Asterisk - The Open Source Telephony Project  GIT-master-e8cda4b
tdd.c
Go to the documentation of this file.
1 /*
2  * Asterisk -- An open source telephony toolkit.
3  *
4  * Copyright (C) 1999 - 2005, Digium, Inc.
5  *
6  * Mark Spencer <markster@digium.com>
7  *
8  * Includes code and algorithms from the Zapata library.
9  *
10  * See http://www.asterisk.org for more information about
11  * the Asterisk project. Please do not directly contact
12  * any of the maintainers of this project for assistance;
13  * the project provides a web site, mailing lists and IRC
14  * channels for your use.
15  *
16  * This program is free software, distributed under the terms of
17  * the GNU General Public License Version 2. See the LICENSE file
18  * at the top of the source tree.
19  */
20 
21 /*! \file
22  *
23  * \brief TTY/TDD Generation support
24  *
25  * \author Mark Spencer <markster@digium.com>
26  *
27  * \note Includes code and algorithms from the Zapata library.
28  */
29 
30 /*** MODULEINFO
31  <support_level>core</support_level>
32  ***/
33 
34 #include "asterisk.h"
35 
36 #include <time.h>
37 #include <math.h>
38 #include <ctype.h>
39 
40 #include "asterisk/logger.h"
41 #include "asterisk/ulaw.h"
42 #include "asterisk/tdd.h"
43 #include "asterisk/fskmodem.h"
44 #include "asterisk/utils.h"
45 #include "ecdisa.h"
46 
47 struct tdd_state {
49  char rawdata[256];
50  short oldstuff[4096];
51  int oldlen;
52  int pos;
53  int modo;
54  int mode;
55  int charnum;
56 };
57 
58 static float dr[4], di[4];
59 static float tddsb = 176.0; /* 45.5 baud */
60 
61 #define TDD_SPACE 1800.0 /* 1800 hz for "0" */
62 #define TDD_MARK 1400.0 /* 1400 hz for "1" */
63 
64 static int tdd_decode_baudot(struct tdd_state *tdd,unsigned char data) /* covert baudot into ASCII */
65 {
66  static char ltrs[32] = { '<','E','\n','A',' ','S','I','U',
67  '\n','D','R','J','N','F','C','K',
68  'T','Z','L','W','H','Y','P','Q',
69  'O','B','G','^','M','X','V','^' };
70  static char figs[32] = { '<','3','\n','-',' ','\'','8','7',
71  '\n','$','4','\'',',','!',':','(',
72  '5','\"',')','2','=','6','0','1',
73  '9','?','+','^','.','/',';','^' };
74  int d = 0; /* return 0 if not decodeable */
75  if (data < 32) {
76  switch (data) {
77  case 0x1f:
78  tdd->modo = 0;
79  break;
80  case 0x1b:
81  tdd->modo = 1;
82  break;
83  default:
84  if (tdd->modo == 0)
85  d = ltrs[data];
86  else
87  d = figs[data];
88  break;
89  }
90  }
91  return d;
92 }
93 
94 void tdd_init(void)
95 {
96  /* Initialize stuff for inverse FFT */
97  dr[0] = cos(TDD_SPACE * 2.0 * M_PI / 8000.0);
98  di[0] = sin(TDD_SPACE * 2.0 * M_PI / 8000.0);
99  dr[1] = cos(TDD_MARK * 2.0 * M_PI / 8000.0);
100  di[1] = sin(TDD_MARK * 2.0 * M_PI / 8000.0);
101 }
102 
103 struct tdd_state *tdd_new(void)
104 {
105  struct tdd_state *tdd;
106  tdd = ast_calloc(1, sizeof(*tdd));
107  if (tdd) {
108 #ifdef INTEGER_CALLERID
109  tdd->fskd.ispb = 176; /* 45.5 baud */
110  /* Set up for 45.5 / 8000 freq *32 to allow ints */
111  tdd->fskd.pllispb = (int)((8000 * 32 * 2) / 90);
112  tdd->fskd.pllids = tdd->fskd.pllispb / 32;
113  tdd->fskd.pllispb2 = tdd->fskd.pllispb / 2;
114  tdd->fskd.hdlc = 0; /* Async */
115  tdd->fskd.nbit = 5; /* 5 bits */
116  tdd->fskd.instop = 1; /* integer rep of 1.5 stop bits */
117  tdd->fskd.parity = 0; /* No parity */
118  tdd->fskd.bw=0; /* Filter 75 Hz */
119  tdd->fskd.f_mark_idx = 0; /* 1400 Hz */
120  tdd->fskd.f_space_idx = 1; /* 1800 Hz */
121  tdd->fskd.xi0 = 0;
122  tdd->fskd.state = 0;
123  tdd->pos = 0;
124  tdd->mode = 0;
125  fskmodem_init(&tdd->fskd);
126 #else
127  tdd->fskd.spb = 176; /* 45.5 baud */
128  tdd->fskd.hdlc = 0; /* Async */
129  tdd->fskd.nbit = 5; /* 5 bits */
130  tdd->fskd.nstop = 1.5; /* 1.5 stop bits */
131  tdd->fskd.parity = 0; /* No parity */
132  tdd->fskd.bw=0; /* Filter 75 Hz */
133  tdd->fskd.f_mark_idx = 0; /* 1400 Hz */
134  tdd->fskd.f_space_idx = 1; /* 1800 Hz */
135  tdd->fskd.pcola = 0; /* No clue */
136  tdd->fskd.cont = 0; /* Digital PLL reset */
137  tdd->fskd.x0 = 0.0;
138  tdd->fskd.state = 0;
139  tdd->pos = 0;
140  tdd->mode = 2;
141 #endif
142  tdd->charnum = 0;
143  } else
144  ast_log(LOG_WARNING, "Out of memory\n");
145  return tdd;
146 }
147 
148 int ast_tdd_gen_ecdisa(unsigned char *outbuf, int len)
149 {
150  int pos = 0;
151  int cnt;
152  while (len) {
153  cnt = len > sizeof(ecdisa) ? sizeof(ecdisa) : len;
154  memcpy(outbuf + pos, ecdisa, cnt);
155  pos += cnt;
156  len -= cnt;
157  }
158  return 0;
159 }
160 
161 int tdd_feed(struct tdd_state *tdd, unsigned char *ubuf, int len)
162 {
163  int mylen = len;
164  int olen;
165  int b = 'X';
166  int res;
167  int c,x;
168  short *buf = ast_calloc(1, 2 * len + tdd->oldlen);
169  short *obuf = buf;
170  if (!buf) {
171  ast_log(LOG_WARNING, "Out of memory\n");
172  return -1;
173  }
174  memcpy(buf, tdd->oldstuff, tdd->oldlen);
175  mylen += tdd->oldlen / 2;
176  for (x = 0; x < len; x++)
177  buf[x + tdd->oldlen / 2] = AST_MULAW(ubuf[x]);
178  c = res = 0;
179  while (mylen >= 1320) { /* has to have enough to work on */
180  olen = mylen;
181  res = fsk_serial(&tdd->fskd, buf, &mylen, &b);
182  if (mylen < 0) {
183  ast_log(LOG_ERROR, "fsk_serial made mylen < 0 (%d) (olen was %d)\n", mylen, olen);
184  ast_free(obuf);
185  return -1;
186  }
187  buf += (olen - mylen);
188  if (res < 0) {
189  ast_log(LOG_NOTICE, "fsk_serial failed\n");
190  ast_free(obuf);
191  return -1;
192  }
193  if (res == 1) {
194  /* Ignore invalid bytes */
195  if (b > 0x7f)
196  continue;
197  c = tdd_decode_baudot(tdd, b);
198  if ((c < 1) || (c > 126))
199  continue; /* if not valid */
200  break;
201  }
202  }
203  if (mylen) {
204  memcpy(tdd->oldstuff, buf, mylen * 2);
205  tdd->oldlen = mylen * 2;
206  } else
207  tdd->oldlen = 0;
208  ast_free(obuf);
209  if (res) {
210  tdd->mode = 2;
211 /* put it in mode where it
212  reliably puts teleprinter in correct shift mode */
213  return(c);
214  }
215  return 0;
216 }
217 
218 void tdd_free(struct tdd_state *tdd)
219 {
220  ast_free(tdd);
221 }
222 
223 static inline float tdd_getcarrier(float *cr, float *ci, int bit)
224 {
225  /* Move along. There's nothing to see here... */
226  float t;
227  t = *cr * dr[bit] - *ci * di[bit];
228  *ci = *cr * di[bit] + *ci * dr[bit];
229  *cr = t;
230 
231  t = 2.0 - (*cr * *cr + *ci * *ci);
232  *cr *= t;
233  *ci *= t;
234  return *cr;
235 }
236 
237 #define PUT_BYTE(a) do { \
238  *(buf++) = (a); \
239  bytes++; \
240 } while(0)
241 
242 #define PUT_AUDIO_SAMPLE(y) do { \
243  int __pas_idx = (short)(rint(8192.0 * (y))); \
244  *(buf++) = AST_LIN2MU(__pas_idx); \
245  bytes++; \
246 } while(0)
247 
248 #define PUT_TDD_MARKMS do { \
249  int x; \
250  for (x = 0; x < 8; x++) \
251  PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
252 } while(0)
253 
254 #define PUT_TDD_BAUD(bit) do { \
255  while (scont < tddsb) { \
256  PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, bit)); \
257  scont += 1.0; \
258  } \
259  scont -= tddsb; \
260 } while(0)
261 
262 #define PUT_TDD_STOP do { \
263  while (scont < (tddsb * 1.5)) { \
264  PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
265  scont += 1.0; \
266  } \
267  scont -= (tddsb * 1.5); \
268 } while(0)
269 
270 
271 #define PUT_TDD(byte) do { \
272  int z; \
273  unsigned char b = (byte); \
274  PUT_TDD_BAUD(0); /* Start bit */ \
275  for (z = 0; z < 5; z++) { \
276  PUT_TDD_BAUD(b & 1); \
277  b >>= 1; \
278  } \
279  PUT_TDD_STOP; /* Stop bit */ \
280 } while(0);
281 
282 /*! Generate TDD hold tone
283  * \param outbuf, buf Result buffer
284  * \todo How big should this be?
285  */
286 int tdd_gen_holdtone(unsigned char *buf)
287 {
288  int bytes = 0;
289  float scont = 0.0, cr = 1.0, ci=0.0;
290  while (scont < tddsb * 10.0) {
291  PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1));
292  scont += 1.0;
293  }
294  return bytes;
295 }
296 
297 int tdd_generate(struct tdd_state *tdd, unsigned char *buf, const char *str)
298 {
299  int bytes = 0;
300  int i,x;
301  char c;
302  /*! Baudot letters */
303  static unsigned char lstr[31] = "\000E\nA SIU\rDRJNFCKTZLWHYPQOBG\000MXV";
304  /*! Baudot figures */
305  static unsigned char fstr[31] = "\0003\n- \00787\r$4',!:(5\")2\0006019?+\000./;";
306  /* Initial carriers (real/imaginary) */
307  float cr = 1.0;
308  float ci = 0.0;
309  float scont = 0.0;
310 
311  for(x = 0; str[x]; x++) {
312  /* Do synch for each 72th character */
313  if ( (tdd->charnum++) % 72 == 0)
314  PUT_TDD(tdd->mode ? 27 /* FIGS */ : 31 /* LTRS */);
315 
316  c = toupper(str[x]);
317 #if 0
318  printf("%c",c); fflush(stdout);
319 #endif
320  if (c == 0) { /* send null */
321  PUT_TDD(0);
322  continue;
323  }
324  if (c == '\r') { /* send c/r */
325  PUT_TDD(8);
326  continue;
327  }
328  if (c == '\n') { /* send c/r and l/f */
329  PUT_TDD(8);
330  PUT_TDD(2);
331  continue;
332  }
333  if (c == ' ') { /* send space */
334  PUT_TDD(4);
335  continue;
336  }
337  for (i = 0; i < 31; i++) {
338  if (lstr[i] == c)
339  break;
340  }
341  if (i < 31) { /* if we found it */
342  if (tdd->mode) { /* if in figs mode, change it */
343  PUT_TDD(31); /* Send LTRS */
344  tdd->mode = 0;
345  }
346  PUT_TDD(i);
347  continue;
348  }
349  for (i = 0; i < 31; i++) {
350  if (fstr[i] == c)
351  break;
352  }
353  if (i < 31) { /* if we found it */
354  if (tdd->mode != 1) { /* if in ltrs mode, change it */
355  PUT_TDD(27); /* send FIGS */
356  tdd->mode = 1;
357  }
358  PUT_TDD(i); /* send byte */
359  continue;
360  }
361  }
362  return bytes;
363 }
void tdd_free(struct tdd_state *tdd)
Definition: tdd.c:218
static float dr[4]
Definition: tdd.c:58
int oldlen
Definition: tdd.c:51
unsigned int cos
Definition: chan_iax2.c:352
Asterisk main include file. File version handling, generic pbx functions.
int tdd_gen_holdtone(unsigned char *buf)
Definition: tdd.c:286
int charnum
Definition: tdd.c:55
Time-related functions and macros.
char buf[BUFSIZE]
Definition: eagi_proxy.c:66
#define LOG_WARNING
Definition: logger.h:274
#define PUT_AUDIO_SAMPLE(y)
Definition: tdd.c:242
static struct test_val d
int tdd_feed(struct tdd_state *tdd, unsigned char *ubuf, int len)
Definition: tdd.c:161
static struct test_val c
int pllids
Definition: fskmodem_int.h:60
int fskmodem_init(fsk_data *fskd)
Definition: fskmodem_int.c:195
const char * str
Definition: app_jack.c:147
int ast_tdd_gen_ecdisa(unsigned char *outbuf, int len)
Definition: tdd.c:148
float cont
Utility functions.
float nstop
#define ast_log
Definition: astobj2.c:42
u-Law to Signed linear conversion
#define M_PI
Definition: resample.c:83
#define AST_MULAW(a)
Definition: ulaw.h:85
int instop
Definition: fskmodem_int.h:46
#define PUT_TDD(byte)
Definition: tdd.c:271
static float tddsb
Definition: tdd.c:59
static float tdd_getcarrier(float *cr, float *ci, int bit)
Definition: tdd.c:223
static unsigned char ecdisa[80]
Definition: ecdisa.h:3
int modo
Definition: tdd.c:53
#define TDD_SPACE
Definition: tdd.c:61
#define LOG_ERROR
Definition: logger.h:285
int pllispb
Definition: fskmodem_int.h:59
int pllispb2
Definition: fskmodem_int.h:61
TTY/TDD Generation support.
static int len(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t buflen)
static float di[4]
Definition: tdd.c:58
int tdd_generate(struct tdd_state *tdd, unsigned char *buf, const char *str)
Definition: tdd.c:297
#define LOG_NOTICE
Definition: logger.h:263
static int tdd_decode_baudot(struct tdd_state *tdd, unsigned char data)
Definition: tdd.c:64
#define ast_free(a)
Definition: astmm.h:182
Definition: tdd.c:47
#define ast_calloc(num, len)
A wrapper for calloc()
Definition: astmm.h:204
int f_space_idx
short oldstuff[4096]
Definition: tdd.c:50
Support for logging to various files, console and syslog Configuration in file logger.conf.
fsk_data fskd
Definition: tdd.c:48
int mode
Definition: tdd.c:54
struct tdd_state * tdd_new(void)
Definition: tdd.c:103
int f_mark_idx
char rawdata[256]
Definition: tdd.c:49
static struct test_val b
FSK Modem Support.
int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte)
#define TDD_MARK
Definition: tdd.c:62
int pos
Definition: tdd.c:52
void tdd_init(void)
Definition: tdd.c:94