Wed Oct 28 15:47:53 2009

Asterisk developer's documentation

---

dsp.c

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/*
 * 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
 * 
 */

/* 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: 58388 $")

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

/* Number of goertzels for progress detect */
#define GSAMP_SIZE_NA 183        /* North America - 350, 440, 480, 620, 950, 1400, 1800 Hz */
#define GSAMP_SIZE_CR 188        /* Costa Rica, Brazil - Only care about 425 Hz */
#define GSAMP_SIZE_UK 160        /* UK disconnect goertzel feed - shoud trigger 400hz */

#define PROG_MODE_NA    0
#define PROG_MODE_CR    1  
#define PROG_MODE_UK    2  

/* For US modes */
#define HZ_350  0
#define HZ_440  1
#define HZ_480  2
#define HZ_620  3
#define HZ_950  4
#define HZ_1400 5
#define HZ_1800 6

/* For CR/BR modes */
#define HZ_425 0

/* For UK mode */
#define HZ_400 0

static struct progalias {
   char *name;
   int 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 {
   int size;
   int freqs[7];
} modes[] = {
   { GSAMP_SIZE_NA, { 350, 440, 480, 620, 950, 1400, 1800 } }, /* North America */
   { GSAMP_SIZE_CR, { 425 } },
   { GSAMP_SIZE_UK, { 400 } },
};

#define DEFAULT_THRESHOLD  512

#define BUSY_PERCENT    10 /* The percentage difference between the two last silence periods */
#define BUSY_PAT_PERCENT   7  /* The percentage difference between measured and actual pattern */
#define BUSY_THRESHOLD     100   /* Max number of ms difference between max and min times in busy */
#define BUSY_MIN     75 /* Busy must be at least 80 ms in half-cadence */
#define 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 */
#define COUNT_THRESH    3  /* Need at least 50ms of stuff to count it */
#define UK_HANGUP_THRESH   60 /* This is the threshold for the UK */


#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 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;
   int gsamp_size;
   int 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;
   len = inf->datalen / 2;
   return __ast_dsp_digitdetect(dsp, s, len, &ign);
}

static inline int pair_there(float p1, float p2, float i1, float i2, float e)
{
   /* See if p1 and p2 are there, relative to i1 and i2 and total energy */
   /* Make sure absolute levels are high enough */
   if ((p1 < TONE_MIN_THRESH) || (p2 < TONE_MIN_THRESH))
      return 0;
   /* Amplify ignored stuff */
   i2 *= TONE_THRESH;
   i1 *= TONE_THRESH;
   e *= TONE_THRESH;
   /* Check first tone */
   if ((p1 < i1) || (p1 < i2) || (p1 < e))
      return 0;
   /* And second */
   if ((p2 < i1) || (p2 < i2) || (p2 < e))
      return 0;
   /* Guess it's there... */
   return 1;
}

int ast_dsp_getdigits (struct ast_dsp *dsp, char *buf, int max)
{
   if (dsp->digitmode & DSP_DIGITMODE_MF) {
      if (max > dsp->td.mf.current_digits)
         max = dsp->td.mf.current_digits;
      if (max > 0) {
         memcpy(buf, dsp->td.mf.digits, max);
         memmove(dsp->td.mf.digits, dsp->td.mf.digits + max, dsp->td.mf.current_digits - max);
         dsp->td.mf.current_digits -= max;
      }
      buf[max] = '\0';
      return  max;
   } else {
      if (max > dsp->td.dtmf.current_digits)
         max = dsp->td.dtmf.current_digits;
      if (max > 0) {
         memcpy (buf, dsp->td.dtmf.digits, max);
         memmove (dsp->td.dtmf.digits, dsp->td.dtmf.digits + max, dsp->td.dtmf.current_digits - max);
         dsp->td.dtmf.current_digits -= max;
      }
      buf[max] = '\0';
      return  max;
   }
}

static int __ast_dsp_call_progress(struct ast_dsp *dsp, short *s, int len)
{
   int x;
   int y;
   int pass;
   int newstate = DSP_TONE_STATE_SILENCE;
   int res = 0;
   int thresh = (dsp->progmode == PROG_MODE_UK) ? UK_HANGUP_THRESH : COUNT_THRESH;
   while(len) {
      /* Take the lesser of the number of samples we need and what we have */
      pass = len;
      if (pass > dsp->gsamp_size - dsp->gsamps) 
         pass = dsp->gsamp_size - dsp->gsamps;
      for (x=0;x<pass;x++) {
         for (y=0;y<dsp->freqcount;y++) 
            goertzel_sample(&dsp->freqs[y], s[x]);
         dsp->genergy += s[x] * s[x];
      }
      s += pass;
      dsp->gsamps += pass;
      len -= pass;
      if (dsp->gsamps == dsp->gsamp_size) {
         float hz[7];
         for (y=0;y<7;y++)
            hz[y] = goertzel_result(&dsp->freqs[y]);
#if 0
         printf("\n350:     425:     440:     480:     620:     950:     1400:    1800:    Energy:   \n");
         printf("%.2e %.2e %.2e %.2e %.2e %.2e %.2e %.2e %.2e\n", 
            hz[HZ_350], hz[HZ_425], hz[HZ_440], hz[HZ_480], hz[HZ_620], hz[HZ_950], hz[HZ_1400], hz[HZ_1800], dsp->genergy);
#endif
         switch(dsp->progmode) {
         case PROG_MODE_NA:
            if (pair_there(hz[HZ_480], hz[HZ_620], hz[HZ_350], hz[HZ_440], dsp->genergy)) {
               newstate = DSP_TONE_STATE_BUSY;
            } else if (pair_there(hz[HZ_440], hz[HZ_480], hz[HZ_350], hz[HZ_620], dsp->genergy)) {
               newstate = DSP_TONE_STATE_RINGING;
            } else if (pair_there(hz[HZ_350], hz[HZ_440], hz[HZ_480], hz[HZ_620], dsp->genergy)) {
               newstate = DSP_TONE_STATE_DIALTONE;
            } else if (hz[HZ_950] > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = DSP_TONE_STATE_SPECIAL1;
            } else if (hz[HZ_1400] > TONE_MIN_THRESH * TONE_THRESH) {
               if (dsp->tstate == DSP_TONE_STATE_SPECIAL1)
                  newstate = DSP_TONE_STATE_SPECIAL2;
            } else if (hz[HZ_1800] > TONE_MIN_THRESH * TONE_THRESH) {
               if (dsp->tstate == DSP_TONE_STATE_SPECIAL2)
                  newstate = DSP_TONE_STATE_SPECIAL3;
            } else if (dsp->genergy > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = DSP_TONE_STATE_TALKING;
            } else
               newstate = DSP_TONE_STATE_SILENCE;
            break;
         case PROG_MODE_CR:
            if (hz[HZ_425] > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = DSP_TONE_STATE_RINGING;
            } else if (dsp->genergy > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = DSP_TONE_STATE_TALKING;
            } else
               newstate = DSP_TONE_STATE_SILENCE;
            break;
         case PROG_MODE_UK:
            if (hz[HZ_400] > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = DSP_TONE_STATE_HUNGUP;
            }
            break;
         default:
            ast_log(LOG_WARNING, "Can't process in unknown prog mode '%d'\n", dsp->progmode);
         }
         if (newstate == dsp->tstate) {
            dsp->tcount++;
            if (dsp->tcount == thresh) {
               if ((dsp->features & DSP_PROGRESS_BUSY) && 
                   dsp->tstate == DSP_TONE_STATE_BUSY) {
                  res = AST_CONTROL_BUSY;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               } else if ((dsp->features & DSP_PROGRESS_TALK) && 
                     dsp->tstate == DSP_TONE_STATE_TALKING) {
                  res = AST_CONTROL_ANSWER;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               } else if ((dsp->features & DSP_PROGRESS_RINGING) && 
                     dsp->tstate == DSP_TONE_STATE_RINGING)
                  res = AST_CONTROL_RINGING;
               else if ((dsp->features & DSP_PROGRESS_CONGESTION) && 
                   dsp->tstate == DSP_TONE_STATE_SPECIAL3) {
                  res = AST_CONTROL_CONGESTION;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               } else if ((dsp->features & DSP_FEATURE_CALL_PROGRESS) &&
                  dsp->tstate == DSP_TONE_STATE_HUNGUP) {
                  res = AST_CONTROL_HANGUP;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               }
            }
         } else {
#if 0
            printf("Newstate: %d\n", newstate);
#endif
            dsp->tstate = newstate;
            dsp->tcount = 1;
         }
         
         /* Reset goertzel */                
         for (x=0;x<7;x++)
            dsp->freqs[x].v2 = dsp->freqs[x].v3 = 0.0;
         dsp->gsamps = 0;
         dsp->genergy = 0.0;
      }
   }
#if 0
   if (res)
      printf("Returning %d\n", res);
#endif      
   return res;
}

int ast_dsp_call_progress(struct ast_dsp *dsp, struct ast_frame *inf)
{
   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;
   }
   return __ast_dsp_call_progress(dsp, inf->data, inf->datalen / 2);
}

static int __ast_dsp_silence(struct ast_dsp *dsp, short *s, int len, int *totalsilence)
{
   int accum;
   int x;
   int res = 0;

   if (!len)
      return 0;
   accum = 0;
   for (x=0;x<len; x++) 
      accum += abs(s[x]);
   accum /= len;
   if (accum < dsp->threshold) {
      /* Silent */
      dsp->totalsilence += len/8;
      if (dsp->totalnoise) {
         /* Move and save history */
         memmove(dsp->historicnoise + DSP_HISTORY - dsp->busycount, dsp->historicnoise + DSP_HISTORY - dsp->busycount +1, dsp->busycount*sizeof(dsp->historicnoise[0]));
         dsp->historicnoise[DSP_HISTORY - 1] = dsp->totalnoise;
/* we don't want to check for busydetect that frequently */
#if 0
         dsp->busymaybe = 1;
#endif
      }
      dsp->totalnoise = 0;
      res = 1;
   } else {
      /* Not silent */
      dsp->totalnoise += len/8;
      if (dsp->totalsilence) {
         int silence1 = dsp->historicsilence[DSP_HISTORY - 1];
         int silence2 = dsp->historicsilence[DSP_HISTORY - 2];
         /* Move and save history */
         memmove(dsp->historicsilence + DSP_HISTORY - dsp->busycount, dsp->historicsilence + DSP_HISTORY - dsp->busycount + 1, dsp->busycount*sizeof(dsp->historicsilence[0]));
         dsp->historicsilence[DSP_HISTORY - 1] = dsp->totalsilence;
         /* check if the previous sample differs only by BUSY_PERCENT from the one before it */
         if (silence1 < silence2) {
            if (silence1 + silence1*BUSY_PERCENT/100 >= silence2)
               dsp->busymaybe = 1;
            else 
               dsp->busymaybe = 0;
         } else {
            if (silence1 - silence1*BUSY_PERCENT/100 <= silence2)
               dsp->busymaybe = 1;
            else 
               dsp->busymaybe = 0;
         }
      }
      dsp->totalsilence = 0;
   }
   if (totalsilence)
      *totalsilence = dsp->totalsilence;
   return res;
}

#ifdef BUSYDETECT_MARTIN
int ast_dsp_busydetect(struct ast_dsp *dsp)
{
   int res = 0, x;
#ifndef BUSYDETECT_TONEONLY
   int avgsilence = 0, hitsilence = 0;
#endif
   int avgtone = 0, hittone = 0;
   if (!dsp->busymaybe)
      return res;
   for (x=DSP_HISTORY - dsp->busycount;x<DSP_HISTORY;x++) {
#ifndef BUSYDETECT_TONEONLY
      avgsilence += dsp->historicsilence[x];
#endif
      avgtone += dsp->historicnoise[x];
   }
#ifndef BUSYDETECT_TONEONLY
   avgsilence /= dsp->busycount;
#endif
   avgtone /= dsp->busycount;
   for (x=DSP_HISTORY - dsp->busycount;x<DSP_HISTORY;x++) {
#ifndef BUSYDETECT_TONEONLY
      if (avgsilence > dsp->historicsilence[x]) {
         if (avgsilence - (avgsilence*BUSY_PERCENT/100) <= dsp->historicsilence[x])
            hitsilence++;
      } else {
         if (avgsilence + (avgsilence*BUSY_PERCENT/100) >= dsp->historicsilence[x])
            hitsilence++;
      }
#endif
      if (avgtone > dsp->historicnoise[x]) {
         if (avgtone - (avgtone*BUSY_PERCENT/100) <= dsp->historicnoise[x])
            hittone++;
      } else {
         if (avgtone + (avgtone*BUSY_PERCENT/100) >= dsp->historicnoise[x])
            hittone++;
      }
   }
#ifndef BUSYDETECT_TONEONLY
   if ((hittone >= dsp->busycount - 1) && (hitsilence >= dsp->busycount - 1) && 
       (avgtone >= BUSY_MIN && avgtone <= BUSY_MAX) && 
       (avgsilence >= BUSY_MIN && avgsilence <= BUSY_MAX)) {
#else
   if ((hittone >= dsp->busycount - 1) && (avgtone >= BUSY_MIN && avgtone <= BUSY_MAX)) {
#endif
#ifdef BUSYDETECT_COMPARE_TONE_AND_SILENCE
#ifdef BUSYDETECT_TONEONLY
#error You cant use BUSYDETECT_TONEONLY together with BUSYDETECT_COMPARE_TONE_AND_SILENCE
#endif
      if (avgtone > avgsilence) {
         if (avgtone - avgtone*BUSY_PERCENT/100 <= avgsilence)
            res = 1;
      } else {
         if (avgtone + avgtone*BUSY_PERCENT/100 >= avgsilence)
            res = 1;
      }
#else
      res = 1;
#endif
   }
   /* If we know the expected busy tone length, check we are in the range */
   if (res && (dsp->busy_tonelength > 0)) {
      if (abs(avgtone - dsp->busy_tonelength) > (dsp->busy_tonelength*BUSY_PAT_PERCENT/100)) {
#if 0
         ast_log(LOG_NOTICE, "busy detector: avgtone of %d not close enough to desired %d\n",
                  avgtone, dsp->busy_tonelength);
#endif
         res = 0;
      }
   }
#ifndef BUSYDETECT_TONEONLY
   /* If we know the expected busy tone silent-period length, check we are in the range */
   if (res && (dsp->busy_quietlength > 0)) {
      if (abs(avgsilence - dsp->busy_quietlength) > (dsp->busy_quietlength*BUSY_PAT_PERCENT/100)) {
#if 0
         ast_log(LOG_NOTICE, "busy detector: avgsilence of %d not close enough to desired %d\n",
                  avgsilence, dsp->busy_quietlength);
#endif
         res = 0;
      }
   }
#endif
#if 1
#ifndef BUSYDETECT_TONEONLY
   if (res)
      ast_log(LOG_DEBUG, "ast_dsp_busydetect detected busy, avgtone: %d, avgsilence %d\n", avgtone, avgsilence);
#endif
#endif
   return res;
}
#endif

#ifdef BUSYDETECT
int ast_dsp_busydetect(struct ast_dsp *dsp)
{
   int x;
   int res = 0;
   int max, min;

#if 0
   if (dsp->busy_hits > 5);
   return 0;
#endif
   if (dsp->busymaybe) {
#if 0
      printf("Maybe busy!\n");
#endif      
      dsp->busymaybe = 0;
      min = 9999;
      max = 0;
      for (x=DSP_HISTORY - dsp->busycount;x<DSP_HISTORY;x++) {
#if 0
         printf("Silence: %d, Noise: %d\n", dsp->historicsilence[x], dsp->historicnoise[x]);
#endif         
         if (dsp->historicsilence[x] < min)
            min = dsp->historicsilence[x];
         if (dsp->historicnoise[x] < min)
            min = dsp->historicnoise[x];
         if (dsp->historicsilence[x] > max)
            max = dsp->historicsilence[x];
         if (dsp->historicnoise[x] > max)
            max = dsp->historicnoise[x];
      }
      if ((max - min < BUSY_THRESHOLD) && (max < BUSY_MAX) && (min > BUSY_MIN)) {
#if 0
         printf("Busy!\n");
#endif         
         res = 1;
      }
#if 0
      printf("Min: %d, max: %d\n", min, max);
#endif      
   }
   return res;
}
#endif

int ast_dsp_silence(struct ast_dsp *dsp, struct ast_frame *f, int *totalsilence)
{
   short *s;
   int len;
   
   if (f->frametype != AST_FRAME_VOICE) {
      ast_log(LOG_WARNING, "Can't calculate silence on a non-voice frame\n");
      return 0;
   }
   if (f->subclass != AST_FORMAT_SLINEAR) {
      ast_log(LOG_WARNING, "Can only calculate silence on signed-linear frames :(\n");
      return 0;
   }
   s = f->data;
   len = f->datalen/2;
   return __ast_dsp_silence(dsp, s, len, totalsilence);
}

struct ast_frame *ast_dsp_process(struct ast_channel *chan, struct ast_dsp *dsp, struct ast_frame *af)
{
   int silence;
   int res;
   int digit;
   int x;
   short *shortdata;
   unsigned char *odata;
   int len;
   int writeback = 0;

#define FIX_INF(inf) do { \
      if (writeback) { \
         switch(inf->subclass) { \
         case AST_FORMAT_SLINEAR: \
            break; \
         case AST_FORMAT_ULAW: \
            for (x=0;x<len;x++) \
               odata[x] = AST_LIN2MU((unsigned short)shortdata[x]); \
            break; \
         case AST_FORMAT_ALAW: \
            for (x=0;x<len;x++) \
               odata[x] = AST_LIN2A((unsigned short)shortdata[x]); \
            break; \
         } \
      } \
   } while(0) 

   if (!af)
      return NULL;
   if (af->frametype != AST_FRAME_VOICE)
      return af;
   odata = af->data;
   len = af->datalen;
   /* Make sure we have short data */
   switch(af->subclass) {
   case AST_FORMAT_SLINEAR:
      shortdata = af->data;
      len = af->datalen / 2;
      break;
   case AST_FORMAT_ULAW:
      shortdata = alloca(af->datalen * 2);
      if (!shortdata) {
         ast_log(LOG_WARNING, "Unable to allocate stack space for data: %s\n", strerror(errno));
         return af;
      }
      for (x=0;x<len;x++) 
         shortdata[x] = AST_MULAW(odata[x]);
      break;
   case AST_FORMAT_ALAW:
      shortdata = alloca(af->datalen * 2);
      if (!shortdata) {
         ast_log(LOG_WARNING, "Unable to allocate stack space for data: %s\n", strerror(errno));
         return af;
      }
      for (x=0;x<len;x++) 
         shortdata[x] = AST_ALAW(odata[x]);
      break;
   default:
      ast_log(LOG_WARNING, "Inband DTMF is not supported on codec %s. Use RFC2833\n", ast_getformatname(af->subclass));
      return af;
   }
   silence = __ast_dsp_silence(dsp, shortdata, len, NULL);
   if ((dsp->features & DSP_FEATURE_SILENCE_SUPPRESS) && silence) {
      memset(&dsp->f, 0, sizeof(dsp->f));
      dsp->f.frametype = AST_FRAME_NULL;
      return &dsp->f;
   }
   if ((dsp->features & DSP_FEATURE_BUSY_DETECT) && ast_dsp_busydetect(dsp)) {
      chan->_softhangup |= AST_SOFTHANGUP_DEV;
      memset(&dsp->f, 0, sizeof(dsp->f));
      dsp->f.frametype = AST_FRAME_CONTROL;
      dsp->f.subclass = AST_CONTROL_BUSY;
      ast_log(LOG_DEBUG, "Requesting Hangup because the busy tone was detected on channel %s\n", chan->name);
      return &dsp->f;
   }
   if ((dsp->features & DSP_FEATURE_DTMF_DETECT)) {
      digit = __ast_dsp_digitdetect(dsp, shortdata, len, &writeback);
#if 0
      if (digit)
         printf("Performing digit detection returned %d, digitmode is %d\n", digit, dsp->digitmode);
#endif         
      if (dsp->digitmode & (DSP_DIGITMODE_MUTECONF | DSP_DIGITMODE_MUTEMAX)) {
         if (!dsp->thinkdigit) {
            if (digit) {
               /* Looks like we might have something.  
                * Request a conference mute for the moment */
               memset(&dsp->f, 0, sizeof(dsp->f));
               dsp->f.frametype = AST_FRAME_DTMF;
               dsp->f.subclass = 'm';
               dsp->thinkdigit = 'x';
               FIX_INF(af);
               if (chan)
                  ast_queue_frame(chan, af);
               ast_frfree(af);
               return &dsp->f;
            }
         } else {
            if (digit) {
               /* Thought we saw one last time.  Pretty sure we really have now */
               if (dsp->thinkdigit) {
                  if ((dsp->thinkdigit != 'x') && (dsp->thinkdigit != digit)) {
                     /* If we found a digit, and we're changing digits, go
                        ahead and send this one, but DON'T stop confmute because
                        we're detecting something else, too... */
                     memset(&dsp->f, 0, sizeof(dsp->f));
                     dsp->f.frametype = AST_FRAME_DTMF;
                     dsp->f.subclass = dsp->thinkdigit;
                     FIX_INF(af);
                     if (chan)
                        ast_queue_frame(chan, af);
                     ast_frfree(af);
                  }
                  dsp->thinkdigit = digit;
                  return &dsp->f;
               }
               dsp->thinkdigit = digit;
            } else {
               if (dsp->thinkdigit) {
                  memset(&dsp->f, 0, sizeof(dsp->f));
                  if (dsp->thinkdigit != 'x') {
                     /* If we found a digit, send it now */
                     dsp->f.frametype = AST_FRAME_DTMF;
                     dsp->f.subclass = dsp->thinkdigit;
                     dsp->thinkdigit = 0;
                  } else {
                     dsp->f.frametype = AST_FRAME_DTMF;
                     dsp->f.subclass = 'u';
                     dsp->thinkdigit = 0;
                  }
                  FIX_INF(af);
                  if (chan)
                     ast_queue_frame(chan, af);
                  ast_frfree(af);
                  return &dsp->f;
               }
            }
         }
      } else if (!digit) {
         /* Only check when there is *not* a hit... */
         if (dsp->digitmode & DSP_DIGITMODE_MF) {
            if (dsp->td.mf.current_digits) {
               memset(&dsp->f, 0, sizeof(dsp->f));
               dsp->f.frametype = AST_FRAME_DTMF;
               dsp->f.subclass = dsp->td.mf.digits[0];
               memmove(dsp->td.mf.digits, dsp->td.mf.digits + 1, dsp->td.mf.current_digits);
               dsp->td.mf.current_digits--;
               FIX_INF(af);
               if (chan)
                  ast_queue_frame(chan, af);
               ast_frfree(af);
               return &dsp->f;
            }
         } else {
            if (dsp->td.dtmf.current_digits) {
               memset(&dsp->f, 0, sizeof(dsp->f));
               dsp->f.frametype = AST_FRAME_DTMF;
               dsp->f.subclass = dsp->td.dtmf.digits[0];
               memmove(dsp->td.dtmf.digits, dsp->td.dtmf.digits + 1, dsp->td.dtmf.current_digits);
               dsp->td.dtmf.current_digits--;
               FIX_INF(af);
               if (chan)
                  ast_queue_frame(chan, af);
               ast_frfree(af);
               return &dsp->f;
            }
         }
      }
   }
   if ((dsp->features & DSP_FEATURE_CALL_PROGRESS)) {
      res = __ast_dsp_call_progress(dsp, shortdata, len);
      if (res) {
         switch(res) {
         case AST_CONTROL_ANSWER:
         case AST_CONTROL_BUSY:
         case AST_CONTROL_RINGING:
         case AST_CONTROL_CONGESTION:
         case AST_CONTROL_HANGUP:
            memset(&dsp->f, 0, sizeof(dsp->f));
            dsp->f.frametype = AST_FRAME_CONTROL;
            dsp->f.subclass = res;
            dsp->f.src = "dsp_progress";
            if (chan) 
               ast_queue_frame(chan, &dsp->f);
            break;
         default:
            ast_log(LOG_WARNING, "Don't know how to represent call progress message %d\n", res);
         }
      }
   }
   FIX_INF(af);
   return af;
}

static void ast_dsp_prog_reset(struct ast_dsp *dsp)
{
   int max = 0;
   int x;
   
   dsp->gsamp_size = modes[dsp->progmode].size;
   dsp->gsamps = 0;
   for (x=0;x<sizeof(modes[dsp->progmode].freqs) / sizeof(modes[dsp->progmode].freqs[0]);x++) {
      if (modes[dsp->progmode].freqs[x]) {
         goertzel_init(&dsp->freqs[x], (float)modes[dsp->progmode].freqs[x], dsp->gsamp_size);
         max = x + 1;
      }
   }
   dsp->freqcount = max;
}

struct ast_dsp *ast_dsp_new(void)
{
   struct ast_dsp *dsp;

   dsp = malloc(sizeof(struct ast_dsp));
   if (dsp) {
      memset(dsp, 0, sizeof(struct ast_dsp));
      dsp->threshold = DEFAULT_THRESHOLD;
      dsp->features = DSP_FEATURE_SILENCE_SUPPRESS;
      dsp->busycount = DSP_HISTORY;
      /* Initialize DTMF detector */
      ast_dtmf_detect_init(&dsp->td.dtmf);
      /* Initialize initial DSP progress detect parameters */
      ast_dsp_prog_reset(dsp);
   }
   return dsp;
}

void ast_dsp_set_features(struct ast_dsp *dsp, int features)
{
   dsp->features = features;
}

void ast_dsp_free(struct ast_dsp *dsp)
{
   free(dsp);
}

void ast_dsp_set_threshold(struct ast_dsp *dsp, int threshold)
{
   dsp->threshold = threshold;
}

void ast_dsp_set_busy_count(struct ast_dsp *dsp, int cadences)
{
   if (cadences < 4)
      cadences = 4;
   if (cadences > DSP_HISTORY)
      cadences = DSP_HISTORY;
   dsp->busycount = cadences;
}

void ast_dsp_set_busy_pattern(struct ast_dsp *dsp, int tonelength, int quietlength)
{
   dsp->busy_tonelength = tonelength;
   dsp->busy_quietlength = quietlength;
   ast_log(LOG_DEBUG, "dsp busy pattern set to %d,%d\n", tonelength, quietlength);
}

void ast_dsp_digitreset(struct ast_dsp *dsp)
{
   int i;
   
   dsp->thinkdigit = 0;
   if (dsp->digitmode & DSP_DIGITMODE_MF) {
      memset(dsp->td.mf.digits, 0, sizeof(dsp->td.mf.digits));
      dsp->td.mf.current_digits = 0;
      /* Reinitialise the detector for the next block */
      for (i = 0;  i < 6;  i++) {
         goertzel_reset(&dsp->td.mf.tone_out[i]);
#ifdef OLD_DSP_ROUTINES
         goertzel_reset(&dsp->td.mf.tone_out2nd[i]);
#endif         
      }
#ifdef OLD_DSP_ROUTINES
      dsp->td.mf.energy = 0.0;
      dsp->td.mf.hit1 = dsp->td.mf.hit2 = dsp->td.mf.hit3 = dsp->td.mf.hit4 = dsp->td.mf.mhit = 0;
#else
      dsp->td.mf.hits[4] = dsp->td.mf.hits[3] = dsp->td.mf.hits[2] = dsp->td.mf.hits[1] = dsp->td.mf.hits[0] = dsp->td.mf.mhit = 0;
#endif      
      dsp->td.mf.current_sample = 0;
   } else {
      memset(dsp->td.dtmf.digits, 0, sizeof(dsp->td.dtmf.digits));
      dsp->td.dtmf.current_digits = 0;
      /* Reinitialise the detector for the next block */
      for (i = 0;  i < 4;  i++) {
         goertzel_reset(&dsp->td.dtmf.row_out[i]);
         goertzel_reset(&dsp->td.dtmf.col_out[i]);
#ifdef OLD_DSP_ROUTINES
         goertzel_reset(&dsp->td.dtmf.row_out2nd[i]);
         goertzel_reset(&dsp->td.dtmf.col_out2nd[i]);
#endif         
      }
#ifdef FAX_DETECT
      goertzel_reset (&dsp->td.dtmf.fax_tone);
#endif
#ifdef OLD_DSP_ROUTINES
#ifdef FAX_DETECT
      goertzel_reset (&dsp->td.dtmf.fax_tone2nd);
#endif
      dsp->td.dtmf.hit1 = dsp->td.dtmf.hit2 = dsp->td.dtmf.hit3 = dsp->td.dtmf.hit4 = dsp->td.dtmf.mhit = 0;
#else
      dsp->td.dtmf.hits[2] = dsp->td.dtmf.hits[1] = dsp->td.dtmf.hits[0] =  dsp->td.dtmf.mhit = 0;
#endif      
      dsp->td.dtmf.energy = 0.0;
      dsp->td.dtmf.current_sample = 0;
   }
}

void ast_dsp_reset(struct ast_dsp *dsp)
{
   int x;
   
   dsp->totalsilence = 0;
   dsp->gsamps = 0;
   for (x=0;x<4;x++)
      dsp->freqs[x].v2 = dsp->freqs[x].v3 = 0.0;
   memset(dsp->historicsilence, 0, sizeof(dsp->historicsilence));
   memset(dsp->historicnoise, 0, sizeof(dsp->historicnoise));  
}

int ast_dsp_digitmode(struct ast_dsp *dsp, int digitmode)
{
   int new;
   int old;
   
   old = dsp->digitmode & (DSP_DIGITMODE_DTMF | DSP_DIGITMODE_MF | DSP_DIGITMODE_MUTECONF | DSP_DIGITMODE_MUTEMAX);
   new = digitmode & (DSP_DIGITMODE_DTMF | DSP_DIGITMODE_MF | DSP_DIGITMODE_MUTECONF | DSP_DIGITMODE_MUTEMAX);
   if (old != new) {
      /* Must initialize structures if switching from MF to DTMF or vice-versa */
      if (new & DSP_DIGITMODE_MF)
         ast_mf_detect_init(&dsp->td.mf);
      else
         ast_dtmf_detect_init(&dsp->td.dtmf);
   }
   dsp->digitmode = digitmode;
   return 0;
}

int ast_dsp_set_call_progress_zone(struct ast_dsp *dsp, char *zone)
{
   int x;
   
   for (x=0;x<sizeof(aliases) / sizeof(aliases[0]);x++) {
      if (!strcasecmp(aliases[x].name, zone)) {
         dsp->progmode = aliases[x].mode;
         ast_dsp_prog_reset(dsp);
         return 0;
      }
   }
   return -1;
}

int ast_dsp_get_tstate(struct ast_dsp *dsp) 
{
   return dsp->tstate;
}

int ast_dsp_get_tcount(struct ast_dsp *dsp) 
{
   return dsp->tcount;
}

---