--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.3/spandsp-0.0.3/src/super_tone_rx.c	Fri Jun 25 16:00:21 2010 +0200
@@ -0,0 +1,420 @@
+/*
+ * 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 General Public License version 2, 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU 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 1.13 2006/11/19 14:07:25 steveu Exp $
+ */
+
+/*! \file */
+
+#ifdef 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 "spandsp/telephony.h"
+#include "spandsp/tone_detect.h"
+#include "spandsp/tone_generate.h"
+#include "spandsp/super_tone_rx.h"
+
+#define THRESHOLD               8.0e7
+
+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 --------------------------------------------------------*/
+
+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 --------------------------------------------------------*/
+
+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 --------------------------------------------------------*/
+
+super_tone_rx_descriptor_t *super_tone_rx_make_descriptor(super_tone_rx_descriptor_t *desc)
+{
+    if (desc == NULL)
+    {
+        desc = (super_tone_rx_descriptor_t *) malloc(sizeof(super_tone_rx_descriptor_t));
+        if (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 --------------------------------------------------------*/
+
+int super_tone_rx_free_descriptor(super_tone_rx_descriptor_t *desc)
+{
+    if (desc)
+        free(desc);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+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 --------------------------------------------------------*/
+
+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 (s == NULL)
+    {
+        s = (super_tone_rx_state_t *) malloc(sizeof(super_tone_rx_state_t) + desc->monitored_frequencies*sizeof(goertzel_state_t));
+        if (s == NULL)
+            return NULL;
+    }
+    if (callback == 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 = 0.0;
+    s->total_energy = 0.0;
+    for (i = 0;  i < desc->monitored_frequencies;  i++)
+        goertzel_init(&s->state[i], &s->desc->desc[i]);
+    return  s;
+}
+/*- End of function --------------------------------------------------------*/
+
+int super_tone_rx_free(super_tone_rx_state_t *s)
+{
+    if (s)
+        free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+int super_tone_rx(super_tone_rx_state_t *s, const int16_t *amp, int samples)
+{
+    int i;
+    int j;
+    int k1;
+    int k2;
+    int x;
+    float res[BINS/2];
+    int sample;
+
+    for (sample = 0;  sample < samples;  sample += x)
+    {
+        x = 0;
+        for (i = 0;  i < s->desc->monitored_frequencies;  i++)
+        {
+            x = goertzel_update(&s->state[i],
+                                amp + sample,
+                                samples - sample);
+            if (i == s->desc->monitored_frequencies - 1)
+            {
+                for (j = 0;  j < x;  j++)
+                    s->energy += amp[sample + j]*amp[sample + j];
+            }
+            if (s->state[i].current_sample >= s->state[i].samples)
+            {
+                res[i] = goertzel_result(&s->state[i]);
+                goertzel_init(&s->state[i], &s->desc->desc[i]);
+                if (i == s->desc->monitored_frequencies - 1)
+                {
+                    /* Scale the energy so it can be compared to the results from the
+                       Goertzel filters. */
+                    s->total_energy = s->energy*(s->state[i].samples/2);
+                    s->energy = 0;
+                    /* Find our two best monitored frequencies, which also have adequate
+                       energy. */
+                    if (s->total_energy < 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] < 0.5*s->total_energy)
+                        {
+                            k1 = -1;
+                            k2 = -1;
+                        }
+                        else if (res[k1] > 4.0*res[k2])
+                        {
+                            k2 = -1;
+                        }
+                        else if (k2 < k1)
+                        {
+                            j = k1;
+                            k1 = k2;
+                            k2 = j;
+                        }
+                    }
+                    /* See if this looks different to 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);
+                                }
+                            }
+                            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);
+                                }
+                            }
+                            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);
+                                break;
+                            }
+                        }
+                    }
+                }
+            }
+        }
+    }
+    return  samples;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/