1 /*****************************************************************************
2 * bat.c: BAT decoder/generator
3 *----------------------------------------------------------------------------
4 * Copyright (C) 2001-2010 VideoLAN
5 * $Id: bat.c 110 2010-04-01 12:52:02Z gbazin $
6 *
7 * Authors: Zhu zhenglu <zhuzlu@gmail.com>
8 * heavily based on nit.c which was written by
9 * Johann Hanne
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 "bat.h"
51 #include "bat_private.h"
52
53 /*****************************************************************************
54 * dvbpsi_bat_attach
55 *****************************************************************************
56 * Initialize a BAT subtable decoder.
57 *****************************************************************************/
dvbpsi_bat_attach(dvbpsi_t * p_dvbpsi,uint8_t i_table_id,uint16_t i_extension,dvbpsi_bat_callback pf_callback,void * p_cb_data)58 bool dvbpsi_bat_attach(dvbpsi_t *p_dvbpsi, uint8_t i_table_id,
59 uint16_t i_extension, dvbpsi_bat_callback pf_callback, void* p_cb_data)
60 {
61 assert(p_dvbpsi);
62 assert(p_dvbpsi->p_decoder);
63
64 dvbpsi_demux_t* p_demux = (dvbpsi_demux_t*)p_dvbpsi->p_decoder;
65 if (dvbpsi_demuxGetSubDec(p_demux, i_table_id, i_extension))
66 {
67 dvbpsi_error(p_dvbpsi, "BAT decoder",
68 "Already a decoder for (table_id == 0x%02x,"
69 "extension == 0x%02x)",
70 i_table_id, i_extension);
71 return false;
72 }
73
74 dvbpsi_bat_decoder_t* p_bat_decoder;
75 p_bat_decoder = (dvbpsi_bat_decoder_t*) dvbpsi_decoder_new(NULL,
76 0, true, sizeof(dvbpsi_bat_decoder_t));
77 if (p_bat_decoder == NULL)
78 return false;
79
80 /* subtable decoder configuration */
81 dvbpsi_demux_subdec_t* p_subdec;
82 p_subdec = dvbpsi_NewDemuxSubDecoder(i_table_id, i_extension, dvbpsi_bat_detach,
83 dvbpsi_bat_sections_gather, DVBPSI_DECODER(p_bat_decoder));
84 if (p_subdec == NULL)
85 {
86 dvbpsi_decoder_delete(DVBPSI_DECODER(p_bat_decoder));
87 return false;
88 }
89
90 /* Attach the subtable decoder to the demux */
91 dvbpsi_AttachDemuxSubDecoder(p_demux, p_subdec);
92
93 /* BAT decoder information */
94 p_bat_decoder->pf_bat_callback = pf_callback;
95 p_bat_decoder->p_cb_data = p_cb_data;
96 p_bat_decoder->p_building_bat = NULL;
97
98 return true;
99 }
100
101 /*****************************************************************************
102 * dvbpsi_bat_detach
103 *****************************************************************************
104 * Close a BAT decoder.
105 *****************************************************************************/
dvbpsi_bat_detach(dvbpsi_t * p_dvbpsi,uint8_t i_table_id,uint16_t i_extension)106 void dvbpsi_bat_detach(dvbpsi_t *p_dvbpsi, uint8_t i_table_id, uint16_t i_extension)
107 {
108 assert(p_dvbpsi);
109 assert(p_dvbpsi->p_decoder);
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, "BAT Decoder",
118 "No such BAT decoder (table_id == 0x%02x,"
119 "extension == 0x%02x)",
120 i_table_id, i_extension);
121 return;
122 }
123
124 dvbpsi_bat_decoder_t* p_bat_decoder;
125 p_bat_decoder = (dvbpsi_bat_decoder_t*)p_subdec->p_decoder;
126 if (p_bat_decoder->p_building_bat)
127 dvbpsi_bat_delete(p_bat_decoder->p_building_bat);
128 p_bat_decoder->p_building_bat = NULL;
129
130 dvbpsi_DetachDemuxSubDecoder(p_demux, p_subdec);
131 dvbpsi_DeleteDemuxSubDecoder(p_subdec);
132 }
133
134 /*****************************************************************************
135 * dvbpsi_bat_init
136 *****************************************************************************
137 * Initialize a pre-allocated dvbpsi_bat_t structure.
138 *****************************************************************************/
dvbpsi_bat_init(dvbpsi_bat_t * p_bat,uint8_t i_table_id,uint16_t i_extension,uint8_t i_version,bool b_current_next)139 void dvbpsi_bat_init(dvbpsi_bat_t* p_bat, uint8_t i_table_id, uint16_t i_extension,
140 uint8_t i_version, bool b_current_next)
141 {
142 assert(p_bat);
143 p_bat->i_table_id = i_table_id;
144 p_bat->i_extension = i_extension;
145
146 p_bat->i_version = i_version;
147 p_bat->b_current_next = b_current_next;
148 p_bat->p_first_ts = NULL;
149 p_bat->p_first_descriptor = NULL;
150 }
151
152 /*****************************************************************************
153 * dvbpsi_bat_new
154 *****************************************************************************
155 * Allocate and initialize a dvbpsi_bat_t structure.
156 *****************************************************************************/
dvbpsi_bat_new(uint8_t i_table_id,uint16_t i_extension,uint8_t i_version,bool b_current_next)157 dvbpsi_bat_t *dvbpsi_bat_new(uint8_t i_table_id, uint16_t i_extension,
158 uint8_t i_version, bool b_current_next)
159 {
160 dvbpsi_bat_t *p_bat = (dvbpsi_bat_t*)malloc(sizeof(dvbpsi_bat_t));
161 if(p_bat != NULL)
162 dvbpsi_bat_init(p_bat, i_table_id, i_extension, i_version, b_current_next);
163 return p_bat;
164 }
165
166 /*****************************************************************************
167 * dvbpsi_bat_empty
168 *****************************************************************************
169 * Clean a dvbpsi_bat_t structure.
170 *****************************************************************************/
dvbpsi_bat_empty(dvbpsi_bat_t * p_bat)171 void dvbpsi_bat_empty(dvbpsi_bat_t* p_bat)
172 {
173 dvbpsi_bat_ts_t* p_ts = p_bat->p_first_ts;
174
175 dvbpsi_DeleteDescriptors(p_bat->p_first_descriptor);
176 p_bat->p_first_descriptor = NULL;
177
178 while (p_ts != NULL)
179 {
180 dvbpsi_bat_ts_t* p_tmp = p_ts->p_next;
181 dvbpsi_DeleteDescriptors(p_ts->p_first_descriptor);
182 free(p_ts);
183 p_ts = p_tmp;
184 }
185 p_bat->p_first_ts = NULL;
186 }
187
188 /*****************************************************************************
189 * dvbpsi_bat_delete
190 *****************************************************************************
191 * Empty and Delere a dvbpsi_bat_t structure.
192 *****************************************************************************/
dvbpsi_bat_delete(dvbpsi_bat_t * p_bat)193 void dvbpsi_bat_delete(dvbpsi_bat_t *p_bat)
194 {
195 if (p_bat)
196 dvbpsi_bat_empty(p_bat);
197 free(p_bat);
198 }
199
200 /*****************************************************************************
201 * dvbpsi_bat_bouquet_descriptor_add
202 *****************************************************************************
203 * Add a descriptor in the BAT.
204 *****************************************************************************/
dvbpsi_bat_bouquet_descriptor_add(dvbpsi_bat_t * p_bat,uint8_t i_tag,uint8_t i_length,uint8_t * p_data)205 dvbpsi_descriptor_t* dvbpsi_bat_bouquet_descriptor_add(dvbpsi_bat_t* p_bat,
206 uint8_t i_tag, uint8_t i_length,
207 uint8_t* p_data)
208 {
209 dvbpsi_descriptor_t* p_descriptor
210 = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
211 if (p_descriptor == NULL)
212 return NULL;
213
214 p_bat->p_first_descriptor = dvbpsi_AddDescriptor(p_bat->p_first_descriptor,
215 p_descriptor);
216 assert(p_bat->p_first_descriptor);
217 if (p_bat->p_first_descriptor == NULL)
218 return NULL;
219
220 return p_descriptor;
221 }
222
223 /*****************************************************************************
224 * dvbpsi_bat_ts_add
225 *****************************************************************************
226 * Add a TS description at the end of the BAT.
227 *****************************************************************************/
dvbpsi_bat_ts_add(dvbpsi_bat_t * p_bat,uint16_t i_ts_id,uint16_t i_orig_network_id)228 dvbpsi_bat_ts_t *dvbpsi_bat_ts_add(dvbpsi_bat_t* p_bat,
229 uint16_t i_ts_id, uint16_t i_orig_network_id)
230 {
231 dvbpsi_bat_ts_t * p_ts
232 = (dvbpsi_bat_ts_t*)malloc(sizeof(dvbpsi_bat_ts_t));
233 if (p_ts == NULL)
234 return NULL;
235
236 p_ts->i_ts_id = i_ts_id;
237 p_ts->i_orig_network_id = i_orig_network_id;
238 p_ts->p_next = NULL;
239 p_ts->p_first_descriptor = NULL;
240
241 if (p_bat->p_first_ts == NULL)
242 p_bat->p_first_ts = p_ts;
243 else
244 {
245 dvbpsi_bat_ts_t * p_last_ts = p_bat->p_first_ts;
246 while(p_last_ts->p_next != NULL)
247 p_last_ts = p_last_ts->p_next;
248 p_last_ts->p_next = p_ts;
249 }
250
251 return p_ts;
252 }
253
254
255 /*****************************************************************************
256 * dvbpsi_bat_ts_descriptor_add
257 *****************************************************************************
258 * Add a descriptor in the BAT TS descriptors, which is in the second loop of BAT.
259 *****************************************************************************/
dvbpsi_bat_ts_descriptor_add(dvbpsi_bat_ts_t * p_bat,uint8_t i_tag,uint8_t i_length,uint8_t * p_data)260 dvbpsi_descriptor_t *dvbpsi_bat_ts_descriptor_add(dvbpsi_bat_ts_t *p_bat,
261 uint8_t i_tag, uint8_t i_length,
262 uint8_t *p_data)
263 {
264 dvbpsi_descriptor_t * p_descriptor
265 = dvbpsi_NewDescriptor(i_tag, i_length, p_data);
266 if (p_descriptor == NULL)
267 return NULL;
268
269 if (p_bat->p_first_descriptor == NULL)
270 p_bat->p_first_descriptor = p_descriptor;
271 else
272 {
273 dvbpsi_descriptor_t *p_last_descriptor = p_bat->p_first_descriptor;
274 while(p_last_descriptor->p_next != NULL)
275 p_last_descriptor = p_last_descriptor->p_next;
276 p_last_descriptor->p_next = p_descriptor;
277 }
278 return p_descriptor;
279 }
280
281 /* */
dvbpsi_ReInitBAT(dvbpsi_bat_decoder_t * p_decoder,const bool b_force)282 static void dvbpsi_ReInitBAT(dvbpsi_bat_decoder_t* p_decoder, const bool b_force)
283 {
284 assert(p_decoder);
285
286 dvbpsi_decoder_reset(DVBPSI_DECODER(p_decoder), b_force);
287
288 /* Force redecoding */
289 if (b_force)
290 {
291 /* Free structures */
292 if (p_decoder->p_building_bat)
293 dvbpsi_bat_delete(p_decoder->p_building_bat);
294 }
295 p_decoder->p_building_bat = NULL;
296 }
297
dvbpsi_CheckBAT(dvbpsi_t * p_dvbpsi,dvbpsi_bat_decoder_t * p_bat_decoder,dvbpsi_psi_section_t * p_section)298 static bool dvbpsi_CheckBAT(dvbpsi_t *p_dvbpsi, dvbpsi_bat_decoder_t *p_bat_decoder,
299 dvbpsi_psi_section_t *p_section)
300 {
301 bool b_reinit = false;
302 assert(p_dvbpsi);
303 assert(p_bat_decoder);
304
305 if (p_bat_decoder->p_building_bat->i_extension != p_section->i_extension)
306 {
307 /* bouquet_id */
308 dvbpsi_error(p_dvbpsi, "BAT decoder", "'bouquet_id' differs"
309 " whereas no TS discontinuity has occured");
310 b_reinit = true;
311 }
312 else if (p_bat_decoder->p_building_bat->i_version
313 != p_section->i_version)
314 {
315 /* version_number */
316 dvbpsi_error(p_dvbpsi, "BAT decoder", "'version_number' differs"
317 " whereas no discontinuity has occured");
318 b_reinit = true;
319 }
320 else if (p_bat_decoder->i_last_section_number !=
321 p_section->i_last_number)
322 {
323 /* last_section_number */
324 dvbpsi_error(p_dvbpsi, "BAT decoder", "'last_section_number' differs"
325 " whereas no discontinuity has occured");
326 b_reinit = true;
327 }
328
329 return b_reinit;
330 }
331
dvbpsi_AddSectionBAT(dvbpsi_t * p_dvbpsi,dvbpsi_bat_decoder_t * p_bat_decoder,dvbpsi_psi_section_t * p_section)332 static bool dvbpsi_AddSectionBAT(dvbpsi_t *p_dvbpsi, dvbpsi_bat_decoder_t *p_bat_decoder,
333 dvbpsi_psi_section_t* p_section)
334 {
335 assert(p_dvbpsi);
336 assert(p_bat_decoder);
337 assert(p_section);
338
339 /* Initialize the structures if it's the first section received */
340 if (!p_bat_decoder->p_building_bat)
341 {
342 p_bat_decoder->p_building_bat = dvbpsi_bat_new(
343 p_section->i_table_id, p_section->i_extension,
344 p_section->i_version, p_section->b_current_next);
345 if (!p_bat_decoder->p_building_bat)
346 return false;
347
348 p_bat_decoder->i_last_section_number = p_section->i_last_number;
349 }
350
351 /* Add to linked list of sections */
352 if (dvbpsi_decoder_psi_section_add(DVBPSI_DECODER(p_bat_decoder), p_section))
353 dvbpsi_debug(p_dvbpsi, "BAT decoder", "overwrite section number %d",
354 p_section->i_number);
355
356 return true;
357 }
358
359 /*****************************************************************************
360 * dvbpsi_bat_sections_gather
361 *****************************************************************************
362 * Callback for the subtable demultiplexor.
363 *****************************************************************************/
dvbpsi_bat_sections_gather(dvbpsi_t * p_dvbpsi,dvbpsi_decoder_t * p_decoder,dvbpsi_psi_section_t * p_section)364 void dvbpsi_bat_sections_gather(dvbpsi_t *p_dvbpsi,
365 dvbpsi_decoder_t *p_decoder,
366 dvbpsi_psi_section_t * p_section)
367 {
368 dvbpsi_demux_t *p_demux = (dvbpsi_demux_t *) p_dvbpsi->p_decoder;
369 dvbpsi_bat_decoder_t * p_bat_decoder = (dvbpsi_bat_decoder_t *) p_decoder;
370
371 assert(p_dvbpsi);
372 assert(p_dvbpsi->p_decoder);
373
374 if (!dvbpsi_CheckPSISection(p_dvbpsi, p_section, 0x4a, "BAT decoder"))
375 {
376 dvbpsi_DeletePSISections(p_section);
377 return;
378 }
379
380 /* We have a valid BAT section */
381 if (p_demux->b_discontinuity)
382 {
383 dvbpsi_ReInitBAT(p_bat_decoder, true);
384 p_bat_decoder->b_discontinuity = false;
385 p_demux->b_discontinuity = false;
386 }
387 else
388 {
389 /* Perform a few sanity checks */
390 if (p_bat_decoder->p_building_bat)
391 {
392 if (dvbpsi_CheckBAT(p_dvbpsi, p_bat_decoder, p_section))
393 dvbpsi_ReInitBAT(p_bat_decoder, true);
394 }
395 else
396 {
397 if ( (p_bat_decoder->b_current_valid)
398 && (p_bat_decoder->current_bat.i_version == p_section->i_version)
399 && (p_bat_decoder->current_bat.b_current_next ==
400 p_section->b_current_next))
401 {
402 /* Don't decode since this version is already decoded */
403 dvbpsi_debug(p_dvbpsi, "BAT decoder",
404 "ignoring already decoded section %d",
405 p_section->i_number);
406 dvbpsi_DeletePSISections(p_section);
407 return;
408 }
409 #if 0 /* FIXME: Is this really needed ? */
410 else if ( (!p_bat_decoder->current_bat.b_current_next)
411 && (p_section->b_current_next))
412 {
413 /* Signal a new BAT if the previous one wasn't active */
414 dvbpsi_bat_t *p_bat = (dvbpsi_bat_t*)malloc(sizeof(dvbpsi_bat_t));
415 if (p_bat)
416 {
417 p_bat_decoder->current_bat.b_current_next = true;
418 memcpy(p_bat, &p_bat_decoder->current_bat, sizeof(dvbpsi_bat_t));
419 p_bat_decoder->pf_bat_callback(p_bat_decoder->p_cb_data, p_bat);
420 }
421 else
422 dvbpsi_error(p_dvbpsi, "BAT decoder", "Could not signal new BAT.");
423 }
424 dvbpsi_DeletePSISections(p_section);
425 return;
426 #endif
427 }
428 }
429
430 /* Add section to BAT */
431 if (!dvbpsi_AddSectionBAT(p_dvbpsi, p_bat_decoder, p_section))
432 {
433 dvbpsi_error(p_dvbpsi, "BAT decoder", "failed decoding section %d",
434 p_section->i_number);
435 dvbpsi_DeletePSISections(p_section);
436 return;
437 }
438
439 /* Check if we have all the sections */
440 if (dvbpsi_decoder_psi_sections_completed(DVBPSI_DECODER(p_bat_decoder)))
441 {
442 assert(p_bat_decoder->pf_bat_callback);
443
444 /* Save the current information */
445 p_bat_decoder->current_bat = *p_bat_decoder->p_building_bat;
446 p_bat_decoder->b_current_valid = true;
447 /* Decode the sections */
448 dvbpsi_bat_sections_decode(p_bat_decoder->p_building_bat,
449 p_bat_decoder->p_sections);
450 /* signal the new BAT */
451 p_bat_decoder->pf_bat_callback(p_bat_decoder->p_cb_data,
452 p_bat_decoder->p_building_bat);
453 /* Delete sections and Reinitialize the structures */
454 dvbpsi_ReInitBAT(p_bat_decoder, false);
455 assert(p_bat_decoder->p_sections == NULL);
456 }
457 }
458
459 /*****************************************************************************
460 * dvbpsi_DecodeBATSection
461 *****************************************************************************
462 * BAT decoder.
463 * p_bat as the output parameter
464 * p_section as the input parameter
465 * similar to dvbpsi_DecodeNITSection
466 *****************************************************************************/
dvbpsi_bat_sections_decode(dvbpsi_bat_t * p_bat,dvbpsi_psi_section_t * p_section)467 void dvbpsi_bat_sections_decode(dvbpsi_bat_t* p_bat,
468 dvbpsi_psi_section_t* p_section)
469 {
470 uint8_t* p_byte, * p_end;
471
472 while(p_section)
473 {
474 /* - first loop descriptors */
475 p_byte = p_section->p_payload_start + 2;
476 p_end = p_byte + (((uint16_t)(p_section->p_payload_start[0] & 0x0f) << 8)
477 | p_section->p_payload_start[1]);
478 if (p_end > p_section->p_payload_end)
479 p_end = p_section->p_payload_end;
480
481 while(p_byte + 2 <= p_end)
482 {
483 uint8_t i_tag = p_byte[0];
484 uint8_t i_length = p_byte[1];
485 if (i_length + 2 <= p_end - p_byte)
486 dvbpsi_bat_bouquet_descriptor_add(p_bat, i_tag, i_length, p_byte + 2);
487 p_byte += 2 + i_length;
488 }
489
490 p_end = 2 + p_byte + (((uint16_t)(p_byte[0] & 0x0f) << 8) | p_byte[1]);
491 if (p_end > p_section->p_payload_end)
492 p_end = p_section->p_payload_end;
493
494 /* - TSs */
495 p_byte += 2;
496 while(p_byte + 6 <= p_end)
497 {
498 uint8_t *p_end2;
499 uint16_t i_ts_id = ((uint16_t)p_byte[0] << 8) | p_byte[1];
500 uint16_t i_orig_network_id = ((uint16_t)p_byte[2] << 8) | p_byte[3];
501 uint16_t i_transport_descriptors_length = ((uint16_t)(p_byte[4] & 0x0f) << 8) | p_byte[5];
502
503 dvbpsi_bat_ts_t* p_ts = dvbpsi_bat_ts_add(p_bat, i_ts_id, i_orig_network_id);
504 if (!p_ts)
505 break;
506
507 /* - TS descriptors */
508 p_byte += 6;
509 p_end2 = p_byte + i_transport_descriptors_length;
510 if (p_end2 > p_section->p_payload_end)
511 p_end2 = p_section->p_payload_end;
512
513 while (p_byte + 2 <= p_end2)
514 {
515 uint8_t i_tag = p_byte[0];
516 uint8_t i_length = p_byte[1];
517 if (i_length + 2 <= p_end2 - p_byte)
518 dvbpsi_bat_ts_descriptor_add(p_ts, i_tag, i_length, p_byte + 2);
519 p_byte += 2 + i_length;
520 }
521 }
522
523 p_section = p_section->p_next;
524 }
525 }
526
527 /*****************************************************************************
528 * dvbpsi_bat_sections_generate
529 *****************************************************************************
530 * Generate BAT sections based on the dvbpsi_bat_t structure.
531 * similar to dvbpsi_nit_sections_generate
532 *****************************************************************************/
dvbpsi_bat_sections_generate(dvbpsi_t * p_dvbpsi,dvbpsi_bat_t * p_bat)533 dvbpsi_psi_section_t* dvbpsi_bat_sections_generate(dvbpsi_t *p_dvbpsi, dvbpsi_bat_t* p_bat)
534 {
535 dvbpsi_psi_section_t* p_result = dvbpsi_NewPSISection(1024);
536 dvbpsi_psi_section_t* p_current = p_result;
537 dvbpsi_psi_section_t* p_prev;
538 dvbpsi_descriptor_t* p_descriptor = p_bat->p_first_descriptor;
539 dvbpsi_bat_ts_t* p_ts = p_bat->p_first_ts;
540 uint16_t i_bouquet_descriptors_length, i_transport_stream_loop_length;
541 uint8_t * p_transport_stream_loop_length;
542
543 if (p_current == NULL)
544 {
545 dvbpsi_error(p_dvbpsi, "BAT encoder", "failed to allocate new PSI section");
546 return NULL;
547 }
548
549 p_current->i_table_id = 0x4a;
550 p_current->b_syntax_indicator = true;
551 p_current->b_private_indicator = true;
552 p_current->i_length = 13; /* including CRC_32 */
553 p_current->i_extension = p_bat->i_extension;
554 p_current->i_version = p_bat->i_version;
555 p_current->b_current_next = p_bat->b_current_next;
556 p_current->i_number = 0;
557 p_current->p_payload_end += 10;
558 p_current->p_payload_start = p_current->p_data + 8;
559
560 /* first loop descriptors */
561 while (p_descriptor != NULL)
562 {
563 /* New section if needed */
564 /* written_data_length + descriptor_length + 2 > 1024 - CRC_32_length */
565 if( (p_current->p_payload_end - p_current->p_data)
566 + p_descriptor->i_length > 1018)
567 {
568 /* bouquet_descriptors_length */
569 i_bouquet_descriptors_length = (p_current->p_payload_end - p_current->p_payload_start) - 2;
570 p_current->p_data[8] = (i_bouquet_descriptors_length >> 8) | 0xf0;
571 p_current->p_data[9] = i_bouquet_descriptors_length;
572
573 /* transport_stream_loop_length */
574 p_current->p_payload_end[0] = 0;
575 p_current->p_payload_end[1] = 0;
576 p_current->p_payload_end += 2;
577
578 p_prev = p_current;
579 p_current = dvbpsi_NewPSISection(1024);
580 if (p_current == NULL)
581 {
582 dvbpsi_error(p_dvbpsi, "BAT encoder", "failed to allocate new PSI section");
583 goto error;
584 }
585 p_prev->p_next = p_current;
586
587 p_current->i_table_id = 0x4a;
588 p_current->b_syntax_indicator = true;
589 p_current->b_private_indicator = true;
590 p_current->i_length = 13; /* including CRC_32 */
591 p_current->i_extension = p_bat->i_extension;
592 p_current->i_version = p_bat->i_version;
593 p_current->b_current_next = p_bat->b_current_next;
594 p_current->i_number = p_prev->i_number + 1;
595 p_current->p_payload_end += 10;
596 p_current->p_payload_start = p_current->p_data + 8;
597 }
598
599 /* p_payload_end is where the descriptor begins */
600 p_current->p_payload_end[0] = p_descriptor->i_tag;
601 p_current->p_payload_end[1] = p_descriptor->i_length;
602 memcpy(p_current->p_payload_end + 2,
603 p_descriptor->p_data,
604 p_descriptor->i_length);
605
606 /* Increase length by descriptor_length + 2 */
607 p_current->p_payload_end += p_descriptor->i_length + 2;
608 p_current->i_length += p_descriptor->i_length + 2;
609
610 p_descriptor = p_descriptor->p_next;
611 }
612
613 /* bouquet_descriptors_length */
614 i_bouquet_descriptors_length = (p_current->p_payload_end - p_current->p_payload_start) - 2;
615 p_current->p_data[8] = (i_bouquet_descriptors_length >> 8) | 0xf0;
616 p_current->p_data[9] = i_bouquet_descriptors_length;
617
618 /* Store the position of the transport_stream_loop_length field
619 and reserve two bytes for it */
620 p_transport_stream_loop_length = p_current->p_payload_end;
621 p_current->p_payload_end += 2;
622
623 /* second loop: BAT TSs */
624 while (p_ts != NULL)
625 {
626 uint8_t* p_ts_start = p_current->p_payload_end;
627 uint16_t i_transport_descriptors_length = 5;
628
629 /* Can the current section carry all the descriptors ? */
630 p_descriptor = p_ts->p_first_descriptor;
631 while( (p_descriptor != NULL)
632 && ((p_ts_start - p_current->p_data) + i_transport_descriptors_length <= 1020))
633 {
634 i_transport_descriptors_length += p_descriptor->i_length + 2;
635 p_descriptor = p_descriptor->p_next;
636 }
637
638 /* If _no_ and the current section isn't empty and an empty section
639 may carry one more descriptor
640 then create a new section */
641 if( (p_descriptor != NULL)
642 && (p_ts_start - p_current->p_data != 12)
643 && (i_transport_descriptors_length <= 1008))
644 {
645 /* transport_stream_loop_length */
646 i_transport_stream_loop_length = (p_current->p_payload_end - p_transport_stream_loop_length) - 2;
647 p_transport_stream_loop_length[0] = (i_transport_stream_loop_length >> 8) | 0xf0;
648 p_transport_stream_loop_length[1] = i_transport_stream_loop_length;
649
650 /* will put more descriptors in an empty section */
651 dvbpsi_debug(p_dvbpsi, "BAT generator",
652 "create a new section to carry more TS descriptors");
653
654 p_prev = p_current;
655 p_current = dvbpsi_NewPSISection(1024);
656 p_prev->p_next = p_current;
657
658 p_current->i_table_id = 0x4a;
659 p_current->b_syntax_indicator = true;
660 p_current->b_private_indicator = true;
661 p_current->i_length = 13; /* including CRC_32 */
662 p_current->i_extension = p_bat->i_extension;
663 p_current->i_version = p_bat->i_version;
664 p_current->b_current_next = p_bat->b_current_next;
665 p_current->i_number = p_prev->i_number + 1;
666 p_current->p_payload_end += 10;
667 p_current->p_payload_start = p_current->p_data + 8;
668
669 /* bouquet_descriptors_length = 0 */
670 p_current->p_data[8] = 0xf0;
671 p_current->p_data[9] = 0x00;
672
673 /* Store the position of the transport_stream_loop_length field
674 and reserve two bytes for it */
675 p_transport_stream_loop_length = p_current->p_payload_end;
676 p_current->p_payload_end += 2;
677
678 p_ts_start = p_current->p_payload_end;
679 }
680
681 /* p_ts_start is where the TS begins */
682 p_ts_start[0] = p_ts->i_ts_id >> 8;
683 p_ts_start[1] = p_ts->i_ts_id & 0xff;
684 p_ts_start[2] = p_ts->i_orig_network_id >> 8;
685 p_ts_start[3] = p_ts->i_orig_network_id & 0xff;
686
687 /* Increase the length by 6 */
688 p_current->p_payload_end += 6;
689 p_current->i_length += 6;
690
691 /* TS descriptors */
692 p_descriptor = p_ts->p_first_descriptor;
693 while( (p_descriptor != NULL)
694 && ( (p_current->p_payload_end - p_current->p_data)
695 + p_descriptor->i_length <= 1018))
696 {
697 /* p_payload_end is where the descriptor begins */
698 p_current->p_payload_end[0] = p_descriptor->i_tag;
699 p_current->p_payload_end[1] = p_descriptor->i_length;
700 memcpy(p_current->p_payload_end + 2,
701 p_descriptor->p_data,
702 p_descriptor->i_length);
703
704 /* Increase length by descriptor_length + 2 */
705 p_current->p_payload_end += p_descriptor->i_length + 2;
706 p_current->i_length += p_descriptor->i_length + 2;
707
708 p_descriptor = p_descriptor->p_next;
709 }
710
711 if (p_descriptor != NULL)
712 dvbpsi_error(p_dvbpsi, "BAT generator", "unable to carry all the TS descriptors");
713
714 /* transport_descriptors_length */
715 i_transport_descriptors_length = p_current->p_payload_end - p_ts_start - 5;
716 p_ts_start[4] = (i_transport_descriptors_length >> 8) | 0xf0;
717 p_ts_start[5] = i_transport_descriptors_length;
718
719 p_ts = p_ts->p_next;
720 }
721
722 /* transport_stream_loop_length */
723 i_transport_stream_loop_length = (p_current->p_payload_end - p_transport_stream_loop_length) - 2;
724 p_transport_stream_loop_length[0] = (i_transport_stream_loop_length >> 8) | 0xf0;
725 p_transport_stream_loop_length[1] = i_transport_stream_loop_length;
726
727 /* Finalization */
728 p_prev = p_result;
729 while (p_prev != NULL)
730 {
731 p_prev->i_last_number = p_current->i_number;
732 dvbpsi_BuildPSISection(p_dvbpsi, p_prev);
733 p_prev = p_prev->p_next;
734 }
735 return p_result;
736
737 error:
738 /* Cleanup on error */
739 p_prev = p_result;
740 dvbpsi_DeletePSISections(p_prev);
741 return NULL;
742 }
743