audiostuff: spandsp-0.0.6pre17/src/super_tone

comparison spandsp-0.0.6pre17/src/super_tone_tx.c @ 4:26cd8f1ef0b1

import spandsp-0.0.6pre17

author	Peter Meerwald <pmeerw@cosy.sbg.ac.at>
date	Fri, 25 Jun 2010 15:50:58 +0200
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-:c6c5a16ce2f2
+:26cd8f1ef0b1
+/*
+* SpanDSP - a series of DSP components for telephony
+*
+* super_tone_tx.c - Flexible telephony supervisory tone generation.
+*
+* 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_tx.c,v 1.30 2009/02/10 17:44:18 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/dds.h"
+#include "spandsp/tone_generate.h"
+#include "spandsp/super_tone_tx.h"
+#include "spandsp/private/tone_generate.h"
+#include "spandsp/private/super_tone_tx.h"
+/*
+The tone played to wake folk up when they have left the phone off hook is an
+oddity amongst supervisory tones. It is designed to sound loud and nasty. Most
+tones are one or two pure sine pitches, or one AM moduluated pitch. This alert
+tone varies between countries, but AT&T are a typical example.
+AT&T Receiver Off-Hook Tone is 1400 Hz, 2060 Hz, 2450 Hz and 2600 Hz at 0dBm0/frequency
+on and off every .1 second. On some older space division switching systems
+Receiver Off-Hook was 1400 Hz, 2060 Hz, 2450 Hz and 2600 Hz at +5 VU on and
+off every .1 second. On a No. 5 ESS this continues for 30 seconds. On a No.
+2/2B ESS this continues for 40 seconds. On some other AT&T switches there are
+two iterations of 50 seconds each.
+*/
+SPAN_DECLARE(super_tone_tx_step_t *) super_tone_tx_make_step(super_tone_tx_step_t *s,
+float f1,
+float l1,
+float f2,
+float l2,
+int length,
+int cycles)
+{
+if (s == NULL)
+{
+if ((s = (super_tone_tx_step_t *) malloc(sizeof(*s))) == NULL)
+return NULL;
+}
+if (f1 >= 1.0f)
+{
+s->tone[0].phase_rate = dds_phase_ratef(f1);
+s->tone[0].gain = dds_scaling_dbm0f(l1);
+}
+else
+{
+s->tone[0].phase_rate = 0;
+s->tone[0].gain = 0.0f;
+}
+if (f2 >= 1.0f)
+{
+s->tone[1].phase_rate = dds_phase_ratef(f2);
+s->tone[1].gain = dds_scaling_dbm0f(l2);
+}
+else
+{
+s->tone[1].phase_rate = 0;
+s->tone[1].gain = 0.0f;
+}
+s->tone_on = (f1 > 0.0f);
+s->length = length*SAMPLE_RATE/1000;
+s->cycles = cycles;
+s->next = NULL;
+s->nest = NULL;
+return s;
+}
+/*- End of function --------------------------------------------------------*/
+SPAN_DECLARE(int) super_tone_tx_free_tone(super_tone_tx_step_t *s)
+{
+super_tone_tx_step_t *t;
+while (s)
+{
+/* Follow nesting... */
+if (s->nest)
+super_tone_tx_free_tone(s->nest);
+t = s;
+s = s->next;
+free(t);
+}
+return 0;
+}
+/*- End of function --------------------------------------------------------*/
+SPAN_DECLARE(super_tone_tx_state_t *) super_tone_tx_init(super_tone_tx_state_t *s, super_tone_tx_step_t *tree)
+{
+if (tree == NULL)
+return NULL;
+if (s == NULL)
+{
+if ((s = (super_tone_tx_state_t *) malloc(sizeof(*s))) == NULL)
+return NULL;
+}
+memset(s, 0, sizeof(*s));
+s->level = 0;
+s->levels[0] = tree;
+s->cycles[0] = tree->cycles;
+s->current_position = 0;
+return s;
+}
+/*- End of function --------------------------------------------------------*/
+SPAN_DECLARE(int) super_tone_tx_release(super_tone_tx_state_t *s)
+{
+return 0;
+}
+/*- End of function --------------------------------------------------------*/
+SPAN_DECLARE(int) super_tone_tx_free(super_tone_tx_state_t *s)
+{
+if (s)
+free(s);
+return 0;
+}
+/*- End of function --------------------------------------------------------*/
+SPAN_DECLARE(int) super_tone_tx(super_tone_tx_state_t *s, int16_t amp[], int max_samples)
+{
+int samples;
+int limit;
+int len;
+int i;
+float xamp;
+super_tone_tx_step_t *tree;
+if (s->level < 0  ||  s->level > 3)
+return  0;
+samples = 0;
+tree = s->levels[s->level];
+while (tree  &&  samples < max_samples)
+{
+if (tree->tone_on)
+{
+/* A period of tone. A length of zero means infinite length. */
+if (s->current_position == 0)
+{
+/* New step - prepare the tone generator */
+for (i = 0;  i < 4;  i++)
+s->tone[i] = tree->tone[i];
+}
+len = tree->length - s->current_position;
+if (tree->length == 0)
+{
+len = max_samples - samples;
+/* We just need to make current position non-zero */
+s->current_position = 1;
+}
+else if (len > max_samples - samples)
+{
+len = max_samples - samples;
+s->current_position += len;
+}
+else
+{
+s->current_position = 0;
+}
+if (s->tone[0].phase_rate < 0)
+{
+for (limit = len + samples;  samples < limit;  samples++)
+{
+/* There must be two, and only two tones */
+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);
+}
+}
+else
+{
+for (limit = len + samples;  samples < limit;  samples++)
+{
+xamp = 0.0f;
+for (i = 0;  i < 4;  i++)
+{
+if (s->tone[i].phase_rate == 0)
+break;
+xamp += dds_modf(&s->phase[i], s->tone[i].phase_rate, s->tone[i].gain, 0);
+}
+amp[samples] = (int16_t) lfastrintf(xamp);
+}
+}
+if (s->current_position)
+return samples;
+}
+else if (tree->length)
+{
+/* A period of silence. The length must always
+be explicitly stated. A length of zero does
+not give infinite silence. */
+len = tree->length - s->current_position;
+if (len > max_samples - samples)
+{
+len = max_samples - samples;
+s->current_position += len;
+}
+else
+{
+s->current_position = 0;
+}
+memset(amp + samples, 0, sizeof(uint16_t)*len);
+samples += len;
+if (s->current_position)
+return samples;
+}
+/* Nesting has priority... */
+if (tree->nest)
+{
+tree = tree->nest;
+s->levels[++s->level] = tree;
+s->cycles[s->level] = tree->cycles;
+}
+else
+{
+/* ...Next comes repeating, and finally moving forward a step. */
+/* When repeating, note that zero cycles really means endless cycles. */
+while (tree->cycles  &&  --s->cycles[s->level] <= 0)
+{
+tree = tree->next;
+if (tree)
+{
+/* A fresh new step. */
+s->levels[s->level] = tree;
+s->cycles[s->level] = tree->cycles;
+break;
+}
+/* If we are nested we need to pop, otherwise this is the end. */
+if (s->level <= 0)
+{
+/* Mark the tone as completed */
+s->levels[0] = NULL;
+break;
+}
+tree = s->levels[--s->level];
+}
+}
+}
+return  samples;
+}
+/*- End of function --------------------------------------------------------*/
+/*- End of file ------------------------------------------------------------*/

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comparison spandsp-0.0.6pre17/src/super_tone_tx.c @ 4:26cd8f1ef0b1