--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/spandsp-0.0.6pre17/src/swept_tone.c	Fri Jun 25 15:50:58 2010 +0200
@@ -0,0 +1,128 @@
+/*
+ * SpanDSP - a series of DSP components for telephony
+ *
+ * swept_tone.c - Swept tone generation
+ *
+ * Written by Steve Underwood <steveu@coppice.org>
+ *
+ * Copyright (C) 2009 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: swept_tone.c,v 1.2 2009/09/23 16:02:59 steveu Exp $
+ */
+
+/*! \file */
+
+#if defined(HAVE_CONFIG_H)
+#include "config.h"
+#endif
+
+#include <stdlib.h>
+#include <inttypes.h>
+#include <string.h>
+#include <stdio.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/logging.h"
+#include "spandsp/complex.h"
+#include "spandsp/vector_float.h"
+#include "spandsp/complex_vector_float.h"
+#include "spandsp/vector_int.h"
+#include "spandsp/complex_vector_int.h"
+#include "spandsp/dds.h"
+
+#include "spandsp/swept_tone.h"
+
+#include "spandsp/private/logging.h"
+#include "spandsp/private/swept_tone.h"
+
+SPAN_DECLARE(swept_tone_state_t *) swept_tone_init(swept_tone_state_t *s, float start, float end, float level, int duration, int repeating)
+{
+    if (s == NULL)
+    {
+        if ((s = (swept_tone_state_t *) malloc(sizeof(*s))) == NULL)
+            return NULL;
+    }
+    memset(s, 0, sizeof(*s));
+    s->current_phase_inc =
+    s->starting_phase_inc = dds_phase_rate(start);
+    s->phase_inc_step = dds_phase_rate((end - start)/(float) duration);
+    s->scale = dds_scaling_dbm0(level);
+    s->duration = duration;
+    s->repeating = repeating;
+    s->pos = 0;
+    s->phase = 0;
+    return s;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) swept_tone(swept_tone_state_t *s, int16_t amp[], int max_len)
+{
+    int i;
+    int len;
+    int chunk_len;
+    
+    for (len = 0;  len < max_len;  )
+    {
+        chunk_len = max_len - len;
+        if (chunk_len > s->duration - s->pos)
+            chunk_len = s->duration - s->pos;
+        for (i = len;  i < len + chunk_len;  i++)
+        {
+            amp[i] = (dds(&s->phase, s->current_phase_inc)*s->scale) >> 15;
+            s->current_phase_inc += s->phase_inc_step;
+        }
+        len += chunk_len;
+        s->pos += chunk_len;
+        if (s->pos >= s->duration)
+        {
+            if (!s->repeating)
+                break;
+            s->pos = 0;
+            s->current_phase_inc = s->starting_phase_inc;
+        }
+    }
+    return len;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(float) swept_tone_current_frequency(swept_tone_state_t *s)
+{
+    return dds_frequency(s->current_phase_inc);
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) swept_tone_release(swept_tone_state_t *s)
+{
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+
+SPAN_DECLARE(int) swept_tone_free(swept_tone_state_t *s)
+{
+    free(s);
+    return 0;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/