl(highest->packet.header.ts) < ntohl(np->packet.header.ts)) {
			if (highest) second_highest = highest;
			highest = np;
		}
	}
	switch_mutex_unlock(jb->list_mutex);

	return second_highest ? second_highest : highest;
}
#endif

static inline void jb_hit(switch_jb_t *jb)
{
	jb->period_good_count++;
	jb->consec_good_count++;
	jb->consec_miss_count = 0;
}

static void jb_frame_inc_line(switch_jb_t *jb, int i, int line)
{
	uint32_t old_frame_len = jb->frame_len;

	if (i == 0) {
		jb->frame_len = jb->min_frame_len;
		goto end;
	}

	if (i > 0) {
		if ((jb->frame_len + i) < jb->max_frame_len) {
			jb->frame_len += i;
		} else {
			jb->frame_len = jb->max_frame_len;
		}

		goto end;
	}

	/* i < 0 */
	if ((jb->frame_len + i) > jb->min_frame_len) {
		jb->frame_len += i;
	} else {
		jb->frame_len = jb->min_frame_len;
	}

 end:

	if (jb->frame_len > jb->highest_frame_len) {
		jb->highest_frame_len = jb->frame_len;
	}

	if (old_frame_len != jb->frame_len) {
		jb_debug(jb, 1, "%d Change framelen from %u to %u\n", line, old_frame_len, jb->frame_len);

		//if (jb->session) {
		//	switch_core_session_request_video_refresh(jb->session);
		//}
	}

}

#define jb_frame_inc(_jb, _i) jb_frame_inc_line(_jb, _i, __LINE__)


static inline void jb_miss(switch_jb_t *jb)
{
	jb->period_miss_count++;
	jb->consec_miss_count++;
	jb->consec_good_count = 0;
}

#if 0
static inline int verify_oldest_frame(switch_jb_t *jb)
{
	switch_jb_node_t *lowest = NULL, *np = NULL;
	int r = 0;

	lowest = jb_find_lowest_node(jb);

	if (!lowest || !(lowest = jb_find_lowest_seq(jb, lowest->packet.header.ts))) {
		goto end;
	}

	switch_mutex_lock(jb->mutex);

	jb->node_list = sort_nodes(jb->node_list, node_cmp);

	for (np = lowest->next; np; np = np->next) {

		if (!np->visible) continue;

		if (ntohs(np->packet.header.seq) != ntohs(np->prev->packet.header.seq) + 1) {
			uint32_t val = (uint32_t)htons(ntohs(np->prev->packet.header.seq) + 1);

			if (!switch_core_inthash_find(jb->missing_seq_hash, val)) {
				switch_core_inthash_insert(jb->missing_seq_hash, val, (void *)(intptr_t)1);
			}
			break;
		}

		if (np->packet.header.ts != lowest->packet.header.ts || !np->next) {
			r = 1;
		}
	}

	switch_mutex_unlock(jb->mutex);

 end:

	return r;
}
#endif

static inline void drop_oldest_frame(switch_jb_t *jb)
{
	uint32_t ts = jb_find_lowest_ts(jb);

	drop_ts(jb, ts);
	jb_debug(jb, 1, "Dropping oldest frame ts:%u\n", ntohl(ts));
}



#if 0
static inline void drop_second_newest_frame(switch_jb_t *jb)
{
	switch_jb_node_t *second_newest = jb_find_penultimate_node(jb);

	if (second_newest) {
		drop_ts(jb, second_newest->packet.header.ts);
		jb_debug(jb, 1, "Dropping second highest frame ts:%u\n", ntohl(second_newest->packet.header.ts));
	}
}
#endif

static inline int check_seq(uint16_t a, uint16_t b)
{
	a = ntohs(a);
	b = ntohs(b);

	if (a >= b || (b > a && b > USHRT_MAX / 2 && a < USHRT_MAX / 2)) {
		return 1;
	}

	return 0;
}

static inline int check_ts(uint32_t a, uint32_t b)
{
	a = ntohl(a);
	b = ntohl(b);

	if (a > b || (b > a && b > UINT_MAX / 2 && a < UINT_MAX / 2)) {
		return 1;
	}

	return 0;
}

static inline void add_node(switch_jb_t *jb, switch_rtp_packet_t *packet, switch_size_t len)
{
	switch_jb_node_t *node = new_node(jb);

	if (!node) {
		return;
	}


	node->packet = *packet;
	node->len = len;

	switch_core_inthash_insert(jb->node_hash, node->packet.header.seq, node);

	if (jb->node_hash_ts) {
		switch_core_inthash_insert(jb->node_hash_ts, node->packet.header.ts, node);
	}

	jb_debug(jb, (packet->header.m ? 2 : 3), "PUT packet last_ts:%u ts:%u seq:%u%s\n",
			 ntohl(jb->highest_wrote_ts), ntohl(node->packet.header.ts), ntohs(node->packet.header.seq), packet->header.m ? " <MARK>" : "");

	if (jb->write_init && jb->type == SJB_VIDEO) {
		int seq_diff = 0, ts_diff = 0;

		if (ntohs(jb->highest_wrote_seq) > (USHRT_MAX - 100) && ntohs(packet->header.seq) < 100) {
			seq_diff = (USHRT_MAX - ntohs(jb->highest_wrote_seq)) + ntohs(packet->header.seq);
		} else {
			seq_diff = abs(((int)ntohs(packet->header.seq) - ntohs(jb->highest_wrote_seq)));
		}

		if (ntohl(jb->highest_wrote_ts) > (UINT_MAX - 1000) && ntohl(node->packet.header.ts) < 1000) {
			ts_diff = (UINT_MAX - ntohl(node->packet.header.ts)) + ntohl(node->packet.header.ts);
		} else {
			ts_diff = abs((int)((int64_t)ntohl(node->packet.header.ts) - (int64_t)ntohl(jb->highest_wrote_ts)));
		}

		if (((seq_diff >= 100) || (ts_diff > (900000 * 5)))) {
			jb_debug(jb, 2, "CHANGE DETECTED, PUNT %u\n", abs(((int)ntohs(packet->header.seq) - ntohs(jb->highest_wrote_seq))));
			jb->jitter.stats.reset_ts_jump++;
			switch_jb_reset(jb);
		}
	}

	if (!jb->write_init || ntohs(packet->header.seq) > ntohs(jb->highest_wrote_seq) ||
		(ntohs(jb->highest_wrote_seq) > USHRT_MAX - 100 && ntohs(packet->header.seq) < 100) ) {
		jb->highest_wrote_seq = packet->header.seq;
	}

	if (jb->type == SJB_VIDEO) {
		jb->packet_count++;
		
		if (jb->write_init && check_seq(packet->header.seq, jb->highest_wrote_seq) && check_ts(node->packet.header.ts, jb->highest_wrote_ts)) {
			jb_debug(jb, 2, "WRITE frame ts: %u complete=%u/%u n:%u\n", ntohl(node->packet.header.ts), jb->complete_frames , jb->frame_len, jb->visible_nodes);
			jb->highest_wrote_ts = packet->header.ts;
			jb->complete_frames++;

			jb->packet_count--;
			if (jb->packet_count > jb->max_packet_len) {
				jb->max_packet_len = jb->packet_count;
			}
			jb->packet_count = 1;
			node->complete_frame_mark = TRUE;
		} else if (!jb->write_init) {
			jb->highest_wrote_ts = packet->header.ts;
		}
	} else {
		if (jb->write_init || jb->type == SJB_TEXT || jb->type == SJB_AUDIO) {
			jb_debug(jb, 2, "WRITE frame ts: %u complete=%u/%u n:%u\n", ntohl(node->packet.header.ts), jb->complete_frames , jb->frame_len, jb->visible_nodes);
			jb->complete_frames++;
		} else {
			jb->highest_wrote_ts = packet->header.ts;
		}
	}

	if (!jb->write_init) jb->write_init = 1;
}

static inline void increment_ts(switch_jb_t *jb)
{
	if (!jb->target_ts) return;

	jb->last_psuedo_seq = jb->psuedo_seq;
	jb->last_target_ts = jb->target_ts;
	jb->target_ts = htonl((ntohl(jb->target_ts) + jb->samples_per_frame));
	jb->psuedo_seq++;
}

static inline void set_read_ts(switch_jb_t *jb, uint32_t ts)
{
	if (!ts) return;

	jb->last_psuedo_seq = jb->psuedo_seq;
	jb->last_target_ts = ts;
	jb->target_ts = htonl((ntohl(jb->last_target_ts) + jb->samples_per_frame));
	jb->psuedo_seq++;
}


static inline void increment_seq(switch_jb_t *jb)
{
	jb->last_target_seq = jb->target_seq;
	jb->target_seq = htons((ntohs(jb->target_seq) + 1));
}

static inline void decrement_seq(switch_jb_t *jb)
{
	jb->last_target_seq = jb->target_seq;
	jb->target_seq = htons((ntohs(jb->target_seq) - 1));
}

static inline void set_read_seq(switch_jb_t *jb, uint16_t seq)
{
	jb->last_target_seq = seq;
	jb->target_seq = htons((ntohs(jb->last_target_seq) + 1));
}

static inline switch_status_t jb_next_packet_by_seq(switch_jb_t *jb, switch_jb_node_t **nodep)
{
	switch_jb_node_t *node = NULL;

 top:

	if (jb->type == SJB_VIDEO) {
		if (jb->dropped) {
			jb->dropped = 0;
			jb_debug(jb, 2, "%s", "DROPPED FRAME DETECTED RESYNCING\n");
			jb->target_seq = 0;

			if (jb->session) {
				switch_core_session_request_video_refresh(jb->session);
			}
		}
	}

	if (!jb->target_seq) {
		if ((node = switch_core_inthash_find(jb->node_hash, jb->target_seq))) {
			jb_debug(jb, 2, "FOUND rollover seq: %u\n", ntohs(jb->target_seq));
		} else if ((node = jb_find_lowest_seq(jb, 0))) {
			jb_debug(jb, 2, "No target seq using seq: %u as a starting point\n", ntohs(node->packet.header.seq));
		} else {
			jb_debug(jb, 1, "%s", "No nodes available....\n");
		}
		jb_hit(jb);
	} else if ((node = switch_core_inthash_find(jb->node_hash, jb->target_seq))) {
		jb_debug(jb, 2, "FOUND desired seq: %u\n", ntohs(jb->target_seq));
		jb_hit(jb);
	} else {
		jb_debug(jb, 2, "MISSING desired seq: %u\n", ntohs(jb->target_seq));
		jb_miss(jb);

		if (jb->type == SJB_VIDEO) {
			int x;

			if (jb->session) {
				switch_core_session_request_video_refresh(jb->session);
			}

			for (x = 0; x < 10; x++) {
				increment_seq(jb);
				if ((node = switch_core_inthash_find(jb->node_hash, jb->target_seq))) {
					jb_debug(jb, 2, "FOUND incremental seq: %u\n", ntohs(jb->target_seq));

					if (node->packet.header.m ||  node->packet.header.ts == jb->highest_read_ts) {
						jb_debug(jb, 2, "%s", "SAME FRAME DROPPING\n");
						jb->dropped++;
						drop_ts(jb, node->packet.header.ts);
						jb->highest_dropped_ts = ntohl(node->packet.header.ts);


						if (jb->period_miss_count > 2 && jb->period_miss_inc < 1) {
							jb->period_miss_inc++;
							jb_frame_inc(jb, 1);
						}

						node = NULL;
						goto top;
					}
					break;
				} else {
					jb_debug(jb, 2, "MISSING incremental seq: %u\n", ntohs(jb->target_seq));
				}
			}
			
		} else {
			increment_seq(jb);
		}
	}

	*nodep = node;

	if (node) {
		set_read_seq(jb, node->packet.header.seq);
		return SWITCH_STATUS_SUCCESS;
	}

	return SWITCH_STATUS_NOTFOUND;

}


static inline switch_status_t jb_next_packet_by_ts(switch_jb_t *jb, switch_jb_node_t **nodep)
{
	switch_jb_node_t *node = NULL;

	if (!jb->target_ts) {
		if ((node = jb_find_lowest_node(jb))) {
			jb_debug(jb, 2, "No target ts using ts: %u as a starting point\n", ntohl(node->packet.header.ts));
		} else {
			jb_debug(jb, 1, "%s", "No nodes available....\n");
		}
		jb_hit(jb);
	} else if ((node = switch_core_inthash_find(jb->node_hash_ts, jb->target_ts))) {
		jb_debug(jb, 2, "FOUND desired ts: %u\n", ntohl(jb->target_ts));
		jb_hit(jb);
	} else {
		jb_debug(jb, 2, "MISSING desired ts: %u\n", ntohl(jb->target_ts));
		jb_miss(jb);
		increment_ts(jb);
	}

	*nodep = node;

	if (node) {
		set_read_ts(jb, node->packet.header.ts);
		node->packet.header.seq = htons(jb->psuedo_seq);
		return SWITCH_STATUS_SUCCESS;
	}

	return SWITCH_STATUS_NOTFOUND;

}

static inline int check_jb_size(switch_jb_t *jb)
{
	switch_jb_node_t *np;
	uint16_t seq_hs, target_seq_hs;
	uint16_t l_seq = 0;
	uint16_t h_seq = 0;
	uint16_t count = 0;
	uint16_t old = 0;

	switch_mutex_lock(jb->list_mutex);

	target_seq_hs = ntohs(jb->target_seq);

	for (np = jb->node_list; np; np = np->next) {
		if (!np->visible) {
			continue;
		}

		seq_hs = ntohs(np->packet.header.seq);
		if (target_seq_hs > seq_hs) {
			hide_node(np, SWITCH_FALSE);
			old++;
			continue;
		}

		if (count == 0) {
			l_seq = h_seq = seq_hs;
		}

		count++;

		if (seq_hs < l_seq) {
			l_seq = seq_hs;
		}

		if (seq_hs > h_seq) {
			h_seq = seq_hs;
		}
	}

	if (count > jb->jitter.stats.size_max) {
		jb->jitter.stats.size_max = count;
	}

	if (jb->jitter.stats.size_est == 0) {
		jb->jitter.stats.size_est = count;
	} else {
		jb->jitter.stats.size_est = ((99 * jb->jitter.stats.size_est) + (1 * count)) / 100;
	}

	/* update the stats every x packets */
	if (target_seq_hs % 50 == 0) {
		int packet_ms = jb->jitter.samples_per_frame / (jb->jitter.samples_per_second / 1000);

		jb->jitter.stats.estimate_ms = (*jb->jitter.estimate) / jb->jitter.samples_per_second * 1000;
		if (jb->channel) {
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_size_max_ms", "%u", jb->jitter.stats.size_max * packet_ms);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_size_est_ms", "%u", jb->jitter.stats.size_est * packet_ms);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_acceleration_ms", "%u", jb->jitter.stats.acceleration * packet_ms);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_expand_ms", "%u", jb->jitter.stats.expand * packet_ms);
		}

		if (jb->jitter.stats.jitter_max_ms < jb->jitter.stats.estimate_ms) {
			jb->jitter.stats.jitter_max_ms = jb->jitter.stats.estimate_ms;
		}

		if (jb->channel) {
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_jitter_max_ms", "%u", jb->jitter.stats.jitter_max_ms);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_jitter_est_ms", "%u", jb->jitter.stats.estimate_ms);
		}
	}

	if (old) {
		sort_free_nodes(jb);
	}

	switch_mutex_unlock(jb->list_mutex);

	jb_debug(jb, SWITCH_LOG_INFO, "JITTER buffersize %u == %u old[%u] target[%u] seq[%u|%u]\n", count, h_seq - l_seq + 1, old, target_seq_hs, l_seq, h_seq);

	return count;
}

static inline switch_status_t jb_next_packet_by_seq_with_acceleration(switch_jb_t *jb, switch_jb_node_t **nodep)
{
	switch_status_t status = jb_next_packet_by_seq(jb, nodep);
	switch_rtp_packet_t *packet;
	uint32_t len;
	uint16_t seq = ntohs(jb->target_seq);

	/* When using a Codec that provides voice activity detection ex. Opus, use it to
	   select packet to drop/accelerate. */

	if (jb->elastic && jb->jitter.estimate && (jb->visible_nodes * jb->jitter.samples_per_frame) > 0 && jb->jitter.samples_per_second) {
		int visible_not_old = check_jb_size(jb);

		jb->jitter.stats.estimate_ms = (int)((*jb->jitter.estimate) / ((jb->jitter.samples_per_second)) * 1000);
		jb->jitter.stats.buffer_size_ms = (int)((visible_not_old * jb->jitter.samples_per_frame) / (jb->jitter.samples_per_second / 1000));

		/* We try to accelerate in order to remove delay when the jitter buffer is 3x larger than the estimation. */
		if (jb->jitter.stats.buffer_size_ms > (3 * jb->jitter.stats.estimate_ms) && jb->jitter.stats.buffer_size_ms > 60) {
			if (status == SWITCH_STATUS_SUCCESS) {
				packet = &(*nodep)->packet;
				seq = ntohs((*nodep)->packet.header.seq);
				len = (*nodep)->len;
			}

			if (jb->jitter.drop_gap > 0) {
				jb_debug(jb, SWITCH_LOG_INFO, "JITTER estimation %dms buffersize %d/%d %dms seq:%u [drop-gap][%d]\n",
						 jb->jitter.stats.estimate_ms, jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms, seq, jb->jitter.drop_gap);
				jb->jitter.drop_gap--;
			} else {
				if (status != SWITCH_STATUS_SUCCESS || packet_vad(jb, packet, len) == SWITCH_FALSE) {
					jb->jitter.drop_gap = 3;
					if (status != SWITCH_STATUS_SUCCESS) {
						jb_debug(jb, SWITCH_LOG_INFO, "JITTER estimation n/a buffersize %d/%d %dms seq:%u [drop-missing/no-plc]\n",
								 jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms, seq);
					} else {
						jb_debug(jb, SWITCH_LOG_INFO, "JITTER estimation %dms buffersize %d/%d %dms seq:%u ACCELERATE [drop]\n",
								 jb->jitter.stats.estimate_ms, jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms, seq);
					}

					jb->jitter.stats.acceleration++;

					return jb_next_packet_by_seq(jb, nodep);
				} else {
					jb_debug(jb, SWITCH_LOG_INFO, "JITTER estimation %dms buffersize %d/%d %dms seq:%u [drop-skip-vad]\n",
							 jb->jitter.stats.estimate_ms, jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms, seq);
				}
			}
		} else {
			jb_debug(jb, 2, "JITTER estimation %dms buffersize %d/%d %dms\n",
					 jb->jitter.stats.estimate_ms, jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms);
		}
	}

	return status;
}

static inline switch_status_t jb_next_packet(switch_jb_t *jb, switch_jb_node_t **nodep)
{
	if (jb->samples_per_frame) {
		return jb_next_packet_by_ts(jb, nodep);
	}

	if (jb->elastic && jb->jitter.estimate) {
		return jb_next_packet_by_seq_with_acceleration(jb, nodep);
	}

	return jb_next_packet_by_seq(jb, nodep);
}

static inline void free_nodes(switch_jb_t *jb)
{
	switch_mutex_lock(jb->list_mutex);
	jb->node_list = NULL;
	switch_mutex_unlock(jb->list_mutex);
}

SWITCH_DECLARE(void) switch_jb_ts_mode(switch_jb_t *jb, uint32_t samples_per_frame, uint32_t samples_per_second)
{
	jb->samples_per_frame = samples_per_frame;
	jb->samples_per_second = samples_per_second;
	switch_core_inthash_init(&jb->node_hash_ts);
}

SWITCH_DECLARE(void) switch_jb_set_jitter_estimator(switch_jb_t *jb, double *jitter, uint32_t samples_per_frame, uint32_t samples_per_second)
{
	if (jb && jitter) {
		memset(&jb->jitter, 0, sizeof(switch_jb_jitter_t));
		if (jb->channel) {
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_max_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_size_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_acceleration_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_expand_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_jitter_max_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_jitter_ms", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_count", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_too_big", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_missing_frames", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_ts_jump", "%u", 0);
			switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_error", "%u", 0);
		}

		jb->jitter.estimate = jitter;
		jb->jitter.samples_per_frame = samples_per_frame;
		jb->jitter.samples_per_second = samples_per_second;
		jb->jitter.drop_gap = 5;
	}
}

SWITCH_DECLARE(void) switch_jb_set_session(switch_jb_t *jb, switch_core_session_t *session)
{
	const char *var;

	if (session) {
		jb->codec = switch_core_session_get_read_codec(session);
		jb->session = session;
		jb->channel = switch_core_session_get_channel(session);
		if (!strcmp(jb->codec->implementation->iananame, "opus")) {
			if (switch_channel_var_true(jb->channel, "rtp_jitter_buffer_accelerate")) {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "codec is %s, accelerate on\n", jb->codec->implementation->iananame);
				jb->elastic = SWITCH_TRUE;
			} else {
				switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "codec is %s, accelerate off\n", jb->codec->implementation->iananame);
				jb->elastic = SWITCH_FALSE;
			}
		} else {
			switch_log_printf(SWITCH_CHANNEL_SESSION_LOG(session), SWITCH_LOG_DEBUG, "codec not opus: %s\n", jb->codec->implementation->iananame);
			jb->elastic = SWITCH_FALSE;
		}

		if (jb->type == SJB_VIDEO && !switch_test_flag(jb, SJB_QUEUE_ONLY) &&
			(var = switch_channel_get_variable_dup(jb->channel, "jb_video_low_bitrate", SWITCH_FALSE, -1))) {
			int tmp = atoi(var);

			if (tmp >= 128 && tmp <= 10240) {
				jb->video_low_bitrate = (uint32_t)tmp;
			}
		}
	}
}

SWITCH_DECLARE(void) switch_jb_set_flag(switch_jb_t *jb, switch_jb_flag_t flag)
{
	switch_set_flag(jb, flag);
}

SWITCH_DECLARE(void) switch_jb_clear_flag(switch_jb_t *jb, switch_jb_flag_t flag)
{
	switch_clear_flag(jb, flag);
}

SWITCH_DECLARE(int) switch_jb_poll(switch_jb_t *jb)
{
	if (jb->type == SJB_TEXT) {
		if (jb->complete_frames < jb->frame_len) {
			if (jb->complete_frames && !jb->buffer_lag) {
				jb->buffer_lag = 10;
			}
			if (jb->buffer_lag && --jb->buffer_lag == 0) {
				jb->flush = 1;
			}
		}
	}

	return (jb->complete_frames >= jb->frame_len) || jb->flush;
}

SWITCH_DECLARE(int) switch_jb_frame_count(switch_jb_t *jb)
{
	return jb->complete_frames;
}

SWITCH_DECLARE(void) switch_jb_debug_level(switch_jb_t *jb, uint8_t level)
{
	jb->debug_level = level;
}

SWITCH_DECLARE(void) switch_jb_reset(switch_jb_t *jb)
{
	jb->jitter.stats.reset++;
	if (jb->channel) {
		switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_count", "%u", jb->jitter.stats.reset);
		switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_too_big", "%u", jb->jitter.stats.reset_too_big);
		switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_missing_frames", "%u", jb->jitter.stats.reset_missing_frames);
		switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_ts_jump", "%u", jb->jitter.stats.reset_ts_jump);
		switch_channel_set_variable_printf(jb->channel, "rtp_jb_reset_error", "%u", jb->jitter.stats.reset_error);
	}

	if (jb->type == SJB_VIDEO) {
		switch_mutex_lock(jb->mutex);
		switch_core_inthash_destroy(&jb->missing_seq_hash);
		switch_core_inthash_init(&jb->missing_seq_hash);
		switch_mutex_unlock(jb->mutex);

		if (jb->session) {
			switch_core_session_request_video_refresh(jb->session);
		}
	}

	jb_debug(jb, 2, "%s", "RESET BUFFER\n");

	switch_mutex_lock(jb->mutex);
	hide_nodes(jb);
	switch_mutex_unlock(jb->mutex);

	jb->drop_flag = 0;
	jb->last_target_seq = 0;
	jb->target_seq = 0;
	jb->write_init = 0;
	jb->highest_wrote_seq = 0;
	jb->highest_wrote_ts = 0;
	jb->next_seq = 0;
	jb->highest_read_ts = 0;
	jb->highest_read_seq = 0;
	jb->read_init = 0;
	jb->complete_frames = 0;
	jb->period_miss_count = 0;
	jb->consec_miss_count = 0;
	jb->period_miss_pct = 0;
	jb->period_good_count = 0;
	jb->consec_good_count = 0;
	jb->period_count = 0;
	jb->period_miss_inc = 0;
	jb->target_ts = 0;
	jb->last_target_ts = 0;
}

SWITCH_DECLARE(uint32_t) switch_jb_get_nack_success(switch_jb_t *jb) 
{
	uint32_t nack_recovered; /*count*/
	switch_mutex_lock(jb->mutex);
	nack_recovered = jb->nack_saved_the_day + jb->nack_didnt_save_the_day;
	switch_mutex_unlock(jb->mutex);
	return nack_recovered;
}

SWITCH_DECLARE(uint32_t) switch_jb_get_packets_per_frame(switch_jb_t *jb) 
{
	uint32_t ppf;
	switch_mutex_lock(jb->mutex);
	ppf = jb->packet_count; /* get current packets per frame */
	switch_mutex_unlock(jb->mutex);
	return ppf;
}

SWITCH_DECLARE(switch_status_t) switch_jb_peek_frame(switch_jb_t *jb, uint32_t ts, uint16_t seq, int peek, switch_frame_t *frame)
{
	switch_jb_node_t *node = NULL;
	if (seq) {
		uint16_t want_seq = seq + peek;
		node = switch_core_inthash_find(jb->node_hash, htons(want_seq));
	} else if (ts && jb->samples_per_frame) {
		uint32_t want_ts = ts + (peek * jb->samples_per_frame);
		node = switch_core_inthash_find(jb->node_hash_ts, htonl(want_ts));
	}

	if (node) {
		frame->seq = ntohs(node->packet.header.seq);
		frame->timestamp = ntohl(node->packet.header.ts);
		frame->m = node->packet.header.m;
		frame->datalen = node->len - SWITCH_RTP_HEADER_LEN;

		if (frame->data && frame->buflen > node->len - SWITCH_RTP_HEADER_LEN) {
			memcpy(frame->data, node->packet.body, node->len - SWITCH_RTP_HEADER_LEN);
		}
		return SWITCH_STATUS_SUCCESS;
	}

	return SWITCH_STATUS_FALSE;
}

SWITCH_DECLARE(switch_status_t) switch_jb_get_frames(switch_jb_t *jb, uint32_t *min_frame_len, uint32_t *max_frame_len, uint32_t *cur_frame_len, uint32_t *highest_frame_len)
{

	switch_mutex_lock(jb->mutex);

	if (min_frame_len) {
		*min_frame_len = jb->min_frame_len;
	}

	if (max_frame_len) {
		*max_frame_len = jb->max_frame_len;
	}

	if (cur_frame_len) {
		*cur_frame_len = jb->frame_len;
	}

	switch_mutex_unlock(jb->mutex);

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(switch_status_t) switch_jb_set_frames(switch_jb_t *jb, uint32_t min_frame_len, uint32_t max_frame_len)
{
	int lowest = 0;

	switch_mutex_lock(jb->mutex);

	if (jb->frame_len == jb->min_frame_len) lowest = 1;

	jb->min_frame_len = min_frame_len;
	jb->max_frame_len = max_frame_len;

	if (jb->frame_len > jb->max_frame_len) {
		jb->frame_len = jb->max_frame_len;
	}

	if (jb->frame_len < jb->min_frame_len) {
		jb->frame_len = jb->min_frame_len;
	}

	if (jb->frame_len > jb->highest_frame_len) {
		jb->highest_frame_len = jb->frame_len;
	}

	if (lowest) {
		jb->frame_len = jb->min_frame_len;
	}

	switch_mutex_unlock(jb->mutex);

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(switch_status_t) switch_jb_create(switch_jb_t **jbp, switch_jb_type_t type,
												 uint32_t min_frame_len, uint32_t max_frame_len, switch_memory_pool_t *pool)
{
	switch_jb_t *jb;
	int free_pool = 0;

	if (!pool) {
		switch_core_new_memory_pool(&pool);
		free_pool = 1;
	}

	jb = switch_core_alloc(pool, sizeof(*jb));
	jb->free_pool = free_pool;
	jb->min_frame_len = jb->frame_len = min_frame_len;
	jb->max_frame_len = max_frame_len;
	jb->pool = pool;
	jb->type = type;
	jb->highest_frame_len = jb->frame_len;

	if (jb->type == SJB_VIDEO) {
		switch_core_inthash_init(&jb->missing_seq_hash);
		jb->period_len = 2500;
	} else {
		jb->period_len = 250;
	}
	
	switch_core_inthash_init(&jb->node_hash);
	switch_mutex_init(&jb->mutex, SWITCH_MUTEX_NESTED, pool);
	switch_mutex_init(&jb->list_mutex, SWITCH_MUTEX_NESTED, pool);

	*jbp = jb;

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(switch_status_t) switch_jb_destroy(switch_jb_t **jbp)
{
	switch_jb_t *jb = *jbp;
	*jbp = NULL;

	if (jb->type == SJB_VIDEO && !switch_test_flag(jb, SJB_QUEUE_ONLY)) {
		jb_debug(jb, 3, "Stats: NACK saved the day: %u\n", jb->nack_saved_the_day);
		jb_debug(jb, 3, "Stats: NACK was late: %u\n", jb->nack_didnt_save_the_day);
		jb_debug(jb, 3, "Stats: Hash entrycount: missing_seq_hash %u\n", switch_hashtable_count(jb->missing_seq_hash));
	}
	if (jb->type == SJB_VIDEO) {
		switch_core_inthash_destroy(&jb->missing_seq_hash);
	}
	switch_core_inthash_destroy(&jb->node_hash);

	if (jb->node_hash_ts) {
		switch_core_inthash_destroy(&jb->node_hash_ts);
	}

	free_nodes(jb);

	if (jb->free_pool) {
		switch_core_destroy_memory_pool(&jb->pool);
	}

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(uint32_t) switch_jb_pop_nack(switch_jb_t *jb)
{
	switch_hash_index_t *hi = NULL;
	uint32_t nack = 0;
	uint16_t blp = 0;
	uint16_t least = 0;
	int i = 0;
	void *val;
	const void *var;

	if (jb->type != SJB_VIDEO) {
		return 0;
	}

	switch_mutex_lock(jb->mutex);

 top:

	for (hi = switch_core_hash_first_iter(jb->missing_seq_hash, hi); hi; hi = switch_core_hash_next(&hi)) {
		uint16_t seq;
		//const char *token;
		switch_time_t then = 0;

		switch_core_hash_this(hi, &var, NULL, &val);
		//token = (const char *) val;

		//if (token == TOKEN_2) {
			//switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "SKIP %u %s\n", ntohs(*((uint16_t *) var)), token);
			//printf("WTf\n");
		//	continue;
		//}

		seq = ntohs(*((uint16_t *) var));
		then = (intptr_t) val;

		if (then != 1 && ((uint32_t)(switch_time_now() - then)) < RENACK_TIME) {
			jb_debug(jb, 3, "NACKABLE seq %u too soon to repeat\n", seq);
			continue;
		}

		//if (then != 1) {
		//	jb_debug(jb, 3, "NACKABLE seq %u not too soon to repeat %lu\n", seq, switch_time_now() - then);
		//}

		if (seq < ntohs(jb->target_seq) - jb->frame_len) {
			jb_debug(jb, 3, "NACKABLE seq %u expired\n", seq);
			switch_core_inthash_delete(jb->missing_seq_hash, (uint32_t)htons(seq));
			goto top;
		}

		if (!least || seq < least) {
			least = seq;
		}
	}

	switch_safe_free(hi);

	if (least && switch_core_inthash_delete(jb->missing_seq_hash, (uint32_t)htons(least))) {
		jb_debug(jb, 3, "Found NACKABLE seq %u\n", least);
		nack = (uint32_t) htons(least);
		switch_core_inthash_insert(jb->missing_seq_hash, nack, (void *) (intptr_t)switch_time_now());

		for(i = 0; i < 16; i++) {
			if (switch_core_inthash_delete(jb->missing_seq_hash, (uint32_t)htons(least + i + 1))) {
				switch_core_inthash_insert(jb->missing_seq_hash, (uint32_t)htons(least + i + 1), (void *)(intptr_t)switch_time_now());
				jb_debug(jb, 3, "Found addtl NACKABLE seq %u\n", least + i + 1);
				blp |= (1 << i);
			}
		}

		blp = htons(blp);
		nack |= (uint32_t) blp << 16;

		//jb_frame_inc(jb, 1);
	}

	switch_mutex_unlock(jb->mutex);


	return nack;
}

SWITCH_DECLARE(switch_status_t) switch_jb_put_packet(switch_jb_t *jb, switch_rtp_packet_t *packet, switch_size_t len)
{
	uint32_t i;
	uint16_t want = ntohs(jb->next_seq), got = ntohs(packet->header.seq);

	if (len >= SWITCH_RTP_MAX_PACKET_LEN) {
		switch_log_printf(SWITCH_CHANNEL_LOG, SWITCH_LOG_WARNING, "trying to put %" SWITCH_SIZE_T_FMT " bytes exceeding buffer, truncate to %" SWITCH_SIZE_T_FMT "\n", len, SWITCH_RTP_MAX_PACKET_LEN);
		len = SWITCH_RTP_MAX_PACKET_LEN;
	}

	switch_mutex_lock(jb->mutex);

	if (jb->highest_dropped_ts) {
		if (ntohl(packet->header.ts) < jb->highest_dropped_ts) {
			jb_debug(jb, 2, "%s", "TS ALREADY DROPPED, DROPPING PACKET\n");
			switch_mutex_unlock(jb->mutex);
			return SWITCH_STATUS_SUCCESS;
		}
		jb->highest_dropped_ts = 0;
	}


	if (!want) want = got;

	if (switch_test_flag(jb, SJB_QUEUE_ONLY) || jb->type == SJB_AUDIO || jb->type == SJB_TEXT) {
		jb->next_seq = htons(got + 1);
	} else {

		if (switch_core_inthash_delete(jb->missing_seq_hash, (uint32_t)htons(got))) {
			if (got < ntohs(jb->target_seq)) {
				jb_debug(jb, 2, "got nacked seq %u too late\n", got);
				jb_frame_inc(jb, 1);
				jb->nack_didnt_save_the_day++;
			} else {
				jb_debug(jb, 2, "got nacked %u saved the day!\n", got);
				jb->nack_saved_the_day++;
			}
		}

		if (got > want) {
			if (got - want > jb->max_frame_len && got - want > 17) {
				jb_debug(jb, 2, "Missing %u frames, Resetting\n", got - want);
				jb->jitter.stats.reset_missing_frames++;
				switch_jb_reset(jb);
			} else {
				if (jb->type != SJB_VIDEO && jb->frame_len < got - want) {
					jb_frame_inc(jb, 1);
				}

				jb_debug(jb, 2, "GOT %u WANTED %u; MARK SEQS MISSING %u - %u\n", got, want, want, got - 1);

				for (i = want; i < got; i++) {
					jb_debug(jb, 2, "MARK MISSING %u ts:%u\n", i, ntohl(packet->header.ts));
					switch_core_inthash_insert(jb->missing_seq_hash, (uint32_t)htons(i), (void *)(intptr_t)1);
				}
			}
		}

		if (got >= want || (want - got) > 1000) {
			jb->next_seq = htons(got + 1);
		}
	}

	add_node(jb, packet, len);

	if (switch_test_flag(jb, SJB_QUEUE_ONLY) && jb->max_packet_len && jb->max_frame_len * 2 > jb->max_packet_len &&
			jb->allocated_nodes > jb->max_frame_len * 2 - 1) {
		while ((jb->max_frame_len * 2 - jb->visible_nodes) < jb->max_packet_len) {
			drop_oldest_frame(jb);
		}
	} else if (switch_test_flag(jb, SJB_QUEUE_ONLY) && jb->max_packet_len && jb->max_frame_len * 2 < jb->max_packet_len) {
		/* rtp_nack_buffer_size less than initial max_packet_len */
		drop_oldest_frame(jb);
	}

	switch_mutex_unlock(jb->mutex);

	return SWITCH_STATUS_SUCCESS;
}

SWITCH_DECLARE(switch_status_t) switch_jb_get_packet_by_seq(switch_jb_t *jb, uint16_t seq, switch_rtp_packet_t *packet, switch_size_t *len)
{
	switch_jb_node_t *node;
	switch_status_t status = SWITCH_STATUS_NOTFOUND;

	switch_mutex_lock(jb->mutex);
	if ((node = switch_core_inthash_find(jb->node_hash, seq))) {
		jb_debug(jb, 2, "Found buffered seq: %u\n", ntohs(seq));
		*packet = node->packet;
		*len = node->len;
		packet->header.version = 2;
		status = SWITCH_STATUS_SUCCESS;
	} else {
		jb_debug(jb, 2, "Missing buffered seq: %u\n", ntohs(seq));
	}
	switch_mutex_unlock(jb->mutex);

	return status;
}

SWITCH_DECLARE(switch_size_t) switch_jb_get_last_read_len(switch_jb_t *jb)
{
	return jb->last_len;
}

SWITCH_DECLARE(switch_status_t) switch_jb_get_packet(switch_jb_t *jb, switch_rtp_packet_t *packet, switch_size_t *len)
{
	switch_jb_node_t *node = NULL;
	switch_status_t status;
	int plc = 0;
	
	switch_mutex_lock(jb->mutex);

	if (jb->complete_frames == 0) {
		jb->flush = 0;
		switch_goto_status(SWITCH_STATUS_BREAK, end);
	}

	if (jb->complete_frames < jb->frame_len) {

		switch_jb_poll(jb);

		if (!jb->flush) {
			jb_debug(jb, 2, "BUFFERING %u/%u\n", jb->complete_frames , jb->frame_len);
			switch_goto_status(SWITCH_STATUS_MORE_DATA, end);
		}
	}

	jb_debug(jb, 2, "GET PACKET %u/%u n:%d\n", jb->complete_frames , jb->frame_len, jb->visible_nodes);

	if (++jb->period_count >= jb->period_len) {

		if (jb->consec_good_count >= (jb->period_len - 5)) {
			jb_frame_inc(jb, -1);
		}

		jb->period_count = 1;
		jb->period_miss_inc = 0;
		jb->period_miss_count = 0;
		jb->period_good_count = 0;
		jb->consec_miss_count = 0;
		jb->consec_good_count = 0;

		if (jb->type == SJB_VIDEO && jb->channel && jb->video_low_bitrate) {
			//switch_time_t now = switch_time_now();
			//int ok = (now - jb->last_bitrate_change) > 10000;

			if (switch_channel_test_flag(jb->channel, CF_VIDEO_BITRATE_UNMANAGABLE) && jb->frame_len == jb->min_frame_len) {
				jb_debug(jb, 2, "%s", "Allow BITRATE changes\n");
				switch_channel_clear_flag_recursive(jb->channel, CF_VIDEO_BITRATE_UNMANAGABLE);
				jb->bitrate_control = 0;
				if (jb->session) {
					switch_core_session_request_video_refresh(jb->session);
				}
			} else if (!switch_channel_test_flag(jb->channel, CF_VIDEO_BITRATE_UNMANAGABLE) && jb->frame_len > jb->max_frame_len / 2) {
				switch_core_session_message_t msg = { 0 };

				jb->bitrate_control = jb->video_low_bitrate;
				
				msg.message_id = SWITCH_MESSAGE_INDICATE_BITRATE_REQ;
				msg.numeric_arg = jb->bitrate_control * 1024;
				msg.from = __FILE__;

				jb_debug(jb, 2, "Force BITRATE to %d\n", jb->bitrate_control);

				switch_core_session_receive_message(jb->session, &msg);
				switch_channel_set_flag_recursive(jb->channel, CF_VIDEO_BITRATE_UNMANAGABLE);
				if (jb->session) {
					switch_core_session_request_video_refresh(jb->session);
				}
			}
		}
	}


	jb->period_miss_pct = ((double)jb->period_miss_count / jb->period_count) * 100;

	//if (jb->period_miss_pct > 60.0f) {
	//	jb_debug(jb, 2, "Miss percent %02f too high, resetting buffer.\n", jb->period_miss_pct);
	//	switch_jb_reset(jb);
	//}

	if ((status = jb_next_packet(jb, &node)) == SWITCH_STATUS_SUCCESS) {
		jb_debug(jb, 2, "Found next frame cur ts: %u seq: %u\n", htonl(node->packet.header.ts), htons(node->packet.header.seq));

		if (!jb->read_init || check_seq(node->packet.header.seq, jb->highest_read_seq)) {
			jb->highest_read_seq = node->packet.header.seq;
		}

		if (jb->type != SJB_VIDEO ||
			(jb->read_init && check_seq(node->packet.header.seq, jb->highest_read_seq) && check_ts(node->packet.header.ts, jb->highest_read_ts))) {

			if (jb->type != SJB_VIDEO) {
				jb->complete_frames--;
			}
			jb_debug(jb, 2, "READ frame ts: %u complete=%u/%u n:%u\n", ntohl(node->packet.header.ts), jb->complete_frames , jb->frame_len, jb->visible_nodes);
			jb->highest_read_ts = node->packet.header.ts;
		} else if (!jb->read_init) {
			jb->highest_read_ts = node->packet.header.ts;
		}

		if (!jb->read_init) jb->read_init = 1;
	} else {
		if (jb->type == SJB_VIDEO) {
			//switch_jb_reset(jb);

			switch(status) {
			case SWITCH_STATUS_RESTART:
				jb_debug(jb, 2, "%s", "Error encountered ask for new keyframe\n");
				switch_goto_status(SWITCH_STATUS_RESTART, end);
			case SWITCH_STATUS_NOTFOUND:
			default:
				jb_debug(jb, 2, "%s", "No frames found wait for more\n");
				switch_goto_status(SWITCH_STATUS_MORE_DATA, end);
			}
		} else {
			switch(status) {
			case SWITCH_STATUS_RESTART:
				jb_debug(jb, 2, "%s", "Error encountered\n");
				jb->jitter.stats.reset_error++;
				switch_jb_reset(jb);
				switch_goto_status(SWITCH_STATUS_RESTART, end);
			case SWITCH_STATUS_NOTFOUND:
			default:
				if (jb->consec_miss_count > jb->frame_len) {
					//switch_jb_reset(jb);
					jb_frame_inc(jb, 1);
					jb_debug(jb, 2, "%s", "Too many frames not found, RESIZE\n");
					switch_goto_status(SWITCH_STATUS_RESTART, end);
				} else {
					if (jb->elastic) {
						int visible_not_old = check_jb_size(jb);

						jb->jitter.stats.estimate_ms = (int)((*jb->jitter.estimate) / ((jb->jitter.samples_per_second)) * 1000);
						jb->jitter.stats.buffer_size_ms = (int)((visible_not_old * jb->jitter.samples_per_frame) / (jb->jitter.samples_per_second / 1000));
						/* When playing PLC, we take the oportunity to expand the buffer if the jitter buffer is smaller than the 3x the estimated jitter. */
						if (jb->jitter.stats.buffer_size_ms < (3 * jb->jitter.stats.estimate_ms)) {
							jb_debug(jb, SWITCH_LOG_INFO, "JITTER estimation %dms buffersize %d/%d %dms EXPAND [plc]\n",
									 jb->jitter.stats.estimate_ms, jb->complete_frames, jb->frame_len, jb->jitter.stats.buffer_size_ms);
							jb->jitter.stats.expand++;
							decrement_seq(jb);
						} else {
							jb_debug(jb, 2, "%s", "Frame not found suggest PLC\n");
						}
					} else {
						jb_debug(jb, 2, "%s", "Frame not found suggest PLC\n");
					}

					plc = 1;
					switch_goto_status(SWITCH_STATUS_NOTFOUND, end);
				}
			}
		}
	}

	if (node) {
		status = SWITCH_STATUS_SUCCESS;

		*packet = node->packet;
		*len = node->len;
		jb->last_len = *len;
		packet->header.version = 2;
		hide_node(node, SWITCH_TRUE);

		jb_debug(jb, 2, "GET packet ts:%u seq:%u %s\n", ntohl(packet->header.ts), ntohs(packet->header.seq), packet->header.m ? " <MARK>" : "");

	} else {
		status = SWITCH_STATUS_MORE_DATA;
	}

 end:

	if (plc) {
		uint16_t seq;
		uint32_t ts = 0;

		if (jb->samples_per_frame) {
			seq = htons(jb->last_psuedo_seq);
			ts = jb->last_target_ts;
		} else {
			seq = jb->last_target_seq;
		}

		packet->header.seq = seq;
		packet->header.ts = ts;
	}

	switch_mutex_unlock(jb->mutex);
	
	if (jb->type == SJB_VIDEO) {
		if (jb->complete_frames > jb->max_frame_len * 2) {
			jb_debug(jb, 2, "JB TOO BIG (%d), RESET\n", jb->complete_frames);
			switch_jb_reset(jb);
		}
	} else {
		int too_big = (int)(jb->max_frame_len * 1.5);
		if (jb->visible_nodes > too_big && status == SWITCH_STATUS_SUCCESS) {
			status = SWITCH_STATUS_TIMEOUT;
		}
	}
	
	return status;
}

/* 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:
 */