---

dsp.c

Go to the documentation of this file.

/*
 * Asterisk -- A telephony toolkit for Linux.
 *
 * Convenience Signal Processing routines
 * 
 * Copyright (C) 2002, Digium
 *
 * Mark Spencer <markster@linux-support.net>
 *
 * This program is free software, distributed under the terms of
 * the GNU General Public License.
 *
 * Goertzel routines are borrowed from Steve Underwood's tremendous work on the
 * DTMF detector.
 *
 */

/* 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 <asterisk/frame.h>
#include <asterisk/channel.h>
#include <asterisk/channel_pvt.h>
#include <asterisk/logger.h>
#include <asterisk/dsp.h>
#include <asterisk/ulaw.h>
#include <asterisk/alaw.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <math.h>
#include <errno.h>
#include <stdio.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 - Only care about 425 Hz */

#define PROG_MODE_NA    0
#define PROG_MODE_CR    1  

/* 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 modes */
#define HZ_425 0

static struct progalias {
   char *name;
   int mode;
} aliases[] = {
   { "us", PROG_MODE_NA },
   { "ca", PROG_MODE_NA },
   { "cr", PROG_MODE_CR },
};

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 } },
};

#define DEFAULT_THRESHOLD 512

#define BUSY_PERCENT    10 /* The percentage diffrence between the two last silence periods */
#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     1100  /* Busy can't be longer than 1100 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 TONE_STATE_SILENCE  0
#define TONE_STATE_RINGING  1 
#define TONE_STATE_DIALTONE 2
#define TONE_STATE_TALKING  3
#define TONE_STATE_BUSY     4
#define TONE_STATE_SPECIAL1   5
#define TONE_STATE_SPECIAL2 6
#define TONE_STATE_SPECIAL3 7

#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

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 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 = TONE_STATE_SILENCE;
   int res = 0;
   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("Got whole dsp state: 350: %e, 440: %e, 480: %e, 620: %e, 950: %e, 1400: %e, 1800: %e, Energy: %e\n", 
            hz_350, hz_440, hz_480, hz_620, hz_950, hz_1400, 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 = TONE_STATE_BUSY;
            } else if (pair_there(hz[HZ_440], hz[HZ_480], hz[HZ_350], hz[HZ_620], dsp->genergy)) {
               newstate = TONE_STATE_RINGING;
            } else if (pair_there(hz[HZ_350], hz[HZ_440], hz[HZ_480], hz[HZ_620], dsp->genergy)) {
               newstate = TONE_STATE_DIALTONE;
            } else if (hz[HZ_950] > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = TONE_STATE_SPECIAL1;
            } else if (hz[HZ_1400] > TONE_MIN_THRESH * TONE_THRESH) {
               if (dsp->tstate == TONE_STATE_SPECIAL1)
                  newstate = TONE_STATE_SPECIAL2;
            } else if (hz[HZ_1800] > TONE_MIN_THRESH * TONE_THRESH) {
               if (dsp->tstate == TONE_STATE_SPECIAL2)
                  newstate = TONE_STATE_SPECIAL3;
            } else if (dsp->genergy > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = TONE_STATE_TALKING;
            } else
               newstate = TONE_STATE_SILENCE;
            break;
         case PROG_MODE_CR:
            if (hz[HZ_425] > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = TONE_STATE_RINGING;
            } else if (dsp->genergy > TONE_MIN_THRESH * TONE_THRESH) {
               newstate = TONE_STATE_TALKING;
            } else
               newstate = TONE_STATE_SILENCE;
            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 == COUNT_THRESH) {
               if (dsp->tstate == TONE_STATE_BUSY) {
                  res = AST_CONTROL_BUSY;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               } else if (dsp->tstate == TONE_STATE_TALKING) {
                  res = AST_CONTROL_ANSWER;
                  dsp->features &= ~DSP_FEATURE_CALL_PROGRESS;
               } else if (dsp->tstate == TONE_STATE_RINGING)
                  res = AST_CONTROL_RINGING;
               else if (dsp->tstate == TONE_STATE_SPECIAL3) {
                  res = AST_CONTROL_CONGESTION;
                  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) {
      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 {
      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 >= silence2)
               dsp->busymaybe = 1;
            else 
               dsp->busymaybe = 0;
         } else {
            if (silence1 - silence1/BUSY_PERCENT <= 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) <= dsp->historicsilence[x])
            hitsilence++;
      } else {
         if (avgsilence + (avgsilence / BUSY_PERCENT) >= dsp->historicsilence[x])
            hitsilence++;
      }
#endif
      if (avgtone > dsp->historicnoise[x]) {
         if (avgtone - (avgtone / BUSY_PERCENT) <= dsp->historicsilence[x])
            hittone++;
      } else {
         if (avgtone + (avgtone / BUSY_PERCENT) >= dsp->historicsilence[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*2) <= avgsilence)
            res = 1;
      } else {
         if (avgtone + avgtone/(BUSY_PERCENT*2) >= avgsilence)
            res = 1;
      }
#else
      res = 1;
#endif
   }
#if 0
   if (res)
      ast_log(LOG_NOTICE, "detected busy, avgtone: %d, avgsilence %d\n", avgtone, avgsilence);
#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;
   unsigned 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(shortdata[x]); \
            break; \
         case AST_FORMAT_ALAW: \
            for (x=0;x<len;x++) \
               odata[x] = AST_LIN2A(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_codec2str(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);
      memset(&dsp->f, 0, sizeof(dsp->f));
      dsp->f.frametype = AST_FRAME_CONTROL;
      if (res) {
         switch(res) {
         case AST_CONTROL_ANSWER:
         case AST_CONTROL_BUSY:
         case AST_CONTROL_RINGING:
         case AST_CONTROL_CONGESTION:
            dsp->f.subclass = res;
            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;
      }
   }
   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_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, 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;
}

---