324 lines
7.0 KiB
C
324 lines
7.0 KiB
C
/*
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* Asterisk -- An open source telephony toolkit.
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*
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* Copyright (C) 1999 - 2005, Digium, Inc.
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*
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* Mark Spencer <markster@digium.com>
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*
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* Includes code and algorithms from the Zapata library.
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*
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* See http://www.asterisk.org for more information about
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* the Asterisk project. Please do not directly contact
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* any of the maintainers of this project for assistance;
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* the project provides a web site, mailing lists and IRC
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* channels for your use.
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*
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* This program is free software, distributed under the terms of
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* the GNU General Public License Version 2. See the LICENSE file
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* at the top of the source tree.
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*/
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/*! \file
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*
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* \brief TTY/TDD Generation support
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*
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* \author Mark Spencer <markster@digium.com>
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*
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* \note Includes code and algorithms from the Zapata library.
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*/
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#include <time.h>
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#include <string.h>
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#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <math.h>
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#include <ctype.h>
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#include "asterisk.h"
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ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
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#include "asterisk/ulaw.h"
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#include "asterisk/tdd.h"
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#include "asterisk/logger.h"
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#include "asterisk/fskmodem.h"
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#include "ecdisa.h"
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struct tdd_state {
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fsk_data fskd;
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char rawdata[256];
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short oldstuff[4096];
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int oldlen;
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int pos;
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int modo;
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int mode;
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};
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static float dr[4], di[4];
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static float tddsb = 176.0; /* 45.5 baud */
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#define TDD_SPACE 1800.0 /* 1800 hz for "0" */
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#define TDD_MARK 1400.0 /* 1400 hz for "1" */
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static int tdd_decode_baudot(struct tdd_state *tdd,unsigned char data) /* covert baudot into ASCII */
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{
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static char ltrs[32]={'<','E','\n','A',' ','S','I','U',
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'\n','D','R','J','N','F','C','K',
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'T','Z','L','W','H','Y','P','Q',
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'O','B','G','^','M','X','V','^'};
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static char figs[32]={'<','3','\n','-',' ',',','8','7',
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'\n','$','4','\'',',','·',':','(',
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'5','+',')','2','·','6','0','1',
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'9','7','·','^','.','/','=','^'};
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int d;
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d=0; /* return 0 if not decodeable */
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switch (data) {
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case 0x1f : tdd->modo=0; break;
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case 0x1b : tdd->modo=1; break;
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default: if (tdd->modo==0) d=ltrs[data]; else d=figs[data]; break;
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}
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return d;
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}
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void tdd_init(void)
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{
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/* Initialize stuff for inverse FFT */
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dr[0] = cos(TDD_SPACE * 2.0 * M_PI / 8000.0);
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di[0] = sin(TDD_SPACE * 2.0 * M_PI / 8000.0);
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dr[1] = cos(TDD_MARK * 2.0 * M_PI / 8000.0);
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di[1] = sin(TDD_MARK * 2.0 * M_PI / 8000.0);
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}
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struct tdd_state *tdd_new(void)
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{
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struct tdd_state *tdd;
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tdd = malloc(sizeof(struct tdd_state));
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if (tdd) {
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memset(tdd, 0, sizeof(struct tdd_state));
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tdd->fskd.spb = 176; /* 45.5 baud */
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tdd->fskd.hdlc = 0; /* Async */
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tdd->fskd.nbit = 5; /* 5 bits */
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tdd->fskd.nstop = 1.5; /* 1.5 stop bits */
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tdd->fskd.paridad = 0; /* No parity */
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tdd->fskd.bw=0; /* Filter 75 Hz */
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tdd->fskd.f_mark_idx = 0; /* 1400 Hz */
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tdd->fskd.f_space_idx = 1; /* 1800 Hz */
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tdd->fskd.pcola = 0; /* No clue */
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tdd->fskd.cont = 0; /* Digital PLL reset */
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tdd->fskd.x0 = 0.0;
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tdd->fskd.state = 0;
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tdd->pos = 0;
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tdd->mode = 2;
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} else
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ast_log(LOG_WARNING, "Out of memory\n");
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return tdd;
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}
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int ast_tdd_gen_ecdisa(unsigned char *outbuf, int len)
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{
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int pos = 0;
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int cnt;
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while(len) {
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cnt = len;
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if (cnt > sizeof(ecdisa))
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cnt = sizeof(ecdisa);
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memcpy(outbuf + pos, ecdisa, cnt);
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pos += cnt;
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len -= cnt;
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}
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return 0;
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}
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int tdd_feed(struct tdd_state *tdd, unsigned char *ubuf, int len)
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{
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int mylen = len;
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int olen;
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int b = 'X';
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int res;
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int c,x;
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short *buf = malloc(2 * len + tdd->oldlen);
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short *obuf = buf;
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if (!buf) {
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ast_log(LOG_WARNING, "Out of memory\n");
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return -1;
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}
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memset(buf, 0, 2 * len + tdd->oldlen);
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memcpy(buf, tdd->oldstuff, tdd->oldlen);
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mylen += tdd->oldlen/2;
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for (x=0;x<len;x++)
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buf[x+tdd->oldlen/2] = AST_MULAW(ubuf[x]);
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c = res = 0;
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while(mylen >= 1320) { /* has to have enough to work on */
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olen = mylen;
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res = fsk_serie(&tdd->fskd, buf, &mylen, &b);
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if (mylen < 0) {
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ast_log(LOG_ERROR, "fsk_serie made mylen < 0 (%d) (olen was %d)\n", mylen,olen);
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free(obuf);
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return -1;
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}
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buf += (olen - mylen);
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if (res < 0) {
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ast_log(LOG_NOTICE, "fsk_serie failed\n");
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free(obuf);
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return -1;
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}
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if (res == 1) {
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/* Ignore invalid bytes */
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if (b > 0x7f)
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continue;
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c = tdd_decode_baudot(tdd,b);
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if ((c < 1) || (c > 126)) continue; /* if not valid */
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break;
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}
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}
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if (mylen) {
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memcpy(tdd->oldstuff, buf, mylen * 2);
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tdd->oldlen = mylen * 2;
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} else
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tdd->oldlen = 0;
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free(obuf);
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if (res) {
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tdd->mode = 2; /* put it in mode where it
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reliably puts teleprinter in correct shift mode */
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return(c);
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}
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return 0;
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}
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void tdd_free(struct tdd_state *tdd)
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{
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free(tdd);
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}
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static inline float tdd_getcarrier(float *cr, float *ci, int bit)
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{
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/* Move along. There's nothing to see here... */
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float t;
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t = *cr * dr[bit] - *ci * di[bit];
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*ci = *cr * di[bit] + *ci * dr[bit];
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*cr = t;
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t = 2.0 - (*cr * *cr + *ci * *ci);
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*cr *= t;
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*ci *= t;
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return *cr;
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}
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#define PUT_BYTE(a) do { \
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*(buf++) = (a); \
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bytes++; \
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} while(0)
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#define PUT_AUDIO_SAMPLE(y) do { \
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int index = (short)(rint(8192.0 * (y))); \
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*(buf++) = AST_LIN2MU(index); \
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bytes++; \
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} while(0)
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#define PUT_TDD_MARKMS do { \
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int x; \
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for (x=0;x<8;x++) \
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PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
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} while(0)
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#define PUT_TDD_BAUD(bit) do { \
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while(scont < tddsb) { \
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PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, bit)); \
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scont += 1.0; \
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} \
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scont -= tddsb; \
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} while(0)
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#define PUT_TDD_STOP do { \
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while(scont < (tddsb * 1.5)) { \
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PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
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scont += 1.0; \
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} \
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scont -= (tddsb * 1.5); \
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} while(0)
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#define PUT_TDD(byte) do { \
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int z; \
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unsigned char b = (byte); \
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PUT_TDD_BAUD(0); /* Start bit */ \
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for (z=0;z<5;z++) { \
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PUT_TDD_BAUD(b & 1); \
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b >>= 1; \
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} \
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PUT_TDD_STOP; /* Stop bit */ \
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} while(0);
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int tdd_generate(struct tdd_state *tdd, unsigned char *buf, const char *str)
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{
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int bytes=0;
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int i,x;
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char c;
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static unsigned char lstr[31] = "\000E\nA SIU\rDRJNFCKTZLWHYPQOBG\000MXV";
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static unsigned char fstr[31] = "\0003\n- \00787\r$4',!:(5\")2\0006019?&\000./;";
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/* Initial carriers (real/imaginary) */
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float cr = 1.0;
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float ci = 0.0;
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float scont = 0.0;
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for(x = 0; str[x]; x++) {
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c = toupper(str[x]);
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#if 0
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printf("%c",c); fflush(stdout);
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#endif
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if (c == 0) /* send null */
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{
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PUT_TDD(0);
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continue;
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}
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if (c == '\r') /* send c/r */
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{
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PUT_TDD(8);
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continue;
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}
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if (c == '\n') /* send c/r and l/f */
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{
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PUT_TDD(8);
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PUT_TDD(2);
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continue;
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}
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if (c == ' ') /* send space */
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{
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PUT_TDD(4);
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continue;
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}
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for(i = 0; i < 31; i++)
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{
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if (lstr[i] == c) break;
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}
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if (i < 31) /* if we found it */
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{
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if (tdd->mode) /* if in figs mode, change it */
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{
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PUT_TDD(31); /* Send LTRS */
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tdd->mode = 0;
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}
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PUT_TDD(i);
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continue;
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}
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for(i = 0; i < 31; i++)
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{
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if (fstr[i] == c) break;
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}
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if (i < 31) /* if we found it */
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{
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if (tdd->mode != 1) /* if in ltrs mode, change it */
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{
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PUT_TDD(27); /* send FIGS */
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tdd->mode = 1;
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}
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PUT_TDD(i); /* send byte */
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continue;
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}
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}
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return bytes;
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}
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