Sat Mar 24 22:57:29 2007

Asterisk developer's documentation


tdd.c File Reference

TTY/TDD Generation support. More...

#include <time.h>
#include <string.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <math.h>
#include <ctype.h>
#include "asterisk.h"
#include "asterisk/ulaw.h"
#include "asterisk/tdd.h"
#include "asterisk/logger.h"
#include "asterisk/fskmodem.h"
#include "ecdisa.h"

Include dependency graph for tdd.c:

Go to the source code of this file.

Data Structures

struct  tdd_state

Defines

#define PUT_AUDIO_SAMPLE(y)
#define PUT_BYTE(a)
#define PUT_TDD(byte)
#define PUT_TDD_BAUD(bit)
#define PUT_TDD_MARKMS
#define PUT_TDD_STOP
#define TDD_MARK   1400.0
#define TDD_SPACE   1800.0

Functions

int ast_tdd_gen_ecdisa (unsigned char *outbuf, int len)
static int tdd_decode_baudot (struct tdd_state *tdd, unsigned char data)
int tdd_feed (struct tdd_state *tdd, unsigned char *ubuf, int len)
void tdd_free (struct tdd_state *tdd)
int tdd_generate (struct tdd_state *tdd, unsigned char *buf, const char *str)
static float tdd_getcarrier (float *cr, float *ci, int bit)
void tdd_init (void)
tdd_statetdd_new (void)

Variables

static float di [4]
static float dr [4]
static float tddsb = 176.0


Detailed Description

TTY/TDD Generation support.

Definition in file tdd.c.


Define Documentation

#define PUT_AUDIO_SAMPLE (  ) 

Value:

do { \
   int index = (short)(rint(8192.0 * (y))); \
   *(buf++) = AST_LIN2MU(index); \
   bytes++; \
} while(0)

Definition at line 210 of file tdd.c.

#define PUT_BYTE (  ) 

Value:

do { \
   *(buf++) = (a); \
   bytes++; \
} while(0)

Definition at line 205 of file tdd.c.

Referenced by callerid_generate(), and vmwi_generate().

#define PUT_TDD ( byte   ) 

Definition at line 239 of file tdd.c.

Referenced by tdd_generate().

#define PUT_TDD_BAUD ( bit   ) 

Definition at line 222 of file tdd.c.

#define PUT_TDD_MARKMS

Value:

do { \
   int x; \
   for (x=0;x<8;x++) \
      PUT_AUDIO_SAMPLE(tdd_getcarrier(&cr, &ci, 1)); \
} while(0)

Definition at line 216 of file tdd.c.

#define PUT_TDD_STOP

Definition at line 230 of file tdd.c.

#define TDD_MARK   1400.0

Definition at line 59 of file tdd.c.

Referenced by tdd_init().

#define TDD_SPACE   1800.0

Definition at line 58 of file tdd.c.

Referenced by tdd_init().


Function Documentation

int ast_tdd_gen_ecdisa ( unsigned char *  outbuf,
int  len 
)

Parameters:
outbuf This is the buffer to receive the tone data
len This is the length (in samples) of the tone data to generate Returns 0 if no error, and -1 if error.

Definition at line 115 of file tdd.c.

References ecdisa, and tdd_state::pos.

Referenced by zt_setoption().

00116 {
00117    int pos = 0;
00118    int cnt;
00119    while(len) {
00120       cnt = len;
00121       if (cnt > sizeof(ecdisa))
00122          cnt = sizeof(ecdisa);
00123       memcpy(outbuf + pos, ecdisa, cnt);
00124       pos += cnt;
00125       len -= cnt;
00126    }
00127    return 0;
00128 }

static int tdd_decode_baudot ( struct tdd_state tdd,
unsigned char  data 
) [static]

Definition at line 61 of file tdd.c.

References tdd_state::modo.

Referenced by tdd_feed().

00062 {
00063    static char ltrs[32]={'<','E','\n','A',' ','S','I','U',
00064             '\n','D','R','J','N','F','C','K',
00065             'T','Z','L','W','H','Y','P','Q',
00066             'O','B','G','^','M','X','V','^'};
00067    static char figs[32]={'<','3','\n','-',' ',',','8','7',
00068             '\n','$','4','\'',',','·',':','(',
00069             '5','+',')','2','·','6','0','1',
00070             '9','7','·','^','.','/','=','^'};
00071    int d;
00072    d=0;  /* return 0 if not decodeable */
00073    switch (data) {
00074    case 0x1f : tdd->modo=0; break;
00075    case 0x1b : tdd->modo=1; break;
00076    default: if (tdd->modo==0) d=ltrs[data]; else d=figs[data]; break;
00077    }
00078    return d;
00079 }

int tdd_feed ( struct tdd_state tdd,
unsigned char *  ubuf,
int  samples 
)

Parameters:
tdd Which state machine to act upon
ubuf containing your samples
samples number of samples contained within the buffer.
Send received audio to the TDD demodulator. Returns -1 on error, 0 for "needs more samples", and > 0 (the character) if reception of a character is complete.

Definition at line 130 of file tdd.c.

References ast_log(), AST_MULAW, free, fsk_serie(), tdd_state::fskd, LOG_ERROR, LOG_NOTICE, LOG_WARNING, malloc, tdd_state::mode, tdd_state::oldlen, tdd_state::oldstuff, and tdd_decode_baudot().

Referenced by zt_read().

00131 {
00132    int mylen = len;
00133    int olen;
00134    int b = 'X';
00135    int res;
00136    int c,x;
00137    short *buf = malloc(2 * len + tdd->oldlen);
00138    short *obuf = buf;
00139    if (!buf) {
00140       ast_log(LOG_WARNING, "Out of memory\n");
00141       return -1;
00142    }
00143    memset(buf, 0, 2 * len + tdd->oldlen);
00144    memcpy(buf, tdd->oldstuff, tdd->oldlen);
00145    mylen += tdd->oldlen/2;
00146    for (x=0;x<len;x++) 
00147       buf[x+tdd->oldlen/2] = AST_MULAW(ubuf[x]);
00148    c = res = 0;
00149    while(mylen >= 1320) { /* has to have enough to work on */
00150       olen = mylen;
00151       res = fsk_serie(&tdd->fskd, buf, &mylen, &b);
00152       if (mylen < 0) {
00153          ast_log(LOG_ERROR, "fsk_serie made mylen < 0 (%d) (olen was %d)\n", mylen,olen);
00154          free(obuf);
00155          return -1;
00156       }
00157       buf += (olen - mylen);
00158       if (res < 0) {
00159          ast_log(LOG_NOTICE, "fsk_serie failed\n");
00160          free(obuf);
00161          return -1;
00162       }
00163       if (res == 1) {
00164          /* Ignore invalid bytes */
00165          if (b > 0x7f)
00166             continue;
00167          c = tdd_decode_baudot(tdd,b);
00168          if ((c < 1) || (c > 126)) continue; /* if not valid */
00169          break;
00170       }
00171    }
00172    if (mylen) {
00173       memcpy(tdd->oldstuff, buf, mylen * 2);
00174       tdd->oldlen = mylen * 2;
00175    } else
00176       tdd->oldlen = 0;
00177    free(obuf);
00178    if (res)  {
00179       tdd->mode = 2; /* put it in mode where it
00180          reliably puts teleprinter in correct shift mode */
00181       return(c);
00182    }
00183    return 0;
00184 }

void tdd_free ( struct tdd_state tdd  ) 

Parameters:
tdd This is the tdd_state state machine to free This function frees tdd_state tdd.

Definition at line 186 of file tdd.c.

References free.

Referenced by zt_setoption().

00187 {
00188    free(tdd);
00189 }

int tdd_generate ( struct tdd_state tdd,
unsigned char *  buf,
const char *  string 
)

Parameters:
tdd tdd structure
buf Buffer to use. This needs to be large enough to accomodate all the generated samples.
string This is the string to send. This function creates a stream of TDD data in ulaw format. It returns the size (in bytes) of the data (if it returns a size of 0, there is probably an error)

Definition at line 250 of file tdd.c.

References tdd_state::mode, and PUT_TDD.

Referenced by zt_sendtext().

00251 {
00252    int bytes=0;
00253    int i,x;
00254    char  c;
00255    static unsigned char lstr[31] = "\000E\nA SIU\rDRJNFCKTZLWHYPQOBG\000MXV";
00256    static unsigned char fstr[31] = "\0003\n- \00787\r$4',!:(5\")2\0006019?&\000./;";
00257    /* Initial carriers (real/imaginary) */
00258    float cr = 1.0;
00259    float ci = 0.0;
00260    float scont = 0.0;
00261 
00262    for(x = 0; str[x]; x++) {
00263       c = toupper(str[x]);
00264 #if   0
00265       printf("%c",c); fflush(stdout);
00266 #endif
00267       if (c == 0) /* send null */
00268          {
00269          PUT_TDD(0);
00270          continue;
00271          }
00272       if (c == '\r') /* send c/r */
00273          {
00274          PUT_TDD(8);
00275          continue;
00276          }
00277       if (c == '\n') /* send c/r and l/f */
00278          {
00279          PUT_TDD(8);
00280          PUT_TDD(2);
00281          continue;
00282          }
00283       if (c == ' ') /* send space */
00284          {
00285          PUT_TDD(4);
00286          continue;
00287          }
00288       for(i = 0; i < 31; i++)
00289          {
00290          if (lstr[i] == c) break;
00291          }
00292       if (i < 31) /* if we found it */
00293          {
00294          if (tdd->mode)  /* if in figs mode, change it */
00295             { 
00296             PUT_TDD(31); /* Send LTRS */
00297             tdd->mode = 0;
00298             }
00299          PUT_TDD(i);
00300          continue;
00301          }
00302       for(i = 0; i < 31; i++)
00303          {
00304          if (fstr[i] == c) break;
00305          }
00306       if (i < 31) /* if we found it */
00307          {
00308          if (tdd->mode != 1)  /* if in ltrs mode, change it */
00309             {
00310             PUT_TDD(27); /* send FIGS */
00311             tdd->mode = 1;
00312             }
00313          PUT_TDD(i);  /* send byte */
00314          continue;
00315          }
00316       }
00317    return bytes;
00318 }

static float tdd_getcarrier ( float *  cr,
float *  ci,
int  bit 
) [inline, static]

Definition at line 191 of file tdd.c.

References t.

00192 {
00193    /* Move along.  There's nothing to see here... */
00194    float t;
00195    t = *cr * dr[bit] - *ci * di[bit];
00196    *ci = *cr * di[bit] + *ci * dr[bit];
00197    *cr = t;
00198    
00199    t = 2.0 - (*cr * *cr + *ci * *ci);
00200    *cr *= t;
00201    *ci *= t;
00202    return *cr;
00203 }  

void tdd_init ( void   ) 

Initializes the TDD system. Mostly stuff for inverse FFT

Definition at line 81 of file tdd.c.

References TDD_MARK, and TDD_SPACE.

Referenced by main().

00082 {
00083    /* Initialize stuff for inverse FFT */
00084    dr[0] = cos(TDD_SPACE * 2.0 * M_PI / 8000.0);
00085    di[0] = sin(TDD_SPACE * 2.0 * M_PI / 8000.0);
00086    dr[1] = cos(TDD_MARK * 2.0 * M_PI / 8000.0);
00087    di[1] = sin(TDD_MARK * 2.0 * M_PI / 8000.0);
00088 }

struct tdd_state* tdd_new ( void   ) 

This function returns a malloc'd instance of the tdd_state data structure. Returns a pointer to a malloc'd tdd_state structure, or NULL on error.

Definition at line 90 of file tdd.c.

References ast_log(), LOG_WARNING, and malloc.

Referenced by zt_setoption().

00091 {
00092    struct tdd_state *tdd;
00093    tdd = malloc(sizeof(struct tdd_state));
00094    if (tdd) {
00095       memset(tdd, 0, sizeof(struct tdd_state));
00096       tdd->fskd.spb = 176;    /* 45.5 baud */
00097       tdd->fskd.hdlc = 0;     /* Async */
00098       tdd->fskd.nbit = 5;     /* 5 bits */
00099       tdd->fskd.nstop = 1.5;  /* 1.5 stop bits */
00100       tdd->fskd.paridad = 0;  /* No parity */
00101       tdd->fskd.bw=0;         /* Filter 75 Hz */
00102       tdd->fskd.f_mark_idx =  0; /* 1400 Hz */
00103       tdd->fskd.f_space_idx = 1; /* 1800 Hz */
00104       tdd->fskd.pcola = 0;    /* No clue */
00105       tdd->fskd.cont = 0;        /* Digital PLL reset */
00106       tdd->fskd.x0 = 0.0;
00107       tdd->fskd.state = 0;
00108       tdd->pos = 0;
00109       tdd->mode = 2;
00110    } else
00111       ast_log(LOG_WARNING, "Out of memory\n");
00112    return tdd;
00113 }


Variable Documentation

float di[4] [static]

Definition at line 55 of file tdd.c.

float dr[4] [static]

Definition at line 55 of file tdd.c.

Referenced by abort_request(), append_transaction(), build_transactions(), cancel_request(), check_request(), discover_transactions(), dundi_do_lookup(), dundi_lookup_exec(), dundi_lookup_internal(), dundi_lookup_local(), dundi_lookup_thread(), dundi_precache_internal(), dundi_prop_precache(), dundi_query_eid_internal(), dundifunc_read(), optimize_transactions(), precache_trans(), precache_transactions(), query_transactions(), register_request(), and unregister_request().

float tddsb = 176.0 [static]

Definition at line 56 of file tdd.c.


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