--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/tone_generate.c	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,239 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * tone_generate.c - General telephony tone generation.
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2001 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: tone_generate.c,v 1.53.4.1 2009/12/23 14:23:49 steveu Exp $
+ */
+
+/*! \file */
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <inttypes.h>
+#include <string.h>
+#include <stdlib.h>
+#include <stdio.h>
+#include <time.h>
+#include <fcntl.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/dc_restore.h"
+#include "spandsp/complex.h"
+#include "spandsp/dds.h"
+#include "spandsp/tone_generate.h"
+
+#include "spandsp/private/tone_generate.h"
+
+#if !defined(M_PI)
+/* C99 systems may not define M_PI */
+#define M_PI 3.14159265358979323846264338327
+#endif
+
+SPAN_DECLARE(void) make_tone_gen_descriptor(tone_gen_descriptor_t *s,
+                                            int f1,
+                                            int l1,
+                                            int f2,
+                                            int l2,
+                                            int d1,
+                                            int d2,
+                                            int d3,
+                                            int d4,
+                                            int repeat)
+{
+    memset(s, 0, sizeof(*s));
+    if (f1)
+    {
+#if defined(SPANDSP_USE_FIXED_POINT)
+        s->tone[0].phase_rate = dds_phase_rate((float) f1);
+        if (f2 < 0)
+            s->tone[0].phase_rate = -s->tone[0].phase_rate;
+        s->tone[0].gain = dds_scaling_dbm0((float) l1);
+#else
+        s->tone[0].phase_rate = dds_phase_ratef((float) f1);
+        if (f2 < 0)
+            s->tone[0].phase_rate = -s->tone[0].phase_rate;
+        s->tone[0].gain = dds_scaling_dbm0f((float) l1);
+#endif
+    }
+    if (f2)
+    {
+#if defined(SPANDSP_USE_FIXED_POINT)
+        s->tone[1].phase_rate = dds_phase_rate((float) abs(f2));
+        s->tone[1].gain = (f2 < 0)  ?  (float) 32767.0f*l2/100.0f  :  dds_scaling_dbm0((float) l2);
+#else
+        s->tone[1].phase_rate = dds_phase_ratef((float) abs(f2));
+        s->tone[1].gain = (f2 < 0)  ?  (float) l2/100.0f  :  dds_scaling_dbm0f((float) l2);
+#endif
+    }
+
+    s->duration[0] = d1*SAMPLE_RATE/1000;
+    s->duration[1] = d2*SAMPLE_RATE/1000;
+    s->duration[2] = d3*SAMPLE_RATE/1000;
+    s->duration[3] = d4*SAMPLE_RATE/1000;
+
+    s->repeat = repeat;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(tone_gen_state_t *) tone_gen_init(tone_gen_state_t *s, tone_gen_descriptor_t *t)
+{
+    int i;
+
+    if (s == NULL)
+        return NULL;
+    for (i = 0;  i < 4;  i++)
+    {
+        s->tone[i] = t->tone[i];
+        s->phase[i] = 0;
+    }
+
+    for (i = 0;  i < 4;  i++)
+        s->duration[i] = t->duration[i];
+    s->repeat = t->repeat;
+
+    s->current_section = 0;
+    s->current_position = 0;
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) tone_gen_release(tone_gen_state_t *s)
+{
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) tone_gen_free(tone_gen_state_t *s)
+{
+    if (s)
+        free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE_NONSTD(int) tone_gen(tone_gen_state_t *s, int16_t amp[], int max_samples)
+{
+    int samples;
+    int limit;
+#if defined(SPANDSP_USE_FIXED_POINT)
+    int16_t xamp;
+#else
+    float xamp;
+#endif
+    int i;
+
+    if (s->current_section < 0)
+        return  0;
+
+    for (samples = 0;  samples < max_samples;  )
+    {
+        limit = samples + s->duration[s->current_section] - s->current_position;
+        if (limit > max_samples)
+            limit = max_samples;
+        
+        s->current_position += (limit - samples);
+        if (s->current_section & 1)
+        {
+            /* A silent section */
+            for (  ;  samples < limit;  samples++)
+                amp[samples] = 0;
+        }
+        else
+        {
+            if (s->tone[0].phase_rate < 0)
+            {
+                /* Modulated tone */
+                for (  ;  samples < limit;  samples++)
+                {
+                    /* There must be two, and only two, tones */
+#if defined(SPANDSP_USE_FIXED_POINT)
+                    xamp = ((int32_t) dds_mod(&s->phase[0], -s->tone[0].phase_rate, s->tone[0].gain, 0)
+                            *(32767 + (int32_t) dds_mod(&s->phase[1], s->tone[1].phase_rate, s->tone[1].gain, 0))) >> 15;
+                    amp[samples] = xamp;
+#else
+                    xamp = dds_modf(&s->phase[0], -s->tone[0].phase_rate, s->tone[0].gain, 0)
+                         *(1.0f + dds_modf(&s->phase[1], s->tone[1].phase_rate, s->tone[1].gain, 0));
+                    amp[samples] = (int16_t) lfastrintf(xamp);
+#endif
+                }
+            }
+            else
+            {
+                for (  ;  samples < limit;  samples++)
+                {
+#if defined(SPANDSP_USE_FIXED_POINT)
+                    xamp = 0;
+#else
+                    xamp = 0.0f;
+#endif
+                    for (i = 0;  i < 4;  i++)
+                    {
+                        if (s->tone[i].phase_rate == 0)
+                            break;
+#if defined(SPANDSP_USE_FIXED_POINT)
+                        xamp += dds_mod(&s->phase[i], s->tone[i].phase_rate, s->tone[i].gain, 0);
+#else
+                        xamp += dds_modf(&s->phase[i], s->tone[i].phase_rate, s->tone[i].gain, 0);
+#endif
+                    }
+                    /* Saturation of the answer is the right thing at this point.
+                       However, we are normally generating well controlled tones,
+                       that cannot clip. So, the overhead of doing saturation is
+                       a waste of valuable time. */
+#if defined(SPANDSP_USE_FIXED_POINT)
+                    amp[samples] = xamp;
+#else
+                    amp[samples] = (int16_t) lfastrintf(xamp);
+#endif
+                }
+            }
+        }
+        if (s->current_position >= s->duration[s->current_section])
+        {
+            s->current_position = 0;
+            if (++s->current_section > 3  ||  s->duration[s->current_section] == 0)
+            {
+                if (!s->repeat)
+                {
+                    /* Force a quick exit */
+                    s->current_section = -1;
+                    break;
+                }
+                s->current_section = 0;
+            }
+        }
+    }
+    return samples;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/