1 /*****************************************************************************
2 * nit.c: NIT decoder/generator
3 *----------------------------------------------------------------------------
4 * Copyright (C) 2001-2012 VideoLAN
5 * $Id$
6 *
7 * Authors: Johann Hanne
8 * heavily based on pmt.c which was written by
9 * Arnaud de Bossoreille de Ribou <bozo@via.ecp.fr>
10 * Jean-Paul Saman <jpsaman@videolan.org>
11 *
12 * This library is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU Lesser General Public
14 * License as published by the Free Software Foundation; either
15 * version 2.1 of the License, or (at your option) any later version.
16 *
17 * This library is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * Lesser General Public License for more details.
21 *
22 * You should have received a copy of the GNU Lesser General Public
23 * License along with this library; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 *
26 *----------------------------------------------------------------------------
27 *
28 *****************************************************************************/
29
30 #include "config.h"
31
32 #include <stdio.h>
33 #include <stdlib.h>
34 #include <stdbool.h>
35 #include <string.h>
36
37 #if defined(HAVE_INTTYPES_H)
38 #include <inttypes.h>
39 #elif defined(HAVE_STDINT_H)
40 #include <stdint.h>
41 #endif
42
43 #include <assert.h>
44
45 #include "../dvbpsi.h"
46 #include "../dvbpsi_private.h"
47 #include "../psi.h"
48 #include "../descriptor.h"
49 #include "../demux.h"
50 #include "nit.h"
51 #include "nit_private.h"
52
53 /*****************************************************************************
54 * dvbpsi_nit_attach
55 *****************************************************************************
56 * Initialize a NIT subtable decoder.
57 *****************************************************************************/
dvbpsi_nit_attach(dvbpsi_t * p_dvbpsi,uint8_t i_table_id,uint16_t i_extension,dvbpsi_nit_callback pf_callback,void * p_cb_data)58 bool dvbpsi_nit_attach(dvbpsi_t* p_dvbpsi, uint8_t i_table_id,
59 uint16_t i_extension, dvbpsi_nit_callback pf_callback,
60 void* p_cb_data)
61 {
62 assert(p_dvbpsi);
63 assert(p_dvbpsi->p_decoder);
64
65 dvbpsi_demux_t* p_demux = (dvbpsi_demux_t*)p_dvbpsi->p_decoder;
66
67 if (dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension))
68 {
69 dvbpsi_error(p_dvbpsi, "NIT decoder",
70 "Already a decoder for (table_id == 0x%02x,"
71 "extension == 0x%02x)",
72 i_table_id, i_extension);
73 return false;
74 }
75
76 dvbpsi_nit_decoder_t* p_nit_decoder;
77 p_nit_decoder = (dvbpsi_nit_decoder_t*) dvbpsi_decoder_new(NULL,
78 0, true, sizeof(dvbpsi_nit_decoder_t));
79 if (p_nit_decoder == NULL)
80 return false;
81
82 /* subtable decoder configuration */
83 dvbpsi_demux_subdec_t* p_subdec;
84 p_subdec = dvbpsi_NewDemuxSubDecoder(i_table_id, i_extension, dvbpsi_nit_detach,
85 dvbpsi_nit_sections_gather, DVBPSI_DECODER(p_nit_decoder));
86 if (p_subdec == NULL)
87 {
88 dvbpsi_decoder_delete(DVBPSI_DECODER(p_nit_decoder));
89 return false;
90 }
91
92 /* Attach the subtable decoder to the demux */
93 dvbpsi_AttachDemuxSubDecoder(p_demux, p_subdec);
94
95 /* NIT decoder information */
96 p_nit_decoder->i_network_id = i_extension;
97 p_nit_decoder->pf_nit_callback = pf_callback;
98 p_nit_decoder->p_cb_data = p_cb_data;
99 p_nit_decoder->p_building_nit = NULL;
100
101 return true;
102 }
103
104 /*****************************************************************************
105 * dvbpsi_nit_detach
106 *****************************************************************************
107 * Close a NIT decoder.
108 *****************************************************************************/
dvbpsi_nit_detach(dvbpsi_t * p_dvbpsi,uint8_t i_table_id,uint16_t i_extension)109 void dvbpsi_nit_detach(dvbpsi_t * p_dvbpsi, uint8_t i_table_id, uint16_t i_extension)
110 {
111 dvbpsi_demux_t *p_demux = (dvbpsi_demux_t *) p_dvbpsi->p_decoder;
112
113 dvbpsi_demux_subdec_t* p_subdec;
114 p_subdec = dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension);
115 if (p_subdec == NULL)
116 {
117 dvbpsi_error(p_dvbpsi, "NIT Decoder",
118 "No such NIT decoder (table_id == 0x%02x,"
119 "extension == 0x%02x)",
120 i_table_id, i_extension);
121 return;
122 }
123
124 dvbpsi_nit_decoder_t* p_nit_decoder;
125 p_nit_decoder = (dvbpsi_nit_decoder_t*)p_subdec->p_decoder;
126 if (p_nit_decoder->p_building_nit)
127 dvbpsi_nit_delete(p_nit_decoder->p_building_nit);
128 p_nit_decoder->p_building_nit = NULL;
129
130 /* Free demux sub table decoder */
131 dvbpsi_DetachDemuxSubDecoder(p_demux, p_subdec);
132 dvbpsi_DeleteDemuxSubDecoder(p_subdec);
133 }
134
135 /****************************************************************************
136 * dvbpsi_nit_init
137 *****************************************************************************
138 * Initialize a pre-allocated dvbpsi_nit_t structure.
139 *****************************************************************************/
dvbpsi_nit_init(dvbpsi_nit_t * p_nit,uint8_t i_table_id,uint16_t i_extension,uint16_t i_network_id,uint8_t i_version,bool b_current_next)140 void dvbpsi_nit_init(dvbpsi_nit_t* p_nit, uint8_t i_table_id, uint16_t i_extension,
141 uint16_t i_network_id, uint8_t i_version, bool b_current_next)
142 {
143 p_nit->i_table_id = i_table_id;
144 p_nit->i_extension = i_extension;
145
146 p_nit->i_network_id = i_network_id;
147 p_nit->i_version = i_version;
148 p_nit->b_current_next = b_current_next;
149 p_nit->p_first_descriptor = NULL;
150 p_nit->p_first_ts = NULL;
151 }
152
153 /****************************************************************************
154 * dvbpsi_nit_new
155 *****************************************************************************
156 * Allocate and initialize a dvbpsi_nit_t structure.
157 *****************************************************************************/
dvbpsi_nit_new(uint8_t i_table_id,uint16_t i_extension,uint16_t i_network_id,uint8_t i_version,bool b_current_next)158 dvbpsi_nit_t *dvbpsi_nit_new(uint8_t i_table_id, uint16_t i_extension,
159 uint16_t i_network_id, uint8_t i_version,
160 bool b_current_next)
161 {
162 dvbpsi_nit_t*p_nit = (dvbpsi_nit_t*)malloc(sizeof(dvbpsi_nit_t));
163 if (p_nit != NULL)
164 dvbpsi_nit_init(p_nit, i_table_id, i_extension, i_network_id,
165 i_version, b_current_next);
166 return p_nit;
167 }
168
169 /*****************************************************************************
170 * dvbpsi_nit_empty
171 *****************************************************************************
172 * Clean a dvbpsi_nit_t structure.
173 *****************************************************************************/
dvbpsi_nit_empty(dvbpsi_nit_t * p_nit)174 void dvbpsi_nit_empty(dvbpsi_nit_t* p_nit)
175 {
176 dvbpsi_nit_ts_t* p_ts = p_nit->p_first_ts;
177
178 dvbpsi_DeleteDescriptors(p_nit->p_first_descriptor);
179
180 while (p_ts != NULL)
181 {
182 dvbpsi_nit_ts_t* p_tmp = p_ts->p_next;
183 dvbpsi_DeleteDescriptors(p_ts->p_first_descriptor);
184 free(p_ts);
185 p_ts = p_tmp;
186 }
187
188 p_nit->p_first_descriptor = NULL;
189 p_nit->p_first_ts = NULL;
190 }
191
192 /****************************************************************************
193 * dvbpsi_nit_delete
194 *****************************************************************************
195 * Clean and delete a dvbpsi_nit_t structure.
196 *****************************************************************************/
dvbpsi_nit_delete(dvbpsi_nit_t * p_nit)197 void dvbpsi_nit_delete(dvbpsi_nit_t *p_nit)
198 {
199 if (p_nit)
200 dvbpsi_nit_empty(p_nit);
201 free(p_nit);
202 }
203
204 /*****************************************************************************
205 * dvbpsi_nit_descriptor_add
206 *****************************************************************************
207 * Add a descriptor in the NIT.
208 *****************************************************************************/
dvbpsi_nit_descriptor_add(dvbpsi_nit_t * p_nit,uint8_t i_tag,uint8_t i_length,uint8_t * p_data)209 dvbpsi_descriptor_t* dvbpsi_nit_descriptor_add(dvbpsi_nit_t* p_nit,
210 uint8_t i_tag, uint8_t i_length,
211 uint8_t* p_data)
212 {
213 dvbpsi_descriptor_t* p_descriptor
214 = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
215 if (p_descriptor == NULL)
216 return NULL;
217
218 if (p_nit->p_first_descriptor == NULL)
219 p_nit->p_first_descriptor = p_descriptor;
220 else
221 {
222 dvbpsi_descriptor_t* p_last_descriptor = p_nit->p_first_descriptor;
223 while(p_last_descriptor->p_next != NULL)
224 p_last_descriptor = p_last_descriptor->p_next;
225 p_last_descriptor->p_next = p_descriptor;
226 }
227 return p_descriptor;
228 }
229
230 /*****************************************************************************
231 * dvbpsi_nit_ts_add
232 *****************************************************************************
233 * Add an TS in the NIT.
234 *****************************************************************************/
dvbpsi_nit_ts_add(dvbpsi_nit_t * p_nit,uint16_t i_ts_id,uint16_t i_orig_network_id)235 dvbpsi_nit_ts_t* dvbpsi_nit_ts_add(dvbpsi_nit_t* p_nit,
236 uint16_t i_ts_id, uint16_t i_orig_network_id)
237 {
238 dvbpsi_nit_ts_t* p_ts = (dvbpsi_nit_ts_t*)malloc(sizeof(dvbpsi_nit_ts_t));
239 if (p_ts == NULL)
240 return NULL;
241
242 p_ts->i_ts_id = i_ts_id;
243 p_ts->i_orig_network_id = i_orig_network_id;
244 p_ts->p_first_descriptor = NULL;
245 p_ts->p_next = NULL;
246
247 if (p_nit->p_first_ts == NULL)
248 p_nit->p_first_ts = p_ts;
249 else
250 {
251 dvbpsi_nit_ts_t* p_last_ts = p_nit->p_first_ts;
252 while(p_last_ts->p_next != NULL)
253 p_last_ts = p_last_ts->p_next;
254 p_last_ts->p_next = p_ts;
255 }
256 return p_ts;
257 }
258
259 /*****************************************************************************
260 * dvbpsi_nit_ts_descriptor_add
261 *****************************************************************************
262 * Add a descriptor in the NIT TS.
263 *****************************************************************************/
dvbpsi_nit_ts_descriptor_add(dvbpsi_nit_ts_t * p_ts,uint8_t i_tag,uint8_t i_length,uint8_t * p_data)264 dvbpsi_descriptor_t* dvbpsi_nit_ts_descriptor_add(dvbpsi_nit_ts_t* p_ts,
265 uint8_t i_tag, uint8_t i_length,
266 uint8_t* p_data)
267 {
268 dvbpsi_descriptor_t* p_descriptor
269 = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
270 if (p_descriptor == NULL)
271 return NULL;
272
273 p_ts->p_first_descriptor = dvbpsi_AddDescriptor(p_ts->p_first_descriptor,
274 p_descriptor);
275 assert(p_ts->p_first_descriptor);
276 if (p_ts->p_first_descriptor == NULL)
277 return NULL;
278
279 return p_descriptor;
280 }
281
282 /* */
dvbpsi_ReInitNIT(dvbpsi_nit_decoder_t * p_decoder,const bool b_force)283 static void dvbpsi_ReInitNIT(dvbpsi_nit_decoder_t* p_decoder, const bool b_force)
284 {
285 assert(p_decoder);
286
287 dvbpsi_decoder_reset(DVBPSI_DECODER(p_decoder), b_force);
288
289 /* Force redecoding */
290 if (b_force)
291 {
292 /* Free structures */
293 if (p_decoder->p_building_nit)
294 dvbpsi_nit_delete(p_decoder->p_building_nit);
295 }
296 p_decoder->p_building_nit = NULL;
297 }
298
dvbpsi_CheckNIT(dvbpsi_t * p_dvbpsi,dvbpsi_nit_decoder_t * p_nit_decoder,dvbpsi_psi_section_t * p_section)299 static bool dvbpsi_CheckNIT(dvbpsi_t *p_dvbpsi, dvbpsi_nit_decoder_t *p_nit_decoder,
300 dvbpsi_psi_section_t *p_section)
301 {
302 assert(p_dvbpsi);
303 assert(p_nit_decoder);
304
305 bool b_reinit = false;
306
307 if (p_nit_decoder->p_building_nit->i_version != p_section->i_version)
308 {
309 /* version_number */
310 dvbpsi_error(p_dvbpsi, "NIT decoder",
311 "'version_number' differs"
312 " whereas no discontinuity has occured");
313 b_reinit = true;
314 }
315 else if (p_nit_decoder->i_last_section_number
316 != p_section->i_last_number)
317 {
318 /* last_section_number */
319 dvbpsi_error(p_dvbpsi, "NIT decoder",
320 "'last_section_number' differs"
321 " whereas no discontinuity has occured");
322 b_reinit = true;
323 }
324
325 return b_reinit;
326 }
327
dvbpsi_AddSectionNIT(dvbpsi_t * p_dvbpsi,dvbpsi_nit_decoder_t * p_nit_decoder,dvbpsi_psi_section_t * p_section)328 static bool dvbpsi_AddSectionNIT(dvbpsi_t *p_dvbpsi, dvbpsi_nit_decoder_t *p_nit_decoder,
329 dvbpsi_psi_section_t* p_section)
330 {
331 assert(p_dvbpsi);
332 assert(p_nit_decoder);
333 assert(p_section);
334
335 /* Initialize the structures if it's the first section received */
336 if (p_nit_decoder->p_building_nit == NULL)
337 {
338 p_nit_decoder->p_building_nit = dvbpsi_nit_new(p_section->i_table_id,
339 p_section->i_extension, p_nit_decoder->i_network_id,
340 p_section->i_version, p_section->b_current_next);
341 if (p_nit_decoder->p_building_nit == NULL)
342 return false;
343 p_nit_decoder->i_last_section_number = p_section->i_last_number;
344 }
345
346 /* Add to linked list of sections */
347 if (dvbpsi_decoder_psi_section_add(DVBPSI_DECODER(p_nit_decoder), p_section))
348 dvbpsi_debug(p_dvbpsi, "NIT decoder", "overwrite section number %d",
349 p_section->i_number);
350
351 return true;
352 }
353
354 /*****************************************************************************
355 * dvbpsi_nit_sections_gather
356 *****************************************************************************
357 * Callback for the PSI decoder.
358 *****************************************************************************/
dvbpsi_nit_sections_gather(dvbpsi_t * p_dvbpsi,dvbpsi_decoder_t * p_private_decoder,dvbpsi_psi_section_t * p_section)359 void dvbpsi_nit_sections_gather(dvbpsi_t *p_dvbpsi,
360 dvbpsi_decoder_t *p_private_decoder,
361 dvbpsi_psi_section_t *p_section)
362 {
363 assert(p_dvbpsi);
364
365 const uint8_t i_table_id = ((p_section->i_table_id == 0x40) ||
366 (p_section->i_table_id == 0x41)) ?
367 p_section->i_table_id : 0x40;
368
369 if (!dvbpsi_CheckPSISection(p_dvbpsi, p_section, i_table_id, "NIT decoder"))
370 {
371 dvbpsi_DeletePSISections(p_section);
372 return;
373 }
374
375 /* */
376 dvbpsi_nit_decoder_t* p_nit_decoder
377 = (dvbpsi_nit_decoder_t*)p_private_decoder;
378
379 /* We have a valid NIT section */
380 if (p_nit_decoder->i_network_id != p_section->i_extension)
381 {
382 /* Invalid program_number */
383 dvbpsi_error(p_dvbpsi, "NIT decoder", "'network_id' don't match");
384 dvbpsi_DeletePSISections(p_section);
385 return;
386 }
387
388 /* TS discontinuity check */
389 if (p_nit_decoder->b_discontinuity)
390 {
391 dvbpsi_ReInitNIT(p_nit_decoder, true);
392 p_nit_decoder->b_discontinuity = false;
393 }
394 else
395 {
396 /* Perform some few sanity checks */
397 if (p_nit_decoder->p_building_nit)
398 {
399 if (dvbpsi_CheckNIT(p_dvbpsi, p_nit_decoder, p_section))
400 dvbpsi_ReInitNIT(p_nit_decoder, true);
401 }
402 else
403 {
404 if ( (p_nit_decoder->b_current_valid)
405 && (p_nit_decoder->current_nit.i_version == p_section->i_version)
406 && (p_nit_decoder->current_nit.b_current_next == p_section->b_current_next))
407 {
408 /* Don't decode since this version is already decoded */
409 dvbpsi_debug(p_dvbpsi, "NIT decoder",
410 "ignoring already decoded section %d",
411 p_section->i_number);
412 dvbpsi_DeletePSISections(p_section);
413 return;;
414 }
415 }
416 }
417
418 /* Add section to NIT */
419 if (!dvbpsi_AddSectionNIT(p_dvbpsi, p_nit_decoder, p_section))
420 {
421 dvbpsi_error(p_dvbpsi, "NIT decoder", "failed decoding section %d",
422 p_section->i_number);
423 dvbpsi_DeletePSISections(p_section);
424 return;
425 }
426
427 /* Check if we have all the sections */
428 if (dvbpsi_decoder_psi_sections_completed(DVBPSI_DECODER(p_nit_decoder)))
429 {
430 assert(p_nit_decoder->pf_nit_callback);
431
432 /* Save the current information */
433 p_nit_decoder->current_nit = *p_nit_decoder->p_building_nit;
434 p_nit_decoder->b_current_valid = true;
435
436 /* Decode the sections */
437 dvbpsi_nit_sections_decode(p_nit_decoder->p_building_nit,
438 p_nit_decoder->p_sections);
439 /* signal the new NIT */
440 p_nit_decoder->pf_nit_callback(p_nit_decoder->p_cb_data,
441 p_nit_decoder->p_building_nit);
442 /* Delete sections and Reinitialize the structures */
443 dvbpsi_ReInitNIT(p_nit_decoder, false);
444 assert(p_nit_decoder->p_sections == NULL);
445 }
446 }
447
448 /*****************************************************************************
449 * dvbpsi_nit_sections_decode
450 *****************************************************************************
451 * NIT decoder.
452 *****************************************************************************/
dvbpsi_nit_sections_decode(dvbpsi_nit_t * p_nit,dvbpsi_psi_section_t * p_section)453 void dvbpsi_nit_sections_decode(dvbpsi_nit_t* p_nit,
454 dvbpsi_psi_section_t* p_section)
455 {
456 uint8_t* p_byte, * p_end;
457
458 while (p_section)
459 {
460 /* - NIT descriptors */
461 p_byte = p_section->p_payload_start + 2;
462 p_end = p_byte + (((uint16_t)(p_section->p_payload_start[0] & 0x0f) << 8)
463 | p_section->p_payload_start[1]);
464
465 while (p_byte + 2 <= p_end)
466 {
467 uint8_t i_tag = p_byte[0];
468 uint8_t i_length = p_byte[1];
469 if (i_length + 2 <= p_end - p_byte)
470 dvbpsi_nit_descriptor_add(p_nit, i_tag, i_length, p_byte + 2);
471 p_byte += 2 + i_length;
472 }
473
474 /* Transport stream loop length */
475 p_end = 2 + p_byte + (((uint16_t)(p_byte[0] & 0x0f) << 8) | p_byte[1]);
476 if (p_end > p_section->p_payload_end)
477 p_end = p_section->p_payload_end;
478
479 p_byte += 2;
480
481 /* - TSs */
482 while(p_byte + 6 <= p_end)
483 {
484 uint8_t *p_end2; /* descriptor loop end */
485
486 uint16_t i_ts_id = ((uint16_t)p_byte[0] << 8) | p_byte[1];
487 uint16_t i_orig_network_id = ((uint16_t)p_byte[2] << 8) | p_byte[3];
488 uint16_t i_ts_length = ((uint16_t)(p_byte[4] & 0x0f) << 8) | p_byte[5];
489
490 dvbpsi_nit_ts_t* p_ts = dvbpsi_nit_ts_add(p_nit, i_ts_id, i_orig_network_id);
491 if (!p_ts)
492 break;
493
494 /* - TS descriptors */
495 p_byte += 6;
496 p_end2 = p_byte + i_ts_length;
497 if (p_end2 > p_section->p_payload_end)
498 p_end2 = p_section->p_payload_end;
499
500 while (p_byte + 2 <= p_end2)
501 {
502 uint8_t i_tag = p_byte[0];
503 uint8_t i_length = p_byte[1];
504 if (i_length + 2 <= p_end2 - p_byte)
505 dvbpsi_nit_ts_descriptor_add(p_ts, i_tag, i_length, p_byte + 2);
506 p_byte += 2 + i_length;
507 }
508 }
509 p_section = p_section->p_next;
510 }
511 }
512
513 /*****************************************************************************
514 * dvbpsi_nit_sections_generate
515 *****************************************************************************
516 * Generate NIT sections based on the dvbpsi_nit_t structure.
517 *****************************************************************************/
dvbpsi_nit_sections_generate(dvbpsi_t * p_dvbpsi,dvbpsi_nit_t * p_nit,uint8_t i_table_id)518 dvbpsi_psi_section_t* dvbpsi_nit_sections_generate(dvbpsi_t *p_dvbpsi,
519 dvbpsi_nit_t* p_nit, uint8_t i_table_id)
520 {
521 dvbpsi_psi_section_t* p_result = dvbpsi_NewPSISection(1024);
522 dvbpsi_psi_section_t* p_current = p_result;
523 dvbpsi_psi_section_t* p_prev;
524 dvbpsi_descriptor_t* p_descriptor = p_nit->p_first_descriptor;
525 dvbpsi_nit_ts_t* p_ts = p_nit->p_first_ts;
526 uint16_t i_network_descriptors_length, i_transport_stream_loop_length;
527 uint8_t * p_transport_stream_loop_length;
528
529 p_current->i_table_id = i_table_id;
530 p_current->b_syntax_indicator = true;
531 p_current->b_private_indicator = false;
532 p_current->i_length = 13; /* including CRC_32 */
533 p_current->i_extension = p_nit->i_network_id;
534 p_current->i_version = p_nit->i_version;
535 p_current->b_current_next = p_nit->b_current_next;
536 p_current->i_number = 0;
537 p_current->p_payload_end += 10;
538 p_current->p_payload_start = p_current->p_data + 8;
539
540 /* NIT descriptors */
541 while (p_descriptor != NULL)
542 {
543 /* New section if needed */
544 /* written_data_length + descriptor_length + 2 > 1024 - CRC_32_length */
545 if ((p_current->p_payload_end - p_current->p_data)
546 + p_descriptor->i_length > 1018)
547 {
548 /* network_descriptors_length */
549 i_network_descriptors_length = (p_current->p_payload_end - p_current->p_payload_start) - 2;
550 p_current->p_data[8] = (i_network_descriptors_length >> 8) | 0xf0;
551 p_current->p_data[9] = i_network_descriptors_length;
552
553 /* transport_stream_loop_length */
554 p_current->p_payload_end[0] = 0;
555 p_current->p_payload_end[1] = 0;
556 p_current->p_payload_end += 2;
557
558 p_prev = p_current;
559 p_current = dvbpsi_NewPSISection(1024);
560 p_prev->p_next = p_current;
561
562 p_current->i_table_id = i_table_id;
563 p_current->b_syntax_indicator = true;
564 p_current->b_private_indicator = false;
565 p_current->i_length = 13; /* including CRC_32 */
566 p_current->i_extension = p_nit->i_network_id;
567 p_current->i_version = p_nit->i_version;
568 p_current->b_current_next = p_nit->b_current_next;
569 p_current->i_number = p_prev->i_number + 1;
570 p_current->p_payload_end += 10;
571 p_current->p_payload_start = p_current->p_data + 8;
572 }
573
574 /* p_payload_end is where the descriptor begins */
575 p_current->p_payload_end[0] = p_descriptor->i_tag;
576 p_current->p_payload_end[1] = p_descriptor->i_length;
577 memcpy(p_current->p_payload_end + 2,
578 p_descriptor->p_data,
579 p_descriptor->i_length);
580
581 /* Increase length by descriptor_length + 2 */
582 p_current->p_payload_end += p_descriptor->i_length + 2;
583 p_current->i_length += p_descriptor->i_length + 2;
584
585 p_descriptor = p_descriptor->p_next;
586 }
587
588 /* network_descriptors_length */
589 i_network_descriptors_length = (p_current->p_payload_end - p_current->p_payload_start) - 2;
590 p_current->p_data[8] = (i_network_descriptors_length >> 8) | 0xf0;
591 p_current->p_data[9] = i_network_descriptors_length;
592
593 /* Store the position of the transport_stream_loop_length field
594 and reserve two bytes for it */
595 p_transport_stream_loop_length = p_current->p_payload_end;
596 p_current->p_payload_end += 2;
597
598 /* NIT TSs */
599 while (p_ts != NULL)
600 {
601 uint8_t* p_ts_start = p_current->p_payload_end;
602 uint16_t i_ts_length = 5;
603
604 /* Can the current section carry all the descriptors ? */
605 p_descriptor = p_ts->p_first_descriptor;
606 while( (p_descriptor != NULL)
607 && ((p_ts_start - p_current->p_data) + i_ts_length <= 1020))
608 {
609 i_ts_length += p_descriptor->i_length + 2;
610 p_descriptor = p_descriptor->p_next;
611 }
612
613 /* If _no_ and the current section isn't empty and an empty section
614 may carry one more descriptor
615 then create a new section */
616 if( (p_descriptor != NULL)
617 && (p_ts_start - p_current->p_data != 12)
618 && (i_ts_length <= 1008))
619 {
620 /* transport_stream_loop_length */
621 i_transport_stream_loop_length = (p_current->p_payload_end - p_transport_stream_loop_length) - 2;
622 p_transport_stream_loop_length[0] = (i_transport_stream_loop_length >> 8) | 0xf0;
623 p_transport_stream_loop_length[1] = i_transport_stream_loop_length;
624
625 /* will put more descriptors in an empty section */
626 dvbpsi_debug(p_dvbpsi, "NIT generator",
627 "create a new section to carry more TS descriptors");
628
629 p_prev = p_current;
630 p_current = dvbpsi_NewPSISection(1024);
631 p_prev->p_next = p_current;
632
633 p_current->i_table_id = i_table_id;
634 p_current->b_syntax_indicator = true;
635 p_current->b_private_indicator = false;
636 p_current->i_length = 13; /* including CRC_32 */
637 p_current->i_extension = p_nit->i_network_id;
638 p_current->i_version = p_nit->i_version;
639 p_current->b_current_next = p_nit->b_current_next;
640 p_current->i_number = p_prev->i_number + 1;
641 p_current->p_payload_end += 10;
642 p_current->p_payload_start = p_current->p_data + 8;
643
644 /* network_descriptors_length = 0 */
645 p_current->p_data[8] = 0xf0;
646 p_current->p_data[9] = 0x00;
647
648 /* Store the position of the transport_stream_loop_length field
649 and reserve two bytes for it */
650 p_transport_stream_loop_length = p_current->p_payload_end;
651 p_current->p_payload_end += 2;
652
653 p_ts_start = p_current->p_payload_end;
654 }
655
656 /* p_ts_start is where the TS begins */
657 p_ts_start[0] = p_ts->i_ts_id >> 8;
658 p_ts_start[1] = p_ts->i_ts_id & 0xff;
659 p_ts_start[2] = p_ts->i_orig_network_id >> 8;
660 p_ts_start[3] = p_ts->i_orig_network_id & 0xff;
661
662 /* Increase the length by 6 */
663 p_current->p_payload_end += 6;
664 p_current->i_length += 6;
665
666 /* TS descriptors */
667 p_descriptor = p_ts->p_first_descriptor;
668 while ( (p_descriptor != NULL)
669 && ( (p_current->p_payload_end - p_current->p_data)
670 + p_descriptor->i_length <= 1018))
671 {
672 /* p_payload_end is where the descriptor begins */
673 p_current->p_payload_end[0] = p_descriptor->i_tag;
674 p_current->p_payload_end[1] = p_descriptor->i_length;
675 memcpy(p_current->p_payload_end + 2,
676 p_descriptor->p_data,
677 p_descriptor->i_length);
678
679 /* Increase length by descriptor_length + 2 */
680 p_current->p_payload_end += p_descriptor->i_length + 2;
681 p_current->i_length += p_descriptor->i_length + 2;
682
683 p_descriptor = p_descriptor->p_next;
684 }
685
686 if (p_descriptor != NULL)
687 dvbpsi_error(p_dvbpsi, "NIT generator", "unable to carry all the TS descriptors");
688
689 /* TS_info_length */
690 i_ts_length = p_current->p_payload_end - p_ts_start - 6;
691 p_ts_start[4] = (i_ts_length >> 8) | 0xf0;
692 p_ts_start[5] = i_ts_length;
693
694 p_ts = p_ts->p_next;
695 }
696
697 /* transport_stream_loop_length */
698 i_transport_stream_loop_length = (p_current->p_payload_end - p_transport_stream_loop_length) - 2;
699 p_transport_stream_loop_length[0] = (i_transport_stream_loop_length >> 8) | 0xf0;
700 p_transport_stream_loop_length[1] = i_transport_stream_loop_length;
701
702 /* Finalization */
703 p_prev = p_result;
704 while (p_prev != NULL)
705 {
706 p_prev->i_last_number = p_current->i_number;
707 dvbpsi_BuildPSISection(p_dvbpsi, p_prev);
708 p_prev = p_prev->p_next;
709 }
710
711 return p_result;
712 }
713