Remove status_response callbacks where they are not needed.
[asterisk/asterisk.git] / main / fskmodem_int.c
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 FSK Modulator/Demodulator 
24  *
25  * \author Mark Spencer <markster@digium.com>
26  *
27  * \arg Includes code and algorithms from the Zapata library.
28  *
29  */
30
31 #include "asterisk.h"
32
33 ASTERISK_FILE_VERSION(__FILE__, "$Revision$")
34
35 #include "asterisk/fskmodem.h"
36
37 #define NBW     2
38 #define BWLIST  {75,800}
39 #define NF      6
40 #define FLIST {1400,1800,1200,2200,1300,2100}
41
42 #define STATE_SEARCH_STARTBIT   0
43 #define STATE_SEARCH_STARTBIT2  1
44 #define STATE_SEARCH_STARTBIT3  2
45 #define STATE_GET_BYTE                  3
46
47 static inline int iget_sample(short **buffer, int *len)
48 {
49         int retval;
50         retval = (int) **buffer;
51         (*buffer)++;
52         (*len)--;
53         return retval;
54 }
55
56 #define IGET_SAMPLE iget_sample(&buffer, len)
57 /*! \brief Coefficients for input filters
58  * Coefficients table, generated by program "mkfilter"  
59  * mkfilter is part of the zapatatelephony.org distribution
60  * Format: coef[IDX_FREC][IDX_BW][IDX_COEF]
61  * IDX_COEF = 0 =>      1/GAIN          
62  * IDX_COEF = 1-6       =>      Coefficientes y[n]                      
63 */
64 static double coef_in[NF][NBW][8]={
65         {  { 1.8229206611e-04,-7.8997325866e-01,2.2401819940e+00,-4.6751353581e+00,5.5080745712e+00,-5.0571565772e+00,2.6215820004e+00,0.0000000000e+00,
66         },  { 9.8532175289e-02,-5.6297236492e-02,3.3146713415e-01,-9.2239200436e-01,1.4844365184e+00,-2.0183258642e+00,2.0074154497e+00,0.0000000000e+00,
67         },  },  {  { 1.8229206610e-04,-7.8997325866e-01,7.7191410839e-01,-2.8075643964e+00,1.6948618347e+00,-3.0367273700e+00,9.0333559408e-01,0.0000000000e+00,
68         },  { 9.8531161839e-02,-5.6297236492e-02,1.1421579050e-01,-4.8122536483e-01,4.0121072432e-01,-7.4834487567e-01,6.9170822332e-01,0.0000000000e+00,
69         },  },  {  { 1.8229206611e-04,-7.8997325866e-01,2.9003821430e+00,-6.1082779024e+00,7.7169345751e+00,-6.6075999680e+00,3.3941838836e+00,0.0000000000e+00,
70         },  { 9.8539686961e-02,-5.6297236492e-02,4.2915323820e-01,-1.2609358633e+00,2.2399213250e+00,-2.9928879142e+00,2.5990173742e+00,0.0000000000e+00,
71         },  },  {  { 1.8229206610e-04,-7.8997325866e-01,-7.7191410839e-01,-2.8075643964e+00,-1.6948618347e+00,-3.0367273700e+00,-9.0333559408e-01,0.0000000000e+00,
72         },  { 9.8531161839e-02,-5.6297236492e-02,-1.1421579050e-01,-4.8122536483e-01,-4.0121072432e-01,-7.4834487567e-01,-6.9170822332e-01,0.0000000000e+00,
73         },  },  {  { 1.8229206611e-04,-7.8997325866e-01,2.5782298908e+00,-5.3629717478e+00,6.5890882172e+00,-5.8012914776e+00,3.0171839130e+00,0.0000000000e+00,
74         },  { 9.8534230718e-02,-5.6297236492e-02,3.8148618075e-01,-1.0848760410e+00,1.8441165168e+00,-2.4860666655e+00,2.3103384142e+00,0.0000000000e+00,
75         },  },  {  { 1.8229206610e-04,-7.8997325866e-01,-3.8715051001e-01,-2.6192408538e+00,-8.3977994034e-01,-2.8329897913e+00,-4.5306444352e-01,0.0000000000e+00,
76         },  { 9.8531160936e-02,-5.6297236492e-02,-5.7284484199e-02,-4.3673866734e-01,-1.9564766257e-01,-6.2028156584e-01,-3.4692356122e-01,0.0000000000e+00,
77         },  }, 
78 };
79
80 /*! \brief Coefficients for output filter
81  * Coefficients table, generated by program "mkfilter"
82  * Format: coef[IDX_BW][IDX_COEF]       
83  * IDX_COEF = 0 =>      1/GAIN  
84  * IDX_COEF = 1-6       =>      Coefficientes y[n]
85 */
86 static double coef_out[NBW][8]={
87         { 1.3868644653e-08,-6.3283665042e-01,4.0895057217e+00,-1.1020074592e+01,1.5850766191e+01,-1.2835109292e+01,5.5477477340e+00,0.0000000000e+00,
88         },  { 3.1262119724e-03,-7.8390522307e-03,8.5209627801e-02,-4.0804129163e-01,1.1157139955e+00,-1.8767603680e+00,1.8916395224e+00,0.0000000000e+00 
89         }, 
90 };
91
92 /*! Integer Pass Band demodulator filter  */
93 static inline int ibpdfilter(struct filter_struct * fs, int in)
94 {
95         int i,j;
96         int s;
97         int64_t s_interim;
98         
99         /* integer filter */
100         s =  in * fs->icoefs[0];
101         fs->ixv[(fs->ip + 6) & 7] = s;
102         
103         s =      (fs->ixv[fs->ip]           + fs->ixv[(fs->ip + 6) & 7]) +
104                 6  * (fs->ixv[(fs->ip + 1) & 7] + fs->ixv[(fs->ip + 5) & 7]) +
105                 15 * (fs->ixv[(fs->ip + 2) & 7] + fs->ixv[(fs->ip + 4) & 7]) +
106                 20 *  fs->ixv[(fs->ip + 3) & 7];
107         
108         for (i = 1, j = fs->ip; i < 7; i++, j++) {
109                 /* Promote operation to 64 bit to prevent overflow that occurred in 32 bit) */
110                 s_interim = (int64_t)(fs->iyv[j & 7]) * 
111                                 (int64_t)(fs->icoefs[i]) /
112                                 (int64_t)(1024);
113                 s += (int) s_interim;
114         }
115         fs->iyv[j & 7] = s;
116         fs->ip++;
117         fs->ip &= 7;
118         return s;
119 }
120
121 /*! Integer Band Pass filter */
122 static inline int ibpfilter(struct filter_struct * fs, int in)
123 {
124         int i, j;
125         int s;
126         int64_t s_interim;
127         
128         /* integer filter */
129         s =  in * fs->icoefs[0] / 256;
130         fs->ixv[(fs->ip + 6) & 7] = s;
131         
132         s = (fs->ixv[(fs->ip + 6) & 7] - fs->ixv[fs->ip])
133                 + 3 * (fs->ixv[(fs->ip + 2) & 7] - fs->ixv[(fs->ip + 4) & 7]);
134         
135         for (i = 1, j = fs->ip; i < 7; i++, j++) { 
136                 s_interim = (int64_t)(fs->iyv[j & 7]) * 
137                                 (int64_t)(fs->icoefs[i]) / 
138                                 (int64_t)(256);
139                 s += (int) s_interim;
140         }
141         fs->iyv[j & 7] = s;
142         fs->ip++;
143         fs->ip &= 7;
144         return s;
145 }
146
147 static inline int idemodulator(fsk_data *fskd, int *retval, int x)
148 {
149         int is, im, id;
150         int ilin2;
151  
152         is = ibpfilter(&fskd->space_filter, x);
153         im = ibpfilter(&fskd->mark_filter, x);
154         
155         ilin2 = ((im * im) - (is * is)) / (256 * 256);
156         
157         id = ibpdfilter(&fskd->demod_filter, ilin2);
158         
159         *retval = id;
160         return 0;
161 }
162
163 static int get_bit_raw(fsk_data *fskd, short *buffer, int *len)
164 {
165         /* This function implements a DPLL to synchronize with the bits */
166         int f;
167
168         int ix;
169         /* PLL coeffs are set up in callerid_new */
170         for (f = 0;;) {
171                 if (idemodulator(fskd, &ix, IGET_SAMPLE)) return(-1);
172                 if ((ix * fskd->xi0) < 0) { /* Transicion */
173                         if (!f) {
174                                 if (fskd->icont < (fskd->pllispb2)) {
175                                         fskd->icont += fskd->pllids; 
176                                 } else {
177                                         fskd->icont -= fskd->pllids;
178                                 }
179                                 f = 1;
180                         }
181                 }
182                 fskd->xi0 = ix;
183                 fskd->icont += 32;
184                 if (fskd->icont > fskd->pllispb) {
185                         fskd->icont -= fskd->pllispb;
186                         break;
187                 }
188         }
189         f = (ix > 0) ? 0x80 : 0;
190         return f;
191 }
192
193 int fskmodem_init(fsk_data *fskd)
194 {
195         int i;
196
197         fskd->space_filter.ip  = 0;
198         fskd->mark_filter.ip   = 0;
199         fskd->demod_filter.ip  = 0;
200
201         for ( i = 0 ; i < 7 ; i++ ) {
202                 fskd->space_filter.icoefs[i] = 
203                         coef_in[fskd->f_space_idx][fskd->bw][i] * 256;
204                 fskd->space_filter.ixv[i] = 0;;
205                 fskd->space_filter.iyv[i] = 0;;
206
207                 fskd->mark_filter.icoefs[i] = 
208                         coef_in[fskd->f_mark_idx][fskd->bw][i] * 256;
209                 fskd->mark_filter.ixv[i] = 0;;
210                 fskd->mark_filter.iyv[i] = 0;;
211
212                 fskd->demod_filter.icoefs[i] = 
213                         coef_out[fskd->bw][i] * 1024;
214                 fskd->demod_filter.ixv[i] = 0;;
215                 fskd->demod_filter.iyv[i] = 0;;
216         }
217         return 0;
218 }
219
220 int fsk_serial(fsk_data *fskd, short *buffer, int *len, int *outbyte)
221 {
222         int a;
223         int i, j, n1, r;
224         int samples = 0;
225         int olen;
226         int beginlen = *len;
227         int beginlenx;
228         
229         switch (fskd->state) {
230                 /* Pick up where we left off */
231         case STATE_SEARCH_STARTBIT2:
232                 goto search_startbit2;
233         case STATE_SEARCH_STARTBIT3:
234                 goto search_startbit3;
235         case STATE_GET_BYTE:
236                 goto getbyte;
237         }
238         /* We await for start bit       */
239         do {
240                 /* this was jesus's nice, reasonable, working (at least with RTTY) code
241                 to look for the beginning of the start bit. Unfortunately, since TTY/TDD's
242                 just start sending a start bit with nothing preceding it at the beginning
243                 of a transmission (what a LOSING design), we cant do it this elegantly */
244                 /* NOT USED
245                                 if (demodulator(zap,&x1)) 
246                                         return -1;
247                                 for(;;) {
248                                         if (demodulator(zap,&x2)) 
249                                                 return -1;
250                                         if (x1>0 && x2<0) break;
251                                         x1=x2;
252                                 }
253                 */
254                 /* this is now the imprecise, losing, but functional code to detect the
255                 beginning of a start bit in the TDD sceanario. It just looks for sufficient
256                 level to maybe, perhaps, guess, maybe that its maybe the beginning of
257                 a start bit, perhaps. This whole thing stinks! */
258                 beginlenx = beginlen; /* just to avoid unused war warnings */
259                 if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE))
260                         return -1;
261                 samples++;
262                 for(;;) {
263 search_startbit2:                  
264                         if (*len <= 0) {
265                                 fskd->state = STATE_SEARCH_STARTBIT2;
266                                 return 0;
267                         }
268                         samples++;
269                         if (idemodulator(fskd, &fskd->xi2, IGET_SAMPLE)) 
270                                 return -1;
271 #if 0
272                         printf("xi2 = %d ", fskd->xi2);
273 #endif                  
274                         if (fskd->xi2 < 512) {
275                                 break;
276                         }
277                 }
278 search_startbit3:                  
279                 /* We await for 0.5 bits before using DPLL */
280                 i = fskd->ispb / 2;
281                 if (*len < i) {
282                         fskd->state = STATE_SEARCH_STARTBIT3;
283                         return 0;
284                 }
285                 for (; i > 0; i--) {
286                         if (idemodulator(fskd, &fskd->xi1, IGET_SAMPLE))
287                                 return(-1); 
288 #if 0
289                         printf("xi1 = %d ", fskd->xi1);
290 #endif
291                         samples++; 
292                 }
293
294                 /* x1 must be negative (start bit confirmation) */
295
296         } while (fskd->xi1 > 0);
297         fskd->state = STATE_GET_BYTE;
298
299 getbyte:
300
301         /* Need at least 80 samples (for 1200) or
302                 1320 (for 45.5) to be sure we'll have a byte */
303         if (fskd->nbit < 8) {
304                 if (*len < 1320)
305                         return 0;
306         } else {
307                 if (*len < 80)
308                         return 0;
309         }
310
311         /* Now we read the data bits */
312         j = fskd->nbit;
313         for (a = n1 = 0; j; j--) {
314                 olen = *len;
315                 i = get_bit_raw(fskd, buffer, len);
316                 buffer += (olen - *len);
317                 if (i == -1) 
318                         return -1;
319                 if (i) 
320                         n1++;
321                 a >>= 1; 
322                 a |= i;
323         }
324         j = 8 - fskd->nbit;
325         a >>= j;
326
327         /* We read parity bit (if exists) and check parity */
328         if (fskd->parity) {
329                 olen = *len;
330                 i = get_bit_raw(fskd, buffer, len); 
331                 buffer += (olen - *len);
332                 if (i == -1) 
333                         return -1;
334                 if (i) 
335                         n1++;
336                 if (fskd->parity == 1) {        /* parity=1 (even) */
337                         if (n1 & 1) 
338                                 a |= 0x100;                     /* error */
339                 } else {                                        /* parity=2 (odd) */
340                         if (!(n1 & 1)) 
341                                 a |= 0x100;                     /* error */
342                 }
343         }
344         
345         /* We read STOP bits. All of them must be 1 */
346         
347         for (j = fskd->instop; j; j--) {
348                 r = get_bit_raw(fskd, buffer, len);
349                 if (r == -1) 
350                         return -1;
351                 if (!r) 
352                         a |= 0x200;
353         }
354
355         /* And finally we return  
356          * Bit 8 : Parity error 
357          * Bit 9 : Framming error
358         */
359                 
360         *outbyte = a;
361         fskd->state = STATE_SEARCH_STARTBIT;
362         return 1;
363 }