1 /*
2 * NIT table parser and generator
3 * Copyright (C) 2010-2011 Unix Solutions Ltd.
4 *
5 * Released under MIT license.
6 * See LICENSE-MIT.txt for license terms.
7 */
8 #include <stdio.h>
9 #include <unistd.h>
10 #include <netdb.h>
11 #include <stdlib.h>
12 #include <string.h>
13
14 #include "tsfuncs.h"
15
ts_nit_alloc()16 struct ts_nit *ts_nit_alloc() {
17 struct ts_nit *nit = calloc(1, sizeof(struct ts_nit));
18 nit->section_header = ts_section_data_alloc();
19 nit->streams_max = 128;
20 nit->streams = calloc(nit->streams_max, sizeof(void *));
21 return nit;
22 }
23
ts_nit_streams_data_free(struct ts_nit * nit)24 static void ts_nit_streams_data_free(struct ts_nit *nit) {
25 int i;
26 for (i=0;i<nit->streams_num;i++) {
27 if (nit->streams[i]) {
28 FREE(nit->streams[i]->descriptor_data);
29 FREE(nit->streams[i]);
30 }
31 }
32 }
33
ts_nit_clear(struct ts_nit * nit)34 void ts_nit_clear(struct ts_nit *nit) {
35 if (!nit)
36 return;
37 // save
38 struct ts_section_header *section_header = nit->section_header;
39 struct ts_nit_stream **streams = nit->streams;
40 int streams_max = nit->streams_max;
41 // free
42 FREE(nit->network_info);
43 ts_nit_streams_data_free(nit);
44 // clear
45 ts_section_data_clear(section_header);
46 memset(nit, 0, sizeof(struct ts_nit));
47 // restore
48 nit->section_header = section_header;
49 nit->streams = streams;
50 nit->streams_max = streams_max;
51 }
52
ts_nit_free(struct ts_nit ** pnit)53 void ts_nit_free(struct ts_nit **pnit) {
54 struct ts_nit *nit = *pnit;
55 if (nit) {
56 ts_section_data_free(&nit->section_header);
57 FREE(nit->network_info);
58 ts_nit_streams_data_free(nit);
59 FREE(nit->streams);
60 FREE(*pnit);
61 }
62 }
63
ts_nit_push_packet(struct ts_nit * nit,uint8_t * ts_packet)64 struct ts_nit *ts_nit_push_packet(struct ts_nit *nit, uint8_t *ts_packet) {
65 struct ts_header ts_header;
66 memset(&ts_header, 0, sizeof(struct ts_header));
67
68 if (ts_packet_header_parse(ts_packet, &ts_header)) {
69 // NIT should be with PID 0x10
70 if (ts_header.pid != 0x10)
71 goto OUT;
72 // Received PUSI packet before table END, clear the table to start gathering new one
73 if (ts_header.pusi && nit->ts_header.pusi)
74 ts_nit_clear(nit);
75 if (!nit->ts_header.pusi)
76 nit->ts_header = ts_header;
77 }
78
79 if (ts_header.pusi) {
80 struct ts_section_header section_header;
81 memset(§ion_header, 0, sizeof(struct ts_section_header));
82
83 uint8_t *section_data = ts_section_header_parse(ts_packet, &nit->ts_header, §ion_header);
84 if (!section_data)
85 goto OUT;
86 // table_id should be 0x40 (network_information_section - actual_network)
87 if (section_header.table_id != 0x40) {
88 memset(&nit->ts_header, 0, sizeof(struct ts_header));
89 goto OUT;
90 }
91
92 // Set correct section_header
93 ts_section_header_parse(ts_packet, &nit->ts_header, nit->section_header);
94 }
95
96 if (!nit->initialized) {
97 ts_section_add_packet(nit->section_header, &ts_header, ts_packet);
98 if (nit->section_header->initialized) {
99 if (!ts_nit_parse(nit))
100 goto ERROR;
101 }
102 }
103
104 OUT:
105 return nit;
106
107 ERROR:
108 ts_nit_clear(nit);
109 return nit;
110 }
111
112
ts_nit_parse(struct ts_nit * nit)113 int ts_nit_parse(struct ts_nit *nit) {
114 uint8_t *section_data = nit->section_header->data;
115 int section_len = nit->section_header->data_len;
116
117 /* Table data (2 bytes) */
118 nit->reserved1 = (section_data[0] &~ 0x0F) >> 4; // xxxx1111
119 nit->network_info_size = ((section_data[0] &~ 0xF0) << 8) | section_data[1]; // 1111xxxx xxxxxxxx
120
121 /* Handle streams */
122 uint8_t *stream_data = section_data + 2 + nit->network_info_size; // +2 is to compensate for reserved1 and network_info_size
123 int stream_len = section_len - nit->network_info_size - 4; // -4 for the CRC at the end
124
125 nit->network_info = NULL;
126 if (nit->network_info_size) {
127 nit->network_info = malloc(nit->network_info_size);
128 if (nit->network_info) {
129 memcpy(nit->network_info, stream_data - nit->network_info_size, nit->network_info_size);
130 }
131 }
132
133 // Before the table there are two more fields
134 nit->reserved2 = (stream_data[0] &~ 0x0F) >> 4; // xxxx1111
135 nit->ts_loop_size = ((stream_data[0] &~ 0xF0) << 8) | stream_data[1]; // 1111xxxx xxxxxxxx
136
137 stream_data += 2;
138 stream_len = nit->ts_loop_size;
139
140 while (stream_len > 0) {
141 if (nit->streams_num == nit->streams_max) {
142 ts_LOGf("!!! Too many streams in NIT, max %d\n", nit->streams_max);
143 break;
144 }
145
146 struct ts_nit_stream *sinfo = calloc(1, sizeof(struct ts_nit_stream));
147
148 sinfo->transport_stream_id = (stream_data[0] << 8) | stream_data[1];
149 sinfo->original_network_id = (stream_data[2] << 8) | stream_data[3];
150
151 sinfo->reserved1 = (stream_data[4] &~ 0x0F) >> 4; // xxxx1111
152 sinfo->descriptor_size = ((stream_data[4] &~ 0xF0) << 8) | stream_data[5]; // 1111xxxx xxxxxxxx
153
154 sinfo->descriptor_data = NULL;
155 if (sinfo->descriptor_size > 0) {
156 sinfo->descriptor_data = malloc(sinfo->descriptor_size);
157 memcpy(sinfo->descriptor_data, &stream_data[6], sinfo->descriptor_size);
158 }
159 nit->streams[nit->streams_num] = sinfo;
160 nit->streams_num++;
161
162 stream_data += 6 + sinfo->descriptor_size;
163 stream_len -= 6 + sinfo->descriptor_size;
164 }
165
166 if (!ts_crc32_section_check(nit->section_header, "NIT"))
167 return 0;
168
169 nit->initialized = 1;
170 return 1;
171 }
172
ts_nit_generate(struct ts_nit * nit,uint8_t ** ts_packets,int * num_packets)173 void ts_nit_generate(struct ts_nit *nit, uint8_t **ts_packets, int *num_packets) {
174 uint8_t *secdata = ts_section_data_alloc_section();
175 ts_section_header_generate(secdata, nit->section_header, 0);
176 int curpos = 8; // Compensate for the section header, frist data byte is at offset 8
177
178 secdata[curpos + 0] = nit->reserved1 << 4; // xxxx1111
179 secdata[curpos + 0] |= nit->network_info_size >> 8; // 1111xxxx xxxxxxxx
180 secdata[curpos + 1] = nit->network_info_size &~ 0xff00;
181 curpos += 2; // For the fields above
182
183 if (nit->network_info_size) {
184 memcpy(secdata + curpos, nit->network_info, nit->network_info_size);
185 curpos += nit->network_info_size;
186 }
187
188 // Before the table there are two more fields
189 secdata[curpos + 0] = nit->reserved2 << 4; // xxxx1111
190 secdata[curpos + 0] |= nit->ts_loop_size >> 8; // 1111xxxx xxxxxxxx
191 secdata[curpos + 1] = nit->ts_loop_size &~ 0xff00;
192 curpos += 2; // For the fields above
193
194 int i;
195 for(i=0;i<nit->streams_num;i++) {
196 struct ts_nit_stream *stream = nit->streams[i];
197
198 secdata[curpos + 0] = stream->transport_stream_id >> 8; // xxxxxxxx xxxxxxxx
199 secdata[curpos + 1] = stream->transport_stream_id &~ 0xff00;
200
201 secdata[curpos + 2] = stream->original_network_id >> 8; // xxxxxxxx xxxxxxxx
202 secdata[curpos + 3] = stream->original_network_id &~ 0xff00;
203
204 secdata[curpos + 4] = stream->reserved1 << 4; // xxxx1111
205 secdata[curpos + 4] |= stream->descriptor_size >> 8; // 1111xxxx xxxxxxxx
206
207 secdata[curpos + 5] = stream->descriptor_size &~ 0xff00;
208
209 curpos += 6; // Compensate for the above
210
211 if (stream->descriptor_size > 0) {
212 memcpy(secdata + curpos, stream->descriptor_data, stream->descriptor_size);
213 curpos += stream->descriptor_size;
214 }
215 }
216 nit->section_header->CRC = ts_section_data_calculate_crc(secdata, curpos);
217 curpos += 4; // CRC
218
219 ts_section_data_gen_ts_packets(&nit->ts_header, secdata, curpos, nit->section_header->pointer_field, ts_packets, num_packets);
220
221 FREE(secdata);
222 }
223
ts_nit_copy(struct ts_nit * nit)224 struct ts_nit *ts_nit_copy(struct ts_nit *nit) {
225 struct ts_nit *newnit = ts_nit_alloc();
226 int i;
227 for (i=0;i<nit->section_header->num_packets; i++) {
228 newnit = ts_nit_push_packet(newnit, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
229 }
230 if (newnit->initialized) {
231 return newnit;
232 } else {
233 ts_LOGf("Error copying nit!\n");
234 ts_nit_free(&newnit);
235 return NULL;
236 }
237 }
238
ts_nit_check_generator(struct ts_nit * nit)239 void ts_nit_check_generator(struct ts_nit *nit) {
240 struct ts_nit *nit1 = ts_nit_alloc();
241 int i;
242 for (i=0;i<nit->section_header->num_packets;i++) {
243 nit1 = ts_nit_push_packet(nit1, nit->section_header->packet_data + (i * TS_PACKET_SIZE));
244 }
245 ts_compare_data("NIT (tspacket->struct)",
246 nit1->section_header->packet_data,
247 nit->section_header->packet_data,
248 nit->section_header->num_packets * TS_PACKET_SIZE);
249 ts_nit_free(&nit1);
250
251 uint8_t *ts_packets;
252 int num_packets;
253 ts_nit_generate(nit, &ts_packets, &num_packets);
254 if (num_packets != nit->section_header->num_packets) {
255 ts_LOGf("ERROR: num_packets:%d != sec->num_packets:%d\n", num_packets, nit->section_header->num_packets);
256 }
257 ts_compare_data("NIT (struct->tspacket)", nit->section_header->packet_data, ts_packets, num_packets * TS_PACKET_SIZE);
258 free(ts_packets);
259 }
260
ts_nit_dump(struct ts_nit * nit)261 void ts_nit_dump(struct ts_nit *nit) {
262 struct ts_section_header *sec = nit->section_header;
263 int i;
264
265 ts_section_dump(sec);
266
267 ts_LOGf(" * NIT data\n");
268 ts_LOGf(" * PID : 0x%04x (%d)\n", nit->ts_header.pid, nit->ts_header.pid);
269 ts_LOGf(" * reserved1 : 0x%02x\n", nit->reserved1);
270 ts_LOGf(" * network_len : 0x%02x (%d)\n", nit->network_info_size, nit->network_info_size);
271 ts_LOGf(" * reserved2 : 0x%02x\n", nit->reserved1);
272 ts_LOGf(" * ts_loop_len : %d\n", nit->ts_loop_size);
273 ts_LOGf(" * num_streams : %d\n", nit->streams_num);
274
275 if (nit->network_info_size > 0) {
276 ts_LOGf(" * Network info:\n");
277 ts_LOGf(" * network info size: %d\n", nit->network_info_size);
278 ts_descriptor_dump(nit->network_info, nit->network_info_size);
279 }
280
281 for(i=0;i<nit->streams_num;i++) {
282 struct ts_nit_stream *stream = nit->streams[i];
283 ts_LOGf(" - [%02d/%02d] | TS_id: 0x%04x (%d) ORG_net_id: 0x%04x (%d) Reserved: 0x%0x Desc_size: %d\n",
284 i+1, nit->streams_num,
285 stream->transport_stream_id, stream->transport_stream_id,
286 stream->original_network_id, stream->original_network_id,
287 stream->reserved1,
288 stream->descriptor_size);
289 if (stream->descriptor_data) {
290 ts_descriptor_dump(stream->descriptor_data, stream->descriptor_size);
291 }
292 }
293
294 ts_nit_check_generator(nit);
295 }
296
ts_nit_is_same(struct ts_nit * nit1,struct ts_nit * nit2)297 int ts_nit_is_same(struct ts_nit *nit1, struct ts_nit *nit2) {
298 if (nit1 == nit2) return 1; // Same
299 if ((!nit1 && nit2) || (nit1 && !nit2)) return 0; // Not same (one is NULL)
300 return ts_section_is_same(nit1->section_header, nit2->section_header);
301 }
302