#include "asterisk.h"
#include "asterisk/fskmodem.h"
Go to the source code of this file.
Defines | |
#define | BWLIST {75,800} |
#define | FLIST {1400,1800,1200,2200,1300,2100} |
#define | IGET_SAMPLE iget_sample(&buffer, len) |
#define | NBW 2 |
#define | NF 6 |
#define | STATE_GET_BYTE 3 |
#define | STATE_SEARCH_STARTBIT 0 |
#define | STATE_SEARCH_STARTBIT2 1 |
#define | STATE_SEARCH_STARTBIT3 2 |
Functions | |
int | fsk_serial (fsk_data *fskd, short *buffer, int *len, int *outbyte) |
int | fskmodem_init (fsk_data *fskd) |
static int | get_bit_raw (fsk_data *fskd, short *buffer, int *len) |
static int | ibpdfilter (struct filter_struct *fs, int in) |
static int | ibpfilter (struct filter_struct *fs, int in) |
static int | idemodulator (fsk_data *fskd, int *retval, int x) |
static int | iget_sample (short **buffer, int *len) |
Variables | |
static double | coef_in [NF][NBW][8] |
Coefficients for input filters Coefficients table, generated by program "mkfilter" mkfilter is part of the zapatatelephony.org distribution Format: coef[IDX_FREC][IDX_BW][IDX_COEF] IDX_COEF = 0 => 1/GAIN IDX_COEF = 1-6 => Coefficientes y[n]. | |
static double | coef_out [NBW][8] |
Coefficients for output filter Coefficients table, generated by program "mkfilter" Format: coef[IDX_BW][IDX_COEF] IDX_COEF = 0 => 1/GAIN IDX_COEF = 1-6 => Coefficientes y[n]. |
Definition in file fskmodem_int.c.
#define BWLIST {75,800} |
Definition at line 38 of file fskmodem_int.c.
#define FLIST {1400,1800,1200,2200,1300,2100} |
Definition at line 40 of file fskmodem_int.c.
#define IGET_SAMPLE iget_sample(&buffer, len) |
#define NBW 2 |
Definition at line 37 of file fskmodem_int.c.
#define NF 6 |
Definition at line 39 of file fskmodem_int.c.
#define STATE_GET_BYTE 3 |
Definition at line 45 of file fskmodem_int.c.
#define STATE_SEARCH_STARTBIT 0 |
Definition at line 42 of file fskmodem_int.c.
#define STATE_SEARCH_STARTBIT2 1 |
Definition at line 43 of file fskmodem_int.c.
#define STATE_SEARCH_STARTBIT3 2 |
Definition at line 44 of file fskmodem_int.c.
int fsk_serial | ( | fsk_data * | fskd, | |
short * | buffer, | |||
int * | len, | |||
int * | outbyte | |||
) |
Definition at line 220 of file fskmodem_int.c.
References demodulator(), GET_SAMPLE, idemodulator(), IGET_SAMPLE, fsk_data::ispb, fsk_data::nbit, ast_frame::samples, fsk_data::spb, fsk_data::state, STATE_GET_BYTE, STATE_SEARCH_STARTBIT2, STATE_SEARCH_STARTBIT3, fsk_data::x1, fsk_data::x2, fsk_data::xi1, and fsk_data::xi2.
00221 { 00222 int a; 00223 int i, j, n1, r; 00224 int samples = 0; 00225 int olen; 00226 int beginlen = *len; 00227 int beginlenx; 00228 00229 switch (fskd->state) { 00230 /* Pick up where we left off */ 00231 case STATE_SEARCH_STARTBIT2: 00232 goto search_startbit2; 00233 case STATE_SEARCH_STARTBIT3: 00234 goto search_startbit3; 00235 case STATE_GET_BYTE: 00236 goto getbyte; 00237 } 00238 /* We await for start bit */ 00239 do { 00240 /* this was jesus's nice, reasonable, working (at least with RTTY) code 00241 to look for the beginning of the start bit. Unfortunately, since TTY/TDD's 00242 just start sending a start bit with nothing preceding it at the beginning 00243 of a transmission (what a LOSING design), we cant do it this elegantly */ 00244 /* NOT USED 00245 if (demodulator(zap,&x1)) 00246 return -1; 00247 for(;;) { 00248 if (demodulator(zap,&x2)) 00249 return -1; 00250 if (x1>0 && x2<0) break; 00251 x1=x2; 00252 } 00253 */ 00254 /* this is now the imprecise, losing, but functional code to detect the 00255 beginning of a start bit in the TDD sceanario. It just looks for sufficient 00256 level to maybe, perhaps, guess, maybe that its maybe the beginning of 00257 a start bit, perhaps. This whole thing stinks! */ 00258 beginlenx = beginlen; /* just to avoid unused war warnings */ 00259 if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) 00260 return -1; 00261 samples++; 00262 for(;;) { 00263 search_startbit2: 00264 if (*len <= 0) { 00265 fskd->state = STATE_SEARCH_STARTBIT2; 00266 return 0; 00267 } 00268 samples++; 00269 if (idemodulator(fskd, &fskd->xi2, IGET_SAMPLE)) 00270 return -1; 00271 #if 0 00272 printf("xi2 = %d ", fskd->xi2); 00273 #endif 00274 if (fskd->xi2 < 512) { 00275 break; 00276 } 00277 } 00278 search_startbit3: 00279 /* We await for 0.5 bits before using DPLL */ 00280 i = fskd->ispb / 2; 00281 if (*len < i) { 00282 fskd->state = STATE_SEARCH_STARTBIT3; 00283 return 0; 00284 } 00285 for (; i > 0; i--) { 00286 if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE)) 00287 return(-1); 00288 #if 0 00289 printf("xi1 = %d ", fskd->xi1); 00290 #endif 00291 samples++; 00292 } 00293 00294 /* x1 must be negative (start bit confirmation) */ 00295 00296 } while (fskd->xi1 > 0); 00297 fskd->state = STATE_GET_BYTE; 00298 00299 getbyte: 00300 00301 /* Need at least 80 samples (for 1200) or 00302 1320 (for 45.5) to be sure we'll have a byte */ 00303 if (fskd->nbit < 8) { 00304 if (*len < 1320) 00305 return 0; 00306 } else { 00307 if (*len < 80) 00308 return 0; 00309 } 00310 00311 /* Now we read the data bits */ 00312 j = fskd->nbit; 00313 for (a = n1 = 0; j; j--) { 00314 olen = *len; 00315 i = get_bit_raw(fskd, buffer, len); 00316 buffer += (olen - *len); 00317 if (i == -1) 00318 return -1; 00319 if (i) 00320 n1++; 00321 a >>= 1; 00322 a |= i; 00323 } 00324 j = 8 - fskd->nbit; 00325 a >>= j; 00326 00327 /* We read parity bit (if exists) and check parity */ 00328 if (fskd->parity) { 00329 olen = *len; 00330 i = get_bit_raw(fskd, buffer, len); 00331 buffer += (olen - *len); 00332 if (i == -1) 00333 return -1; 00334 if (i) 00335 n1++; 00336 if (fskd->parity == 1) { /* parity=1 (even) */ 00337 if (n1 & 1) 00338 a |= 0x100; /* error */ 00339 } else { /* parity=2 (odd) */ 00340 if (!(n1 & 1)) 00341 a |= 0x100; /* error */ 00342 } 00343 } 00344 00345 /* We read STOP bits. All of them must be 1 */ 00346 00347 for (j = fskd->instop; j; j--) { 00348 r = get_bit_raw(fskd, buffer, len); 00349 if (r == -1) 00350 return -1; 00351 if (!r) 00352 a |= 0x200; 00353 } 00354 00355 /* And finally we return 00356 * Bit 8 : Parity error 00357 * Bit 9 : Framming error 00358 */ 00359 00360 *outbyte = a; 00361 fskd->state = STATE_SEARCH_STARTBIT; 00362 return 1; 00363 }
int fskmodem_init | ( | fsk_data * | fskd | ) |
Definition at line 193 of file fskmodem_int.c.
References fsk_data::bw, coef_in, coef_out, fsk_data::demod_filter, fsk_data::f_mark_idx, fsk_data::f_space_idx, filter_struct::icoefs, filter_struct::ip, filter_struct::ixv, filter_struct::iyv, fsk_data::mark_filter, and fsk_data::space_filter.
Referenced by callerid_new(), and tdd_new().
00194 { 00195 int i; 00196 00197 fskd->space_filter.ip = 0; 00198 fskd->mark_filter.ip = 0; 00199 fskd->demod_filter.ip = 0; 00200 00201 for ( i = 0 ; i < 7 ; i++ ) { 00202 fskd->space_filter.icoefs[i] = 00203 coef_in[fskd->f_space_idx][fskd->bw][i] * 256; 00204 fskd->space_filter.ixv[i] = 0;; 00205 fskd->space_filter.iyv[i] = 0;; 00206 00207 fskd->mark_filter.icoefs[i] = 00208 coef_in[fskd->f_mark_idx][fskd->bw][i] * 256; 00209 fskd->mark_filter.ixv[i] = 0;; 00210 fskd->mark_filter.iyv[i] = 0;; 00211 00212 fskd->demod_filter.icoefs[i] = 00213 coef_out[fskd->bw][i] * 1024; 00214 fskd->demod_filter.ixv[i] = 0;; 00215 fskd->demod_filter.iyv[i] = 0;; 00216 } 00217 return 0; 00218 }
static int get_bit_raw | ( | fsk_data * | fskd, | |
short * | buffer, | |||
int * | len | |||
) | [static] |
Definition at line 163 of file fskmodem_int.c.
References f, idemodulator(), and IGET_SAMPLE.
00164 { 00165 /* This function implements a DPLL to synchronize with the bits */ 00166 int f; 00167 00168 int ix; 00169 /* PLL coeffs are set up in callerid_new */ 00170 for (f = 0;;) { 00171 if (idemodulator(fskd, &ix, IGET_SAMPLE)) return(-1); 00172 if ((ix * fskd->xi0) < 0) { /* Transicion */ 00173 if (!f) { 00174 if (fskd->icont < (fskd->pllispb2)) { 00175 fskd->icont += fskd->pllids; 00176 } else { 00177 fskd->icont -= fskd->pllids; 00178 } 00179 f = 1; 00180 } 00181 } 00182 fskd->xi0 = ix; 00183 fskd->icont += 32; 00184 if (fskd->icont > fskd->pllispb) { 00185 fskd->icont -= fskd->pllispb; 00186 break; 00187 } 00188 } 00189 f = (ix > 0) ? 0x80 : 0; 00190 return f; 00191 }
static int ibpdfilter | ( | struct filter_struct * | fs, | |
int | in | |||
) | [inline, static] |
Integer Pass Band demodulator filter
Definition at line 93 of file fskmodem_int.c.
References filter_struct::icoefs, filter_struct::ip, filter_struct::ixv, filter_struct::iyv, and s.
Referenced by idemodulator().
00094 { 00095 int i,j; 00096 int s; 00097 int64_t s_interim; 00098 00099 /* integer filter */ 00100 s = in * fs->icoefs[0]; 00101 fs->ixv[(fs->ip + 6) & 7] = s; 00102 00103 s = (fs->ixv[fs->ip] + fs->ixv[(fs->ip + 6) & 7]) + 00104 6 * (fs->ixv[(fs->ip + 1) & 7] + fs->ixv[(fs->ip + 5) & 7]) + 00105 15 * (fs->ixv[(fs->ip + 2) & 7] + fs->ixv[(fs->ip + 4) & 7]) + 00106 20 * fs->ixv[(fs->ip + 3) & 7]; 00107 00108 for (i = 1, j = fs->ip; i < 7; i++, j++) { 00109 /* Promote operation to 64 bit to prevent overflow that occurred in 32 bit) */ 00110 s_interim = (int64_t)(fs->iyv[j & 7]) * 00111 (int64_t)(fs->icoefs[i]) / 00112 (int64_t)(1024); 00113 s += (int) s_interim; 00114 } 00115 fs->iyv[j & 7] = s; 00116 fs->ip++; 00117 fs->ip &= 7; 00118 return s; 00119 }
static int ibpfilter | ( | struct filter_struct * | fs, | |
int | in | |||
) | [inline, static] |
Integer Band Pass filter
Definition at line 122 of file fskmodem_int.c.
References filter_struct::icoefs, filter_struct::ip, filter_struct::ixv, filter_struct::iyv, and s.
Referenced by idemodulator().
00123 { 00124 int i, j; 00125 int s; 00126 int64_t s_interim; 00127 00128 /* integer filter */ 00129 s = in * fs->icoefs[0] / 256; 00130 fs->ixv[(fs->ip + 6) & 7] = s; 00131 00132 s = (fs->ixv[(fs->ip + 6) & 7] - fs->ixv[fs->ip]) 00133 + 3 * (fs->ixv[(fs->ip + 2) & 7] - fs->ixv[(fs->ip + 4) & 7]); 00134 00135 for (i = 1, j = fs->ip; i < 7; i++, j++) { 00136 s_interim = (int64_t)(fs->iyv[j & 7]) * 00137 (int64_t)(fs->icoefs[i]) / 00138 (int64_t)(256); 00139 s += (int) s_interim; 00140 } 00141 fs->iyv[j & 7] = s; 00142 fs->ip++; 00143 fs->ip &= 7; 00144 return s; 00145 }
static int idemodulator | ( | fsk_data * | fskd, | |
int * | retval, | |||
int | x | |||
) | [inline, static] |
Definition at line 147 of file fskmodem_int.c.
References fsk_data::demod_filter, ibpdfilter(), ibpfilter(), id, fsk_data::mark_filter, and fsk_data::space_filter.
Referenced by fsk_serial(), and get_bit_raw().
00148 { 00149 int is, im, id; 00150 int ilin2; 00151 00152 is = ibpfilter(&fskd->space_filter, x); 00153 im = ibpfilter(&fskd->mark_filter, x); 00154 00155 ilin2 = ((im * im) - (is * is)) / (256 * 256); 00156 00157 id = ibpdfilter(&fskd->demod_filter, ilin2); 00158 00159 *retval = id; 00160 return 0; 00161 }
static int iget_sample | ( | short ** | buffer, | |
int * | len | |||
) | [inline, static] |
Definition at line 47 of file fskmodem_int.c.
00048 { 00049 int retval; 00050 retval = (int) **buffer; 00051 (*buffer)++; 00052 (*len)--; 00053 return retval; 00054 }
double coef_in[NF][NBW][8] [static] |
Coefficients for input filters Coefficients table, generated by program "mkfilter" mkfilter is part of the zapatatelephony.org distribution Format: coef[IDX_FREC][IDX_BW][IDX_COEF] IDX_COEF = 0 => 1/GAIN IDX_COEF = 1-6 => Coefficientes y[n].
Definition at line 64 of file fskmodem_int.c.
double coef_out[NBW][8] [static] |
Initial value:
{ { 1.3868644653e-08,-6.3283665042e-01,4.0895057217e+00,-1.1020074592e+01,1.5850766191e+01,-1.2835109292e+01,5.5477477340e+00,0.0000000000e+00, }, { 3.1262119724e-03,-7.8390522307e-03,8.5209627801e-02,-4.0804129163e-01,1.1157139955e+00,-1.8767603680e+00,1.8916395224e+00,0.0000000000e+00 }, }
Definition at line 86 of file fskmodem_int.c.