libtsfuncs is a library for mpeg PSI parsing and generation. https://georgi.unixsol.org/programs/libtsfuncs/

nit.c 9.1KB

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  1. #include <stdio.h>
  2. #include <unistd.h>
  3. #include <netdb.h>
  4. #include <stdlib.h>
  5. #include <string.h>
  6. #include "tsfuncs.h"
  7. struct ts_nit *ts_nit_alloc() {
  8. struct ts_nit *nit = calloc(1, sizeof(struct ts_nit));
  9. nit->section_header = ts_section_data_alloc();
  10. nit->streams_max = 128;
  11. nit->streams = calloc(nit->streams_max, sizeof(void *));
  12. return nit;
  13. }
  14. static void ts_nit_streams_data_free(struct ts_nit *nit) {
  15. int i;
  16. for (i=0;i<nit->streams_num;i++) {
  17. if (nit->streams[i]) {
  18. FREE(nit->streams[i]->descriptor_data);
  19. FREE(nit->streams[i]);
  20. }
  21. }
  22. }
  23. void ts_nit_clear(struct ts_nit *nit) {
  24. if (!nit)
  25. return;
  26. // save
  27. struct ts_section_header *section_header = nit->section_header;
  28. struct ts_nit_stream **streams = nit->streams;
  29. int streams_max = nit->streams_max;
  30. // free
  31. FREE(nit->network_info);
  32. ts_nit_streams_data_free(nit);
  33. // clear
  34. ts_section_data_clear(section_header);
  35. memset(nit, 0, sizeof(struct ts_nit));
  36. // restore
  37. nit->section_header = section_header;
  38. nit->streams = streams;
  39. nit->streams_max = streams_max;
  40. }
  41. void ts_nit_free(struct ts_nit **pnit) {
  42. struct ts_nit *nit = *pnit;
  43. if (nit) {
  44. ts_section_data_free(&nit->section_header);
  45. FREE(nit->network_info);
  46. ts_nit_streams_data_free(nit);
  47. FREE(nit->streams);
  48. FREE(*pnit);
  49. }
  50. }
  51. struct ts_nit *ts_nit_push_packet(struct ts_nit *nit, uint8_t *ts_packet) {
  52. struct ts_header ts_header;
  53. memset(&ts_header, 0, sizeof(struct ts_header));
  54. if (ts_packet_header_parse(ts_packet, &ts_header)) {
  55. // NIT should be with PID 0x10
  56. if (ts_header.pid != 0x10)
  57. goto OUT;
  58. if (!nit->ts_header.pusi)
  59. nit->ts_header = ts_header;
  60. }
  61. if (ts_header.pusi) {
  62. struct ts_section_header section_header;
  63. memset(&section_header, 0, sizeof(struct ts_section_header));
  64. uint8_t *section_data = ts_section_header_parse(ts_packet, &nit->ts_header, &section_header);
  65. if (!section_data)
  66. goto OUT;
  67. // table_id should be 0x40 (network_information_section - actual_network)
  68. if (section_header.table_id != 0x40) {
  69. memset(&nit->ts_header, 0, sizeof(struct ts_header));
  70. goto OUT;
  71. }
  72. // Set correct section_header
  73. ts_section_header_parse(ts_packet, &nit->ts_header, nit->section_header);
  74. }
  75. if (!nit->initialized) {
  76. ts_section_add_packet(nit->section_header, &ts_header, ts_packet);
  77. if (nit->section_header->initialized) {
  78. if (!ts_nit_parse(nit))
  79. goto ERROR;
  80. }
  81. }
  82. OUT:
  83. return nit;
  84. ERROR:
  85. ts_nit_clear(nit);
  86. return nit;
  87. }
  88. int ts_nit_parse(struct ts_nit *nit) {
  89. uint8_t *section_data = nit->section_header->data;
  90. int section_len = nit->section_header->data_len;
  91. /* Table data (2 bytes) */
  92. nit->reserved1 = (section_data[0] &~ 0x0F) >> 4; // xxxx1111
  93. nit->network_info_size = ((section_data[0] &~ 0xF0) << 8) | section_data[1]; // 1111xxxx xxxxxxxx
  94. /* Handle streams */
  95. uint8_t *stream_data = section_data + 2 + nit->network_info_size; // +2 is to compensate for reserved1 and network_info_size
  96. int stream_len = section_len - nit->network_info_size - 4; // -4 for the CRC at the end
  97. nit->network_info = NULL;
  98. if (nit->network_info_size) {
  99. nit->network_info = malloc(nit->network_info_size);
  100. if (nit->network_info) {
  101. memcpy(nit->network_info, stream_data - nit->network_info_size, nit->network_info_size);
  102. }
  103. }
  104. // Before the table there are two more fields
  105. nit->reserved2 = (stream_data[0] &~ 0x0F) >> 4; // xxxx1111
  106. nit->ts_loop_size = ((stream_data[0] &~ 0xF0) << 8) | stream_data[1]; // 1111xxxx xxxxxxxx
  107. stream_data += 2;
  108. stream_len = nit->ts_loop_size;
  109. while (stream_len > 0) {
  110. if (nit->streams_num == nit->streams_max) {
  111. ts_LOGf("!!! Too many streams in NIT, max %d\n", nit->streams_max);
  112. break;
  113. }
  114. struct ts_nit_stream *sinfo = calloc(1, sizeof(struct ts_nit_stream));
  115. sinfo->transport_stream_id = (stream_data[0] << 8) | stream_data[1];
  116. sinfo->original_network_id = (stream_data[2] << 8) | stream_data[3];
  117. sinfo->reserved1 = (stream_data[4] &~ 0x0F) >> 4; // xxxx1111
  118. sinfo->descriptor_size = ((stream_data[4] &~ 0xF0) << 8) | stream_data[5]; // 1111xxxx xxxxxxxx
  119. sinfo->descriptor_data = NULL;
  120. if (sinfo->descriptor_size > 0) {
  121. sinfo->descriptor_data = malloc(sinfo->descriptor_size);
  122. memcpy(sinfo->descriptor_data, &stream_data[6], sinfo->descriptor_size);
  123. }
  124. nit->streams[nit->streams_num] = sinfo;
  125. nit->streams_num++;
  126. stream_data += 6 + sinfo->descriptor_size;
  127. stream_len -= 6 + sinfo->descriptor_size;
  128. }
  129. if (!ts_crc32_section_check(nit->section_header, "NIT"))
  130. return 0;
  131. nit->initialized = 1;
  132. return 1;
  133. }
  134. void ts_nit_generate(struct ts_nit *nit, uint8_t **ts_packets, int *num_packets) {
  135. uint8_t *secdata = ts_section_data_alloc_section();
  136. ts_section_header_generate(secdata, nit->section_header, 0);
  137. int curpos = 8; // Compensate for the section header, frist data byte is at offset 8
  138. secdata[curpos + 0] = nit->reserved1 << 4; // xxxx1111
  139. secdata[curpos + 0] |= nit->network_info_size >> 8; // 1111xxxx xxxxxxxx
  140. secdata[curpos + 1] = nit->network_info_size &~ 0xff00;
  141. curpos += 2; // For the fields above
  142. if (nit->network_info_size) {
  143. memcpy(secdata + curpos, nit->network_info, nit->network_info_size);
  144. curpos += nit->network_info_size;
  145. }
  146. // Before the table there are two more fields
  147. secdata[curpos + 0] = nit->reserved2 << 4; // xxxx1111
  148. secdata[curpos + 0] |= nit->ts_loop_size >> 8; // 1111xxxx xxxxxxxx
  149. secdata[curpos + 1] = nit->ts_loop_size &~ 0xff00;
  150. curpos += 2; // For the fields above
  151. int i;
  152. for(i=0;i<nit->streams_num;i++) {
  153. struct ts_nit_stream *stream = nit->streams[i];
  154. secdata[curpos + 0] = stream->transport_stream_id >> 8; // xxxxxxxx xxxxxxxx
  155. secdata[curpos + 1] = stream->transport_stream_id &~ 0xff00;
  156. secdata[curpos + 2] = stream->original_network_id >> 8; // xxxxxxxx xxxxxxxx
  157. secdata[curpos + 3] = stream->original_network_id &~ 0xff00;
  158. secdata[curpos + 4] = stream->reserved1 << 4; // xxxx1111
  159. secdata[curpos + 4] |= stream->descriptor_size >> 8; // 1111xxxx xxxxxxxx
  160. secdata[curpos + 5] = stream->descriptor_size &~ 0xff00;
  161. curpos += 6; // Compensate for the above
  162. if (stream->descriptor_size > 0) {
  163. memcpy(secdata + curpos, stream->descriptor_data, stream->descriptor_size);
  164. curpos += stream->descriptor_size;
  165. }
  166. }
  167. nit->section_header->CRC = ts_section_data_calculate_crc(secdata, curpos);
  168. curpos += 4; // CRC
  169. ts_section_data_gen_ts_packets(&nit->ts_header, secdata, curpos, nit->section_header->pointer_field, ts_packets, num_packets);
  170. FREE(secdata);
  171. }
  172. struct ts_nit *ts_nit_copy(struct ts_nit *nit) {
  173. struct ts_nit *newnit = ts_nit_alloc();
  174. int i;
  175. for (i=0;i<nit->section_header->num_packets; i++) {
  176. newnit = ts_nit_push_packet(newnit, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
  177. }
  178. if (newnit->initialized) {
  179. return newnit;
  180. } else {
  181. ts_LOGf("Error copying nit!\n");
  182. ts_nit_free(&newnit);
  183. return NULL;
  184. }
  185. }
  186. void ts_nit_check_generator(struct ts_nit *nit) {
  187. struct ts_nit *nit1 = ts_nit_alloc();
  188. int i;
  189. for (i=0;i<nit->section_header->num_packets;i++) {
  190. nit1 = ts_nit_push_packet(nit1, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
  191. }
  192. ts_compare_data("NIT (tspacket->struct)",
  193. nit1->section_header->packet_data,
  194. nit->section_header->packet_data,
  195. nit->section_header->num_packets * TS_PACKET_SIZE);
  196. ts_nit_free(&nit1);
  197. uint8_t *ts_packets;
  198. int num_packets;
  199. ts_nit_generate(nit, &ts_packets, &num_packets);
  200. if (num_packets != nit->section_header->num_packets) {
  201. ts_LOGf("ERROR: num_packets:%d != sec->num_packets:%d\n", num_packets, nit->section_header->num_packets);
  202. }
  203. ts_compare_data("NIT (struct->tspacket)", nit->section_header->packet_data, ts_packets, num_packets * TS_PACKET_SIZE);
  204. free(ts_packets);
  205. }
  206. void ts_nit_dump(struct ts_nit *nit) {
  207. struct ts_section_header *sec = nit->section_header;
  208. int i;
  209. ts_section_dump(sec);
  210. ts_LOGf(" * NIT data\n");
  211. ts_LOGf(" * PID : 0x%04x (%d)\n", nit->ts_header.pid, nit->ts_header.pid);
  212. ts_LOGf(" * reserved1 : 0x%02x\n", nit->reserved1);
  213. ts_LOGf(" * network_len : 0x%02x (%d)\n", nit->network_info_size, nit->network_info_size);
  214. ts_LOGf(" * reserved2 : 0x%02x\n", nit->reserved1);
  215. ts_LOGf(" * ts_loop_len : %d\n", nit->ts_loop_size);
  216. ts_LOGf(" * num_streams : %d\n", nit->streams_num);
  217. if (nit->network_info_size > 0) {
  218. ts_LOGf(" * Network info:\n");
  219. ts_LOGf(" * network info size: %d\n", nit->network_info_size);
  220. ts_descriptor_dump(nit->network_info, nit->network_info_size);
  221. }
  222. for(i=0;i<nit->streams_num;i++) {
  223. struct ts_nit_stream *stream = nit->streams[i];
  224. ts_LOGf(" - [%02d/%02d] | TS_id: 0x%04x (%d) ORG_net_id: 0x%04x (%d) Reserved: 0x%0x Desc_size: %d\n",
  225. i+1, nit->streams_num,
  226. stream->transport_stream_id, stream->transport_stream_id,
  227. stream->original_network_id, stream->original_network_id,
  228. stream->reserved1,
  229. stream->descriptor_size);
  230. if (stream->descriptor_data) {
  231. ts_descriptor_dump(stream->descriptor_data, stream->descriptor_size);
  232. }
  233. }
  234. ts_nit_check_generator(nit);
  235. }
  236. int ts_nit_is_same(struct ts_nit *nit1, struct ts_nit *nit2) {
  237. if (nit1 == nit2) return 1; // Same
  238. if ((!nit1 && nit2) || (nit1 && !nit2)) return 0; // Not same (one is NULL)
  239. return ts_section_is_same(nit1->section_header, nit2->section_header);
  240. }