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

tsfuncs_nit.c 8.5KB

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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. ts_nit_streams_data_free(nit);
  32. // clear
  33. ts_section_data_clear(section_header);
  34. memset(nit, 0, sizeof(struct ts_nit));
  35. // restore
  36. nit->section_header = section_header;
  37. nit->streams = streams;
  38. nit->streams_max = streams_max;
  39. }
  40. void ts_nit_free(struct ts_nit **pnit) {
  41. struct ts_nit *nit = *pnit;
  42. if (nit) {
  43. ts_section_data_free(&nit->section_header);
  44. FREE(nit->network_info);
  45. ts_nit_streams_data_free(nit);
  46. FREE(nit->streams);
  47. FREE(*pnit);
  48. }
  49. }
  50. struct ts_nit *ts_nit_push_packet(struct ts_nit *nit, uint8_t *ts_packet) {
  51. struct ts_header ts_header;
  52. memset(&ts_header, 0, sizeof(struct ts_header));
  53. if (ts_packet_header_parse(ts_packet, &ts_header)) {
  54. // NIT should be with PID 0x10
  55. if (ts_header.pid != 0x10)
  56. goto OUT;
  57. if (!nit->ts_header.pusi)
  58. nit->ts_header = ts_header;
  59. }
  60. if (ts_header.pusi) {
  61. struct ts_section_header section_header;
  62. memset(&section_header, 0, sizeof(struct ts_section_header));
  63. uint8_t *section_data = ts_section_header_parse(ts_packet, &nit->ts_header, &section_header);
  64. if (!section_data)
  65. goto OUT;
  66. // table_id should be 0x40 (network_information_section - actual_network)
  67. if (section_header.table_id != 0x40) {
  68. memset(&nit->ts_header, 0, sizeof(struct ts_header));
  69. goto OUT;
  70. }
  71. // Set correct section_header
  72. ts_section_header_parse(ts_packet, &nit->ts_header, nit->section_header);
  73. }
  74. if (!nit->initialized) {
  75. ts_section_add_packet(nit->section_header, &ts_header, ts_packet);
  76. if (nit->section_header->initialized) {
  77. if (!ts_nit_parse(nit))
  78. goto ERROR;
  79. }
  80. }
  81. OUT:
  82. return nit;
  83. ERROR:
  84. ts_nit_clear(nit);
  85. return nit;
  86. }
  87. int ts_nit_parse(struct ts_nit *nit) {
  88. uint8_t *section_data = nit->section_header->data;
  89. int section_len = nit->section_header->data_len;
  90. /* Table data (2 bytes) */
  91. nit->reserved1 = (section_data[0] &~ 0x0F) >> 4; // xxxx1111
  92. nit->network_info_size = ((section_data[0] &~ 0xF0) << 8) | section_data[1]; // 1111xxxx xxxxxxxx
  93. /* Handle streams */
  94. uint8_t *stream_data = section_data + 2 + nit->network_info_size; // +2 is to compensate for reserved1 and network_info_size
  95. int stream_len = section_len - nit->network_info_size - 4; // -4 for the CRC at the end
  96. nit->network_info = NULL;
  97. if (nit->network_info_size) {
  98. nit->network_info = malloc(nit->network_info_size);
  99. if (nit->network_info) {
  100. memcpy(nit->network_info, stream_data - nit->network_info_size, nit->network_info_size);
  101. }
  102. }
  103. // Before the table there are two more fields
  104. nit->reserved2 = (stream_data[0] &~ 0x0F) >> 4; // xxxx1111
  105. nit->ts_loop_size = ((stream_data[0] &~ 0xF0) << 8) | stream_data[1]; // 1111xxxx xxxxxxxx
  106. stream_data += 2;
  107. stream_len = nit->ts_loop_size;
  108. while (stream_len > 0) {
  109. if (nit->streams_num == nit->streams_max) {
  110. ts_LOGf("!!! Too many streams in NIT, max %d\n", nit->streams_max);
  111. break;
  112. }
  113. struct ts_nit_stream *sinfo = calloc(1, sizeof(struct ts_nit_stream));
  114. sinfo->transport_stream_id = (stream_data[0] << 8) | stream_data[1];
  115. sinfo->original_network_id = (stream_data[2] << 8) | stream_data[3];
  116. sinfo->reserved1 = (stream_data[4] &~ 0x0F) >> 4; // xxxx1111
  117. sinfo->descriptor_size = ((stream_data[4] &~ 0xF0) << 8) | stream_data[5]; // 1111xxxx xxxxxxxx
  118. sinfo->descriptor_data = NULL;
  119. if (sinfo->descriptor_size > 0) {
  120. sinfo->descriptor_data = malloc(sinfo->descriptor_size);
  121. memcpy(sinfo->descriptor_data, &stream_data[6], sinfo->descriptor_size);
  122. }
  123. nit->streams[nit->streams_num] = sinfo;
  124. nit->streams_num++;
  125. stream_data += 6 + sinfo->descriptor_size;
  126. stream_len -= 6 + sinfo->descriptor_size;
  127. }
  128. if (!ts_crc32_section_check(nit->section_header, "NIT"))
  129. return 0;
  130. nit->initialized = 1;
  131. return 1;
  132. }
  133. void ts_nit_generate(struct ts_nit *nit, uint8_t **ts_packets, int *num_packets) {
  134. uint8_t *secdata = ts_section_data_alloc_section();
  135. ts_section_header_generate(secdata, nit->section_header, 0);
  136. int curpos = 8; // Compensate for the section header, frist data byte is at offset 8
  137. secdata[curpos + 0] = nit->reserved1 << 4; // xxxx1111
  138. secdata[curpos + 0] |= nit->network_info_size >> 8; // 1111xxxx xxxxxxxx
  139. secdata[curpos + 1] = nit->network_info_size &~ 0xff00;
  140. curpos += 2; // For the fields above
  141. if (nit->network_info_size) {
  142. memcpy(secdata + curpos, nit->network_info, nit->network_info_size);
  143. curpos += nit->network_info_size;
  144. }
  145. // Before the table there are two more fields
  146. secdata[curpos + 0] = nit->reserved2 << 4; // xxxx1111
  147. secdata[curpos + 0] |= nit->ts_loop_size >> 8; // 1111xxxx xxxxxxxx
  148. secdata[curpos + 1] = nit->ts_loop_size &~ 0xff00;
  149. curpos += 2; // For the fields above
  150. int i;
  151. for(i=0;i<nit->streams_num;i++) {
  152. struct ts_nit_stream *stream = nit->streams[i];
  153. secdata[curpos + 0] = stream->transport_stream_id >> 8; // xxxxxxxx xxxxxxxx
  154. secdata[curpos + 1] = stream->transport_stream_id &~ 0xff00;
  155. secdata[curpos + 2] = stream->original_network_id >> 8; // xxxxxxxx xxxxxxxx
  156. secdata[curpos + 3] = stream->original_network_id &~ 0xff00;
  157. secdata[curpos + 4] = stream->reserved1 << 4; // xxxx1111
  158. secdata[curpos + 4] |= stream->descriptor_size >> 8; // 1111xxxx xxxxxxxx
  159. secdata[curpos + 5] = stream->descriptor_size &~ 0xff00;
  160. curpos += 6; // Compensate for the above
  161. if (stream->descriptor_size > 0) {
  162. memcpy(secdata + curpos, stream->descriptor_data, stream->descriptor_size);
  163. curpos += stream->descriptor_size;
  164. }
  165. }
  166. nit->section_header->CRC = ts_section_data_calculate_crc(secdata, curpos);
  167. curpos += 4; // CRC
  168. ts_section_data_gen_ts_packets(&nit->ts_header, secdata, curpos, nit->section_header->pointer_field, ts_packets, num_packets);
  169. FREE(secdata);
  170. }
  171. void ts_nit_check_generator(struct ts_nit *nit) {
  172. struct ts_nit *nit1 = ts_nit_alloc();
  173. int i;
  174. for (i=0;i<nit->section_header->num_packets;i++) {
  175. nit1 = ts_nit_push_packet(nit1, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
  176. }
  177. ts_compare_data("NIT (tspacket->struct)",
  178. nit1->section_header->packet_data,
  179. nit->section_header->packet_data,
  180. nit->section_header->num_packets * TS_PACKET_SIZE);
  181. ts_nit_free(&nit1);
  182. uint8_t *ts_packets;
  183. int num_packets;
  184. ts_nit_generate(nit, &ts_packets, &num_packets);
  185. if (num_packets != nit->section_header->num_packets) {
  186. ts_LOGf("ERROR: num_packets:%d != sec->num_packets:%d\n", num_packets, nit->section_header->num_packets);
  187. }
  188. ts_compare_data("NIT (struct->tspacket)", nit->section_header->packet_data, ts_packets, num_packets * TS_PACKET_SIZE);
  189. free(ts_packets);
  190. }
  191. void ts_nit_dump(struct ts_nit *nit) {
  192. struct ts_section_header *sec = nit->section_header;
  193. int i;
  194. ts_section_dump(sec);
  195. ts_LOGf(" * NIT data\n");
  196. ts_LOGf(" * PID : 0x%04x (%d)\n", nit->ts_header.pid, nit->ts_header.pid);
  197. ts_LOGf(" * reserved1 : 0x%02x\n", nit->reserved1);
  198. ts_LOGf(" * network_len : 0x%02x (%d)\n", nit->network_info_size, nit->network_info_size);
  199. ts_LOGf(" * reserved2 : 0x%02x\n", nit->reserved1);
  200. ts_LOGf(" * ts_loop_len : %d\n", nit->ts_loop_size);
  201. ts_LOGf(" * num_streams : %d\n", nit->streams_num);
  202. if (nit->network_info_size > 0) {
  203. ts_LOGf(" * Network info:\n");
  204. ts_LOGf(" * network info size: %d\n", nit->network_info_size);
  205. ts_descriptor_dump(nit->network_info, nit->network_info_size);
  206. }
  207. for(i=0;i<nit->streams_num;i++) {
  208. struct ts_nit_stream *stream = nit->streams[i];
  209. ts_LOGf(" - [%02d/%02d] | TS_id: 0x%04x (%d) ORG_net_id: 0x%04x (%d) Reserved: 0x%0x Desc_size: %d\n",
  210. i+1, nit->streams_num,
  211. stream->transport_stream_id, stream->transport_stream_id,
  212. stream->original_network_id, stream->original_network_id,
  213. stream->reserved1,
  214. stream->descriptor_size);
  215. if (stream->descriptor_data) {
  216. ts_descriptor_dump(stream->descriptor_data, stream->descriptor_size);
  217. }
  218. }
  219. ts_nit_check_generator(nit);
  220. }