dsp.c

/*
 * Asterisk -- An open source telephony toolkit.
 *
 * Copyright (C) 1999 - 2005, Digium, Inc.
 *
 * Mark Spencer <markster@digium.com>
 *
 * Goertzel routines are borrowed from Steve Underwood's tremendous work on the
 * DTMF detector.
 *
 * See http://www.asterisk.org for more information about
 * the Asterisk project. Please do not directly contact
 * any of the maintainers of this project for assistance;
 * the project provides a web site, mailing lists and IRC
 * channels for your use.
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License Version 2. See the LICENSE file
 * at the top of the source tree.
 */

/*! \file
 *
 * \brief Convenience Signal Processing routines
 *
 * \author Mark Spencer <markster@digium.com>
 * \author Steve Underwood <steveu@coppice.org>
 */

/* Some routines from tone_detect.c by Steven Underwood as published under the zapata library */
/*
	tone_detect.c - General telephony tone detection, and specific
                        detection of DTMF.

        Copyright (C) 2001  Steve Underwood <steveu@coppice.org>

        Despite my general liking of the GPL, I place this code in the
        public domain for the benefit of all mankind - even the slimy
        ones who might try to proprietize my work and use it to my
        detriment.
*/

#include <sys/types.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <errno.h>
#include <stdio.h>

#include "asterisk.h"

ASTERISK_FILE_VERSION(__FILE__, "$Revision$")

#include "asterisk/frame.h"
#include "asterisk/channel.h"
#include "asterisk/logger.h"
#include "asterisk/dsp.h"
#include "asterisk/ulaw.h"
#include "asterisk/alaw.h"
#include "asterisk/utils.h"

/*! Number of goertzels for progress detect */
enum gsamp_size {
	GSAMP_SIZE_NA = 183,			/*!< North America - 350, 440, 480, 620, 950, 1400, 1800 Hz */
	GSAMP_SIZE_CR = 188,			/*!< Costa Rica, Brazil - Only care about 425 Hz */
	GSAMP_SIZE_UK = 160 			/*!< UK disconnect goertzel feed - should trigger 400hz */
};

enum prog_mode {
	PROG_MODE_NA = 0,
	PROG_MODE_CR,
	PROG_MODE_UK
};

enum freq_index { 
	/*! For US modes { */
	HZ_350 = 0,
	HZ_440,
	HZ_480,
	HZ_620,
	HZ_950,
	HZ_1400,
	HZ_1800, /*!< } */

	/*! For CR/BR modes */
	HZ_425 = 0,

	/*! For UK mode */
	HZ_400 = 0
};

static struct progalias {
	char *name;
	enum prog_mode mode;
} aliases[] = {
	{ "us", PROG_MODE_NA },
	{ "ca", PROG_MODE_NA },
	{ "cr", PROG_MODE_CR },
	{ "br", PROG_MODE_CR },
	{ "uk", PROG_MODE_UK },
};

static struct progress {
	enum gsamp_size size;
	int freqs[7];
} modes[] = {
	{ GSAMP_SIZE_NA, { 350, 440, 480, 620, 950, 1400, 1800 } },	/*!< North America */
	{ GSAMP_SIZE_CR, { 425 } },                                	/*!< Costa Rica, Brazil */
	{ GSAMP_SIZE_UK, { 400 } },                                	/*!< UK */
};

#define DEFAULT_THRESHOLD	512

enum busy_detect {
	BUSY_PERCENT = 10,   	/*!< The percentage difference between the two last silence periods */
	BUSY_PAT_PERCENT = 7,	/*!< The percentage difference between measured and actual pattern */
	BUSY_THRESHOLD = 100,	/*!< Max number of ms difference between max and min times in busy */
	BUSY_MIN = 75,       	/*!< Busy must be at least 80 ms in half-cadence */
	BUSY_MAX =3100       	/*!< Busy can't be longer than 3100 ms in half-cadence */
};

/*! Remember last 15 units */
#define DSP_HISTORY 		15

/*! Define if you want the fax detector -- NOT RECOMMENDED IN -STABLE */
#define FAX_DETECT

#define TONE_THRESH		10.0	/*!< How much louder the tone should be than channel energy */
#define TONE_MIN_THRESH 	1e8	/*!< How much tone there should be at least to attempt */

/*! All THRESH_XXX values are in GSAMP_SIZE chunks (us = 22ms) */
enum gsamp_thresh {
	THRESH_RING = 8,        	/*!< Need at least 150ms ring to accept */
	THRESH_TALK = 2,        	/*!< Talk detection does not work continuously */
	THRESH_BUSY = 4,        	/*!< Need at least 80ms to accept */
	THRESH_CONGESTION = 4,  	/*!< Need at least 80ms to accept */
	THRESH_HANGUP = 60,     	/*!< Need at least 1300ms to accept hangup */
	THRESH_RING2ANSWER = 300	/*!< Timeout from start of ring to answer (about 6600 ms) */
};

#define	MAX_DTMF_DIGITS		128

/* Basic DTMF specs:
 *
 * Minimum tone on = 40ms
 * Minimum tone off = 50ms
 * Maximum digit rate = 10 per second
 * Normal twist <= 8dB accepted
 * Reverse twist <= 4dB accepted
 * S/N >= 15dB will detect OK
 * Attenuation <= 26dB will detect OK
 * Frequency tolerance +- 1.5% will detect, +-3.5% will reject
 */

#define DTMF_THRESHOLD		8.0e7
#define FAX_THRESHOLD		8.0e7
#define FAX_2ND_HARMONIC	2.0     /* 4dB */
#define DTMF_NORMAL_TWIST	6.3     /* 8dB */
#ifdef	RADIO_RELAX
#define DTMF_REVERSE_TWIST          ((digitmode & DSP_DIGITMODE_RELAXDTMF) ? 6.5 : 2.5)     /* 4dB normal */
#else
#define DTMF_REVERSE_TWIST          ((digitmode & DSP_DIGITMODE_RELAXDTMF) ? 4.0 : 2.5)     /* 4dB normal */
#endif
#define DTMF_RELATIVE_PEAK_ROW	6.3     /* 8dB */
#define DTMF_RELATIVE_PEAK_COL	6.3     /* 8dB */
#define DTMF_2ND_HARMONIC_ROW       ((digitmode & DSP_DIGITMODE_RELAXDTMF) ? 1.7 : 2.5)     /* 4dB normal */
#define DTMF_2ND_HARMONIC_COL	63.1    /* 18dB */
#define DTMF_TO_TOTAL_ENERGY	42.0

#ifdef OLD_DSP_ROUTINES
#define MF_THRESHOLD		8.0e7
#define MF_NORMAL_TWIST		5.3     /* 8dB */
#define MF_REVERSE_TWIST	4.0     /* was 2.5 */
#define MF_RELATIVE_PEAK	5.3     /* 8dB */
#define MF_2ND_HARMONIC		1.7	/* was 2.5  */
#else
#define BELL_MF_THRESHOLD	1.6e9
#define BELL_MF_TWIST		4.0     /* 6dB */
#define BELL_MF_RELATIVE_PEAK	12.6    /* 11dB */
#endif

#if !defined(BUSYDETECT_MARTIN) && !defined(BUSYDETECT) && !defined(BUSYDETECT_TONEONLY) && !defined(BUSYDETECT_COMPARE_TONE_AND_SILENCE)
#define BUSYDETECT_MARTIN
#endif

typedef struct {
	float v2;
	float v3;
	float fac;
#ifndef OLD_DSP_ROUTINES
	int samples;
#endif	
} goertzel_state_t;

typedef struct
{
	goertzel_state_t row_out[4];
	goertzel_state_t col_out[4];
#ifdef FAX_DETECT
	goertzel_state_t fax_tone;
#endif
#ifdef OLD_DSP_ROUTINES
	goertzel_state_t row_out2nd[4];
	goertzel_state_t col_out2nd[4];
#ifdef FAX_DETECT
	goertzel_state_t fax_tone2nd;    
#endif
	int hit1;
	int hit2;
	int hit3;
	int hit4;
#else
	int hits[3];
#endif	
	int mhit;
	float energy;
	int current_sample;

	char digits[MAX_DTMF_DIGITS + 1];
	
	int current_digits;
	int detected_digits;
	int lost_digits;
	int digit_hits[16];
#ifdef FAX_DETECT
	int fax_hits;
#endif
} dtmf_detect_state_t;

typedef struct
{
	goertzel_state_t tone_out[6];
	int mhit;
#ifdef OLD_DSP_ROUTINES
	int hit1;
	int hit2;
	int hit3;
	int hit4;
	goertzel_state_t tone_out2nd[6];
	float energy;
#else
	int hits[5];
#endif
	int current_sample;
	
	char digits[MAX_DTMF_DIGITS + 1];

	int current_digits;
	int detected_digits;
	int lost_digits;
#ifdef FAX_DETECT
	int fax_hits;
#endif
} mf_detect_state_t;

static float dtmf_row[] =
{
	697.0,  770.0,  852.0,  941.0
};
static float dtmf_col[] =
{
	1209.0, 1336.0, 1477.0, 1633.0
};

static float mf_tones[] =
{
	700.0, 900.0, 1100.0, 1300.0, 1500.0, 1700.0
};

#ifdef FAX_DETECT
static float fax_freq = 1100.0;
#endif

static char dtmf_positions[] = "123A" "456B" "789C" "*0#D";

#ifdef OLD_DSP_ROUTINES
static char mf_hit[6][6] = {
	/*  700 + */ {   0, '1', '2', '4', '7', 'C' },
	/*  900 + */ { '1',   0, '3', '5', '8', 'A' },
	/* 1100 + */ { '2', '3',   0, '6', '9', '*' },
	/* 1300 + */ { '4', '5', '6',   0, '0', 'B' },
	/* 1500 + */ { '7', '8', '9', '0',  0, '#' },
	/* 1700 + */ { 'C', 'A', '*', 'B', '#',  0  },
};
#else
static char bell_mf_positions[] = "1247C-358A--69*---0B----#";
#endif

static inline void goertzel_sample(goertzel_state_t *s, short sample)
{
	float v1;
	float fsamp  = sample;
	
	v1 = s->v2;
	s->v2 = s->v3;
	s->v3 = s->fac * s->v2 - v1 + fsamp;
}

static inline void goertzel_update(goertzel_state_t *s, short *samps, int count)
{
	int i;
	
	for (i=0;i<count;i++) 
		goertzel_sample(s, samps[i]);
}


static inline float goertzel_result(goertzel_state_t *s)
{
	return s->v3 * s->v3 + s->v2 * s->v2 - s->v2 * s->v3 * s->fac;
}

static inline void goertzel_init(goertzel_state_t *s, float freq, int samples)
{
	s->v2 = s->v3 = 0.0;
	s->fac = 2.0 * cos(2.0 * M_PI * (freq / 8000.0));
#ifndef OLD_DSP_ROUTINES
	s->samples = samples;
#endif
}

static inline void goertzel_reset(goertzel_state_t *s)
{
	s->v2 = s->v3 = 0.0;
}

struct ast_dsp {
	struct ast_frame f;
	int threshold;
	int totalsilence;
	int totalnoise;
	int features;
	int ringtimeout;
	int busymaybe;
	int busycount;
	int busy_tonelength;
	int busy_quietlength;
	int historicnoise[DSP_HISTORY];
	int historicsilence[DSP_HISTORY];
	goertzel_state_t freqs[7];
	int freqcount;
	int gsamps;
	enum gsamp_size gsamp_size;
	enum prog_mode progmode;
	int tstate;
	int tcount;
	int digitmode;
	int thinkdigit;
	float genergy;
	union {
		dtmf_detect_state_t dtmf;
		mf_detect_state_t mf;
	} td;
};

static void ast_dtmf_detect_init (dtmf_detect_state_t *s)
{
	int i;

#ifdef OLD_DSP_ROUTINES
	s->hit1 = 
	s->mhit = 
	s->hit3 =
	s->hit4 = 
	s->hit2 = 0;
#else
	s->hits[0] = s->hits[1] = s->hits[2] = 0;
#endif
	for (i = 0;  i < 4;  i++) {
		goertzel_init (&s->row_out[i], dtmf_row[i], 102);
		goertzel_init (&s->col_out[i], dtmf_col[i], 102);
#ifdef OLD_DSP_ROUTINES
		goertzel_init (&s->row_out2nd[i], dtmf_row[i] * 2.0, 102);
		goertzel_init (&s->col_out2nd[i], dtmf_col[i] * 2.0, 102);
#endif	
		s->energy = 0.0;
	}
#ifdef FAX_DETECT
	/* Same for the fax dector */
	goertzel_init (&s->fax_tone, fax_freq, 102);

#ifdef OLD_DSP_ROUTINES
	/* Same for the fax dector 2nd harmonic */
	goertzel_init (&s->fax_tone2nd, fax_freq * 2.0, 102);
#endif	
#endif /* FAX_DETECT */
	s->current_sample = 0;
	s->detected_digits = 0;
	s->current_digits = 0;
	memset(&s->digits, 0, sizeof(s->digits));
	s->lost_digits = 0;
	s->digits[0] = '\0';
}

static void ast_mf_detect_init (mf_detect_state_t *s)
{
	int i;
#ifdef OLD_DSP_ROUTINES
	s->hit1 = 
	s->hit2 = 0;
#else	
	s->hits[0] = s->hits[1] = s->hits[2] = s->hits[3] = s->hits[4] = 0;
#endif
	for (i = 0;  i < 6;  i++) {
		goertzel_init (&s->tone_out[i], mf_tones[i], 160);
#ifdef OLD_DSP_ROUTINES
		goertzel_init (&s->tone_out2nd[i], mf_tones[i] * 2.0, 160);
		s->energy = 0.0;
#endif
	}
	s->current_digits = 0;
	memset(&s->digits, 0, sizeof(s->digits));
	s->current_sample = 0;
	s->detected_digits = 0;
	s->lost_digits = 0;
	s->digits[0] = '\0';
	s->mhit = 0;
}

static int dtmf_detect (dtmf_detect_state_t *s, int16_t amp[], int samples, 
		 int digitmode, int *writeback, int faxdetect)
{
	float row_energy[4];
	float col_energy[4];
#ifdef FAX_DETECT
	float fax_energy;
#ifdef OLD_DSP_ROUTINES
	float fax_energy_2nd;
#endif	
#endif /* FAX_DETECT */
	float famp;
	float v1;
	int i;
	int j;
	int sample;
	int best_row;
	int best_col;
	int hit;
	int limit;

	hit = 0;
	for (sample = 0;  sample < samples;  sample = limit) {
		/* 102 is optimised to meet the DTMF specs. */
		if ((samples - sample) >= (102 - s->current_sample))
			limit = sample + (102 - s->current_sample);
		else
			limit = samples;
#if defined(USE_3DNOW)
		_dtmf_goertzel_update (s->row_out, amp + sample, limit - sample);
		_dtmf_goertzel_update (s->col_out, amp + sample, limit - sample);
#ifdef OLD_DSP_ROUTINES
		_dtmf_goertzel_update (s->row_out2nd, amp + sample, limit2 - sample);
		_dtmf_goertzel_update (s->col_out2nd, amp + sample, limit2 - sample);
#endif		
		/* XXX Need to fax detect for 3dnow too XXX */
		#warning "Fax Support Broken"
#else
		/* The following unrolled loop takes only 35% (rough estimate) of the 
		   time of a rolled loop on the machine on which it was developed */
		for (j=sample;j<limit;j++) {
			famp = amp[j];
			s->energy += famp*famp;
			/* With GCC 2.95, the following unrolled code seems to take about 35%
			   (rough estimate) as long as a neat little 0-3 loop */
			v1 = s->row_out[0].v2;
			s->row_out[0].v2 = s->row_out[0].v3;
			s->row_out[0].v3 = s->row_out[0].fac*s->row_out[0].v2 - v1 + famp;
			v1 = s->col_out[0].v2;
			s->col_out[0].v2 = s->col_out[0].v3;
			s->col_out[0].v3 = s->col_out[0].fac*s->col_out[0].v2 - v1 + famp;
			v1 = s->row_out[1].v2;
			s->row_out[1].v2 = s->row_out[1].v3;
			s->row_out[1].v3 = s->row_out[1].fac*s->row_out[1].v2 - v1 + famp;
			v1 = s->col_out[1].v2;
			s->col_out[1].v2 = s->col_out[1].v3;
			s->col_out[1].v3 = s->col_out[1].fac*s->col_out[1].v2 - v1 + famp;
			v1 = s->row_out[2].v2;
			s->row_out[2].v2 = s->row_out[2].v3;
			s->row_out[2].v3 = s->row_out[2].fac*s->row_out[2].v2 - v1 + famp;
			v1 = s->col_out[2].v2;
			s->col_out[2].v2 = s->col_out[2].v3;
			s->col_out[2].v3 = s->col_out[2].fac*s->col_out[2].v2 - v1 + famp;
			v1 = s->row_out[3].v2;
			s->row_out[3].v2 = s->row_out[3].v3;
			s->row_out[3].v3 = s->row_out[3].fac*s->row_out[3].v2 - v1 + famp;
			v1 = s->col_out[3].v2;
			s->col_out[3].v2 = s->col_out[3].v3;
			s->col_out[3].v3 = s->col_out[3].fac*s->col_out[3].v2 - v1 + famp;
#ifdef FAX_DETECT
			/* Update fax tone */
			v1 = s->fax_tone.v2;
			s->fax_tone.v2 = s->fax_tone.v3;
			s->fax_tone.v3 = s->fax_tone.fac*s->fax_tone.v2 - v1 + famp;
#endif /* FAX_DETECT */
#ifdef OLD_DSP_ROUTINES
			v1 = s->col_out2nd[0].v2;
			s->col_out2nd[0].v2 = s->col_out2nd[0].v3;
			s->col_out2nd[0].v3 = s->col_out2nd[0].fac*s->col_out2nd[0].v2 - v1 + famp;
			v1 = s->row_out2nd[0].v2;
			s->row_out2nd[0].v2 = s->row_out2nd[0].v3;
			s->row_out2nd[0].v3 = s->row_out2nd[0].fac*s->row_out2nd[0].v2 - v1 + famp;
			v1 = s->col_out2nd[1].v2;
			s->col_out2nd[1].v2 = s->col_out2nd[1].v3;
			s->col_out2nd[1].v3 = s->col_out2nd[1].fac*s->col_out2nd[1].v2 - v1 + famp;
			v1 = s->row_out2nd[1].v2;
			s->row_out2nd[1].v2 = s->row_out2nd[1].v3;
			s->row_out2nd[1].v3 = s->row_out2nd[1].fac*s->row_out2nd[1].v2 - v1 + famp;
			v1 = s->col_out2nd[2].v2;
			s->col_out2nd[2].v2 = s->col_out2nd[2].v3;
			s->col_out2nd[2].v3 = s->col_out2nd[2].fac*s->col_out2nd[2].v2 - v1 + famp;
			v1 = s->row_out2nd[2].v2;
			s->row_out2nd[2].v2 = s->row_out2nd[2].v3;
			s->row_out2nd[2].v3 = s->row_out2nd[2].fac*s->row_out2nd[2].v2 - v1 + famp;
			v1 = s->col_out2nd[3].v2;
			s->col_out2nd[3].v2 = s->col_out2nd[3].v3;
			s->col_out2nd[3].v3 = s->col_out2nd[3].fac*s->col_out2nd[3].v2 - v1 + famp;
			v1 = s->row_out2nd[3].v2;
			s->row_out2nd[3].v2 = s->row_out2nd[3].v3;
			s->row_out2nd[3].v3 = s->row_out2nd[3].fac*s->row_out2nd[3].v2 - v1 + famp;
#ifdef FAX_DETECT
			/* Update fax tone */            
			v1 = s->fax_tone.v2;
			s->fax_tone2nd.v2 = s->fax_tone2nd.v3;
			s->fax_tone2nd.v3 = s->fax_tone2nd.fac*s->fax_tone2nd.v2 - v1 + famp;
#endif /* FAX_DETECT */
#endif
		}
#endif
		s->current_sample += (limit - sample);
		if (s->current_sample < 102) {
			if (hit && !((digitmode & DSP_DIGITMODE_NOQUELCH))) {
				/* If we had a hit last time, go ahead and clear this out since likely it
				   will be another hit */
				for (i=sample;i<limit;i++) 
					amp[i] = 0;
				*writeback = 1;
			}
			continue;
		}
#ifdef FAX_DETECT
		/* Detect the fax energy, too */
		fax_energy = goertzel_result(&s->fax_tone);
#endif
		/* We are at the end of a DTMF detection block */
		/* Find the peak row and the peak column */
		row_energy[0] = goertzel_result (&s->row_out[0]);
		col_energy[0] = goertzel_result (&s->col_out[0]);

		for (best_row = best_col = 0, i = 1;  i < 4;  i++) {
			row_energy[i] = goertzel_result (&s->row_out[i]);
			if (row_energy[i] > row_energy[best_row])
				best_row = i;
			col_energy[i] = goertzel_result (&s->col_out[i]);
			if (col_energy[i] > col_energy[best_col])
				best_col = i;
		}
		hit = 0;
		/* Basic signal level test and the twist test */
		if (row_energy[best_row] >= DTMF_THRESHOLD && 
		    col_energy[best_col] >= DTMF_THRESHOLD &&
		    col_energy[best_col] < row_energy[best_row]*DTMF_REVERSE_TWIST &&
		    col_energy[best_col]*DTMF_NORMAL_TWIST > row_energy[best_row]) {
			/* Relative peak test */
			for (i = 0;  i < 4;  i++) {
				if ((i != best_col &&
				    col_energy[i]*DTMF_RELATIVE_PEAK_COL > col_energy[best_col]) ||
				    (i != best_row 
				     && row_energy[i]*DTMF_RELATIVE_PEAK_ROW > row_energy[best_row])) {
					break;
				}
			}
#ifdef OLD_DSP_ROUTINES
			/* ... and second harmonic test */
			if (i >= 4 && 
			    (row_energy[best_row] + col_energy[best_col]) > 42.0*s->energy &&
                	    goertzel_result(&s->col_out2nd[best_col])*DTMF_2ND_HARMONIC_COL < col_energy[best_col]
			    && goertzel_result(&s->row_out2nd[best_row])*DTMF_2ND_HARMONIC_ROW < row_energy[best_row]) {
#else
			/* ... and fraction of total energy test */
			if (i >= 4 &&
			    (row_energy[best_row] + col_energy[best_col]) > DTMF_TO_TOTAL_ENERGY*s->energy) {
#endif
				/* Got a hit */
				hit = dtmf_positions[(best_row << 2) + best_col];
				if (!(digitmode & DSP_DIGITMODE_NOQUELCH)) {
					/* Zero out frame data if this is part DTMF */
					for (i=sample;i<limit;i++) 
						amp[i] = 0;
					*writeback = 1;
				}
				/* Look for two successive similar results */
				/* The logic in the next test is:
				   We need two successive identical clean detects, with
				   something different preceeding it. This can work with
				   back to back differing digits. More importantly, it
				   can work with nasty phones that give a very wobbly start
				   to a digit */
#ifdef OLD_DSP_ROUTINES
				if (hit == s->hit3  &&  s->hit3 != s->hit2) {
					s->mhit = hit;
					s->digit_hits[(best_row << 2) + best_col]++;
					s->detected_digits++;
					if (s->current_digits < MAX_DTMF_DIGITS) {
						s->digits[s->current_digits++] = hit;
						s->digits[s->current_digits] = '\0';
					} else {
						s->lost_digits++;
					}
				}
#else				
				if (hit == s->hits[2]  &&  hit != s->hits[1]  &&  hit != s->hits[0]) {
					s->mhit = hit;
					s->digit_hits[(best_row << 2) + best_col]++;
					s->detected_digits++;
					if (s->current_digits < MAX_DTMF_DIGITS) {
						s->digits[s->current_digits++] = hit;
						s->digits[s->current_digits] = '\0';
					} else {
						s->lost_digits++;
					}
				}
#endif
			}
		} 
#ifdef FAX_DETECT
		if (!hit && (fax_energy >= FAX_THRESHOLD) && 
			(fax_energy >= DTMF_TO_TOTAL_ENERGY*s->energy) &&
			(faxdetect)) {
#if 0
			printf("Fax energy/Second Harmonic: %f\n", fax_energy);
#endif					
			/* XXX Probably need better checking than just this the energy XXX */
			hit = 'f';
			s->fax_hits++;
		} else {
			if (s->fax_hits > 5) {
				hit = 'f';
				s->mhit = 'f';
				s->detected_digits++;
				if (s->current_digits < MAX_DTMF_DIGITS) {
					s->digits[s->current_digits++] = hit;
					s->digits[s->current_digits] = '\0';
				} else {
					s->lost_digits++;
				}
			}
			s->fax_hits = 0;
		}
#endif /* FAX_DETECT */
#ifdef OLD_DSP_ROUTINES
		s->hit1 = s->hit2;
		s->hit2 = s->hit3;
		s->hit3 = hit;
#else
		s->hits[0] = s->hits[1];
		s->hits[1] = s->hits[2];
		s->hits[2] = hit;
#endif		
		/* Reinitialise the detector for the next block */
		for (i = 0;  i < 4;  i++) {
			goertzel_reset(&s->row_out[i]);
			goertzel_reset(&s->col_out[i]);
#ifdef OLD_DSP_ROUTINES
			goertzel_reset(&s->row_out2nd[i]);
			goertzel_reset(&s->col_out2nd[i]);
#endif			
		}
#ifdef FAX_DETECT
		goertzel_reset (&s->fax_tone);
#ifdef OLD_DSP_ROUTINES
		goertzel_reset (&s->fax_tone2nd);
#endif			
#endif
		s->energy = 0.0;
		s->current_sample = 0;
	}
	if ((!s->mhit) || (s->mhit != hit)) {
		s->mhit = 0;
		return(0);
	}
	return (hit);
}

/* MF goertzel size */
#ifdef OLD_DSP_ROUTINES
#define	MF_GSIZE 160
#else
#define MF_GSIZE 120
#endif

static int mf_detect (mf_detect_state_t *s, int16_t amp[],
                 int samples, int digitmode, int *writeback)
{
#ifdef OLD_DSP_ROUTINES
	float tone_energy[6];
	int best1;
	int best2;
	float max;
	int sofarsogood;
#else
	float energy[6];
	int best;
	int second_best;
#endif
	float famp;
	float v1;
	int i;
	int j;
	int sample;
	int hit;
	int limit;

	hit = 0;
	for (sample = 0;  sample < samples;  sample = limit) {
		/* 80 is optimised to meet the MF specs. */
		if ((samples - sample) >= (MF_GSIZE - s->current_sample))
			limit = sample + (MF_GSIZE - s->current_sample);
		else
			limit = samples;
#if defined(USE_3DNOW)
		_dtmf_goertzel_update (s->row_out, amp + sample, limit - sample);
		_dtmf_goertzel_update (s->col_out, amp + sample, limit - sample);
#ifdef OLD_DSP_ROUTINES
		_dtmf_goertzel_update (s->row_out2nd, amp + sample, limit2 - sample);
		_dtmf_goertzel_update (s->col_out2nd, amp + sample, limit2 - sample);
#endif
		/* XXX Need to fax detect for 3dnow too XXX */
		#warning "Fax Support Broken"
#else
		/* The following unrolled loop takes only 35% (rough estimate) of the 
		   time of a rolled loop on the machine on which it was developed */
		for (j = sample;  j < limit;  j++) {
			famp = amp[j];
#ifdef OLD_DSP_ROUTINES
			s->energy += famp*famp;
#endif
			/* With GCC 2.95, the following unrolled code seems to take about 35%
			   (rough estimate) as long as a neat little 0-3 loop */
			v1 = s->tone_out[0].v2;
			s->tone_out[0].v2 = s->tone_out[0].v3;
			s->tone_out[0].v3 = s->tone_out[0].fac*s->tone_out[0].v2 - v1 + famp;
			v1 = s->tone_out[1].v2;
			s->tone_out[1].v2 = s->tone_out[1].v3;
			s->tone_out[1].v3 = s->tone_out[1].fac*s->tone_out[1].v2 - v1 + famp;
			v1 = s->tone_out[2].v2;
			s->tone_out[2].v2 = s->tone_out[2].v3;
			s->tone_out[2].v3 = s->tone_out[2].fac*s->tone_out[2].v2 - v1 + famp;
			v1 = s->tone_out[3].v2;
			s->tone_out[3].v2 = s->tone_out[3].v3;
			s->tone_out[3].v3 = s->tone_out[3].fac*s->tone_out[3].v2 - v1 + famp;
			v1 = s->tone_out[4].v2;
			s->tone_out[4].v2 = s->tone_out[4].v3;
			s->tone_out[4].v3 = s->tone_out[4].fac*s->tone_out[4].v2 - v1 + famp;
			v1 = s->tone_out[5].v2;
			s->tone_out[5].v2 = s->tone_out[5].v3;
			s->tone_out[5].v3 = s->tone_out[5].fac*s->tone_out[5].v2 - v1 + famp;
#ifdef OLD_DSP_ROUTINES
			v1 = s->tone_out2nd[0].v2;
			s->tone_out2nd[0].v2 = s->tone_out2nd[0].v3;
			s->tone_out2nd[0].v3 = s->tone_out2nd[0].fac*s->tone_out2nd[0].v2 - v1 + famp;
			v1 = s->tone_out2nd[1].v2;
			s->tone_out2nd[1].v2 = s->tone_out2nd[1].v3;
			s->tone_out2nd[1].v3 = s->tone_out2nd[1].fac*s->tone_out2nd[1].v2 - v1 + famp;
			v1 = s->tone_out2nd[2].v2;
			s->tone_out2nd[2].v2 = s->tone_out2nd[2].v3;
			s->tone_out2nd[2].v3 = s->tone_out2nd[2].fac*s->tone_out2nd[2].v2 - v1 + famp;
			v1 = s->tone_out2nd[3].v2;
			s->tone_out2nd[3].v2 = s->tone_out2nd[3].v3;
			s->tone_out2nd[3].v3 = s->tone_out2nd[3].fac*s->tone_out2nd[3].v2 - v1 + famp;
			v1 = s->tone_out2nd[4].v2;
			s->tone_out2nd[4].v2 = s->tone_out2nd[4].v3;
			s->tone_out2nd[4].v3 = s->tone_out2nd[4].fac*s->tone_out2nd[2].v2 - v1 + famp;
			v1 = s->tone_out2nd[3].v2;
			s->tone_out2nd[5].v2 = s->tone_out2nd[6].v3;
			s->tone_out2nd[5].v3 = s->tone_out2nd[6].fac*s->tone_out2nd[3].v2 - v1 + famp;
#endif
		}
#endif
		s->current_sample += (limit - sample);
		if (s->current_sample < MF_GSIZE) {
			if (hit && !((digitmode & DSP_DIGITMODE_NOQUELCH))) {
				/* If we had a hit last time, go ahead and clear this out since likely it
				   will be another hit */
				for (i=sample;i<limit;i++) 
					amp[i] = 0;
				*writeback = 1;
			}
			continue;
		}
#ifdef OLD_DSP_ROUTINES		
		/* We're at the end of an MF detection block.  Go ahead and calculate
		   all the energies. */
		for (i=0;i<6;i++) {
			tone_energy[i] = goertzel_result(&s->tone_out[i]);
		}
		/* Find highest */
		best1 = 0;
		max = tone_energy[0];
		for (i=1;i<6;i++) {
			if (tone_energy[i] > max) {
				max = tone_energy[i];
				best1 = i;
			}
		}

		/* Find 2nd highest */
		if (best1) {
			max = tone_energy[0];
			best2 = 0;
		} else {
			max = tone_energy[1];
			best2 = 1;
		}

		for (i=0;i<6;i++) {
			if (i == best1) continue;
			if (tone_energy[i] > max) {
				max = tone_energy[i];
				best2 = i;
			}
		}
		hit = 0;
		if (best1 != best2) 
			sofarsogood=1;
		else 
			sofarsogood=0;
		/* Check for relative energies */
		for (i=0;i<6;i++) {
			if (i == best1) 
				continue;
			if (i == best2) 
				continue;
			if (tone_energy[best1] < tone_energy[i] * MF_RELATIVE_PEAK) {
				sofarsogood = 0;
				break;
			}
			if (tone_energy[best2] < tone_energy[i] * MF_RELATIVE_PEAK) {
				sofarsogood = 0;
				break;
			}
		}
		
		if (sofarsogood) {
			/* Check for 2nd harmonic */
			if (goertzel_result(&s->tone_out2nd[best1]) * MF_2ND_HARMONIC > tone_energy[best1]) 
				sofarsogood = 0;
			else if (goertzel_result(&s->tone_out2nd[best2]) * MF_2ND_HARMONIC > tone_energy[best2])
				sofarsogood = 0;
		}
		if (sofarsogood) {
			hit = mf_hit[best1][best2];
			if (!(digitmode & DSP_DIGITMODE_NOQUELCH)) {
				/* Zero out frame data if this is part DTMF */
				for (i=sample;i<limit;i++) 
					amp[i] = 0;
				*writeback = 1;
			}
			/* Look for two consecutive clean hits */
			if ((hit == s->hit3) && (s->hit3 != s->hit2)) {
				s->mhit = hit;
				s->detected_digits++;
				if (s->current_digits < MAX_DTMF_DIGITS - 2) {
					s->digits[s->current_digits++] = hit;
					s->digits[s->current_digits] = '\0';
				} else {
					s->lost_digits++;
				}
			}
		}
		
		s->hit1 = s->hit2;
		s->hit2 = s->hit3;
		s->hit3 = hit;
		/* Reinitialise the detector for the next block */
		for (i = 0;  i < 6;  i++) {
			goertzel_reset(&s->tone_out[i]);
			goertzel_reset(&s->tone_out2nd[i]);
		}
		s->energy = 0.0;
		s->current_sample = 0;
	}
#else
		/* We're at the end of an MF detection block.  */
		/* Find the two highest energies. The spec says to look for
		   two tones and two tones only. Taking this literally -ie
		   only two tones pass the minimum threshold - doesn't work
		   well. The sinc function mess, due to rectangular windowing
		   ensure that! Find the two highest energies and ensure they
		   are considerably stronger than any of the others. */
		energy[0] = goertzel_result(&s->tone_out[0]);
		energy[1] = goertzel_result(&s->tone_out[1]);
		if (energy[0] > energy[1]) {
			best = 0;
			second_best = 1;
		} else {
			best = 1;
			second_best = 0;
		}
		/*endif*/
		for (i=2;i<6;i++) {
			energy[i] = goertzel_result(&s->tone_out[i]);
			if (energy[i] >= energy[best]) {
				second_best = best;
				best = i;
			} else if (energy[i] >= energy[second_best]) {
				second_best = i;
			}
		}
		/* Basic signal level and twist tests */
		hit = 0;
		if (energy[best] >= BELL_MF_THRESHOLD && energy[second_best] >= BELL_MF_THRESHOLD
	            && energy[best] < energy[second_best]*BELL_MF_TWIST
	            && energy[best]*BELL_MF_TWIST > energy[second_best]) {
			/* Relative peak test */
			hit = -1;
			for (i=0;i<6;i++) {
				if (i != best && i != second_best) {
					if (energy[i]*BELL_MF_RELATIVE_PEAK >= energy[second_best]) {
						/* The best two are not clearly the best */
						hit = 0;
						break;
					}
				}
			}
		}
		if (hit) {
			/* Get the values into ascending order */
			if (second_best < best) {
				i = best;
				best = second_best;
				second_best = i;
			}
			best = best*5 + second_best - 1;
			hit = bell_mf_positions[best];
			/* Look for two successive similar results */
			/* The logic in the next test is:
			   For KP we need 4 successive identical clean detects, with
			   two blocks of something different preceeding it. For anything
			   else we need two successive identical clean detects, with
			   two blocks of something different preceeding it. */
			if (hit == s->hits[4] && hit == s->hits[3] &&
			   ((hit != '*' && hit != s->hits[2] && hit != s->hits[1])||
			    (hit == '*' && hit == s->hits[2] && hit != s->hits[1] && 
			    hit != s->hits[0]))) {
				s->detected_digits++;
				if (s->current_digits < MAX_DTMF_DIGITS) {
					s->digits[s->current_digits++] = hit;
					s->digits[s->current_digits] = '\0';
				} else {
					s->lost_digits++;
				}
			}
		} else {
			hit = 0;
		}
		s->hits[0] = s->hits[1];
		s->hits[1] = s->hits[2];
		s->hits[2] = s->hits[3];
		s->hits[3] = s->hits[4];
		s->hits[4] = hit;
		/* Reinitialise the detector for the next block */
		for (i = 0;  i < 6;  i++)
			goertzel_reset(&s->tone_out[i]);
		s->current_sample = 0;
	}
#endif	
	if ((!s->mhit) || (s->mhit != hit)) {
		s->mhit = 0;
		return(0);
	}
	return (hit);
}

static int __ast_dsp_digitdetect(struct ast_dsp *dsp, short *s, int len, int *writeback)
{
	int res;
	
	if (dsp->digitmode & DSP_DIGITMODE_MF)
		res = mf_detect(&dsp->td.mf, s, len, dsp->digitmode & DSP_DIGITMODE_RELAXDTMF, writeback);
	else
		res = dtmf_detect(&dsp->td.dtmf, s, len, dsp->digitmode & DSP_DIGITMODE_RELAXDTMF, writeback, dsp->features & DSP_FEATURE_FAX_DETECT);
	return res;
}

int ast_dsp_digitdetect(struct ast_dsp *dsp, struct ast_frame *inf)
{
	short *s;
	int len;
	int ign=0;

	if (inf->frametype != AST_FRAME_VOICE) {
		ast_log(LOG_WARNING, "Can't check call progress of non-voice frames\n");
		return 0;
	}
	if (inf->subclass != AST_FORMAT_SLINEAR) {
		ast_log(LOG_WARNING, "Can only check call progress in signed-linear frames\n");
		return 0;
	}
	s = inf->data;