add ability to provide parameters to echo cancelers on a per-channel basis, and remove the three versions of the 'Mark' echo canceler (later replaced by KB1 and then by MG2)

git-svn-id: http://svn.digium.com/svn/zaptel/branches/1.4@3524 5390a7c7-147a-4af0-8ec9-7488f05a26cb

1 files changed, 0 insertions, 257 deletions

diff --git a/mec3.h b/mec3.h
deleted file mode 100644
index 6de41f5..0000000
--- a/mec3.h
+++ /dev/null
@@ -1,257 +0,0 @@
-/*
- * Mark's Third Echo Canceller
- *
- * Copyright (C) 2003, Digium, Inc.
- *
- * This program is free software and may be used
- * and distributed under the terms of the GNU General Public 
- * License, incorporated herein by reference.  
- *
- * Dedicated to the crew of the Columbia, STS-107 for their
- * bravery and courageous sacrifice for science.
- *
- */
-
-#ifndef _MARK3_ECHO_H
-#define _MARK3_ECHO_H
-
-
-
-#ifdef __KERNEL__
-#include <linux/kernel.h>
-#include <linux/slab.h>
-#define MALLOC(a) kmalloc((a), GFP_KERNEL)
-#define FREE(a) kfree(a)
-#else
-#include <stdlib.h>
-#include <unistd.h>
-#include <stdint.h>
-#include <string.h>
-#include <math.h>
-#define MALLOC(a) malloc(a)
-#define FREE(a) free(a)
-#endif
-
-/* Features */
-
-/*
- * DO_BACKUP -- Backup coefficients, and revert in the presense of double talk to try to prevent
- * them from diverging during the ramp-up before the DTD kicks in
- */
-/* #define DO_BACKUP */
-
-#define STEP_SHIFT			2		/* Convergence rate higher = slower / better (as a shift) */
-
-#define SIGMA_REF_PWR		655		/* Keep denominator from being 0 */
-
-#define MIN_TX_ENERGY		256		/* Must have at least this much reference */
-#define MIN_RX_ENERGY		 32		/* Must have at least this much receive energy */
-
-#define MAX_ATTENUATION_SHIFT	6		/* Maximum amount of loss we care about */
-#define MAX_BETA			1024
-
-#define SUPPR_SHIFT			  4				/* Amount of loss at which we suppress audio */
-
-#define HANG_TIME			600		/* Hangover time */
-
-#define NTAPS				256			/* Number of echo can taps */
-
-#define BACKUP				256			/* Backup every this number of samples */
-
-#define POWER_OFFSET		5			/* Shift power by this amount to be sure we don't overflow the
-										   reference power.  Higher = less likely to overflow, lower = more accurage */
-
-#include "arith.h"
-
-typedef struct {
-	short buf[NTAPS * 2];
-	short max;
-	int maxexp;
-} cbuf_s;
-
-struct echo_can_state {
-	short	a_s[NTAPS];				/* Coefficients in shorts */
-	int  	a_i[NTAPS];				/* Coefficients in ints*/
-#ifdef DO_BACKUP
-	int  	b_i[NTAPS];				/* Coefficients (backup1) */
-	int  	c_i[NTAPS];				/* Coefficients (backup2) */
-#endif	
-	cbuf_s 	ref;					/* Reference excitation */
-	cbuf_s 	sig;					/* Signal (echo + near end + noise) */
-	cbuf_s	e;						/* Error */
-	int		refpwr;					/* Reference power */
-	int		taps;					/* Number of taps */
-	int		tappwr;					/* Power of taps */
-	int		hcntr;					/* Hangtime counter */
-	int pos;						/* Position in curcular buffers */
-	int backup;						/* Backup timer */
-};
-
-static void echo_can_init(void)
-{
-	printk("Zaptel Echo Canceller: MARK3%s\n", ZAPTEL_ECHO_AGGRESSIVE);
-}
-
-static void echo_can_identify(char *buf, size_t len)
-{
-	strncpy(buf, "MARK3", len);
-}
-
-static void echo_can_shutdown(void)
-{
-}
-
-static inline void echo_can_free(struct echo_can_state *ec)
-{
-	FREE(ec);
-}
-
-static inline void buf_add(cbuf_s *b, short sample, int pos, int taps)
-{
-	/* Store and keep track of maxima */
-	int x;
-	b->buf[pos] = sample;
-	b->buf[pos + taps] = sample;
-	if (sample > b->max) {
-		b->max = sample;
-		b->maxexp = taps;
-	} else {
-		b->maxexp--;
-		if (!b->maxexp) {
-			b->max = 0;
-			for (x=0;x<taps;x++)
-				if (b->max < abs(b->buf[pos + x])) {
-					b->max = abs(b->buf[pos + x]);
-					b->maxexp = x + 1;
-				}
-		}
-	}
-}
-
-static inline short echo_can_update(struct echo_can_state *ec, short ref, short sig)
-{
-	int x;
-	short u;
-	int refpwr;
-	int beta;			/* Factor */
-	int se;			/* Simulated echo */
-#ifdef DO_BACKUP
-	if (!ec->backup) {
-		/* Backup coefficients periodically */
-		ec->backup = BACKUP;
-		memcpy(ec->c_i,ec->b_i,sizeof(ec->c_i));
-		memcpy(ec->b_i,ec->a_i,sizeof(ec->b_i));
-	} else
-		ec->backup--;
-#endif		
-	/* Remove old samples from reference power calculation */
-	ec->refpwr -= ((ec->ref.buf[ec->pos] * ec->ref.buf[ec->pos]) >> POWER_OFFSET);
-
-	/* Store signal and reference */
-	buf_add(&ec->ref, ref, ec->pos, ec->taps);
-	buf_add(&ec->sig, sig, ec->pos, ec->taps);
-
-	/* Add new reference power */	
-	ec->refpwr += ((ec->ref.buf[ec->pos] * ec->ref.buf[ec->pos]) >> POWER_OFFSET);
-
-
-	/* Calculate simulated echo */
-	se = CONVOLVE2(ec->a_s, ec->ref.buf + ec->pos, ec->taps);		
-	se >>= 15;
-	
-	u = sig - se;
-	if (ec->hcntr)
-		ec->hcntr--;
-
-	/* Store error */
-	buf_add(&ec->e, u, ec->pos, ec->taps);
-	if ((ec->ref.max > MIN_TX_ENERGY) && 
-	    (ec->sig.max > MIN_RX_ENERGY) &&
-		(ec->e.max > (ec->ref.max >> MAX_ATTENUATION_SHIFT))) {
-		/* We have sufficient energy */
-		if (ec->sig.max < (ec->ref.max >> 1))  {
-			/* No double talk */
-			if (!ec->hcntr) {
-				refpwr = ec->refpwr >> (16 - POWER_OFFSET);
-				if (refpwr < SIGMA_REF_PWR)
-					refpwr = SIGMA_REF_PWR;
-				beta = (u << 16) / refpwr;
-				beta >>= STEP_SHIFT;
-				if (beta > MAX_BETA)	
-					beta = MAX_BETA;
-				if (beta < -MAX_BETA)
-					beta = -MAX_BETA;
-				/* Update coefficients */
-				for (x=0;x<ec->taps;x++) {
-					ec->a_i[x] += beta * ec->ref.buf[ec->pos + x];
-					ec->a_s[x] = ec->a_i[x] >> 16;
-				}
-			}
-		} else {
-#ifdef DO_BACKUP
-			if (!ec->hcntr) {
-				/* Our double talk detector is turning on for the first time.  Revert
-				   our coefficients, since we're probably well into the double talk by now */
-				memcpy(ec->a_i, ec->c_i, sizeof(ec->a_i));
-				for (x=0;x<ec->taps;x++) {
-					ec->a_s[x] = ec->a_i[x] >> 16;
-				}
-			}
-#endif			
-			/* Reset hang-time counter, and prevent backups */
-			ec->hcntr = HANG_TIME;
-#ifdef DO_BACKUP
-			ec->backup = BACKUP;
-#endif			
-		}
-	}
-#ifndef NO_ECHO__SUPPRESSOR	
-	if (ec->e.max < (ec->ref.max >> SUPPR_SHIFT)) {
-		/* Suppress residual echo */
-		u *= u;
-		u >>= 16;
-	} 
-#endif	
-	ec->pos--;
-	if (ec->pos < 0)
-		ec->pos = ec->taps-1;
-	return u;
-}
-
-static inline struct echo_can_state *echo_can_create(int taps, int adaption_mode)
-{
-	struct echo_can_state *ec;
-	int x;
-
-	taps = NTAPS;
-	ec = MALLOC(sizeof(struct echo_can_state));
-	if (ec) {
-		memset(ec, 0, sizeof(struct echo_can_state));
-		ec->taps = taps;
-		ec->pos = ec->taps-1;
-		for (x=0;x<31;x++) {
-			if ((1 << x) >= ec->taps) {
-				ec->tappwr = x;
-				break;
-			}
-		}
-	}
-	return ec;
-}
-
-static inline int echo_can_traintap(struct echo_can_state *ec, int pos, short val)
-{
-	/* Reset hang counter to avoid adjustments after
-	   initial forced training */
-	ec->hcntr = ec->taps << 1;
-	if (pos >= ec->taps)
-		return 1;
-	ec->a_i[pos] = val << 17;
-	ec->a_s[pos] = val << 1;
-	if (++pos >= ec->taps)
-		return 1;
-	return 0;
-}
-
-
-#endif