--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/super_tone_rx.c	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,470 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * super_tone_rx.c - Flexible telephony supervisory tone detection.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2003 Steve Underwood
+ *
+ * All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License version 2.1,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ * $Id: super_tone_rx.c,v 1.33.4.1 2009/12/19 09:47:56 steveu Exp $
+ */
+
+/*! \file */
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <fcntl.h>
+#include <ctype.h>
+#include <time.h>
+#include <inttypes.h>
+#if defined(HAVE_TGMATH_H)
+#include <tgmath.h>
+#endif
+#if defined(HAVE_MATH_H)
+#include <math.h>
+#endif
+#include "floating_fudge.h"
+
+#include "spandsp/telephony.h"
+#include "spandsp/fast_convert.h"
+#include "spandsp/complex.h"
+#include "spandsp/vector_float.h"
+#include "spandsp/complex_vector_float.h"
+#include "spandsp/tone_detect.h"
+#include "spandsp/tone_generate.h"
+#include "spandsp/super_tone_rx.h"
+
+#include "spandsp/private/super_tone_rx.h"
+
+#if defined(SPANDSP_USE_FIXED_POINT)
+#define DETECTION_THRESHOLD         16439           /* -42dBm0 */
+#define TONE_TWIST                  4               /* 6dB */
+#define TONE_TO_TOTAL_ENERGY        64              /* -3dB */
+#else
+#define DETECTION_THRESHOLD         269338317.0f    /* -42dBm0 [((128.0*32768.0/1.4142)*10^((-42 - DBM0_MAX_SINE_POWER)/20.0))^2 => 269338317.0] */
+#define TONE_TWIST                  3.981f          /* 6dB */
+#define TONE_TO_TOTAL_ENERGY        1.995f          /* 3dB */
+#define DTMF_TO_TOTAL_ENERGY        64.152f         /* -3dB [BINS*10^(-3/10.0)] */
+#endif
+
+static int add_super_tone_freq(super_tone_rx_descriptor_t *desc, int freq)
+{
+    int i;
+
+    if (freq == 0)
+        return -1;
+    /* Look for an existing frequency */
+    for (i = 0;  i < desc->used_frequencies;  i++)
+    {
+        if (desc->pitches[i][0] == freq)
+            return desc->pitches[i][1];
+    }
+    /* Look for an existing tone which is very close. We may need to merge
+       the detectors. */
+    for (i = 0;  i < desc->used_frequencies;  i++)
+    {
+        if ((desc->pitches[i][0] - 10) <= freq  &&  freq <= (desc->pitches[i][0] + 10))
+        {
+            /* Merge these two */
+            desc->pitches[desc->used_frequencies][0] = freq;
+            desc->pitches[desc->used_frequencies][1] = i;
+            make_goertzel_descriptor(&desc->desc[desc->pitches[i][1]], (float) (freq + desc->pitches[i][0])/2, BINS);
+            desc->used_frequencies++;
+            return desc->pitches[i][1];
+        }
+    }
+    desc->pitches[i][0] = freq;
+    desc->pitches[i][1] = desc->monitored_frequencies;
+    if (desc->monitored_frequencies%5 == 0)
+    {
+        desc->desc = (goertzel_descriptor_t *) realloc(desc->desc, (desc->monitored_frequencies + 5)*sizeof(goertzel_descriptor_t));
+    }
+    make_goertzel_descriptor(&desc->desc[desc->monitored_frequencies++], (float) freq, BINS);
+    desc->used_frequencies++;
+    return desc->pitches[i][1];
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx_add_tone(super_tone_rx_descriptor_t *desc)
+{
+    if (desc->tones%5 == 0)
+    {
+        desc->tone_list = (super_tone_rx_segment_t **) realloc(desc->tone_list, (desc->tones + 5)*sizeof(super_tone_rx_segment_t *));
+        desc->tone_segs = (int *) realloc(desc->tone_segs, (desc->tones + 5)*sizeof(int));
+    }
+    desc->tone_list[desc->tones] = NULL;
+    desc->tone_segs[desc->tones] = 0;
+    desc->tones++;
+    return desc->tones - 1;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx_add_element(super_tone_rx_descriptor_t *desc,
+                                            int tone,
+                                            int f1,
+                                            int f2,
+                                            int min,
+                                            int max)
+{
+    int step;
+
+    step = desc->tone_segs[tone];
+    if (step%5 == 0)
+    {
+        desc->tone_list[tone] = (super_tone_rx_segment_t *) realloc(desc->tone_list[tone], (step + 5)*sizeof(super_tone_rx_segment_t));
+    }
+    desc->tone_list[tone][step].f1 = add_super_tone_freq(desc, f1);
+    desc->tone_list[tone][step].f2 = add_super_tone_freq(desc, f2);
+    desc->tone_list[tone][step].min_duration = min*8;
+    desc->tone_list[tone][step].max_duration = (max == 0)  ?  0x7FFFFFFF  :  max*8;
+    desc->tone_segs[tone]++;
+    return step;
+}
+/*- End of function --------------------------------------------------------*/
+
+static int test_cadence(super_tone_rx_segment_t *pattern,
+                        int steps,
+                        super_tone_rx_segment_t *test,
+                        int rotation)
+{
+    int i;
+    int j;
+
+    if (rotation >= 0)
+    {
+        /* Check only for the sustaining of a tone in progress. This means
+           we only need to check each block if the latest step is compatible
+           with the tone template. */
+        if (steps < 0)
+        {
+            /* A -ve value for steps indicates we just changed step, and need to
+               check the last one ended within spec. If we don't do this
+               extra test a low duration segment might be accepted as OK. */
+            steps = -steps;
+            j = (rotation + steps - 2)%steps;
+            if (pattern[j].f1 != test[8].f1  ||  pattern[j].f2 != test[8].f2)
+                return  0;
+            if (pattern[j].min_duration > test[8].min_duration*BINS
+                ||
+                pattern[j].max_duration < test[8].min_duration*BINS)
+            {
+                return  0;
+            }
+        }
+        j = (rotation + steps - 1)%steps;
+        if (pattern[j].f1 != test[9].f1  ||  pattern[j].f2 != test[9].f2)
+            return  0;
+        if (pattern[j].max_duration < test[9].min_duration*BINS)
+            return  0;
+    }
+    else
+    {
+        /* Look for a complete template match. */
+        for (i = 0;  i < steps;  i++)
+        {
+            j = i + 10 - steps;
+            if (pattern[i].f1 != test[j].f1  ||  pattern[i].f2 != test[j].f2)
+                return  0;
+            if (pattern[i].min_duration > test[j].min_duration*BINS
+                ||
+                pattern[i].max_duration < test[j].min_duration*BINS)
+            {
+                return  0;
+            }
+        }
+    }
+    return  1;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(super_tone_rx_descriptor_t *) super_tone_rx_make_descriptor(super_tone_rx_descriptor_t *desc)
+{
+    if (desc == NULL)
+    {
+        if ((desc = (super_tone_rx_descriptor_t *) malloc(sizeof(*desc))) == NULL)
+            return NULL;
+    }
+    desc->tone_list = NULL;
+    desc->tone_segs = NULL;
+
+    desc->used_frequencies = 0;
+    desc->monitored_frequencies = 0;
+    desc->desc = NULL;
+    desc->tones = 0;
+    return desc;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx_free_descriptor(super_tone_rx_descriptor_t *desc)
+{
+    int i;
+
+    if (desc)
+    {
+        for (i = 0; i < desc->tones; i++)
+        {
+            if (desc->tone_list[i])
+                free(desc->tone_list[i]);
+        }
+        if (desc->tone_list)
+            free(desc->tone_list);
+        if (desc->tone_segs)
+            free(desc->tone_segs);
+        if (desc->desc)
+            free(desc->desc);
+        free(desc);
+    }
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(void) super_tone_rx_segment_callback(super_tone_rx_state_t *s,
+                                                  void (*callback)(void *data, int f1, int f2, int duration))
+{
+    s->segment_callback = callback;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(super_tone_rx_state_t *) super_tone_rx_init(super_tone_rx_state_t *s,
+                                                         super_tone_rx_descriptor_t *desc,
+                                                         tone_report_func_t callback,
+                                                         void *user_data)
+{
+    int i;
+
+    if (desc == NULL)
+        return NULL;
+    if (callback == NULL)
+        return NULL;
+    if (s == NULL)
+    {
+        if ((s = (super_tone_rx_state_t *) malloc(sizeof(*s) + desc->monitored_frequencies*sizeof(goertzel_state_t))) == NULL)
+            return NULL;
+    }
+
+    for (i = 0;  i < 11;  i++)
+    {
+        s->segments[i].f1 = -1;
+        s->segments[i].f2 = -1;
+        s->segments[i].min_duration = 0;
+    }
+    s->segment_callback = NULL;
+    s->tone_callback = callback;
+    s->callback_data = user_data;
+    if (desc)
+        s->desc = desc;
+    s->detected_tone = -1;
+    s->energy = 0.0f;
+    for (i = 0;  i < desc->monitored_frequencies;  i++)
+        goertzel_init(&s->state[i], &s->desc->desc[i]);
+    return  s;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx_release(super_tone_rx_state_t *s)
+{
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx_free(super_tone_rx_state_t *s)
+{
+    if (s)
+        free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+static void super_tone_chunk(super_tone_rx_state_t *s)
+{
+    int i;
+    int j;
+    int k1;
+    int k2;
+#if defined(SPANDSP_USE_FIXED_POINT)
+    int32_t res[BINS/2];
+#else
+    float res[BINS/2];
+#endif
+
+    for (i = 0;  i < s->desc->monitored_frequencies;  i++)
+        res[i] = goertzel_result(&s->state[i]);
+    /* Find our two best monitored frequencies, which also have adequate energy. */
+    if (s->energy < DETECTION_THRESHOLD)
+    {
+        k1 = -1;
+        k2 = -1;
+    }
+    else
+    {
+        if (res[0] > res[1])
+        {
+            k1 = 0;
+            k2 = 1;
+        }
+        else
+        {
+            k1 = 1;
+            k2 = 0;
+        }
+        for (j = 2;  j < s->desc->monitored_frequencies;  j++)
+        {
+            if (res[j] >= res[k1])
+            {
+                k2 = k1;
+                k1 = j;
+            }
+            else if (res[j] >= res[k2])
+            {
+                k2 = j;
+            }
+        }
+        if ((res[k1] + res[k2]) < TONE_TO_TOTAL_ENERGY*s->energy)
+        {
+            k1 = -1;
+            k2 = -1;
+        }
+        else if (res[k1] > TONE_TWIST*res[k2])
+        {
+            k2 = -1;
+        }
+        else if (k2 < k1)
+        {
+            j = k1;
+            k1 = k2;
+            k2 = j;
+        }
+    }
+    /* See if this differs from last time. */
+    if (k1 != s->segments[10].f1  ||  k2 != s->segments[10].f2)
+    {
+        /* It is different, but this might just be a transitional quirk, or
+           a one shot hiccup (eg due to noise). Only if this same thing is
+           seen a second time should we change state. */
+        s->segments[10].f1 = k1;
+        s->segments[10].f2 = k2;
+        /* While things are hopping around, consider this a continuance of the
+           previous state. */
+        s->segments[9].min_duration++;
+    }
+    else
+    {
+        if (k1 != s->segments[9].f1  ||  k2 != s->segments[9].f2)
+        {
+            if (s->detected_tone >= 0)
+            {
+                /* Test for the continuance of the existing tone pattern, based on our new knowledge of an
+                   entire segment length. */
+                if (!test_cadence(s->desc->tone_list[s->detected_tone], -s->desc->tone_segs[s->detected_tone], s->segments, s->rotation++))
+                {
+                    s->detected_tone = -1;
+                    s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
+                }
+            }
+            if (s->segment_callback)
+            {
+                s->segment_callback(s->callback_data,
+                                    s->segments[9].f1,
+                                    s->segments[9].f2,
+                                    s->segments[9].min_duration*BINS/8);
+            }
+            memcpy (&s->segments[0], &s->segments[1], 9*sizeof(s->segments[0]));
+            s->segments[9].f1 = k1;
+            s->segments[9].f2 = k2;
+            s->segments[9].min_duration = 1;
+        }
+        else
+        {
+            /* This is a continuance of the previous state */
+            if (s->detected_tone >= 0)
+            {
+                /* Test for the continuance of the existing tone pattern. We must do this here, so we can sense the
+                   discontinuance of the tone on an excessively long segment. */
+                if (!test_cadence(s->desc->tone_list[s->detected_tone], s->desc->tone_segs[s->detected_tone], s->segments, s->rotation))
+                {
+                    s->detected_tone = -1;
+                    s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
+                }
+            }
+            s->segments[9].min_duration++;
+        }
+    }
+    if (s->detected_tone < 0)
+    {
+        /* Test for the start of any of the monitored tone patterns */
+        for (j = 0;  j < s->desc->tones;  j++)
+        {
+            if (test_cadence(s->desc->tone_list[j], s->desc->tone_segs[j], s->segments, -1))
+            {
+                s->detected_tone = j;
+                s->rotation = 0;
+                s->tone_callback(s->callback_data, s->detected_tone, -10, 0);
+                break;
+            }
+        }
+    }
+#if defined(SPANDSP_USE_FIXED_POINT)
+    s->energy = 0;
+#else
+    s->energy = 0.0f;
+#endif
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) super_tone_rx(super_tone_rx_state_t *s, const int16_t amp[], int samples)
+{
+    int i;
+    int x;
+    int sample;
+#if defined(SPANDSP_USE_FIXED_POINT)
+    int16_t xamp;
+#else
+    float xamp;
+#endif
+
+    x = 0;
+    for (sample = 0;  sample < samples;  sample += x)
+    {
+        for (i = 0;  i < s->desc->monitored_frequencies;  i++)
+            x = goertzel_update(&s->state[i], amp + sample, samples - sample);
+        for (i = 0;  i < x;  i++)
+        {
+            xamp = goertzel_preadjust_amp(amp[sample + i]);
+#if defined(SPANDSP_USE_FIXED_POINT)
+            s->energy += ((int32_t) xamp*xamp);
+#else
+            s->energy += xamp*xamp;
+#endif
+        }
+        if (s->state[0].current_sample >= BINS)
+        {
+            /* We have finished a Goertzel block. */
+            super_tone_chunk(s);
+            s->energy = 0;
+        }
+    }
+    return samples;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/