xref: /linux/drivers/media/test-drivers/vidtv/vidtv_psi.h (revision cdd38c5f1ce4398ec58fec95904b75824daab7b5)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  * This file contains the logic to work with MPEG Program-Specific Information.
4  * These are defined both in ISO/IEC 13818-1 (systems) and ETSI EN 300 468.
5  * PSI is carried in the form of table structures, and although each table might
6  * technically be broken into one or more sections, we do not do this here,
7  * hence 'table' and 'section' are interchangeable for vidtv.
8  *
9  * Copyright (C) 2020 Daniel W. S. Almeida
10  */
11 
12 #ifndef VIDTV_PSI_H
13 #define VIDTV_PSI_H
14 
15 #include <linux/types.h>
16 
17 /*
18  * all section lengths start immediately after the 'section_length' field
19  * see ISO/IEC 13818-1 : 2000 and ETSI EN 300 468 V 1.10.1 for
20  * reference
21  */
22 #define PAT_LEN_UNTIL_LAST_SECTION_NUMBER 5
23 #define PMT_LEN_UNTIL_PROGRAM_INFO_LENGTH 9
24 #define SDT_LEN_UNTIL_RESERVED_FOR_FUTURE_USE 8
25 #define NIT_LEN_UNTIL_NETWORK_DESCRIPTOR_LEN 7
26 #define EIT_LEN_UNTIL_LAST_TABLE_ID 11
27 #define MAX_SECTION_LEN 1021
28 #define EIT_MAX_SECTION_LEN 4093 /* see ETSI 300 468 v.1.10.1 p. 26 */
29 #define VIDTV_PAT_PID 0 /* mandated by the specs */
30 #define VIDTV_SDT_PID 0x0011 /* mandated by the specs */
31 #define VIDTV_NIT_PID 0x0010 /* mandated by the specs */
32 #define VIDTV_EIT_PID 0x0012 /*mandated by the specs */
33 
34 enum vidtv_psi_descriptors {
35 	REGISTRATION_DESCRIPTOR	= 0x05, /* See ISO/IEC 13818-1 section 2.6.8 */
36 	NETWORK_NAME_DESCRIPTOR = 0x40, /* See ETSI EN 300 468 section 6.2.27 */
37 	SERVICE_LIST_DESCRIPTOR = 0x41, /* See ETSI EN 300 468 section 6.2.35 */
38 	SERVICE_DESCRIPTOR = 0x48, /* See ETSI EN 300 468 section 6.2.33 */
39 	SHORT_EVENT_DESCRIPTOR = 0x4d, /* See ETSI EN 300 468 section 6.2.37 */
40 };
41 
42 enum vidtv_psi_stream_types {
43 	STREAM_PRIVATE_DATA = 0x06, /* see ISO/IEC 13818-1 2000 p. 48 */
44 };
45 
46 /*
47  * struct vidtv_psi_desc - A generic PSI descriptor type.
48  * The descriptor length is an 8-bit field specifying the total number of bytes of the data portion
49  * of the descriptor following the byte defining the value of this field.
50  */
51 struct vidtv_psi_desc {
52 	struct vidtv_psi_desc *next;
53 	u8 type;
54 	u8 length;
55 	u8 data[];
56 } __packed;
57 
58 /*
59  * struct vidtv_psi_desc_service - Service descriptor.
60  * See ETSI EN 300 468 section 6.2.33.
61  */
62 struct vidtv_psi_desc_service {
63 	struct vidtv_psi_desc *next;
64 	u8 type;
65 	u8 length;
66 
67 	u8 service_type;
68 	u8 provider_name_len;
69 	char *provider_name;
70 	u8 service_name_len;
71 	char *service_name;
72 } __packed;
73 
74 /*
75  * struct vidtv_psi_desc_registration - A registration descriptor.
76  * See ISO/IEC 13818-1 section 2.6.8
77  */
78 struct vidtv_psi_desc_registration {
79 	struct vidtv_psi_desc *next;
80 	u8 type;
81 	u8 length;
82 
83 	/*
84 	 * The format_identifier is a 32-bit value obtained from a Registration
85 	 * Authority as designated by ISO/IEC JTC 1/SC 29.
86 	 */
87 	__be32 format_id;
88 	/*
89 	 * The meaning of additional_identification_info bytes, if any, are
90 	 * defined by the assignee of that format_identifier, and once defined
91 	 * they shall not change.
92 	 */
93 	u8 additional_identification_info[];
94 } __packed;
95 
96 /*
97  * struct vidtv_psi_desc_network_name - A network name descriptor
98  * see ETSI EN 300 468 v1.15.1 section 6.2.27
99  */
100 struct vidtv_psi_desc_network_name {
101 	struct vidtv_psi_desc *next;
102 	u8 type;
103 	u8 length;
104 	char *network_name;
105 } __packed;
106 
107 struct vidtv_psi_desc_service_list_entry {
108 	__be16 service_id;
109 	u8 service_type;
110 	struct vidtv_psi_desc_service_list_entry *next;
111 } __packed;
112 
113 /*
114  * struct vidtv_psi_desc_service_list - A service list descriptor
115  * see ETSI EN 300 468 v1.15.1 section 6.2.35
116  */
117 struct vidtv_psi_desc_service_list {
118 	struct vidtv_psi_desc *next;
119 	u8 type;
120 	u8 length;
121 	struct vidtv_psi_desc_service_list_entry *service_list;
122 } __packed;
123 
124 /*
125  * struct vidtv_psi_desc_short_event - A short event descriptor
126  * see ETSI EN 300 468 v1.15.1 section 6.2.37
127  */
128 struct vidtv_psi_desc_short_event {
129 	struct vidtv_psi_desc *next;
130 	u8 type;
131 	u8 length;
132 	char *iso_language_code;
133 	u8 event_name_len;
134 	char *event_name;
135 	u8 text_len;
136 	char *text;
137 } __packed;
138 
139 struct vidtv_psi_desc_short_event
140 *vidtv_psi_short_event_desc_init(struct vidtv_psi_desc *head,
141 				 char *iso_language_code,
142 				 char *event_name,
143 				 char *text);
144 
145 /*
146  * struct vidtv_psi_table_header - A header that is present for all PSI tables.
147  */
148 struct vidtv_psi_table_header {
149 	u8  table_id;
150 
151 	__be16 bitfield; /* syntax: 1, zero: 1, one: 2, section_length: 13 */
152 
153 	__be16 id; /* TS ID */
154 	u8  current_next:1;
155 	u8  version:5;
156 	u8  one2:2;
157 	u8  section_id;	/* section_number */
158 	u8  last_section; /* last_section_number */
159 } __packed;
160 
161 /*
162  * struct vidtv_psi_table_pat_program - A single program in the PAT
163  * See ISO/IEC 13818-1 : 2000 p.43
164  */
165 struct vidtv_psi_table_pat_program {
166 	__be16 service_id;
167 	__be16 bitfield; /* reserved: 3, program_map_pid/network_pid: 13 */
168 	struct vidtv_psi_table_pat_program *next;
169 } __packed;
170 
171 /*
172  * struct vidtv_psi_table_pat - The Program Allocation Table (PAT)
173  * See ISO/IEC 13818-1 : 2000 p.43
174  */
175 struct vidtv_psi_table_pat {
176 	struct vidtv_psi_table_header header;
177 	u16 num_pat;
178 	u16 num_pmt;
179 	struct vidtv_psi_table_pat_program *program;
180 } __packed;
181 
182 /*
183  * struct vidtv_psi_table_sdt_service - Represents a service in the SDT.
184  * see ETSI EN 300 468 v1.15.1 section 5.2.3.
185  */
186 struct vidtv_psi_table_sdt_service {
187 	__be16 service_id;
188 	u8 EIT_present_following:1;
189 	u8 EIT_schedule:1;
190 	u8 reserved:6;
191 	__be16 bitfield; /* running_status: 3, free_ca:1, desc_loop_len:12 */
192 	struct vidtv_psi_desc *descriptor;
193 	struct vidtv_psi_table_sdt_service *next;
194 } __packed;
195 
196 /*
197  * struct vidtv_psi_table_sdt - Represents the Service Description Table
198  * see ETSI EN 300 468 v1.15.1 section 5.2.3.
199  */
200 
201 struct vidtv_psi_table_sdt {
202 	struct vidtv_psi_table_header header;
203 	__be16 network_id; /* original_network_id */
204 	u8  reserved;
205 	struct vidtv_psi_table_sdt_service *service;
206 } __packed;
207 
208 /*
209  * enum service_running_status - Status of a SDT service.
210  * see ETSI EN 300 468 v1.15.1 section 5.2.3 table 6.
211  */
212 enum service_running_status {
213 	RUNNING = 0x4,
214 };
215 
216 /*
217  * enum service_type - The type of a SDT service.
218  * see ETSI EN 300 468 v1.15.1 section 6.2.33, table 81.
219  */
220 enum service_type {
221 	/* see ETSI EN 300 468 v1.15.1 p. 77 */
222 	DIGITAL_TELEVISION_SERVICE = 0x1,
223 	DIGITAL_RADIO_SOUND_SERVICE = 0X2,
224 };
225 
226 /*
227  * struct vidtv_psi_table_pmt_stream - A single stream in the PMT.
228  * See ISO/IEC 13818-1 : 2000 p.46.
229  */
230 struct vidtv_psi_table_pmt_stream {
231 	u8 type;
232 	__be16 bitfield; /* reserved: 3, elementary_pid: 13 */
233 	__be16 bitfield2; /*reserved: 4, zero: 2, desc_length: 10 */
234 	struct vidtv_psi_desc *descriptor;
235 	struct vidtv_psi_table_pmt_stream *next;
236 } __packed;
237 
238 /*
239  * struct vidtv_psi_table_pmt - The Program Map Table (PMT).
240  * See ISO/IEC 13818-1 : 2000 p.46.
241  */
242 struct vidtv_psi_table_pmt {
243 	struct vidtv_psi_table_header header;
244 	__be16 bitfield; /* reserved:3, pcr_pid: 13 */
245 	__be16 bitfield2; /* reserved: 4, zero: 2, desc_len: 10 */
246 	struct vidtv_psi_desc *descriptor;
247 	struct vidtv_psi_table_pmt_stream *stream;
248 } __packed;
249 
250 /**
251  * struct psi_write_args - Arguments for the PSI packetizer.
252  * @dest_buf: The buffer to write into.
253  * @from: PSI data to be copied.
254  * @len: How much to write.
255  * @dest_offset: where to start writing in the dest_buffer.
256  * @pid: TS packet ID.
257  * @new_psi_section: Set when starting a table section.
258  * @continuity_counter: Incremented on every new packet.
259  * @is_crc: Set when writing the CRC at the end.
260  * @dest_buf_sz: The size of the dest_buffer
261  * @crc: a pointer to store the crc for this chunk
262  */
263 struct psi_write_args {
264 	void *dest_buf;
265 	void *from;
266 	size_t len;
267 	u32 dest_offset;
268 	u16 pid;
269 	bool new_psi_section;
270 	u8 *continuity_counter;
271 	bool is_crc;
272 	u32 dest_buf_sz;
273 	u32 *crc;
274 };
275 
276 /**
277  * struct desc_write_args - Arguments in order to write a descriptor.
278  * @dest_buf: The buffer to write into.
279  * @dest_offset: where to start writing in the dest_buffer.
280  * @desc: A pointer to the descriptor
281  * @pid: TS packet ID.
282  * @continuity_counter: Incremented on every new packet.
283  * @dest_buf_sz: The size of the dest_buffer
284  * @crc: a pointer to store the crc for this chunk
285  */
286 struct desc_write_args {
287 	void *dest_buf;
288 	u32 dest_offset;
289 	struct vidtv_psi_desc *desc;
290 	u16 pid;
291 	u8 *continuity_counter;
292 	u32 dest_buf_sz;
293 	u32 *crc;
294 };
295 
296 /**
297  * struct crc32_write_args - Arguments in order to write the CRC at the end of
298  * the PSI tables.
299  * @dest_buf: The buffer to write into.
300  * @dest_offset: where to start writing in the dest_buffer.
301  * @crc: the CRC value to write
302  * @pid: TS packet ID.
303  * @continuity_counter: Incremented on every new packet.
304  * @dest_buf_sz: The size of the dest_buffer
305  */
306 struct crc32_write_args {
307 	void *dest_buf;
308 	u32 dest_offset;
309 	__be32 crc;
310 	u16 pid;
311 	u8 *continuity_counter;
312 	u32 dest_buf_sz;
313 };
314 
315 /**
316  * struct header_write_args - Arguments in order to write the common table
317  * header
318  * @dest_buf: The buffer to write into.
319  * @dest_offset: where to start writing in the dest_buffer.
320  * @h: a pointer to the header.
321  * @pid: TS packet ID.
322  * @continuity_counter: Incremented on every new packet.
323  * @dest_buf_sz: The size of the dest_buffer
324  * @crc: a pointer to store the crc for this chunk
325  */
326 struct header_write_args {
327 	void *dest_buf;
328 	u32 dest_offset;
329 	struct vidtv_psi_table_header *h;
330 	u16 pid;
331 	u8 *continuity_counter;
332 	u32 dest_buf_sz;
333 	u32 *crc;
334 };
335 
336 struct vidtv_psi_desc_service *vidtv_psi_service_desc_init(struct vidtv_psi_desc *head,
337 							   enum service_type service_type,
338 							   char *service_name,
339 							   char *provider_name);
340 
341 struct vidtv_psi_desc_registration
342 *vidtv_psi_registration_desc_init(struct vidtv_psi_desc *head,
343 				  __be32 format_id,
344 				  u8 *additional_ident_info,
345 				  u32 additional_info_len);
346 
347 struct vidtv_psi_desc_network_name
348 *vidtv_psi_network_name_desc_init(struct vidtv_psi_desc *head, char *network_name);
349 
350 struct vidtv_psi_desc_service_list
351 *vidtv_psi_service_list_desc_init(struct vidtv_psi_desc *head,
352 				  struct vidtv_psi_desc_service_list_entry *entry);
353 
354 struct vidtv_psi_table_pat_program
355 *vidtv_psi_pat_program_init(struct vidtv_psi_table_pat_program *head,
356 			    u16 service_id,
357 			    u16 program_map_pid);
358 
359 struct vidtv_psi_table_pmt_stream*
360 vidtv_psi_pmt_stream_init(struct vidtv_psi_table_pmt_stream *head,
361 			  enum vidtv_psi_stream_types stream_type,
362 			  u16 es_pid);
363 
364 struct vidtv_psi_table_pat *vidtv_psi_pat_table_init(u16 transport_stream_id);
365 
366 struct vidtv_psi_table_pmt *vidtv_psi_pmt_table_init(u16 program_number,
367 						     u16 pcr_pid);
368 
369 struct vidtv_psi_table_sdt *vidtv_psi_sdt_table_init(u16 network_id,
370 						     u16 transport_stream_id);
371 
372 struct vidtv_psi_table_sdt_service*
373 vidtv_psi_sdt_service_init(struct vidtv_psi_table_sdt_service *head,
374 			   u16 service_id,
375 			   bool eit_schedule,
376 			   bool eit_present_following);
377 
378 void
379 vidtv_psi_desc_destroy(struct vidtv_psi_desc *desc);
380 
381 void
382 vidtv_psi_pat_program_destroy(struct vidtv_psi_table_pat_program *p);
383 
384 void
385 vidtv_psi_pat_table_destroy(struct vidtv_psi_table_pat *p);
386 
387 void
388 vidtv_psi_pmt_stream_destroy(struct vidtv_psi_table_pmt_stream *s);
389 
390 void
391 vidtv_psi_pmt_table_destroy(struct vidtv_psi_table_pmt *pmt);
392 
393 void
394 vidtv_psi_sdt_table_destroy(struct vidtv_psi_table_sdt *sdt);
395 
396 void
397 vidtv_psi_sdt_service_destroy(struct vidtv_psi_table_sdt_service *service);
398 
399 /**
400  * vidtv_psi_sdt_service_assign - Assigns the service loop to the SDT.
401  * @sdt: The SDT to assign to.
402  * @service: The service loop (one or more services)
403  *
404  * This will free the previous service loop in the table.
405  * This will assign ownership of the service loop to the table, i.e. the table
406  * will free this service loop when a call to its destroy function is made.
407  */
408 void
409 vidtv_psi_sdt_service_assign(struct vidtv_psi_table_sdt *sdt,
410 			     struct vidtv_psi_table_sdt_service *service);
411 
412 /**
413  * vidtv_psi_desc_assign - Assigns a descriptor loop at some point
414  * @to: Where to assign this descriptor loop to
415  * @desc: The descriptor loop that will be assigned.
416  *
417  * This will free the loop in 'to', if any.
418  */
419 void vidtv_psi_desc_assign(struct vidtv_psi_desc **to,
420 			   struct vidtv_psi_desc *desc);
421 
422 /**
423  * vidtv_pmt_desc_assign - Assigns a descriptor loop at some point in a PMT section.
424  * @pmt: The PMT section that will contain the descriptor loop
425  * @to: Where in the PMT to assign this descriptor loop to
426  * @desc: The descriptor loop that will be assigned.
427  *
428  * This will free the loop in 'to', if any.
429  * This will assign ownership of the loop to the table, i.e. the table
430  * will free this loop when a call to its destroy function is made.
431  */
432 void vidtv_pmt_desc_assign(struct vidtv_psi_table_pmt *pmt,
433 			   struct vidtv_psi_desc **to,
434 			   struct vidtv_psi_desc *desc);
435 
436 /**
437  * vidtv_sdt_desc_assign - Assigns a descriptor loop at some point in a SDT.
438  * @sdt: The SDT that will contain the descriptor loop
439  * @to: Where in the PMT to assign this descriptor loop to
440  * @desc: The descriptor loop that will be assigned.
441  *
442  * This will free the loop in 'to', if any.
443  * This will assign ownership of the loop to the table, i.e. the table
444  * will free this loop when a call to its destroy function is made.
445  */
446 void vidtv_sdt_desc_assign(struct vidtv_psi_table_sdt *sdt,
447 			   struct vidtv_psi_desc **to,
448 			   struct vidtv_psi_desc *desc);
449 
450 /**
451  * vidtv_psi_pat_program_assign - Assigns the program loop to the PAT.
452  * @pat: The PAT to assign to.
453  * @p: The program loop (one or more programs)
454  *
455  * This will free the previous program loop in the table.
456  * This will assign ownership of the program loop to the table, i.e. the table
457  * will free this program loop when a call to its destroy function is made.
458  */
459 void vidtv_psi_pat_program_assign(struct vidtv_psi_table_pat *pat,
460 				  struct vidtv_psi_table_pat_program *p);
461 
462 /**
463  * vidtv_psi_pmt_stream_assign - Assigns the stream loop to the PAT.
464  * @pmt: The PMT to assign to.
465  * @s: The stream loop (one or more streams)
466  *
467  * This will free the previous stream loop in the table.
468  * This will assign ownership of the stream loop to the table, i.e. the table
469  * will free this stream loop when a call to its destroy function is made.
470  */
471 void vidtv_psi_pmt_stream_assign(struct vidtv_psi_table_pmt *pmt,
472 				 struct vidtv_psi_table_pmt_stream *s);
473 
474 struct vidtv_psi_desc *vidtv_psi_desc_clone(struct vidtv_psi_desc *desc);
475 
476 /**
477  * vidtv_psi_pmt_create_sec_for_each_pat_entry - Create a PMT section for each
478  * program found in the PAT
479  * @pat: The PAT to look for programs.
480  * @pcr_pid: packet ID for the PCR to be used for the program described in this
481  * PMT section
482  */
483 struct vidtv_psi_table_pmt**
484 vidtv_psi_pmt_create_sec_for_each_pat_entry(struct vidtv_psi_table_pat *pat, u16 pcr_pid);
485 
486 /**
487  * vidtv_psi_pmt_get_pid - Get the TS PID for a PMT section.
488  * @section: The PMT section whose PID we want to retrieve.
489  * @pat: The PAT table to look into.
490  *
491  * Returns: the TS PID for 'section'
492  */
493 u16 vidtv_psi_pmt_get_pid(struct vidtv_psi_table_pmt *section,
494 			  struct vidtv_psi_table_pat *pat);
495 
496 /**
497  * vidtv_psi_pat_table_update_sec_len - Recompute and update the PAT section length.
498  * @pat: The PAT whose length is to be updated.
499  *
500  * This will traverse the table and accumulate the length of its components,
501  * which is then used to replace the 'section_length' field.
502  *
503  * If section_length > MAX_SECTION_LEN, the operation fails.
504  */
505 void vidtv_psi_pat_table_update_sec_len(struct vidtv_psi_table_pat *pat);
506 
507 /**
508  * vidtv_psi_pmt_table_update_sec_len - Recompute and update the PMT section length.
509  * @pmt: The PMT whose length is to be updated.
510  *
511  * This will traverse the table and accumulate the length of its components,
512  * which is then used to replace the 'section_length' field.
513  *
514  * If section_length > MAX_SECTION_LEN, the operation fails.
515  */
516 void vidtv_psi_pmt_table_update_sec_len(struct vidtv_psi_table_pmt *pmt);
517 
518 /**
519  * vidtv_psi_sdt_table_update_sec_len - Recompute and update the SDT section length.
520  * @sdt: The SDT whose length is to be updated.
521  *
522  * This will traverse the table and accumulate the length of its components,
523  * which is then used to replace the 'section_length' field.
524  *
525  * If section_length > MAX_SECTION_LEN, the operation fails.
526  */
527 void vidtv_psi_sdt_table_update_sec_len(struct vidtv_psi_table_sdt *sdt);
528 
529 /**
530  * struct vidtv_psi_pat_write_args - Arguments for writing a PAT table
531  * @buf: The destination buffer.
532  * @offset: The offset into the destination buffer.
533  * @pat: A pointer to the PAT.
534  * @buf_sz: The size of the destination buffer.
535  * @continuity_counter: A pointer to the CC. Incremented on every new packet.
536  *
537  */
538 struct vidtv_psi_pat_write_args {
539 	char *buf;
540 	u32 offset;
541 	struct vidtv_psi_table_pat *pat;
542 	u32 buf_sz;
543 	u8 *continuity_counter;
544 };
545 
546 /**
547  * vidtv_psi_pat_write_into - Write PAT as MPEG-TS packets into a buffer.
548  * @args: An instance of struct vidtv_psi_pat_write_args
549  *
550  * This function writes the MPEG TS packets for a PAT table into a buffer.
551  * Calling code will usually generate the PAT via a call to its init function
552  * and thus is responsible for freeing it.
553  *
554  * Return: The number of bytes written into the buffer. This is NOT
555  * equal to the size of the PAT, since more space is needed for TS headers during TS
556  * encapsulation.
557  */
558 u32 vidtv_psi_pat_write_into(struct vidtv_psi_pat_write_args *args);
559 
560 /**
561  * struct vidtv_psi_sdt_write_args - Arguments for writing a SDT table
562  * @buf: The destination buffer.
563  * @offset: The offset into the destination buffer.
564  * @sdt: A pointer to the SDT.
565  * @buf_sz: The size of the destination buffer.
566  * @continuity_counter: A pointer to the CC. Incremented on every new packet.
567  *
568  */
569 
570 struct vidtv_psi_sdt_write_args {
571 	char *buf;
572 	u32 offset;
573 	struct vidtv_psi_table_sdt *sdt;
574 	u32 buf_sz;
575 	u8 *continuity_counter;
576 };
577 
578 /**
579  * vidtv_psi_sdt_write_into - Write SDT as MPEG-TS packets into a buffer.
580  * @args: an instance of struct vidtv_psi_sdt_write_args
581  *
582  * This function writes the MPEG TS packets for a SDT table into a buffer.
583  * Calling code will usually generate the SDT via a call to its init function
584  * and thus is responsible for freeing it.
585  *
586  * Return: The number of bytes written into the buffer. This is NOT
587  * equal to the size of the SDT, since more space is needed for TS headers during TS
588  * encapsulation.
589  */
590 u32 vidtv_psi_sdt_write_into(struct vidtv_psi_sdt_write_args *args);
591 
592 /**
593  * struct vidtv_psi_pmt_write_args - Arguments for writing a PMT section
594  * @buf: The destination buffer.
595  * @offset: The offset into the destination buffer.
596  * @pmt: A pointer to the PMT.
597  * @pid: Program ID
598  * @buf_sz: The size of the destination buffer.
599  * @continuity_counter: A pointer to the CC. Incremented on every new packet.
600  * @pcr_pid: The TS PID used for the PSI packets. All channels will share the
601  * same PCR.
602  */
603 struct vidtv_psi_pmt_write_args {
604 	char *buf;
605 	u32 offset;
606 	struct vidtv_psi_table_pmt *pmt;
607 	u16 pid;
608 	u32 buf_sz;
609 	u8 *continuity_counter;
610 	u16 pcr_pid;
611 };
612 
613 /**
614  * vidtv_psi_pmt_write_into - Write PMT as MPEG-TS packets into a buffer.
615  * @args: an instance of struct vidtv_psi_pmt_write_args
616  *
617  * This function writes the MPEG TS packets for a PMT section into a buffer.
618  * Calling code will usually generate the PMT section via a call to its init function
619  * and thus is responsible for freeing it.
620  *
621  * Return: The number of bytes written into the buffer. This is NOT
622  * equal to the size of the PMT section, since more space is needed for TS headers
623  * during TS encapsulation.
624  */
625 u32 vidtv_psi_pmt_write_into(struct vidtv_psi_pmt_write_args *args);
626 
627 /**
628  * vidtv_psi_find_pmt_sec - Finds the PMT section for 'program_num'
629  * @pmt_sections: The sections to look into.
630  * @nsections: The number of sections.
631  * @program_num: The 'program_num' from PAT pointing to a PMT section.
632  *
633  * Return: A pointer to the PMT, if found, or NULL.
634  */
635 struct vidtv_psi_table_pmt *vidtv_psi_find_pmt_sec(struct vidtv_psi_table_pmt **pmt_sections,
636 						   u16 nsections,
637 						   u16 program_num);
638 
639 u16 vidtv_psi_get_pat_program_pid(struct vidtv_psi_table_pat_program *p);
640 u16 vidtv_psi_pmt_stream_get_elem_pid(struct vidtv_psi_table_pmt_stream *s);
641 
642 /**
643  * struct vidtv_psi_table_transport - A entry in the TS loop for the NIT and/or other tables.
644  * See ETSI 300 468 section 5.2.1
645  * @transport_id: The TS ID being described
646  * @network_id: The network_id that contains the TS ID
647  * @bitfield: Contains the descriptor loop length
648  * @descriptor: A descriptor loop
649  * @next: Pointer to the next entry
650  *
651  */
652 struct vidtv_psi_table_transport {
653 	__be16 transport_id;
654 	__be16 network_id;
655 	__be16 bitfield; /* desc_len: 12, reserved: 4 */
656 	struct vidtv_psi_desc *descriptor;
657 	struct vidtv_psi_table_transport *next;
658 } __packed;
659 
660 /**
661  * struct vidtv_psi_table_nit - A Network Information Table (NIT). See ETSI 300
662  * 468 section 5.2.1
663  * @header: A PSI table header
664  * @bitfield: Contains the network descriptor length
665  * @descriptor: A descriptor loop describing the network
666  * @bitfield2: Contains the transport stream loop length
667  * @transport: The transport stream loop
668  *
669  */
670 struct vidtv_psi_table_nit {
671 	struct vidtv_psi_table_header header;
672 	__be16 bitfield; /* network_desc_len: 12, reserved:4 */
673 	struct vidtv_psi_desc *descriptor;
674 	__be16 bitfield2; /* ts_loop_len: 12, reserved: 4 */
675 	struct vidtv_psi_table_transport *transport;
676 } __packed;
677 
678 struct vidtv_psi_table_nit
679 *vidtv_psi_nit_table_init(u16 network_id,
680 			  u16 transport_stream_id,
681 			  char *network_name,
682 			  struct vidtv_psi_desc_service_list_entry *service_list);
683 
684 /**
685  * struct vidtv_psi_nit_write_args - Arguments for writing a NIT section
686  * @buf: The destination buffer.
687  * @offset: The offset into the destination buffer.
688  * @nit: A pointer to the NIT
689  * @buf_sz: The size of the destination buffer.
690  * @continuity_counter: A pointer to the CC. Incremented on every new packet.
691  *
692  */
693 struct vidtv_psi_nit_write_args {
694 	char *buf;
695 	u32 offset;
696 	struct vidtv_psi_table_nit *nit;
697 	u32 buf_sz;
698 	u8 *continuity_counter;
699 };
700 
701 /**
702  * vidtv_psi_nit_write_into - Write NIT as MPEG-TS packets into a buffer.
703  * @args: an instance of struct vidtv_psi_nit_write_args
704  *
705  * This function writes the MPEG TS packets for a NIT table into a buffer.
706  * Calling code will usually generate the NIT via a call to its init function
707  * and thus is responsible for freeing it.
708  *
709  * Return: The number of bytes written into the buffer. This is NOT
710  * equal to the size of the NIT, since more space is needed for TS headers during TS
711  * encapsulation.
712  */
713 u32 vidtv_psi_nit_write_into(struct vidtv_psi_nit_write_args *args);
714 
715 void vidtv_psi_nit_table_destroy(struct vidtv_psi_table_nit *nit);
716 
717 /*
718  * struct vidtv_psi_desc_short_event - A short event descriptor
719  * see ETSI EN 300 468 v1.15.1 section 6.2.37
720  */
721 struct vidtv_psi_table_eit_event {
722 	__be16 event_id;
723 	u8 start_time[5];
724 	u8 duration[3];
725 	__be16 bitfield; /* desc_length: 12, free_CA_mode: 1, running_status: 1 */
726 	struct vidtv_psi_desc *descriptor;
727 	struct vidtv_psi_table_eit_event *next;
728 } __packed;
729 
730 /*
731  * struct vidtv_psi_table_eit - A Event Information Table (EIT)
732  * See ETSI 300 468 section 5.2.4
733  */
734 struct vidtv_psi_table_eit {
735 	struct vidtv_psi_table_header header;
736 	__be16 transport_id;
737 	__be16 network_id;
738 	u8 last_segment;
739 	u8 last_table_id;
740 	struct vidtv_psi_table_eit_event *event;
741 } __packed;
742 
743 struct vidtv_psi_table_eit
744 *vidtv_psi_eit_table_init(u16 network_id,
745 			  u16 transport_stream_id,
746 			  __be16 service_id);
747 
748 /**
749  * struct vidtv_psi_eit_write_args - Arguments for writing an EIT section
750  * @buf: The destination buffer.
751  * @offset: The offset into the destination buffer.
752  * @eit: A pointer to the EIT
753  * @buf_sz: The size of the destination buffer.
754  * @continuity_counter: A pointer to the CC. Incremented on every new packet.
755  *
756  */
757 struct vidtv_psi_eit_write_args {
758 	char *buf;
759 	u32 offset;
760 	struct vidtv_psi_table_eit *eit;
761 	u32 buf_sz;
762 	u8 *continuity_counter;
763 };
764 
765 /**
766  * vidtv_psi_eit_write_into - Write EIT as MPEG-TS packets into a buffer.
767  * @args: an instance of struct vidtv_psi_nit_write_args
768  *
769  * This function writes the MPEG TS packets for a EIT table into a buffer.
770  * Calling code will usually generate the EIT via a call to its init function
771  * and thus is responsible for freeing it.
772  *
773  * Return: The number of bytes written into the buffer. This is NOT
774  * equal to the size of the EIT, since more space is needed for TS headers during TS
775  * encapsulation.
776  */
777 u32 vidtv_psi_eit_write_into(struct vidtv_psi_eit_write_args *args);
778 
779 void vidtv_psi_eit_table_destroy(struct vidtv_psi_table_eit *eit);
780 
781 /**
782  * vidtv_psi_eit_table_update_sec_len - Recompute and update the EIT section length.
783  * @eit: The EIT whose length is to be updated.
784  *
785  * This will traverse the table and accumulate the length of its components,
786  * which is then used to replace the 'section_length' field.
787  *
788  * If section_length > EIT_MAX_SECTION_LEN, the operation fails.
789  */
790 void vidtv_psi_eit_table_update_sec_len(struct vidtv_psi_table_eit *eit);
791 
792 /**
793  * vidtv_psi_eit_event_assign - Assigns the event loop to the EIT.
794  * @eit: The EIT to assign to.
795  * @e: The event loop
796  *
797  * This will free the previous event loop in the table.
798  * This will assign ownership of the stream loop to the table, i.e. the table
799  * will free this stream loop when a call to its destroy function is made.
800  */
801 void vidtv_psi_eit_event_assign(struct vidtv_psi_table_eit *eit,
802 				struct vidtv_psi_table_eit_event *e);
803 
804 struct vidtv_psi_table_eit_event
805 *vidtv_psi_eit_event_init(struct vidtv_psi_table_eit_event *head, u16 event_id);
806 
807 void vidtv_psi_eit_event_destroy(struct vidtv_psi_table_eit_event *e);
808 
809 #endif // VIDTV_PSI_H
810