aboutsummaryrefslogtreecommitdiffstats
path: root/lib/libucsi/dvb/nit_section.h
blob: 77ab1a0208c2e33b11ebc2b24225fdaa357b2160 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
/*
 * section and descriptor parser
 *
 * Copyright (C) 2005 Kenneth Aafloy (kenneth@linuxtv.org)
 * Copyright (C) 2005 Andrew de Quincey (adq_dvb@lidskialf.net)
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 */

#ifndef _UCSI_DVB_NIT_SECTION_H
#define _UCSI_DVB_NIT_SECTION_H 1

#ifdef __cplusplus
extern "C"
{
#endif

#include <libucsi/section.h>

/**
 * dvb_nit_section structure.
 */
struct dvb_nit_section {
	struct section_ext head;

  EBIT2(uint16_t reserved_1			: 4; ,
	uint16_t network_descriptors_length	:12; );
	/* struct descriptor descriptors[] */
	/* struct dvb_nit_section_part2 part2 */
};

/**
 * Second part of a dvb_nit_section, following the variable length descriptors field.
 */
struct dvb_nit_section_part2 {
  EBIT2(uint16_t reserved_2			: 4; ,
	uint16_t transport_stream_loop_length	:12; );
	/* struct dvb_nit_transport transports[] */
} __ucsi_packed;

/**
 * An entry in the transports field of a dvb_nit_section_part2
 */
struct dvb_nit_transport {
	uint16_t transport_stream_id;
	uint16_t original_network_id;
  EBIT2(uint16_t reserved			: 4; ,
	uint16_t transport_descriptors_length	:12; );
	/* struct descriptor descriptors[] */
} __ucsi_packed;

/**
 * Process a dvb_nit_section.
 *
 * @param section Generic section_ext pointer.
 * @return dvb_nit_section pointer, or NULL on error.
 */
struct dvb_nit_section * dvb_nit_section_codec(struct section_ext *section);

/**
 * Accessor for the network_id field of a NIT.
 *
 * @param nit NIT pointer.
 * @return The network_id.
 */
static inline uint16_t dvb_nit_section_network_id(struct dvb_nit_section *nit)
{
	return nit->head.table_id_ext;
}

/**
 * Iterator over the descriptors field in a dvb_nit_section.
 *
 * @param nit dvb_nit_section pointer.
 * @param pos Variable containing a pointer to the current descriptor.
 */
#define dvb_nit_section_descriptors_for_each(nit, pos) \
	for ((pos) = dvb_nit_section_descriptors_first(nit); \
	     (pos); \
	     (pos) = dvb_nit_section_descriptors_next(nit, pos))

/**
 * Accessor for a pointer to the dvb_nit_section_part2 structure.
 *
 * @param nit dvb_nit_section pointer.
 * @return dvb_nit_section_part2 pointer.
 */
static inline struct dvb_nit_section_part2 *dvb_nit_section_part2(struct dvb_nit_section * nit)
{
	return (struct dvb_nit_section_part2 *)
		((uint8_t*) nit + sizeof(struct dvb_nit_section) +
		 nit->network_descriptors_length);
}

/**
 * Iterator over the transports field in a dvb_nit_section_part2.
 *
 * @param nit dvb_nit_section pointer.
 * @param part2 dvb_nit_section_part2 pointer.
 * @param pos Pointer to the current dvb_nit_transport.
 */
#define dvb_nit_section_transports_for_each(nit, part2, pos) \
	for ((pos) = dvb_nit_section_transports_first(part2); \
	     (pos); \
	     (pos) = dvb_nit_section_transports_next(part2, pos))

/**
 * Iterator over the descriptors field in a dvb_nit_transport.
 *
 * @param transport dvb_nit_transport pointer.
 * @param pos Pointer to the current descriptor.
 */
#define dvb_nit_transport_descriptors_for_each(transport, pos) \
	for ((pos) = dvb_nit_transport_descriptors_first(transport); \
	     (pos); \
	     (pos) = dvb_nit_transport_descriptors_next(transport, pos))










/******************************** PRIVATE CODE ********************************/
static inline struct descriptor *
	dvb_nit_section_descriptors_first(struct dvb_nit_section * nit)
{
	if (nit->network_descriptors_length == 0)
		return NULL;

	return (struct descriptor *)
		((uint8_t *) nit + sizeof(struct dvb_nit_section));
}

static inline struct descriptor *
	dvb_nit_section_descriptors_next(struct dvb_nit_section * nit,
					 struct descriptor* pos)
{
	return next_descriptor((uint8_t*) nit + sizeof(struct dvb_nit_section),
			      nit->network_descriptors_length,
			      pos);
}

static inline struct dvb_nit_transport *
	dvb_nit_section_transports_first(struct dvb_nit_section_part2 *part2)
{
	if (part2->transport_stream_loop_length == 0)
		return NULL;

	return (struct dvb_nit_transport *)
		((uint8_t *)part2 + sizeof(struct dvb_nit_section_part2));
}

static inline struct dvb_nit_transport *
	dvb_nit_section_transports_next(struct dvb_nit_section_part2 *part2,
					struct dvb_nit_transport *pos)
{
	uint8_t *end = (uint8_t*) part2 + sizeof(struct dvb_nit_section_part2) +
		part2->transport_stream_loop_length;
	uint8_t *next = (uint8_t*) pos + sizeof(struct dvb_nit_transport) +
		pos->transport_descriptors_length;

	if (next >= end)
		return NULL;

	return (struct dvb_nit_transport *) next;
}

static inline struct descriptor *
	dvb_nit_transport_descriptors_first(struct dvb_nit_transport *t)
{
	if (t->transport_descriptors_length == 0)
		return NULL;

	return (struct descriptor *)
		((uint8_t*) t + sizeof(struct dvb_nit_transport));
}

static inline struct descriptor *
	dvb_nit_transport_descriptors_next(struct dvb_nit_transport *t,
					   struct descriptor* pos)
{
	return next_descriptor((uint8_t*) t + sizeof(struct dvb_nit_transport),
			      t->transport_descriptors_length,
			      pos);
}

#ifdef __cplusplus
}
#endif

#endif